HomeMy WebLinkAboutNC0000272_BleachProcessEnvEval_20010612 •� r
BLUE RIDGE
PAPER PRODUCTS INC.
June 12, 2001 I (j
JW 1 2 20 IIJI
Forrest Westall WATER PpLIALli f SECTION
ASHEVILLC REGIONAL OFFICE
Regional Supervisor
Division of Water Quality
59 Woodfin Place
Asheville,NC 28801
Dear Mr. Westall,
Attached is the Bleach Environmental Process Evaluation and Report prepared by Dr. Norm
Liebergott, PhD Liebergott & Associates Consulting Inc. and Mr. Lewis Shackford GL&V Pulp
Group Inc.
Please contact me if you have any questions regarding this report.
Sincerely,
Derric Brown l
Manager, Environmental Affairs
copy: Don Anderson
[-Keitfi Iiaynes:7
Mike Myers
175 Main Street • P.O. Box 4000
Canton, North Carolina 28716 • Phone: 828-646-2000
Raising Your Expectations
V
BLUE RIDGE PAPER PRODUCTS, INC.
FOR: CANTON MILL
AND
CLEAN WATER FUND OF NORTH CAROLINA
ON BEHALF OF THE ENVIRONMENTAL COALITION ON BRPP
BLEACH ENVIRONMENTAL PROCESS
EVALUATION AND REPORT
JUNE 8, 2001
V
GIN
JUN I r 7.001' _�
,AL OFFICE
BLUE RIDGE PAPER PRODUCTS, INC.
FOR: CANTON MILL
AND
CLEAN WATER FUND OF NORTH CAROLINA
ON BEHALF OF THE ENVIRONMENTAL COALITION ON BRPP
BLEACH ENVIRONMENTAL PROCESS
EVALUATION AND REPORT
JUNE 812001
NLJUN 12
WATER ppUALITY SECTION
ASHEVILLE REGIONAL OFFICE
vGIN
BLUE RIDGE PAPER PRODUCTS, INC.
FOR: CANTON MILL
AND
CLEAN WATER FUND OF NORTH CAROLINA
ON BEHALF OF THE ENVIRONMENTAL COALITION ON BRPP
BLEACH ENVIRONMENTAL PROCESS
EVALUATION AND REPORT
JUNE 812001
CONFIDENTIAL
VGLAI
ACKNOWLEDGEMENTS
The authors of this report gratefully acknowledge several Blue Ridge dedication
of their time during the site visit, and sharing of their knowledge and expertise of
the Blue Ridge Paper Products Inc. mill operations during the course of this
study.
Michael P. Ferguson
Derric Brown
Bill Adams
Melanie Hager
Randy Worley
Jimmy Deitz
Stephen J. Single
RESPECTFULLY SUBMITTED
Dr. Norman Liebergott, PhD Lewis D. Shackford, P.E., and
Liebergott & Associates Consulting Inc. William J. Miller
5825 Shalom Avenue, Suite 802 GL&V Pulp Group, Inc.
Cote St. Luc,Quebec, 150 Burke Street
Canada H4W 3A5 Nashua, NH 03060 USA
TEL. (514) 369-5575 TEL. (603) 598-7840
FAX (514) 369-5575 FAX (603) 598-7830
E-mail: liebergott(aDsymoatico.ca E-mail: lewis.shackfordeglv.com
E-mail: bill.miller(g)glv.com
JUNE 89 2001
CONFIDENTIAL 1.
VGnt
Table of Contents
• Executive Summary 3
• Background and Introduction 8
• Environmental Performance Benchmarking 11
• Site Audit and Performance Review 13
• Introduction 13
• Recommendations 13
• Benchmark Operation 14
• No. 1 and No. 2 Fiberline Audit Observations 19
• Overview of Technology Options 21
• Introduction 21
• In-Process Options 21
• Pulping Technologies 23
• Bleaching Technologies 29
• Emerging Pulping and Bleaching Technologies 38
• Pulp Washing and Effluent Flow Reduction 40
• External Treatment Options 44
• Jacobs Study Commentary 44
• Emerging External Treatments 46
• Methods for Recycling Effluent 48
• References 51
• Options for Improved Environmental Performance 57
• Basis for Study 57
• Process Optimization 62
• Conversion to Extended Delignification 64
• Conversion to Two Stage Oxygen Delignification 67
• Conversion to ZD stage 71
• Conversion of EO/EOP stages to (PO)/PHT stages 77
• Implementation of the BFR® process on the hardwood line 82
• Conversion to Totally Chlorine Free (TCF) bleaching 84
Appendices 88
1. Confidentiality Agreement 89
2. Resumes of Audit Personnel 93
3. Glossary of Terms 99
4. Blue Ridge Paper Products Inc. Fiberline Overview 101
CONFIDENTIAL 2
V
Executive Summary
Blue Ridge Paper Products Inc. has undertaken a continuous, comprehensive
program to improve effluent quality, particularly in the level of color discharge,
since purchasing the mill from Champion International Corporation. As a
program initiative towards, Blue Ridge Paper Products Inc. and the Clean Water
Fund of North Carolina contracted Liebergott and Associates, Inc., and GL&V
Pulp Group to evaluate the current operation of the fiberlines, and prepare a
report identifying options for effluent color reduction at the facility. A Site Review
and Audit was conducted at the mill from April 30 — May 2, 2001.
Process Optimization
A preliminary review of the operation of the hardwood and pine fiberlines was
conducted, and several opportunities were identified to potentially reduce
operating cost of the fiberlines. The current operation of the fiberlines has been
compared to the expected performance when fully optimized. Specific
recommendations have been made to improve the performance in Site Audit and
Performance Review:
• Repair and/or replace the medium consistency pumps feeding the
oxygen reactors and the brightness and residual sensors on all of
the chlorine dioxide stages.
• Optimization of the performance of the No. 3 softwood brown stock
washer, and the hardwood D, and Eo washers.
• Investigating the potential to reduce digester k-No. variability, and
increase the frequency of k-No. monitoring and reporting.
• Optimization of chemical application in each bleaching stage.
• Consider implementing a 'refresher" operator training course
We project that these optimization efforts may lead to a reduction of chlorine
dioxide use of 8 #/ton on hardwood and 11 #/ton on hardwood and pine,
respectively, which represents a significant operating cost savings.
The reductions in chlorine dioxide use should also lead to reductions in effluent
AOX and color; however, there is no published commercial operating data to
support the quantitative impact of these changes on environmental parameters.
We believe that color reductions of up to 700 #/day on hardwood and up to 400
#/day on pine may potentially be achieved.
Options for Improved Environmental Performance
The technologies that may be considered for short term or long term
implementation have been summarized in an Overview of Technology Options.
CONFIDENTIAL 3
VGLAI
There are two different strategies that may be considered to achieve color
reduction: "In-Process" changes and External Treatment ("end-of-pipe").
In-Process Changes
Five key technologies, which modify the cooking, oxygen delignification, or
bleaching operation for the hardwood and/or pine fiberlines, have been evaluated
in further detail. In addition, we have commented on the option to add the BFR®
process on the hardwood line. Estimated color reductions of 1430-5400#/day for
hardwood and 1730-2800#/day for pine may be achieved using modifications to
the fiberline and maintaining ECF pulp production. An option for the conversion
of the fiberlines to produce TCF pulp has also been included, with a potential
color reduction of 9750-12850 #/day for hardwood and pine, respectively.
However, we consider this to be a high risk option, as there is no current
commercial experience with TCF bleaching for pulp grades similar to those
produced at Blue Ridge Paper Products, Inc. The option is included as a
reference, such that changes made to the fiberlines now may ultimately be
"building blocks" towards a TCF concept, when demonstrated to be viable for the
Canton mill.
The impact of these options on the mill operation are summarized in tabular form
on the next two pages, and detailed in the Options for Improved Environmental
Performance. There is the potential for greater color reduction by combining two
or more of these technologies on hardwood or pine pulp; however, the benefits in
color reduction are not additive, so various combinations of technologies need to
be separately estimated. All environmental impact projections are based on
outflow from the bleach plant to the effluent treatment plant.
External Treatment
A number of emerging technologies for effluent treatment have been described in
the Overview of Technology Options. These options may be considered for color
reduction, but this strategy incurs significant capital expenditure while increasing
operating and maintenance costs. The recent study completed by Jacobs
Engineering has been reviewed and the authors concur with the conclusions
from that report. The summary of options from the Jacobs report is reproduced
in the next pages. Y
One or more of these external treatments may be considered for treatment of
individual sewer streams, but this is beyond the scope of this study. The
treatment of whole mill effluent by any of these technologies does not appear
financially viable.
CONFIDENTIAL 4
SUMMARY OF OPTIONS FOR ENVIRONMENTAL IMPROVEMENT
HARDWOOD LINE
Extended Two Stage ZD Conversion (PO)/PHT Addition of TCF
Delignification Oxygen Conversion BFR® Conversion
Color Current#/Day 14,270 14,270 14,270 14,270 14,270 14,270
Reduction % 20% 10% 25% 33% 27 90%
Reduction #/Day -2,850 -1,430 -3550 -4700 -5400 -12,850
Impact
Water Use, gal/ton N/C N/C N/C N/C 0 -2400
Effluent Flow, gal/ton N/C N/C N/C N/C - 2200 -1900
AOX kg/t -0.11 -0.06 -0.27 -0.3 -0.16 background
Toxicity N/C N/C N/C N/C N/C N/C
Temperature N/C N/C N/C increased increased Increased
Pulp Quality increased N/C N/C N/C N/C decreased
Commercial Experience High High Moderate Moderate Low Low
Operating Cost decreased decreased decreased increased increased increased
Capital Cost Very High Moderate Moderate/High Moderate/Low Very High Very High
Commercial Experience Capital Cost
Low 0-3 similar installations in operation Low <$1 million
Moderate 4-10 similar installations in operation Moderate $1-5 million
High >10 similar installations in operation High $5-10 million
Very High >$10 million
Capital costs are preliminary estimates
NOTES:
1. Technologies are.not additive in impact; combinations of two or more technologies require further estimation.
2. All technologies r1equire more detailed study for performance and installation feasibility.
3. Capital cost estimates are limited to only changes in the fiberline equipment; utilities and support services not included.
4. All environmental impact projections are based on outflow from the bleach plant to the effluent treatment plant.
5
v cwv
(SUMMARY OF OPTIONS FOR ENVIRONMENTAL IMPROVEMENT
SOFTWOOD LINE
Extended Two Stage ZD Conversion (PO)/PHT TCF
Delignification Oxygen Conversion Conversion
Color Current#/Day 10,830 10,830 10,830 10,830 10,830
Reduction % 20% 16% 20% 26% 90%
Reduction #/Day -2170 -1,730 -2800 -2800 -9,750
Impact
Water Use, gal/ton N/C N/C N/C N/C -2400
Effluent Flow, gal/ton N/C N/C N/C N/C -1900
AOX kg/t -0.26 -0.115 -0.27 -0.36 background
Toxicity N/C N/C N/C N/C N/C
Temperature N/C N/C N/C increased increased
Pulp Quality increased N/C N/C N/C decreased
Commercial Experience High High Moderate Moderate Low
Operating Cost decreased decreased decreased increased increased
Capital Cost Very High Moderate Moderate/High Moderate/Low Very High
Commercial Experience Capital Cost
Low 0-3 similar installations in operation Low <$1 million
Moderate 4-10 similar installations in operation Moderate $1-5 million
High >10 similar installations in operation High $5-10 million
Very High >$10 million
Capital costs are preliminary estimates
NOTES:
1. Technologies are not additive in impact; combinations of two or more technologies require further estimation.
2. All technologies require more detailed study for performance and installation feasibility.
3. Capital cost estimates are limited to only changes in the fiberline equipment; utilities and support services not included.
4. All environmental impact projections are based on outflow from the bleach plant to the effluent treatment plant.
CONFIDENTIAL 6
V GLA
Background and Introduction
Blue Ridge Paper Products Inc. purchased this mill from Champion International
Corporation. This mill is unique in the world, being the only mill to incorporate
the BFR® process in the fiberline. The BFR® process is installed on the softwood
line, and allows a major portion of the D, and Eo bleach plant effluent to be
recycled through the brown stock washing system and to the chemical recovery
process. This process has been extensively evaluated, and is operated at a
degree of filtrate closure where the penalty in bleach chemical use and pulp
quality parameters is minimized, while maximizing the environmental benefit.
Blue Ridge Paper Products Inc. has undertaken a continuous improvement
process to reduce effluent outfall, particularly in discharge of color, since
purchasing the mill from Champion International Corporation. The mill has
recently undertaken a major study of extemal treatment options, but learned that
all options studied would require major capital expenditures, would increase the
operating cost of the mill, and are technically and/or economically unfeasible.
As a further initiative towards color reduction, Blue Ridge Paper Products Inc.
and the Clean Water Fund of North Carolina contracted Liebergott and
Associates, Inc., and GL&V Pulp Group to evaluate the current operation of the
fiberlines, and prepare a report identifying options for color reduction at the
facility. The Clean Water Fund of North Carolina has represented that it is acting
on behalf of the "Environmental Coalition on BRPP". The "Environmental
Coalition on BRPP" is understood to include the Dead Pigeon River Council,
American Canoe Association, Charlotte Lackey, Western NC Alliance,
Appalachian Voices, National Forest Protection Alliance, Southern Appalachian
Biodiversity Project, Dogwood Alliance, and the Tennessee Environmental
Council.
It was agreed that the study would include four parts.
A. Environmental Performance Benchmarking
A comparison between the final effluent quality of the Blue Ridge Mill would
be compared with other similar chemical pulp producing mills. This will
provide an understanding of the current demonstrated environmental
performance of the Canton mill. This will include a review of the published
literature of effluent quality of similar mills in the U.S.A. and Canada, as well
as any other data that can be readily obtained from operating mills.
CONFIDENTIAL 8
vGIN
B. Site Review and Audit
A current performance review of the fiberlines would be performed, and
specific operating parameters that may be changed to improve
environmental and financial performance will be identified.
C. Options for Improving Environmental Performance
Based on a clear understanding of the current operation of the Blue Ridge
facility, a list of options that may provide improved environmental
performance will be prepared. This list of options would specifically
include strategies which may be implemented into the fiberline ("in situ"),
as well as those which may be implemented externally ("end of pipe").
D. Bleach Environmental Short Course
In order that all participants in the study may have a common understanding
of fiberline technology which may be considered in this study, a classroom
style course was presented to Blue Ridge Paper Products Inc. and the
Environmental Coalitions with regards to the current operating sequences at
the facility. The effect of chemistry, operating parameters on pulp and
effluent quality were presented by Dr. Norman Liebergott, and copies of all
material presented was transmitted to Blue Ridge Paper Products Inc. and
the Clean Water Fund of North Carolina. This part of the study was
completed on the afternoon of April 30, 2001.
Part D of the scope of this contract was completed during the visit to the mill. Parts
A, B, and C are included in this report.
Prior to the study, Blue Ridge Paper Products Inc. provided to Liebergott and
Associates Inc. and GL&V Pulp Group, Inc. copies of all information requested in
the Study Proposal. This included flow schematics of both fiberlines, historical
environmental data, operations logs from a stable operating period in 2000, as well
as all specific data requested. As this data includes sensitive operations data, a
Confidentiality Agreement was executed among the parties prior to the start of work
at the mill. A copy of this Confidentiality Agreement is included.in Appendix 1 of
this report.
The data received in advance offered the opportunity for Liebergott and Associates
Inc. and GL&V Pulp Group, Inc. to identify areas of the fiberline that may have
opportunities for improvement in operating economy and/or environmental
performance.
CONFIDENTIAL 9
V VIN
On April 30, 2001, Dr. Norman Liebergott of Liebergott and Associates, and Lewis
D. Shackford and William J. Miller of GL&V Pulp Group, Inc. arrived at the mill in
Canton, N.C.
On the morning of April 30, Blue Ridge Paper Products, Inc. offered a tour of the
mill, and was responsive to all requests for operating information as well as
requested data and historical reports for review. This provided a good
understanding of the current operation of the fiberlines for the parties.
On the afternoon of April 30, the Bleach Environmental Short Course was
presented to Blue Ridge Paper Products Inc. and the Environmental Coalitions at
an offsite location. This presentation and discussion continued until there were no
further requests for any additional presentation material or questions to be
answered. A copy of all of the presentation material had been previously
transmitted to Blue Ridge Paper Products Inc. and the Clean Water Fund of North
Carolina.
During the next two days, May 1-2, 2001, a site survey was completed, and a list of
options for consideration developed by Liebergott and Associates, Inc. and GL&V
Pulp Group, Inc. A significant portion of this time was spent in the mill observing
operations, and discussing operations with mill engineers and operators. Where
potential options were identified, additional time was spent reviewing the particular
area of the fiberline to which the proposed changes pertained.
On the afternoon of May 2, 2001, prior to the departure of Liebergott and
Associates, Inc. and GL&V Pulp Group, Inc., a meeting was held to which the
management of Blue Ridge Paper Products Inc. and the Environmental Coalitions
were invited. During this meeting, a proposed table of contents of the Study Report
was presented. In addition, examples of the proposed format of the type of data for
environmental improvement performance projections were shown. The contents of
the report were agreed in this meeting. It was requested that as much data as
possible be included on the capital cost implications of the options be included. It
was agreed that a general range of capital cost would be included, ranked as "love',
"moderate", "high", and "very high". However, it was suggested to the group that
any option that may be of interest should be separately studied, as capital
requirements for retrofit installations of this nature are very site specific.
As there are no exclusions to be identified relative to the scope of the Study
Proposal, this report constitutes fulfilment of the obligations of Liebergott and
Associates, Inc., and GL&V Pulp Group, Inc.
CONFIDENTIAL 10
V GI
Environmental Performance Benchmarkina
A comparison between selected effluent parameters; AOX, TSS, BOD, COD,
Color and Effluent outflow between the Blue Ridge Paper Products Inc, mill and
other mills in the U.S.A., Canada and Finland have been made. The USA data
includes results from 30 facilities with similar paper products to those produced at
Blue Ridge Paper Products Inc. The Canadian data was taken from a
comprehensive report in the "1996 Environmental Conditions of the Pulp and
Paper Mill in Canada", which was prepared by HASimons, and published by
CPPA. The value and average from the forty-three mills were used in the
comparison. Also included were two recent mill updates, including data
produced in the year 2000 for two Canadian mills, one of which had introduced
ozone into the chlorine dioxide delignification stage. Effluent data from 3 facilities
in Finland were also evaluated. The information is shown in following table.
There were no COD, BOD, or Color values lower than those produced by the
Canton mill. There was one mill in the NCASI survey that reported a lower TSS
value than shown by Canton mill value. The average AOX reported by the TCF
mill in Finland are 0.07 lb/ton of pulp, lower than the 0.17 lb/ton listed for the
Canton facility. Finnish TCF mills sometimes do produce ECF grades of pulp
and hence do produce AOX. The low AOX values shown are averages taken
combining both ECF and TCF regimes, which may bias the data.
CONFIDENTIAL 11
g tO G
A Comparison between Selected Effluent Parameters from the Blue RidgePaper Products Inc Canton Mill
Bleach Plant Effluent and Other Facilities in the U.S.A.. Canada and Finland (Integrated Mills)
Pulp
Production
BHWK BSWK AOX TSS BOD COD Color Flow*
Data From ADMT ADMT Lbs/ton Lbs/ton Lbs/ton Lbs/ton Lbs/ton Gal/ton
Canton Mill 1999 765 655 0.17 2.08 0.73 13.69 31.22 15,145
Canton Mill 1995 0.33 2.81 1.34 30.80 56.20 19,547
NCASI Studv
Avg 2.16 6.68 4.13 76.88 200.55 20,637
Min 0.20 1.00 0.91 13.90 31.90 13,413
Max 16.78 23.00 16.06 224.00 581.00 42,000
Espanola Mill, 2000 450 550 0.36 7.2 4.00 19.02 124.20** 20,800
Boyle Alberta Mill, 2000(2) 1700 1480 1 0.40 4.8 0.41 1 15.0 51.11 22,890
CPPA Study
30HW,4SW, 38-43 mills
9 HW/SW-Avg 1.20 8.1 5.20 68.20 146.22 22,140
Min 0.32 4.3 0.41 15.90 24.20 19,800
Max 2.35 24.60 28.20 83.96 297.20 29,000
TCF Finland (mills
produce TCF and ECF HW & HW& 0.10 N/A 1.6 30.02 40.3 9,000
pulps based on demand) SW SW
(1) 1995 NCASI Solid Waste Survey (23 mills) - overall average of 17 to 30 mills
(2) 2000 (2) Canadian Mill data (Softwood pulp bleached on different days)
(3) 1996 CPPA Environmental Study (48 mills)
(4) 1999 Finnish mill data - (3 mills)
* Flow is Total Mill Effluent Flow
** Reported Data is Color from the effluent treatment plant; estimated color in bleach plant effluent is 175
Lbs/ton. All other data in the table is bleach plant effluent (in flow to the effluent treatment plant).
CONFIDENTIAL 12
vGIN
Site Audit and Performance Review
Operation Review of the No. 1 and No. 2 Fiberlines at
Blue Ridge Paper Products Inc., Canton, North Carolina
Introduction-
The pulping and bleaching operations of Blue Ridge Paper mill located in
Canton, N.C. were toured on April 30 and May 1-2, 2001 by Bill Miller and Lew
Shackford of GL&V Pulp Group Inc. and Norm Liebergott of Liebergott and
Associates.
The areas toured on April 30 and May 1 were;
• The No. 1 hardwood fiberline brownstock washing, OZ delignification
and bleaching.
• The No. 2 softwood fiberline brownstock washing, 02 delignification
and bleaching.
• The central control room for both No.1 and No.2 fiberlines.
• The metals removal process (MRP) and the chloride removal process
(CRP).
The following suggestions are made based on steady state operating data
provided by the mill and observations made during the tours.
Recommendations:
The following recommendations are suggested to incrementally improve the
present process operations of the No. 1 and No. 2 Fiberlines, with minimal capital
investment. In many cases, there is a return on investment to be realized
through reduction in bleach chemical usage. It is also logica�to assume that an
incremental reduction in bleach plant effluent color and AOX may also be
realized through optimized operation. It is very difficult, if not impossible, to
predict color reduction from process optimization, as the individual bleach stage
flow numbers are already very low and the variability is difficult to correlate to
process variables Color generated due to the chemistry taking place during
sewer blending is also a little understood variable making incremental color
reductions very difficult to predict.
CONFIDENTIAL 13
fYGB/
1. Monitor hardwood digester k-numbers and post OZ k-numbers at least hourly,
to provide operators with lead-time for upset conditions. Kappa analyzers are
the optimum solution, but are very costly.
2. Investigate methods to reduce digester k-number variability.
3. Upgrade No.1 OZ reactor feed pump to maintain higher and more consistent
reactor pressure control.
4. Monitor 02 operation for performance improvement.
5. Calibrate and/or upgrade No. 1 D, and D2 control instrumentation.
6. Reduce No. 1 Di stage kappa factor to 0.20-0.24 range (0.30 now).
7. Reduce 02 charge to No.1 EoP stage to 0.3% (0.5% now).
8. Propose a H2O2 trial on Eo stage, only after kappa factor has been reduced
(#5). Recommend considering MgSO4 addition during trial.
9. Optimize No.3 softwood brownstock washer operation to improve discharge
consistency and reduce carryover to No.2 OZ reactor.
10.Upgrade No.2 02 reactor feed pump to maintain higher and more consistent
reactor pressure control.
11.Calibrate and/or upgrade No. 2 Di and DZ control instrumentation.
12.Optimize No. 2 D, and EoP washer operation.
13.Reduce No. 2 Di kappa factor to 0.20-0.22 (0.25 now).
14.Run MgSO4 trial on No. 2 EoP stage.
15.Optimize D2 stage operation and reduce CI02 addition.
16.Conduct training course for washer and bleach plant operators.
Benchmark Operation:
Prior to the visit, steady state operating data for the No. 1 and No. 2 brownstock
and bleaching lines was sent to GL&V and Liebergott & Associates. The steady
state operating data, in two hour snapshots, was from the period July to August,
2000.
Data from this period were used to establish the Canton operating benchmarks.
This mill operating data, referenced as Canton benchmark, were compared to the
performance expected for fiberlines of this design. These operating parameters
are derived from GL&V pulping and bleaching operations similar to the Canton
operation.
The following tables show only the Canton mill benchmarks that are out of range
from expected performance.
CONFIDENTIAL 14
V GIN
No 1. Hardwood Fiberline
Stage Parameter Canton Expected
Benchmark
02 OZ charge, % 1.4% 1.5-2.0
NaOH, % 2.0 1.5-2.0
pH (vat) 11.2 10.2-10.5
Pressure, psig 72 100
Delignification, % 33 35-40
Di Kappa factor 0.30 0.22
CI02, % 1.1 0.8
EoP OZ, charge, % 0.5 0.3
H2O2 charge, % 0 0.3
k-no NA 2.0-2.5
% ISO 72-75 70-72
D2 CIOZ charge, % 0.6% 0.6- 0.8%
Final pH 3.1 3.8-4.0
Final ISO, % 186 86
Retention, min. 160-180 240
No 2. Softwood Fiberline
Stage Parameter Canton Expected
Benchmark
OZ Pressure, psig 87.5 100
Consistency, % 8.5 12
Delignification, % 40.2 40-45
Di Kappa factor 0.25 0.20-0.22
CI02, % 1.3 1.05-1.15
EoP 02, charge, % 0.7 0.5
NaOH charge, % 2.5 1.5-2.0
pH 10.1 10.5
k-no 2.3 2.5-3.0
% ISO 61.7 55
D2 CI02 charge, % 1.4 1.0-1.2
Final pH 3.5 3.8-4.0
Final ISO, % 86.6 1 86
Retention, min. 240 1240
CONFIDENTIAL 15
VGIN
r
Summary of Benchmark Operation:
No. 1 Hardwood Fiberline:
The No. 1 OZ delignification system is performing below standard operation.
There appears to be a number of factors leading to the low performance.
The low reactor operating pressure (72 psig vs 100 psig) can increase the gas
volume in the pulp slurry and adversely affect the efficiency of the 02 gas mixing
and subsequent 02 gas retention in the reactor. The cause of this low operating
pressure is the accelerated wear cycle on the Clove-Rotorrm pump, which feeds
the OZ reactor while maintaining the operating pressure. The wear cycle is
caused by excess sand and dirt in the pulp due to the screening system being
located in the post Oz position. A solution to this problem is to replace the Clove-
RotorTm with a medium consistency centrifugal pump. This pump design will also
wear, but with a higher design pump head and external de-gas, it allows reactor
pressure to be maintained much longer into the wear cycle.
The applied NaOH (as OWL) charge is essentially base loaded to production; the
operators making no adjustments for changing process conditions. The NaOH
charge is not excessive but it is not being effectively consumed. This is evident
from the 11.2 pH manually measured in the first post 02 washer vat. A measured
pH from this location should be in the 10.2 -10.5 range.
The hardwood OZ gas charge is also base loaded. It is not excessive, but at the
lower operating pressure, the oxygen gas volume in the pulp slurry will be high,
so it is not being efficiently utilized at the mixer. The lower operating pressure
also promotes gas coalescing, further reducing gas utilization and retention time.
Poor utilization of 02 gas also leads to poor alkali consumption.
Hardwood 02 systems in North America have a spotty performance record in
comparison to softwood 02 systems. This is due in part to the wide range of
hardwood species encountered, and the changes in species�-ratio as seasonal
harvesting areas change. Due to this variation, which also affects cooking and
washing, maintaining optimum performance with hardwood 02 systems requires
equal or more monitoring and maintenance than the softwood systems.
The Di stage kappa factor, or applied CI02 is excessive at 0.30 kappa factor
(0.8% CIOZ). This is a bleaching strategy common in three stage bleach plants. It
is an operator habit that develops due to lightly monitored brownstock pulp and
CONFIDENTIAL 16
VGBI
washing systems. These pulp and washing systems can display a great deal of
k-number and carryover variability. The process sampling and testing is spread
out over long periods. A high kappa factor is the operator's defense to reduce
the variability in the bleach plant feed and maintain the final brightness target.
High kappa factor bleaching often results in overshooting the final brightness
target and excessive overall CI02 usage.
First chlorine dioxide stages that operate at high kappa factors are known to
generate relatively high levels of color in the effluent. This acid color can
increase when subjected to alkali, and often this effect is irreversible. This can
occur in the sewer or in the Eop stage, if the first chlorine dioxide stage washing
is poor.
The Eo stage operates within the standard conditions. The final brightness range
is high at 72-75% ISO indicating excessive application of chemical in the D,
stage. No k-number is measured. As H2O2 is not applied to this stage, the high
brightness development is primarily due to the CI02 applied in the D, stage. As
delignification and oxidation are overdone with CI02 in the Di stage, the use of
H2O2 in the Eo stage would have minimal or no effect on the overall bleaching. A
previous H2O2 trial made no impact on overall No. 1 brightness performance.
The final D2 stage is under utilized due to the aggressive Di bleaching previously
discussed. This under utilization is part of the previously discussed operator
strategy, allowing D2 stage brightness recovery in from process upsets. The D2
stage operates at a lower pH (3.1) and retention time (160 -180 minutes) than
standard.
The lower pH (3.1) is for shive reduction. This pH range typically slows the
brightening kinetics of CI02. Given this strategy, there seems to be adequate
retention time at 160-180 minutes to reach the 86% ISO target. However, further
optimization of the screen room performance can reduce or eliminate the need
for this operating strategy.
No. 2 Softwood Fiberline:
The 02 delignification system is performing at a delignification rate of 40.2%,
which is at the low end of the expected performance range'There, are some
operating factors that can be improved for an incremental performance
improvement.
For the same issues referenced with the hardwood system, the low reactor
operating pressure (87.5 psig vs. 100 psig) can adversely affect the system
performance. The root cause is the same pump wear issue as exists on the
hardwood line. Although theoretically the pressure should not significantly affect
CONFIDENTIAL 17
VGLAI
delignification, it is likely that the pressure reaches a low enough point that the
quantity of oxygen gas needed cannot be effectively mixed with the pulp.
The pulp consistency to the 02 reactor is reported to 8.5% (versus recommended
consistency of > 10%). At this low consistency there is a danger of promoting
pulp channeling, resulting in a severe loss of retention time, coalescing of gas
bubbles, and thus loss of delignification performance.
Tracer tests to determine reactor retention time show 50 minutes for a 60 minute
design. This does not necessarily indicate channeling, but loss of retention time
may be due to increased pulp volume at the lower consistency. This additional
filtrate increases the COD and dissolved solids content carried into the reactor,
which increases consumption of OZ and NaOH. This increased chemical
consumption limits the achievable level of delignification. Oxidation of COD in OZ
reactors is often accompanied by a high exotherm. The exotherm in the No. 2
softwood reactor appears to be >10°F. A typical exotherm for a softwood
reactor is 3-5°F. This is an indication-of parallel oxidation reaction with the COD
carryover, which can also have a minor impact on viscosity.
This low consistency is a result of poor pre-Oz washer performance, which is
designed to discharge at 12-14% consistency. This washer (the pre-02 washer
system) requires an operational audit to determine the reasons for operational
deficiencies.
The D, stage kappa factor is high at 0.25 (1.3%). The dose is controlled based
on the measured (in line kappa analyzer) incoming k-number. The sample for the
analyzer is taken at the D, stage feed. A manually measured k-number is also
taken at the pre-washer feed. The manual k-number averages 9.8 and the
analyzer k-number averages 10.3. It can be assumed from these numbers that
the controlled kappa factor may actually be slightly higher than the reported
control target.
The higher kappa factor control target is due to a similar operator control strategy
as the previously described hardwood strategy. The No. 2 Line pulping and
washing system is monitored more closely than the No. 1 Line, but operation still
favors the conservative approach. This also is partially due to the increased
carryover levels around the D, stage"due to BFR®.
The Eo stage final brightness is too high and the -k-number too low. This is
partially due to high level of CI02 applied to the D, stage, resulting in an
inefficient Eop stage operation. A softwood EoP stage following an aggressive
first D stage becomes a brightening stage and an inefficient delignification stage.
The 02 charge is high and most of the applied H2O2 goes to brightness
CONFIDENTIAL 18
GSY
development. The EoP brightness is a false brightness and contributes very little
to the final brightness.
The 2.5% NaOH addition level to the EoP stage is high, while the resulting final
pH is slightly below standard at 10.1. At the reference NaOH addition rate, the
final pH should be close to 11.0. This suggests an imbalance in the Eop stage
chemistry that can lead to inefficiency in the EoP stage operation. Do washer
operation, H2O2 decomposition, or other parameters can cause this loss of alkali.
An MgSO4 addition trial on the EoP stage may help stabilize operation. This
unique operation could be a result of the implementation of the MRP process at
Canton, and there are no other references in the world to use as a benchmark.
The benchmark DZ stage CIOZ addition rate of 1.4% is very high. Addition rates
as high as 1.6% -1.8% were noted, with final pH below 3.0. The operators use
high DZ addition rates, low pH, and the long retention time as final buffer to
attaining the final brightness target and reducing shives. The result is
overshooting the final brightness target of 86% ISO. The brightness curve for this
sequence, at the benchmark conditions, is very flat at the 86% target range. A
great deal of applied CI02 (active Cl2) is lost to chlorate and chlorite formation.
The result of over bleaching for a 0.5+%ISO cushion and shive is very expensive
in CI02 usage. The operation of the screen room should be reviewed and
optimized to assure that maximum shive removal is being achieved prior to the
bleach plant.
No.1 and No.2 Fiberline Audit Observations:
No. 1 Hardwood Fiberline:
The hardwood cooking system operation suffers from several control
deficiencies. These deficiencies lead to variability in production rate, k-number
and brownstock washing. One of the biggest problems cited was digesters that
do not blow clean (hardwood digesters only). This leads to deviation from blow
cycle, fluctuation in blowtank consistency and washing variability in the washing
operation.
K-numbers and pH are manually measured every two hours, before and after the
OZ system. These are the only inputs operators receive to make adjustments to
the bleach plant operation: Given a 16-20 minute blow cycle,6-8 digesters are
blown before any changes in k-numbers are noted. Adjustments to the 02
system are seldom made as the operators feel they never really know when the
next k-number swing will occur. A low digester k-number may already be through
the system by the time the operator sees the test.
The same is true for the k-number entering the D, stage of the No. 1 bleach
plant. Here, the operator has inline residual and brightness control probes to
CONFIDENTIAL 19
VGOV
detect these swings. Unfortunately, the residual sensor does not detect the
changes in CIOZ concentration due to k-number swings and carryover, and the
brightness probe is not sensitive due to the higher brightness of OZ delignified
hardwood pulps. The operators, having little faith in these controls as a line of
defense to detect process changes, elect to run the D, stage very aggressively.
Log sheets from earlier in May indicated that steady digester and washing
operation results in a dramatically different No.1 bleach plant operation. These
logs indicate a 0.2-0.22 kappa factor can be achieved when operators feel
confident no upsets are in the system.
In the Di stage, the operator watches the brightness response (Cormac) signal
only. In the DZ stage, both sensors are considered unresponsive and not used
for control.
No.2 Softwood Fiberline:
The softwood brownstock and 02 system is monitored with kappa analyzers
before and after the OZ reactor and the bleach pre-washer discharge. K-
numbers are manually checked every two hours before the 02 reactor and feed
to the bleach pre-washer.
The residual and brightness control sensors (compensated brightness) on the D,
and DZ stages do not have the response to be used for automatic cascade
control. The D, stage CI02 addition is controlled by kappa factor. The operator
pays little attention to the brightness and residual analyzers in the Di stage,
controlling compensated brightness locally which is frequently adjusted as
hardwood bleach plant DE k- numbers shift.
CI02 usage in the DZ (first brightening) stage continues to be very high. Levels
as high as 2.0% were noted.
The EoP washer operation is marginal. Speed control in automatic operation
results in the washer rapidly slowing down until it plugs. This happens faster
than the operator can respond. The result is the washer operating in manual, at
a 50% pond level. This critical bleach plant washer is not performing to full
capability. This problem has been very difficult to identify, bu fecently has been
identified in the hydraulic drive.
Poor EoP washing has a very negative impact on Dz performance. Evidence of
poor EoP washing can be found in the D2 stage pH. At the very high CI02
applications noted, the D2 stage pH should be below 3.0. It often operates in the
3.0-3.5 pH range. This pH is being buffered by excess amounts of residual alkali
being carried over from the previous EoP stage. This EoP residual alkali also
carries CI02 consuming organic compounds.
CONFIDENTIAL 20
vGIN
Overview of Technology Options
Introduction
The color in pulp and paper industry wastewater results from four major
operations: chemical pulping carryover from washers, spills and other losses,
pulp bleaching chemical reactions of lignin and carbohydrate fraction of pulp and
from colored paper production. Unfortunately, the compounds responsible for
color are not easily biodegradable. The highly polymerized nature of the
chromophores accounts for their biorefractory nature. Secondary biological
treatment plants typically provide a 20-40% reduction in color load.
Color problems may be handled in three ways: control color within the system by
using oxidative chemicals, a recycle system that allows recovery and burning, or
external tertiary treatment.
During the course of the Study, a number of options were identified that may be
considered to improve environmental performance, particularly in respect to the
outfall of color. Reduced color in the effluent can be achieved through in process
changes or by treating effluents externally. Both options were reviewed, and
projections made as to the potential benefit each option may offer.
In-Process Options
Decreasing Effluent Loading
As bleached kraft pulp mills in North America strive to comply with stricter
effluent quality regulations, most of them have stopped using chlorine as a
bleaching chemical. Because of the variety of the mills, they have found different
ways to -modify their bleaching sequences to reduce AOX, color and other
detrimental compounds in effluent discharges. The number of alternatives to
elemental chlorine bleaching is growing as a result of accelerated research
carried out by pulp producers, research institutions, chemical producers and
equipment manufacturers. There are at least thirty different methods in pulping
and bleaching to reduce the lignin content of pulp and to modify the bleaching
processes, and integrate system closure alternatives, as shown in the following
table.
CONFIDENTIAL 21
VGIN
Technologies to Reduce Bleaching Pollution
Process Technique Options
Reduce lignin in Extended MCC, EMCC
pulp delignification
Kraft RDH, low solids
Superbatch
Additives Anthraquinone
Polysulphides
Other cooking Organic solvent Alcell
chemicals Organocell
Others
Sulphite ASAM
Others
Partial Oxygen 02 delignification
delignification Eo
before chlorination Eop
Pressurized PO
PHT
QP
00
Enzymes
Peroxide P and pressurized
PO
PHT
QP (Lignox)
QP (others)
NO2 PreNOX
Non-chlorine Ozone ZD, DZ
substantial Peracids
replacement PXA
Activated oxygen
Reduce or Treatment Addition
eliminate chlorine conditions Mixing
compounds in Substitute CI02 for pH
delignification CIZ
Reduce chlorine Peroxide P
compounds in Pressurized PO,
brightening PHT
Peracids Peracetic Acid
Ozone PXA
Reduce lignin in Washing
solution MC "C" stage
CONFIDENTIAL 22
VGLN
Pulping Technologies
The retrofit of existing batch or continuous digesters to extended delignification
technology would be prohibitively expensive in most mills and technically
impractical in many of them. Those mills that install extended delignification will
generally install new digester systems. Excessive kappa reduction in extended
delignification can adversely affect pulp strength and yield, but this loss can be
mitigated by the addition of anthraquinone or polysulfide.
Oxygen delignification can be easily implemented into existing mill operations.
This technology is now well established commercially with more than 200
installations worldwide (14 in Canada and 52 in the USA). This trend is expected
to increase in the next 5 to 10 years. Although oxygen delignification has a high
capital cost, it provides significantly lower operating costs.
Technically, pulping modifications such as extended delignification and oxygen
delignification are readily integrated into the liquor cycle. As these technologies
redirect organic material away from the effluent and into the liquor cycle, they
increase the recovery boiler loading that will adversely impact pulp production
capabilities in a recovery limited mill.
Since extended delignification and oxygen delignification reduce the kappa
number of pulp entering the bleach plant, bleaching chemical application can be
reduced.
Extended Delignification
Extended delignification in cooking is an option for reducing the lignin content of
the pulp going to the bleach plant. Lower kappa numbers entering the bleach
plant reduces bleaching chemical usage, and therefore minimizes the effluent
load from bleaching. Extended delignification results in improved selectivity,
lower rejects, and improved yield. The benefits of extended delignification can
be achieved by(1-3):
i) High sulfide concentration during initial and early bulk phase of the
delignification,
ii) Low and uniform alkali concentration throughout the cook, and
iii) Removal of dissolved lignin from the reaction medium.
This technology can be practiced in either continuous-or batch digester systems,
and has the following benefits:
• Lower effluent discharges
• Chemical cost savings
• Maintain or improve pulp quality
• Suitable for short sequence bleaching
CONFIDENTIAL 23
• More selective than conventional cooking
• Improved bleachability of pulp
• Improved yield
I
These benefits are achieved by providing for the reduction in cooked kappa
number without a prohibitive yield loss that would be encountered in conventional
cooking processes. For example, softwood pulp, in conventional batch or
continuous digesters commercially operate in the range of 28-32 kappa number
as an optimum economic point considering all costs of steam, power, bleach
chemical, wood use, etc. Applying the principles of extended delignification will
allow for a reduction in kappa number by about 6.5 units, while maintaining the
same wood consumption (same yield). This results in a kappa to bleaching in
the range of 22-25. This lower kappa number results in lower bleach chemical
costs.
It is possible, with extended delignification, to cook to even lower kappa pulp,
with good preservation of yield down to about a kappa number of 18-20 for
softwood pulps; however, below this point, the yield drops dramatically. With this
yield drop comes a reduction in production capacity in a recovery boiler limited
mill. This makes operation of this process to such low kappa numbers not
economically feasible. Mills which currently operate at these very low kappa
numbers are those who are producing TCF pulps, where brightness cannot be
achieved unless the kappa number to bleach plant is extremely low.
Oxygen Delignification
Oxygen delignification systems were developed in the late 1960's and early
1970's in order to minimize and/or avoid the cost of external effluent treatment
facilities. This technology provided a significant reduction in lignin content to the
bleach plant by delignifying with oxygen and alkali and returning the dissolved
wood solids to the recovery boiler. Early oxygen delignification systems were
practiced at high consistency (30%) as it was perceived to be difficult or
impossible to mix sufficient quantities of oxygen gas with medium consistency
(10-14%) pulp to achieve the delignification effect. In the early 1980's, the
advent of the High Shear mixer allowed the practice of oxygen reinforced alkali
extraction (Eo) and subsequently oxygen delignification stages.
Since the development of the High Shear Mixing Technology, most of the oxygen
delignification systems have been installed to operate at medium consistency,
and integrated into existing fiberlines which conventionally had drum type
washers operating at medium consistency discharge. The release of solids
dissolved in the oxygen delignification stages requires careful consideration of
pulp washing requirements both before the oxygen stage and after the oxygen
stage (prior to the bleach plant). Normally 3-4 stages of.washing are required
CONFIDENTIAL 24
Ic VGLAI
before the oxygen stage, and 2-3 stages of washing are required between the
oxygen stage and the bleach plant.
Recently, there have been numerous configurations of oxygen delignification
system installed and operated commercially. These are shown in the simplified
schematics as follows:
"Mini" design, 15 minutes,
LV 25 - 30% kappa drop
Single stage, 60 minutes,
L 40-45% kappa drop
1
Two stage, 15/60 minutes,
50-55% kappa drop
The level of delignification to be achieved in a mill is site specific, and the
average levels of delignification cited above are averages that may be achieved
with these various technologies for softwood pulps. There have been a number
of surveys done on oxygen delignification performance in mills around the world,
and the variability is quite wide. One such survey(4), which included 14 mills in
CONFIDENTIAL 25
IGIN
the U.S. and Canada showed an average delignification in single stage systems
medium consistency systems of about 35%, with two stage systems in the range
of 39-40% (one high consistency system response showed 50% for that
installation).
There are a number of factors that can contribute to limited performance in
delignification, which are particularly applicable in "retrofit" installations:
High Solids Carryover to the Oxygen Reactor
Low Consistency to the Oxygen Reactor
Poor Oxygen Gas Mixing
Low Reactor Pressure
Limited Steam Availability
However, it is clear that a well designed and operated oxygen delignification
system can achieve an average delignification of 45% for a single stage systems,
or 55% for a two stage system on a typical softwood pulp. Beyond this level of
delignification, the selectivity of the reaction becomes poorer, and excessive
viscosity losses can occur, which may lead to a concurrent loss in pulp strength.
To achieve these averages requires disciplined operating practice, and good
control of kappa number to the oxygen stage, as well as good washing upstream
of the reactor.
It is known that there are a few oxygen systems in the world, which achieve
greater than 55% delignification pn a regular basis. However, many of these
installations are on acid sulfite pulps or on kraft pulps where the oxygen stage is
preceded by an acid wash or chelation stage. The incremental benefit in
chemical savings to achieve 60-65% delignification versus 55% delignification is
too small to economically justify the installation of such a pre-oxygen stage in a
retrofit installation. In most cases, on kraft pulps, this type of system is installed
where maximum delignification is demanded and/or in new fiberline installations
where TCF pulp is produced. For TCF pulps, it is known that the kappa number
to the bleach plant must be maintained well below 10 to achieve reasonable
brightness, and pulp strength approaching that of conventional ECF kraft pulps.
There are two installations in North America where >55% delignification is
claimed to be achieved on regular basis (reported 60-63%), however, this should
be checked by reviewing long term averages from several Moths' of operating
logs. If this investigation confirms the long term average results of >60%
delignification, it may be due to wood species dependant, or may be viable due
to final product quality specifications. In any case, the Canton pulps should be
tested to quantify the oxygen delignification response on Canton pulps, before
projecting a long term average result of greater than 55% delignification.
CONFIDENTIAL 26
IvG1W
There are numerous publications that address the issues of oxygen stage
performance in relation to ECF and TCF bleaching of kraft pulps(5-12).
A schematic diagram which shows the required equipment to convert a single
stage oxygen delignification stage to a two stage systems is shown in the next
figure.
CONFIDENTIAL 27
e
V GU
Retrofit of a Single Stage Oxygen Delignification System to a Two Stage System
60 Min.
Reactor
Discharger
I I FIR
Pui in 10-30 Min. '
I p Pre- Reactor)
I NaOH, I
�— LP Steam
Sri' y
I I NaOH
Oz
yy h plc
Steam .a
I Med %' HI-ShearrM HI-Shear m
I Mixer I Mixer Blowtank
- - - - - - - � MP Steam
CONFIDENTIAL 28
V, Gnf
Bleaching Technologies
Medium Consistency Chlorine Dioxide in First Stage
As mills have moved towards 100% replacement of chlorine by chlorine dioxide,
the order for injection of chlorine and chlorine dioxide becomes irrelevant.
Multiple point chlorine dioxide addition is not necessary, since they do not reduce "
chlorine dioxide usage. Medium consistency Dion bleaching provides improved
bleaching response that allows reduction in chlorine dioxide charge for a given
degree of delignification. A preferred method to achieve medium consistency in
the first bleaching stage is the installation of a "pre-bleach washer" ahead of the
first D stage, after the brown stock high density storage tower. Although the
initial capital outlay may be expensive, its implementation can normally be easily
justified when a major fiberline rebuild is undertaken. A medium consistency first
chlorine dioxide stage preceded by a "pre-bleach washer" may be considered
"state of the art" in modern bleach plants, and this technology is incorporated at
the Canton mill.
Ozone Bleaching
Ozone bleaching has been installed worldwide in 26 mills, with another two mills
announcing the intention of installing ozone systems. The technologies
operating commercially today are those which operate at medium (10-14%)
consistency and high (40%) consistency. Recently, it has been proposed that
this technology, especially for applications of low doses of ozone, and particularly
when used in combination with chlorine dioxide in a single stage, may be
practiced at low (2-4%) consistency. Market demands will justify ozone use in a
limited number of mills. However, it remains to be seen if further regulatory
demands may require widespread implementation. There are numerous
published articles regarding the implementation and use of ozone and peroxide
in bleaching sequences.(5•7 .13-1e)
Ozone was first proposed as early as the late 1960's in order to allow full recycle
of bleach plant effluents for reduction or elimination of effluent outfall. As with
oxygen delignification systems, the first systems proposed were based on high
consistency gas phase reactor systems. The first of these-installations was
installed in the late 1980s at International Paper's mill in Franklin, Virginia. The
bleaching sequence is OZED, and most of the effluentfrom the Z and E stages is
recycled to recovery. The final D stage effluent is sewered. This process gives a
dramatic reduction in AOX, COD, BOD, Color, and effluent flow. This sequence
is also used StoraEnso's mill (former Consolidated Papers) in Wisconsin Rapids,
Wl. The capital cost for an installation of this type is very high for a retrofit
installation, due to the requirement of providing high consistency pulp (40%). In
all cases, this technology was incorporated into existing mills during a major
CONFIDENTIAL 29
fiberline rebuild. It is a technology that can be considered cost competitive in a
new fiberline installation. This technology has not been considered viable for the
Canton installation, as this mill appears to be quite sensitive to viscosity of the
pulp to the paper mill, particularly the #19 machine. It is well accepted that
bleaching sequences using relatively high ozone charge (0.8-1% 03 on pulp)
results in a pulp with a relatively low viscosity, even though the strength
properties for fine papers is acceptable.
Combining ozone and chlorine compounds in a single stage (HZ, DCZ, CZ, ZC,
DZ, ZD) was known since 1967. Six mills have reported using a sequential ZD or
DZ stage in these sequences(19) The implementation of ozone in combination
with chlorine dioxide in the first stage of bleaching has risen significantly in the
last 2-3 years, and can be practiced at either high or medium consistency. This
is differentiated from a full ozone stage by the limited amount of ozone gas which
is applied to the pulp (typically less than 0.3% on pulp). Due to the low dose of
ozone, pulp strength and viscosity normally do not decrease with implementation
of this technology. The retrofit of an existing bleaching sequence to practice the
"ZD" technology is much less capital intensive when installed using medium
consistency technology.
There are currently nine "ZD" stages installed or on order in the world:
Nippon Paper— Nichinan, Japan
Votorantim (VCP) —Jacarei, Brasil
Oji — Jufutsu, Japan
Domtar (Eddy Forest) — Espanola, Ontario, Canada
Votorantim (VCP) — Luiz Antonio, Brasil
Votorantim (VCP) —Jacarei, Brasil
Wisaforest— Pietersaari, Finland
Wisaforest— Pietersaari, Finland
SAPPI — Ngodwana, South Africa
The incorporation of an ozone stage in combination with an existing chlorine
dioxide stage in the fiberline is relatively simple with low space requirements. Of
greater cost and space requirements is the ozone generation system to provide
compressed ozone gas to the system. The basic system configuration is shown
on the next page, and comprises the following additions/modifications:
1. New MC Pump to feed the ozone mixer
2. Sulfuric acid delivery system modifications
3. New Ozone Gas Mixer
4. New piping and pressurized upflow tube for Z stage
5. Gas separation system and potential tie-in to ozone gas recovery system
6. Tie-in to existing D1 mixer and tower
CONFIDENTIAL 30
e
Ozone Reactor
Gas to Destruct
10 F
fGas
Separator
Compressed
Ozone ,L
n
Pulp to CIOz Tower
CONFIDENTIAL 31
VGBI
7. Complete ozone gas generation
8. Ozone gas compression system
9. Piping and controls for ozone gas delivery to Z stage
10. New gas monitoring, safety training and procedure development
11. Ozone gas destruct and potential oxygen recovery system
A system of this design has recently been installed and started-up at Domtar's in
Espanola, Ontario, Canada. This is the best reference to cite due to the amount
of performance data already published, including data on color reduction.
In summary, "the ZD stage incorporated in Espanola's hardwood modernization
has improved bleaching economy, improved pulp quality, and reduced the
effluent load from the bleach plant. Incorporation of ozone into the ECF
bleaching sequence has:
• Reduced ECF bleaching chemical cost by 8% while increasing final
brightness by 0.5%
• Reduced DCM extractives content by 30-50%
• Reduced pulp TOX content by 50-70%
• Had no impact on pulp mechanical strength or viscosity
• Reduced hardwood bleach plant effluent AOX by 65%
• Reduced hardwood bleach plant effluent COD by 18%
• Reduced total mill effluent color by 27%"(20)
However, this mill is rather unique in that the major species processed on the
hardwood line is birch, which is known to be difficult to bleach. Historically, a
kappa factor of 0.4-0.45 was required to achieved final bleached pulp brightness
in this bleaching line. Therefore, it is difficult to extrapolate these results to other
hardwood bleach plants without further study.
Hot Peroxide Stage
The use of hydrogen peroxide continues to steadily increase in ECF bleaching.
This technology was first implemented to overcome the decrease in effectiveness
of Dloo versus chlorination stages. It has since been demonstrated in most mills
that a small quantity of hydrogen peroxide (0.2-0.3% on pulpyis very effective in
reducing the total active chlorine demand in replacement ratios such that lower
bleaching cost is achieved. There are, however, some-mills in which this practice
has not been successful. The benefit in the use of hydrogen peroxide in the Eo
stage is to achieve a reduction in the kappa factor in the first stage, and not
necessarily in the final bleaching stage. Generally, the technology is not as
attractive for mills that tend to use a very high kappa factor, or those who attempt
to reduce the final chlorine dioxide stage charge.
CONFIDENTIAL 32
Iv
GIN
More recently, the advent of hot pressurized peroxide stages(311-13,21-30) has been
demonstrated to be capable of consuming significant quantities of peroxide (up to
2-3% on pulp) and to significantly reduce the total active chlorine demand. Most
of these stages have been installed primarily to operate in fiberlines where totally
chlorine fr6e (TCF) pulp is produced either continuously, or in campaigns.
Generally, the use of high quantities of hydrogen peroxide in the first alkaline
extraction stage does not reduce bleach chemical cost. However, the relative
cost.of chlorine dioxide and hydrogen peroxide has been changing such that the
operating cost penalty is reduced or eliminated at some mills. This economic
situation is geographically dependant, as well as dependant on the stage of
purchase contracts for hydrogen peroxide and chlorate.
This technology uses high temperature and extended retention time to effectively
consume the peroxide in the stage. The temperature of this stage is generally in
the range of 90-110°C (195-230°F), with retention time from 1-3 hours. There
are two technologies proposed for practice of this technology:
1. The use of a pressurized 60-180 minute reactor vessel, very similar to an
oxygen reactor is used in place of the Eo stage. This is commonly
referred to as a (PO) stage.
2. The use of a short, high temperature upflow tube, in combination with an
existing atmospheric downflow tower for added retention. The
combination of a 10-20 minute high temperature upflow tube, followed by
30-120 minutes of atmospheric retention has been shown in laboratory
studies to achieve results similar to those achieve with high temperature
pressurized retention throughout the entire reaction time. This is
commonly referred to as a PHT stage.
In both cases, alkali, hydrogen peroxide, and a viscosity protector are added
ahead of a steam mixer and a chemical mixer. Steam is added to achieve
reaction temperature, and oxygen gas may or may not be required to achieve
best results, depending on the position of the stage in the fiberline. A simplified
schematic of the PHT design is shown on the next page. (The (PO) stage design
is the same as a single oxygen delignification system, but.
. without added
washers.)
r
The use of chelants for proper management of trace metals is important to
improve effectiveness and selectivity of peroxide, oxygen and ozone stages in
both ECF and TCF bleaching. In both cases of hot peroxide bleaching stage
design, the use of chelants for proper management of trace metals and/or the
use of magnesium salts for preservation of viscosity must be considered.
CONFIDENTIAL 33
V GUY
e
Upflow Section:
Pressurized: 4 bar
Temperature: 90 - 130°C Downflow Section:
Atmospheric Condition
Temperature: 95 - 980C
Pump
Mixer
CONFIDENTIAL 34
VGIN
TCF Bleachinq
In the early 90s, there was a strong trend towards the implementation of non-
chlorine, or totally chlorine free (TCF) bleaching, particularly for those mills
furnishing pulp and paper into the Germanic speaking countries of Europe. The
first implementation of TCF bleaching was in sulfite mills in Europe. Sulfite pulps
have inherently higher bleachability compared to kraft pulps, and most mills were
able to achieve this goal using only oxygen and peroxide. The growth rate for
ECF and TCF pulps is shown in the figure above. In the last 5 years, the growth
rate of TCF pulps has slowed, while.the growth rate of ECF pulps has increased.
60
Other
N
N
40
0
w
0
N F —5 mt/y
c
20
TCF
0 _ -- - ____�..___ --
_ ._0_1 mt/y
1988 1990 1992 1994 1996
Year
The development of quality TCF pulps from the kraft was proven to be more
problematic, especially when targeting the same brightness and pulp quality
targets of conventional kraft ECF pulps. There continue to be number of mills,
especially in Scandinavia that produce TCF pulps from hardwood and softwood
on a continuous basis. However, some mills have displaced some production to
be "ECF-Light" pulps, where only a very small amount of chlorine dioxide is used,
but higher brightness and quality can be achieved compared to TCF pulps.
In North America, there is only one kraft mill producing TCF pulp from softwood
pulps, in Samoa, California. In this mill, oxygen, alkali, chelants, and hydrogen
peroxide are used as the active bleaching chemicals. The bleaching cost is
extraordinary high, as this mill typically uses 4-5% peroxide on pulp.
CONFIDENTIAL 35
AO-
Although technically, TCF pulp can be produced at the Canton mill, there is no
published commercial experience with this technology in the world to produce the
paper and paperboard grades manufactured at Canton.
The sequence QPZP is used for reference in this study. A typical schematic for a
similar sequence AEQPZQPHT is shown on the next page for reference. A detailed
laboratory investigation is necessary to define the optimum TCF sequence that
may be used for this pulp.
The basic system configuration shown requires the following additions and/or
modifications for the conversion of the Canton bleach sequences to TCF pulp
production:
1.. Implementation of an acid soak or chelation step after the post oxygen
washers (potential relining of the high density storage tower)
2. Conversion of both chlorine dioxide towers to peroxide towers
3. Conversion of the existing EQP tower to a chelation step
4. Addition of chelant supply and control system (including pH control loops
5. Sulfuric acid delivery system modifications
6. New Ozone Gas Mixer
7. New piping and pressurized upflow tube for Z stage
8. Gas separation system and potential tie-in to ozone gas recovery system
9. Complete ozone gas generation
10. Ozone gas compression system
11. Piping and controls for ozone gas delivery to Z stage
12. New gas monitoring, safety training and procedure development
13. Ozone gas destruct and potential oxygen recovery system
14. Expansion of peroxide delivery and control system,
15. Addition of pressurized upflow tube(s) to the D stages for conversion to
PHT stage(s), [or replacement of D towers with pressurized reactors for
(PO) stage(s)].
BFR® Process for Hardwood Line
The BFR® Process has been demonstrated to significantly improve the effluent
qualtiy on the softwood line at the Canton mill due to reuse of bleach effluent for
oxygen washing. This process can be incorporated on the rardwood line, and
the results can be expected to be similar. However, this approach is similar to
pursuing external treatment options, as there will be-9 high capital cost required
for implementation, and the operating cost of the mill will increase.
CONFIDENTIAL 36
V GLA
AEOPZEQPHT (or "QPZP") Bleach Plant
NaOH ° °
e ° ° EDTA
I
EoP PHT
so°c 1 1o°ci
A Q se°c
sa°c 7o°c
y
RA 0A
H2SO4 NaOH
Eoa OZ
Oz H202 03 ZoNaOH PHT
02 EDTA
Acid Purge
CONFIDENTIAL 37
VGIN
Emerging Pulping and Bleaching Technologies
There are a number of other developing technologies which may be considered
in the future for implementation at the Canton mill. These technologies are not
included in the evaluated options, as we believe that there has not been sufficient
commercial experience to implement at this time and assure performance in
color reduction or financial benefit will be achieved.
LIGNOX
The LIGNOX process is one of several processes that use chelating agents,
oxygen delignification and hydrogen peroxide treatments. These types of
processes, as well as (PO) and PHT stages, are becoming more widely used as
efforts to reduce chlorine-containing compounds are increased.
Enzymes
The potential for use of enzymes has been decreased as other technologies
such as extended delignification and oxygen delignification are implemented.
However, some mills have implemented this technology on a full time basis (10-
20 mills globally). Most mills who have implemented this technology did so due
to limitations in the application of chlorine dioxide in the bleach plant. There are
some mills, however, that have found a slight reduction in operating cost,
particularly on hardwood pulps. The success of enzymes in a particular mill is
very dependent on the wood species processed. This technology could be
incorporated by adding enzymes and controlling pH in the brown stock high
density storage tower. However, the viability will also depend on the cleanliness
of the pulp, the actual temperature of the pulp, and the temperature variations
encountered in normal operation at the high density storage tower.
Molybdate Activated Peroxide Delignification and NetFloc® Recovery Process
Addition of acidic peroxide activated by catalytic amounts of a molybdate(31) (mP) is
an alternate delignification method that can be used on hardwood pulps after
oxygen delignification. The reaction may be carried out in the brown stock storage
tower (if metallurgy is acceptable)with no large capital investment required. If the
effluent is either used for back washing or sent to the secondary treatment as an
acid stream, only the equipment for charging the chemicals, sulphuric acid,
hydrogen peroxide and molybdate is needed. The reaction is done at 10%-12%
consistency for 2-4 hours at 70-90°C, and pH 4-5. Besides decreasing the kappa
number 4 to 5 units of the kraft hardwood pulp the mP treatment removes
hexenuronic acids and bound COD thus reducing the formation of oxalate in the
following stages. Mill scale results have shown a usage of 2.6 lbs. hydrogen
CONFIDENTIAL 38
V GLAI
peroxide per unit kappa number drop. Molybdate usage is 0.8 lbs. but may be
recovered with some new schemes now being tested.
Accompanying the decrease in Kappa number of 4-5 units the kappa factor would
also decrease to 0.20 from the initial value of 0.30. Thus, for an oxygen, Mp,
washed delignified pulp kappa number 5, the chlorine dioxide charge in the D,
stage would be 7.6 Ibs CI02/ton of pulp. This means the AOX would be further
reduced while color may be decreased by 5700 Ibs/ton.
The Kemira Company, which provides chemicals for the mP technique also,
endorses the NetFloc( 2) process (the use of polyethylene oxide as a flocculant) to
remove extractives, non-process elements, and color from process effluent.
Recovery of the molybdate and color from this stage as well as from the Eop stage
is being tested at a mill site.
This technology is in the early phases of commercial demonstration in Finland. It is
expected that this technology will be quite sensitive to black liquor carryover, so
further study should be made before considering this technology.
Peracids
Distilled peracids have proven to be viable for use in chlorine and chlorine-free
bleaching sequences. The pulp quality parameters are generally as good or
better than for ozone, but the low capital costs are attractive particularly as mills
assess the viability of ozone. Peracids have been evaluated in both pilot plant
stage and are now used in four mills in Finland. This is potentially a promising
new area of pulp bleaching research and it is possible that peracids will become
an additive or alternative to CI02, ozone or peroxide when used in conjunction
with ECF and TCF sequences. At present, however, the use of peracids
generally results in an increase in operating cost, so their use today is primarily in
mills that are producing TCF pulps.
Acid Hydrolysis
The use of a hot (>95°C, >200°F), long retention time (2-4 hours) acid hydrolysis
stage (pH < 3) prior to the bleach plant has been shown to remove the majority of
the hexenuronic acids from the pulp. These hexenuronic acids, if retained in the
pulp, consume active bleaching chemicals in the bleaching. This technology is
most effective on hardwood pulps, and particularly those hardwood pulps with a
high xylan content. There are a few commercially operating systems in the world
today. The major issues with this technology are yield, corrosion, and scaling. It
is difficult to assess changes in yield in a laboratory environment, and much more
difficult to assess yield in a mill operation; however, some detailed evaluations
show significant yield loss by this acid hydrolysis which is not fully offset by
CONFIDENTIAL 39
reduced yield loss in subsequent bleaching. The application of sulfuric acid at
high temperature creates a very corrosive environment, and some mills have
reported failures of austenetic stainless steel equipment and piping. Where this
effluent is recycled to the post-oxygen washing, care must be taken to prevent
scale buildup on equipment and piping.
Hot Chlorine Dioxide Stage
Recently, laboratory work has shown the benefits of increased temperature in
combination with extended retention time in the first chlorine dioxide stage.
Chlorine dioxide savings of 10-20% have been reported when operating the
stage at 70-800C (160-175°F) for 1-2 hours retention time. This technology is not
included as a primary option in this study as there are currently no commercial
installations, and it is known that the Canton mill has a limitation in steam supply
that would make it difficult to practice.
Pulp Washing and Effluent Flow Reduction
The only reason there is any process effluent from a bleach plant is that we wash
the pulp after each bleaching stage and there is the need to purge dissolved
solids from the system which, if retained, would inhibit production, consume
chemicals, or adversely affect product properties. If these contaminants could be
completely removed through internal systems such as BFR®, there would be no
need for process effluent; the mill water effluent system would be substantially
decreased. However, to date, no technology, including the BFR® process has
been demonstrated to eliminate liquid effluent from kraft pulp bleach plants.
Notwithstanding some of the findings from previous work (33-35) washing in the
modern bleach plant is important in that more costly bleaching chemicals are
being used, especially in TCF bleaching. In addition, hydrogen peroxide,
peracids, and ozone are very sensitive to transition metals. Finally, efficient
washing must be used if the industry is to achieve the 'low effluent flow bleach
plant'.
Over the last two decades, the pulp and paper industry has made significant
gains in its efforts to use recycled effluent to reduce fresh water usage and
minimize effluent discharges.
The effluent quantity from bleached kraft pulp mills has also been reduced, while
the effluent quality, as measured by toxicity, BOD, COD, color, odor and foam,
has been improved. This is especially true if bleach plant closure is made part of
the comparison where it has been shown that the old filter bleach plant which
used to emit 12,000 gal/ton, is modernized to a filter ECF bleach plant, the
volume would decrease to 2,880 gal/ton. For the same degree of filtrate closure
CONFIDENTIAL 40
it has been shown that a corresponding press-based bleach plant would only
emit 1,920 gal/ton(36)
The Canton mill is one of the most modern mills in the world relative to water
reuse, minimization of effluent flow, and minimization of environmental impact
from the bleach plant effluent. There are a number of principles of pulp washing
and water reuse that are pertinent to any modern mill; most if not all of these
have been addressed or are practiced at the Canton mill. A review of these
principles may be of value in planning future potential changes to the mill
operation.
Conventional washing techniques include (a) direct counter-current, (b) split flow
and (c)jump-stage counter-current which were all tried to effect lower fresh water
use. "The key to filtrate recycling is remembering that 'like goes with like'. For
example, if pulp is going into a Dion stage, D100 filtrate can be used for dilution,
similarly for the other stages. If the washer showers allow for two different
filtrates to be used for washing, the top or last shower can use filtrate from a
following stage. To avoid mixing acid and alkaline filtrates, it is important to not
break through the pulp sheet with the filtrate from the subsequent stage.
Breakthrough will not occur if the last shower flow is more than half the total
shower flow, where the total shower flow is about a dilution factor of 2. The
philosophy of using two different filtrate flows for showers is employed with the
split-flow counter-current washing system. Direct countercurrent recycling is
generally not recommended as it may increase chemical consumption and may
cause pitch and foaming problems."(3
The following is a list of some opportunities for water reduction that can typically
be found in pulp mills today(38)
a. For all washing stages, improving the discharge consistency of the washer
will improve pulp washing. Discharge consistency drops on older and
overloaded washers. The most common operating problems on vacuum
drum washers are low operating vacuum, improper application of wash water,
high washer speed, low discharge consistency, inadequately or unevenly
washed pulp and difficult pulp discharge.
b. Improving the wash shower type to get better shower disf ibution and more
efficient washing.
c. Replacing older washer drums with new drums having anti-rewet decking will
result in several points increase in discharge consistency and offer the
potential for reducing wash water requirements.
CONFIDENTIAL 41
d. Use of filtrates on wire cleaning showers and operating the cleaning showers
intermittently can reduce water consumption.
e. Use recycled filtrates for repulper dilution and any standpipe dilution (often a
16% washer discharge is diluted to 12% with repulper dilution). Generally
pump standpipe dilution can operate on the filtrate from the following washing
stage, although this is often connected to hot or warm water for ease of start-
up. Non-compatible construction materials may be an issue.
f. Water doctors can often be replaced with air doctors or operate on washing
filtrate for that stage. Sometimes this will require installation of fiber filters.
g. It may be possible to recycle excess white water from the pulp or paper
machine or bleach screening system to showers where hot or fresh water is
being used.
h. The bleached pulp screen room can be closed.
i. Typically, washer showers are set at a constant flow but flow control can be
installed to enable wash ratio or dilution factor control.
j. Washer seal tanks should be put on level control to avoid spillage for
effective level control. However, seal tanks are often too small to make this
practical in older mills.
k. Converting the D/C or D,00 stage from low to medium consistency can
improve the water economy.
I. In general, organic material carried forward (black liquor solids from
brownstock washing) into the first bleaching stage (C, C/D, D or even Z)
appears to use two to four times more chemical than organic solids carried
back from an Eo or EZ stage. Reductions in carry over can reduce chemical
application and the volume of water associated with the chemicals.
m. If an open wash stage is used before the bleach plant, then the filtrate flows
can be reused in the brownstock areas, effectively extending.the brownstock
washing system into the bleach plant. Split showers on this washer may
allow for future use of D/C filtrate here.
n. Spill recovery is generally for fiber only, but filtrates could also be recovered
and returned to the high-density dilution or possibly back to the brownstock
screen room.
CONFIDENTIAL 42
vGLAI
o. It may also be possible to leave washers out, for example by converting a
D100EoDED sequence to a D100EoPDD sequence.
The direction of the industry is to ever greater recovery of the filtrates from the
kraft process and reduce water usage. The application of extended
delignification during pulping and oxygen delignification (which reduce the
amount of organic material in the remaining effluent) are already being used in
some mills. One reason often stated as a major cause for not applying tight
water usage — the build-up of chlorides - has already been dealt with effectively
in coastal mills where chloride-laden logs are used in the pulping process. By
the appropriate design and operation of the recovery process and by not
returning all the chloride-rich electrostatic precipitator dust to the process, a
steady-state chloride level can be maintained and a certain amount of chloride
can be tolerated in the recovery system. This operating experience shows that it
is unnecessary to totally eliminate chlorides from the filtrates which are to be
recycled and that a certain usage of chlorine dioxide could be tolerated in a
closed-cycle mill.
The Key Elements in Achieving Water Reduction in a Mill are:
• Decrease effluent volume (this will permit economic treatment of the effluent)
• Decrease process water (in washing and raising consistency of bleaching
stages)
• Reuse evaporator condensate
• Reuse machine white water
• Recover and reuse heat from process
• Standardize temperature.
Based on the site survey undertaken by the authors of this report, most, if not all,
of the principles of water reduction have been addressed and are being practices
at the Canton mill. One observation made on site is that the water use on the
washers seems to be at a flow that is borderline to achieve best economic
operation of the fiberline. Specific recommendations on some current problem
areas have been made in the "Site Audit and Performance Review" section of
this report. An increase in water use should be studied as a means to reduce
bleach chemical consumption and thus reduce operating cost.
The "Bleach Filtrate Recycle" process (BFR) which was developed at, and is
currently practiced at the Canton mill is a benchmark for low effluent flow in the
worldt39
Another system of closed cycle bleach plant operation while still using chlorine
dioxide was the source of a technical presentation at a recent meeting("). The
new technology developed jointly by Jaakko Pbyry, Stora Billerud and Eka Nobel
CONFIDENTIAL 43
VGVV
claim water volume reduction (to 10-15 m3/ADt) and uses electrodialysis to purge
chlorine and inorganics from the filtrate. Capital cost for 1000 adtpd bleached
softwood mill is estimated at $35 million with an operating cost of $15/ton.
External Treatment Options
Jacobs Study Commentary
Blue Ridge has engaged the Jacobs Engineering Group Inc. to evaluate and
report on end-of-pipe color technology. A comprehensive report(41) on eight
different color technologies clearly delineated to what extent color removal could
be expected and the economics associated with a particular technology was sent
to the mill in early spring of 2001.
The technologies reviewed were:
Alum Color Removal System
Lime Color Removal System
Polyamine Color Removal System
Ultrafiltration System
Carbon Adsorption System
Storage and Time Release System
Ozonation System
Crystallization System
The basis of the analysis of these systems was the mill data on:
Average flow 24.8 MG/Day
Peak flow 28.7 MG/Day
Average color 41,188 lbs/day
Maximum color 65,888 Ibs/day
A summary of the results of the above-mentioned review is reproduced on the
next-page. It is not the intention of the authors of this report to further describe
each of the eight technological systems mentioned in the Jacobs Engineering
report. We agree with comments that the end of pipe color treatments are not
economically feasible because they require high capital investment and ongoing
operations expenses. However, some thoughts and concerns- are stated in the
next several pages particularly relative to treatment of individual bleach effluent
streams using similar technology. All of these technologies have the same
disadvantage as the "End-of-Pipe" options in that they incur capital to install and
result in increased operations and maintenance costs for the mill. Thus they are
not favored in light of alternative in plant process changes.
CONFIDENTIAL 44
GIB/
Emerging External Treatments
Chemical Destruction
The mineralization of AOX is the hydrolysis of organic chlorine compounds under
alkaline conditions to produce inorganic chlorides. Subjecting E-stage
ultrafiltration concentrates at pH's up to 12.5 to high temperature (100°C)
decreases AOX concentrations by up to 50%(4i.42). AOX reduction by hydrolysis
also will take place in a conventional wastewater treatment plant when
chlorination effluent is subjected to an alkaline pH, increased temperature and
time(43). At usual bleach plant operating temperatures (60 to 800C),AOX removal
of from 54 to 67% was obtained at pH of 11 using Ca(OH) or NaOH respectively.
Substituting weak black liquor for NaOH increased the AOX removal by up to
30% more 44). Increasing the temperature to 1500C and pressure to 475 kPa
increased the AOX removal to 80%44).
Biological Treatment
Certain fungi such as white-rot fungus, Phanerochaete Chrysosporium in a
rotating biological contactor has been found to remove AOX and color for a
bleach plant effluent stream. Most methods using biological treatment depend
upon treating selected bleach plant effluent or concentrated streams of effluent
from active carbon adsorption or ultrafiltration processes(45,46) White-rot fungus
dechlorinates the bleach plant effluent by converting the organically bound
chlorine to inorganic chloride. Color and AOX destruction by the fungus is
accomplished by a family of enzymes the fungus excretes; there are some 15
extracellular enzymes that are produced by the fungus(47). These enzymes which
can degrade lignin and lignin modified during pulping and bleaching are called
peroxidates(47).
To decrease the potentially high cost of this type of treatment ($6-$8/adt), the
white-rot fungus was immobilized on granular activated carbon. One major
problem was the dissociation of the hydrogen peroxide produced by the fungus
on the activated charcoal carbon structure. Research on bench scale fluidized
fungal experimental systems where the fungi is immobilized on granular activated
carbon and employing a recirculating reactor loop showed that the chlorinated
organics were reduced to below the limits of detection within eight hours(49).
Photo-oxidations
Photo-degradation reactions are initiated when bonding electrons absorb a
quantum of light whose energy corresponds to an energy difference in the
electronic state of the absorbers °). Results of studies showed that when whole
mill effluent was irradiated at 254 nm in the presence of an oxidant catalyst, Ti02,
CONFIDENTIAL 46
VG1W
the degradation of the effluent was greatly increased at 50°C; the degradation is
strongly dependent on the intensity of the irradiation.
Aeration of the effluent by oxygen not only maximizes the degradation but cause
the rate to be independent of pH, improving the techniques applicability to
different bleaching effluent streams. Under the best present known condition a
dark colored mill effluent can be treated by photo-oxidation to produce a clear
solution with low or no toxicity in less then 30 minutes(49).
Thermal Destruction
As bleached kraft mills move towards closed mill technologies using either
polymer, resin, ultrafiltration or activated carbon treatment they will produce
concentrated effluent streams that may contain high concentrations of
chlorinated organic and inorganic chlorides(51). Presently the only mill technology
for treating these concentrates is by treatment in multiple-effect evaporators
followed by burning in the recovery furnace. This raises the problem of the high
chloride residual in the various process streams and the possible corrosion of the
evaporators.
As an alternate technology the thermal destruction approach in equipment other
then a kraft recovery furnace is now under investigation. Initial results were
obtained by examining effluent concentrates obtained by ultrafiltration and
reverse osmosis. These concentrates were analyzed for their solid content, color,
AOX, total organic carbon, metals, heating value and ash content. Ultrafiltration
concentrates were found to be more desirable as a fuel then the reverse osmosis
concentrates due to the higher level of carbon organic to inorganic ratio, heating
value and lower levels of ash. The heating values of ultrafiltration concentrates
are in the range of 12,000 to 19,200 kJ/kg which are in the same range as that of
black liquor solids. The organic content to inorganic content also effect the
heating values, since the organics are major contributors to the net heating value
while the inorganics are not. It is important to note that the air emission should
be monitored for potential PCDD/PCDF emissions which may be eliminated
when the effluent concentrates are mixed with a small quantity of black liquor or
other suitable absorbers are used(51).
Thermal destruction technologies include: rotary kiln incinerators, circulating
fluidized bed combustors, gasification of waste to medium or low BTU fuel gas,
and co-firing waste with other fuel, such as black liquor bark, coal, oil and gas.
CONFIDENTIAL 47
VGU/
Methods for Recycling Effluent
Other methods of closing up existing mills, as well as in Greenfield mill, include
technologies for bleach plant in-plant and external control using:
• Membrane process: ultrafiltration and reverse osmosis
• Resin process
• Activated carbon adsorption
• Chemical coagulation:
(a) lime
(b) alum
(c) ferric chloride or sulfate
(d) organic polymer treatment
Paper machine white water reuse in the bleach plant
• New bleaching sequences
Membrane Processes
1. Ultrafiltration is a membrane process that can decrease color and AOX in the
effluent. The process involves a physical separation of the components by
applying pressure to the fluids being cleaned. The selectivity of the
membrane depends upon its pore size. Ultrafiltration is usually done in the
10 to 175 psi pressure range and the molecular weight separation can be
varied from 1,000 to 1,000,000. Ultrafiltration is used primarily on extraction
stage filtrate, where approximately 80 to 90% of the color, 70% of the COD
and 25% of the BOD are removed(52) It has also been reported that a
significant fraction of the resin and fatty acid are removed but low molecular
chlorinated phenolics are not removed(53). Typical operating costs are $6/adt
for the filtration equipment and $15-20 million for installation cost excluding
incremental evaporation capacity.
2. Reverse osmosis is a high pressure membrane process in which dissolved
solids are separated from water by applying a pressure higher than the
osmotic pressure. Applying pressure to the feed stream of effluent, water
will permeate through the membrane from the area of high dissolved solids
concentrated to the area of low solids concentration, producing clean water.
Reverse osmosis membranes are made from a multitude of materials
including acetate, polyacrylic acid, cellulose and other cross-linked polymers.
The reserve osmosis system usually operates at'pressures of 100 to 1500
psi. Information from laboratory and pilot plant studies have been reported(54)
and a full-scale reverse osmosis system was installed at a NSSC corrugating
mill(55) but later abandoned due to the unavailability of suitable membranes.
Cost of operating a reverse osmosis system in conjunction with ultrafiltration
or diafiltration or freeze concentration of the concentrated material ranges
CONFIDENTIAL 48
VGIN
from $10-30/adt with a capital investment on $40 million for a 1000 t/d
mill(53,56)
Areas of Further Research
• Evaluation of different membranes for various applications as membrane
fouling results in flux reduction.
• Low flux rates and a decline in flux rates with time of membrane operation.
• Effect on the recovery system on burning ultrafiltration and reverse osmosis
concentrates. The effect of air emissions.
Resins
Resins, through ion exchange or sorption, remove selected chemicals from a
solution.—The resin-technology involves pretreatment of the effluent to remove
large particles and to effectively optimize the effluent pH from pH 2.5 to 7
depending on the type of resin used. The effluent is then passed through a resin
column where color and some organic compound ions are removed. When the
removal rate of the column drops it is replaced and the resin regenerated. The
material collected from the regeneration process is concentrated and eliminated
from the system. Processes tested and reported upon are the Rohm and Haas
process(57), the Dow process(58) and the Billerud-Uddeholm pro'cess(59) for color
reduction. The latter process is said to also remove organic material (chlorinated
phenols and guaiacols), therefore decreasing effluent toxicity. Color reductions
from 80 to 90% are achieved, while BOD decreases of 50% have been
reported(59). The estimated operating cost in 1981 was between $7.75-10.25/adt
assuming a 2-year life of the resin. The equipment and installation costs were
$1,300,000 for a 1000 AD/t pulp production.
Area of Further Research
Evaluation of different resins for various applications, including removal of other
chemical components.
Active Carbon Adsopition
The use of activated carbon for removing organics from effluent streams has
been known for many years. Activated carbon characterized by a very large
surface area per unit mass (450 to 1800 m2/g) has an extreme)y,high capacity for
surface adsorption of organic molecules with relatively low water solubility.
It has been reported that activated carbon in laboratory and pilot glant studies
removed greater than 90% of the color from extraction stage filtrates 0,61) and that
the spent carbon could be regenerated several times with caustic before thermal
regeneration was required.
CONFIDENTIAL 49
VGLAI
The annual operation cost, including depreciation and capital cost recovery for
this system, was estimated to be $42 million (1987 costs) while the cost of
installation of an activated carbon system at a mill to treat the entire secondary
effluent was said to be $117 million(6 2).
Further Research Needs
Problems to be solved include:
• Frequent plugging of carbon beds with suspended solids
• Absence of a reliable technology for treating the concentrates from carbon
regeneration at bleached kraft Mills.
• Biological growth in carbon columns along with gassing off.
—Chemical Coa ulation----- — -
Chemical coagulants such as lime, alum, ferric salt, ferric chloride and ferric
sulfate, along with organic polymer (polyelectrolyte), are known to destabilize
large organic molecules contributing to the color of the effluent and produce
flocs. The resulting flocs can be separated from the water by settling or air
flotation and thus removed. Only lime treatments will be discussed since all the
above processes remove color, but lime has been shown to also remove AOX.
Lime Treatment
Several massive lime treatment processes are known and the results from the
International Paper Company's mill at Springhill, Louisiana study reported(63)
slaked lime was applied to a colored extraction filtrate and allowed to settle out in
a primary clarifier. The clarifier effluent was recarbonated with CO2 to recover
the soluble lime. The results show that 90-95% of the color can be .removed.
Recently(64), it was shown that 80% of the AOX can also be removed by massive
lime treatment. Only one such system is presently operating.
Cost for operating this system was estimated to be $23 million a year, which
included depreciation and capital recovery. The cost for installing a lime color
removal system was estimated to be $55 million (1987 cost).
Further Research Needs
Given the sludge from the clarifier would be dewatered and sent to the lime kiln,
the effect of chloride ions along with other metals would have to be fully
examined.
The effect of increased dissolved solids resulting from implementing this
technology is not known and would have to be elucidated.
CONFIDENTIAL 50
IvGIN
Paper Machine White Water Reuse in the Bleach Plant
To decrease fresh water use in several mills, the bleach screen room and paper
white water are used for diluting pulp entering the bleach plant from the HD
storage chest but usually for diluting pulp leaving the final bleach plant washer.
Some mills reported using machine white water on showers of the chlorination
and extraction stage washers. Shower washers are required to operate a large
number of sprays. The quality of water coming from the paper machine was both
screened and clarified to remove impurities that may affect the bleaching
process.
References
1. Sjoblom, K., Mjoberg, J., and Hartler, N. - Paperi ja Puu 65:227 (1983).
2. Axegard, P., and Wiken, J.E. - Svensk Papperstidning (86):R178 (1983).
3. Hartler, N., and Olsson, L.A- Svensk Papperstidning (75):Nr13 (1972).
4. Bennington, C.P.J. and Pineault, I., Pulp & Paper Canada 100:12(1999).
5. Germgard, U., and Norden, S„ "OZP - Bleaching of Kraft Pulps to Full
Brightness", 1994 International Bleaching Conference, Vancouver, BC,
TAPPI, SPCI, EUCEPA, and CPPA, p. 53-58.
6. Tibbling, P. and Dinner, B., 'TCF Bleaching can be Carried Out with
Difference Bleaching Systems", 25th EUCEPA Conference, 1993 Vienna,
Austria, 842 pp.
7. Dillner, B., and Tibbling, P., "Optimum Use of Peroxide and Ozone in TCF
Bleaching", 1994 International Bleaching Conference, Vancouver, BC,
TAPPI, SPCI, EUCEPA, and CPPA, pp. 319-333.
8. Sjodin, L., Ssolverg, N., and Bomar, R., "Extended Delignification in Oxygen
and Hydrogen Peroxide in ECF and TCF Sequences", Proceedings of the
1994 TAPPI Pulping Conference, San Diego, pp.21-27.
9. Basta, J., Holtinger, L., Lundgren, P., Fasten, H., Freddksson, R.,
"Alternatives for Achieving High Brightness TCF Pulps". Proc. of Non-
Chlorine Bleaching, Amelia Island, FL, USA, 1994.
10. Axegard, P., Ekholm, U., `Peroxide-Based TCF Bleaching Basics and New
Development", Workshop on Emerg. Pulp Tech., Durham, April 1995.
CONFIDENTIAL 51
VGU/
11. Basta, J., Holtinger, L., Hermansson, W., and Lundgren, P., "Metal
Management in TCF Bleaching", 1994 Int. Pulp Bleaching Conference,
Vancouver, BC, TAPPI, SPCI, EUCEPA, and CPPA, p. 29.
12. Basta, J., Holtinger, L., Lundgren, P., and Persson, C., "Emerging
Technologies in TCF Bleaching". Proceedings of the 1995 TAPPI Pulping
Conference, Chicago, p. 53-57.
13. Breed, D., Shackford, L.D., Pereira, E.R., and Colodette, J.L., "Cost-
Effective Retrofit of Existing Bleach Plants to ECF and TCF Bleached Pulp
Production Using a Novel Peroxide Bleaching Process". Proceedings of the
1995 TAPPI Pulping Conference, Chicago, p. 779-788.
14. Liebergoft, N., 'The Use of Ozone in the Bleaching and Brightening of Wood
Pulps", 1979 Preprints of Fundamentals of Ozone Technology Seminar, The
Center for Professional Advancements, East Brunswick, NJ, July 23-25,
1979.
15. Lachenal, D., Taverdet, M.T., Muguet, M., "Improvement in the ozone
Bleaching of Kraft Pulps", Intern. Pulp Bleaching conference, SPCI,
Stockholm, 1991, pp. 33-43.
16. Dillner, P., and Tibbling, P., "Use of ozone at medium consistency for fully
bleached pulp. process concept and effluent characteristics. TCF bleaching
can be carried out with different bleaching systems", Intern. Pulp Bleaching
Conference, SPCI, Stockholm, 1991, pp. 59-73.
17. Tsai, T.Y., US Pat. No. 4,959,124 (Sept. 25, 1990).
18. Lachenal, D., Muguet, M., "Degradation of Residual Lignin in Kraft Pulp with
Ozone", Nordic Pulp & Pap. Res. Journal, No. 1/1992, pp. 25-29.
19. Liebergott, N.L., Ozone Tutorial. Preprints of the 1996 INCBC, Orlando,
Florida.
20. Munro, F., and Griffiths, J., "Operating Experience with n Ozone Based
ECF Bleach Sequence.
21. Stromberg, B., and Szopinski, R., "Pressafized Hydrogen Peroxide
Bleaching for Improved TCF Bleaching", 1994 International Bleaching
Conference, Vancouver, BC, TAPPI, SPCI, EUCEPA, and CPPA, pp. 199-
209.
CONFIDENTIAL 52
1- tGnI
22. Wiltshire, K., Steffes, F., and Reeves, R., "Pressurized Peroxide - A Good
Fit for both the Bleach Plant of Today and the Future", Proc. 1995 Spring
Conf. CPPA Technical Section, Whistler, BC, Canada. Preprints.
23. Str6mberg, B., 'Pressurized Hydrogen Peroxide Bleaching for Improved
TCF Bleaching", 1995 TAPPI Emerging Pulping and Bleaching Technol.
Workshop, Durham, NC. preprints.
24. Devenyns, J., Desprez, F., and Detroz, R., "Enhanced Hydrogen Peroxide
Bleaching Stages for Chemical Pulps". 1995 TAPPI Emerging Pulping and
Bleaching Technol.Workshop, Durham, NC. Preprints.
25. Boman, R., Reeves, R., and Nordgren, B'., "Pressurized Peroxide Bleaching
- An Important Tool for Modern ECF and TCF Bleach Sequences", Proc.
Nonchlorine Bleaching Conf., Amelia Island, FL, USA, March 5-9, 1995.
Preprints.
26. Breed, D., Colodette, J.L., "Pushing the Peroxide Window", 1995 TAPPI
Emerging PUlping and Bleaching Technol. Workshop, Durham, NC.
Preprints.
27. Reeves, R., Boman, R., and Norden, S., 'Impact of Sequence Position for
Pressurized (PO) Stages in ECF Bleaching", Proceedings of the 1995
TAPPI Pulping Conference, Chicago, p. 264-279.
28. Roy, B.P., van Lierop, B., Berry, R.M., and Audet, A., "High Temperature
Alkaline Peroxide Bleaching of Kraft Pulps". Proceedings of the 1995 TAPPI
Conference, Chicago, pp. 771-778.
29. Hill, R.T., Walsh, Walker, S.D., and Dutton, D.B., "An Evaluation of
Pressurized Hydrogen Peroxide Systems for Delignification and Bleaching".
Proceedings of the 1995 TAPPI Conference, Chicago, PP. 789-806.
30. Wigren, G.A., Canadian Patent 769,631 (Oct. 17, 1967).
31. Paren, A and Jakara, J. Molybdate Activated Peroxide in ECF Bleaching of
Hardwood Kraft Pulps, Preprints of the 10th International Symposium on
Wood and Pulping Chemistry, June 1999.
32. Roberts, J. "The Organ of Closure", Pulp and Paper Europe, July/August,
1999
33. Gullichen, J., "Displacement Bleaching", The Bleaching of Pulp, TAPPI,
Atlanta, GA, 1979, Chapter 10, pp. 275-291.
CONFIDENTIAL 53
VGIN
34. Cook, R.A., "A Bleaching Process for Minimizing AOX Discharges", Appita
44:(3), p. 179, 1991.
35. Lachenal, D., and Magent, M., "Reducing TOCI with OXO with the OXO
Process". Pulp Pap. Mg. Can. 92:12, T297-301, 1992.
30. Histed, J.A., "Simplified Bleaching Process", US Patent 4,238,281, Dec.. 9,
1980.
36. Germgard, U., and Steffes, F., "Pulp Washing in a Closed Bleach Plant".
Preprints, Minimum Effluent Mill Symposium, Atlanta, GA, Jan. 22-24, 1996,
p. 115.
37. Luer, M. and Cunnington, R., "Pulp Washing — Controlling Water Use",
Tech. 95 Bleaching Course Notes, CPPA Tech.Sect. 1995.
38. Turner, P., "Water Use Reduction in the Pulp and Paper Industry", 1st
edition, 1994.
39. Manninen, D. Status Report— another step forward towards the effluent-free
mill. Finnish Trade Review, pp. 14-15, April 1993.
40. Johansson, N.G., Fletcher, D.E. and Clark, F.E. New technology
developments for closed cycle bleach plant. Minutes of the 1995 Spring
Meeting of Tech. Sect.CPPA Bleaching Committee meeting. Castlegar, BC,
May 1995.
41. Blue Ridge Paper Products Inc.: 2001 Color Removal Technology
Assessments.
42. SUN, Y.B., ET AL, Tappi 72(9):209(1989).
43. German Pat. 3620980 KRAUSE, T. ET AL "Continuously Processing Pulp-
Bleach Effluent", Jan. 14, 1988.
44. DORICA, J., "Removal of AOX from Bleach Plant Ef Iluents by Alkaline
Hydrolysis", JPPS 18:6 P J 231, Nov. 1992.
45. EATON, D. ET AL, "Fungal Decolourization of Kraft Bleach Plant Effluent
the Chromophoric Material", Tappi 64(9):145, 1980.
46. MATSUMOTO, Y., YIN ET AL "Degradation of Chlorinated Lignin and
Chlorinated Organics by White-Rot Fungus". Proceedings of the 1985
CONFIDENTIAL 54
vGIN
International Symposium on Wood and Pulping Chemistry, Vancouver BC,
Canada, Aug. 26-30.
47. HAMMEL, K. ET AL "Oxidation of Aromatic Pollutant by Phanerachaete
Crysosporium Ligninese". Proceedings of the International Seminar on
Lignin Enzymatic and Microbial Degradation, Paris April 23-24 1987.
48. KIRK, J., 'Enzymatic Combustion: The Degradation of Lignin by White-Rot
Fungi". Proceedings of the International Seminar on Lignin Enzymatic and
Microbial Degradation, Paris, April 23-24 1987.
49. NCASI TECHNICAL BULLETIN NO. 609, "In-plant and Closed Cycle
Technologies R&D Program-Add On Control Technologies", May 1991.
50. RANBY, B. ET AL, Photodegradation, Photo-Oxidation and
Photostabilization of Polymers", Wiley-Interscience, N. Y.(1975).
51. ADAMS, T.N. et al "Kraft Recovery Boiler Physical and Chemical
Processes", The American Paper Institute, New York, NY, (1988).
52. Lundahl, H. and Manssin, I., "Ultrafiltration for Removing Color from Bleach
Plant Effluent", TAPPI 63:4, p.97, April 1980.
53. Dorica, J., et al, "Complete Effluent Recycling in the Bleach Plant with
Ultrafiltration and Reverse Osmosis", TAPPI 69:5, p. 122, May 1963.
54. Morris, D.C., et al, "Recycle of Papermill Waste Water and Application of
Reverse Osmosis", US EPA, WCRS Report No. 12040 FUB, January 1972.
55. MacLeod, J.M., Will Achieves Maximum Reuse of Water with Reverse
Osmosis", Pulp and Paper(48):12, pp. 62-64, November 1974.
56. Rock, S.L. et al, "Decolourization of Kraft Mill Effluent with Polymeric
Adsorbent:. TAPPI Environmental Conference, April 17-19, 1974.
57. Chamberlain, T.A. et al, "Colour Removal from Bleached Kraft Effluents",
TAPPI Environmental Conference Preprint, pp. 35-45, Mdy'14-16, 1975.
58. Lindberg, S. and Lund, L.B., "A Non-Polluting Bleach Plant", TAPPI (63):3,
p. 65, March 1980.
59. Timpe, W.G. and Lang, E.W., "Activated Carbon Treatment of Unbleached
Kraft Effluent for Reuse. Pilot Plant Results", TAPPI Environmental
Conference Proceedings, pp. 203-218, May 1973.
CONFIDENTIAL 55
VGIN
60. Lang, E.W., "Activated Carbon Treatment of Unbleached Kraft Effluent for
Reuse: Final Report on Part 1", EPA/660/2-76-004, April 1975.
61. Report by Sirrine Environmental Consultants, "Effluent Color Treatment,
Carbon Adsorption — Color Removal'. Canton Mill, Champion International
Corporation Mill, North Carolina, April 1987.
62. Oswalt, J.L. and Land, J:G., "Color Removal from Kraft Pulp Mill Effluent by
Massive Lime Treatment', US EPA Environmental Protection Technology
Series, report No. EPA-R-2-73-086 (EPA 12040DYD), February 1973.
63. Dorica, J., Private Communication.
64. Narum, Q.A. and Moaller, D.J., "Water Quality Protection at the Shasta Mill",
TAPPI Environmental Conference Proceedings, April 1977.
CONFIDENTIAL 56
VG
Options for Improved Environmental Performance
Basis for Study
The Blue Ridge Paper Products Inc. mill includes a pulp mill with a nominal
production capacity of 1420 ADBT/day of softwood and hardwood pulp. Prior to
its being purchased by Blue Ridge Paper Products Inc from Champion
International, a major modernization project was undertaken to reduce the
effluent outfall from the mill, and improve the effluent quality. Included in this
modernization was the complete rebuild of the hardwood and softwood fiberlines
and the incorporation of novel technology to improve environmental performance.
Since the mill was purchased from Champion, Blue Ridge Paper Products Inc.
has continued to improve its environmental performance through process
changes and incremental operating practice improvements.
An overview of the current softwood pulp production specifications is as follows:
Softwood Pulp
Production = 655 ADBT/Day
Digester K#= 17.5
Post-Oxygen K#= 10.5
CEK# = 2.2
Final Quality Targets
86 % ISO Brightness
15.5 cP viscosity
3 Dirt Count
The mechanical equipment on the softwood line includes conventional batch
digesters, knotting system, brown stock washers, single stage oxygen
delignification, post-oxygen washers, fine screening system, a vacuum decker
followed by unbleached pulp storage. The bleach plant includes a pre-bleach
washer followed by a conventional D1EoPD2 bleach plant. All washers are
Compaction Baffle Washers, except for the second stage post-oxygen washer
(decker) after screening, which is a vacuum washer.
The softwood fiberline is unique in the world due to: the incorporation of the
Bleach Filtrate Recycle (BFR) process. in this process, the D, filtrate is treated
in-a Metals Removal Process (MRP), after which is recycled for washing on the
bleach pre-washer and the D, washer as shower water. Metals are purged from
the system in the acid effluent. The EoP filtrate is largely recycled to the decker
filtrate. This process results in the transfer of a high level of chlorides to the
recovery cycle. An additional component of the BFR® process is a Chlorides
CONFIDENTIAL 57
10GLAI
Removal Process (CRP) installed at the electrostatic precipitator. It is at this
point that chlorides are removed from the system to prevent buildup of chlorides
in the recovery cycle and prevent potential boiler corrosion.
This process has been optimized such that 80% of the bleach effluent is recycled
to the recovery process, thus achieving a very low effluent volume, and
subsequently less discharge of undesirable characteristics, in particular color and
toxicity.
An overview of the current hardwood pulp production specifications is as follows:
Hardwood Pulp
Production = 765 ADBT/day
Digester K# = 11.0
Post-Oxygen K#= 6.5
CEK# = 2.4
Final Quality Targets
86% ISO Brightness
18 cP viscosity
3 Dirt Count
The mechanical equipment on the hardwood line includes equipment that had
largely been in operation prior to the major modernization project, but with
reconfiguration and upgrades to key pieces of machinery for improved
performance. The line includes conventional batch digesters, knotting system,
four stage vacuum brown stock washers, single stage oxygen delignification
system, a vacuum first�post-oxygen washer followed by screening and two
deckers in parallel, followed by unbleached pulp storage. The bleach plant
includes a pre=bleach vacuum washer followed by a conventional DrEoDZ bleach
plant. All washers are vacuum washers.
A copy of'a recent presentation on the past and present configuration of the Blue
Ridge Paper Products Inc. mill is included as Appendix 3 in this report.
Based on the current configuration of the mill, and the operating practices
reviewed during the Site Audit, we have evaluated seMral options for
consideration for reducing color discharges, while not increasing effluent toxicity.
The commercial status of each of these technologies are summarized in the
previous section of this report entitled "Overview of Technology Options". Except
for the option to convert to TCF bleaching, all of these technologies may be
considered commercially demonstrated, and may achieved the projected
performance with a high level of confidence. However, any option which is
deemed of interest to Blue Ridge Paper Products Inc. must be studied in further
CONFIDENTIAL 58
VGIN
detail, including comprehensive laboratory simulations and in some cases, mill
scale trials in advance of any decision to proceed.
The basis upon which effluent color reductions are based is as follows, and is
based on data given by the mill. Should a different baseline be identified, the
color reductions will increase or decrease in direct proportion to the change in the
baseline:
Pine Sewer
Stage Color, #/day Color, #/ton
D, 7020 10.4
Eop 2690 4.0
D2 1120 1.6
Total 10,830 #/day 16 #/t
Hardwood
Sewer
Stage Color, #/day Color, #/ton
DI 7460 8.9
EoP 6810 8.1
Total 14,270#/day 17 #/t
Combined Total 25,100 #/day
Acid (from Bleach Stages)
Stage Color, #/day
Pine Di 7020
D2 1120
HW D1 7460
Total 15,600
#/day
Alkaline (from Bleach
Stages)
Stage Color, #/day
Pine Eo 2690
HW Eo 6810.
Total 9,600 #/day
Combined Total 25,100#/day
All environmental impact projections are based on outflow from the bleach plant
to the effluent treatment plant.
CONFIDENTIAL 59
V
Options Studied for In-Process Changes
Several of the technologies described in the previous section have been
commercially demonstrated sufficiently to make reasonable projections on the
impact that these technologies may have on the Canton mill. Each of these
technologies appear to be viable technologies for implementation at the Canton
mill, but we recommend that each case be studied in further detail to confirm
logistics of implementation, and confirm availability of power and other utilities
that may be required for operation. The technologies that have been reviewed
are:
Process Optimization
Conversion to Extended Delignification
Conversion to Two Stage Oxygen Delignification
Conversion to ZD Stage (Add Ozone in the First Bleaching Stage)
Conversion of Eop Stages to Hot Peroxide Stages
Implementation of the BFR®process on the Hardwood Line
Conversion to Totally Chlorine Free (TCF) Bleaching
In each case, we have quantified the impact on bleach chemical use, water use,
and effluent flow, and commented on other impacts which will need to be
assessed in greater detail, such as space requirements, utilities required (steam,
power, etc.). In addition to the impact on color in the effluent, we have
summarized in tabular form,,for each option, the impact on the water use, effluent
flow, AOX, Toxicity, Temperature, and Pulp Quality.
We have also categorized the level of commercial experience with each
technology as it relates to the products manufactured at the Canton mill site.
Low 0-3 similar installations in operation
Moderate 4-10 similar installations in operation
High >10 similar installations in operation.
During the site audit, it became apparent that there are a number of current
limitations at the mill regarding space and utilities supply. In many cases, the
changes which may be considered for the Canton mill may require incremental
utilities (steam and power), or may increase the load-�on the existing
infrastructure (causticizing and lime kiln).
At this level of detail in a study of this nature, it is difficult to arrive at capital cost
estimates with any significant level of confidence. Installation costs at existing
mills are very site specific and require the development of process flowsheets
and preliminary layouts of equipment. However, as requested, we have included
CONFIDENTIAL 60
V
and preliminary layouts of equipment. However, as requested, we have included
a rough estimate of capital cost for each option, and have identified a category of
possible capital cost for each option as follows:
Low <$1 million
Moderate $1-5 million
High $5-10 million
Very High >$10 million
In some cases, the capital cost of support facilities (steam and power, in
particular) may be far greater than the cost of the changes to the fiberline. The
categories of capital cost consider only the changes to the fiberline.
CONFIDENTIAL 61
VGBI
PROCESS OPTIMIZATION
CONFIDENTIAL 62
�J INGUll
Process Optimization
Based on the audit, we believe that there is significant opportunity to improve'the
performance of the current fiberline by implementing recommendations listed in
the "Site Audit and Performance Review" section of this report. The following
table provides projections on potential bleach chemical cost savings and the
impact on environmental parameters.
Current Benchmark
Hardwood Softwood Hardwood Softwood
D, Kappa Factor (KF) 0.30 0.25 0.22 0.20-0.22
CI02 1.1% 1.4% 0.8 1.1-1.2%
Reduction 27% 18%
A AOX(kg/t) - - -0.16 -0.11-0.16
A Color (#/day)
(20% CIOz savings) 0-770 0-400
Epp NaOH (% on pulp) 1% 2.2% 1% 2.2%
Reduction - - 0% 0%
02 (% on pulp) 0.50 0.70 0.30 0.50
Reduction - - -40% -30%
H2O2(% on pulp) - 0.5 0.3 0.5
Reduction NA 0%
D2 CI02 0.7 1.4 0.6 1.1
Reduction - -14% -21%
Total Active Chlorine, #/t 95 147 74 118
-22% -20%
Commercial Experience Moderate Moderate
Operating Cost decrease decrease
Capital Cost Low Low
A projection on color reduction is included, however, there is no significant
operating data from other mills to quantify the actual results that may be
achieved. We estimate that up to 20% of the reduction in CI02 savings in the
first D stage may be achieved in color reduction.
The key benefit of the process optimization is to reduce bleach chemical costs,
although there may be a small concurrent benefit in effluent color and AOX. This
is a relatively low cost project, but will require significant internal and potentially
external personnel resources for training and monitoring of results.
CONFIDENTIAL 63
VGIN
CONVERSION TO EXTENDED DELIGNIFICATION
CONFIDENTIAL 64
IvGIN
Conversion to Extended Delignification
Most major rebuilds of fiberlines today include digester designs that are capable
of extended delignification. The strategy in operation of the cooking system;
however, is site specific. The optimum kappa number for any given pulp is
dependent on the yield characteristics of the wood, the steam/power balance in
the mill, and the bleaching sequence/bleach chemical costs. Extended
delignification may be implemented at the Canton mill with low risk, but high
capital cost.
Hardwood Softwood
Kappa
Digester 15.4 25
Post-02 10.1 14.3
Future
Digester 11-12 18-20
Post-02 8 9-10
Bleach Chemical
Kf 0.30->0.30 0.25
D, 1.12->0.9 1.4->0.9
Eo/Eop NaOH 1.02->0.09 2.2-1.8
D2 0.6-0.7->0.6-0.7 1.5-1.3
Color Current#/Day 14,270 10,830
Reduction % 20% 20%
Reduction #/Day -2,850 -2170
Impact
Water Use N/C N/C
Effluent Flow N/C N/C
AOX kg/t -0.11 -0.26
Toxicity N/C N/C
Temperature N/C N/C
Pulp Quality Significant Increase Significant Increase
Commercial Experience High High
Operating Cost decrease decrease
Capital Cost Very High Very High
The replacement of the conventional batch digesters at the Canton mill will have
a major, positive impact on the overall energy balance of the mill. Modern
displacement batch and modern continuous digesters have been demonstrated
to have very low steam use (about 0.5 and 0.9 t steam/t pulp, respectively), and
produce high quality, high yield pulps. The barrier to cooking to lower kappa
numbers is usually that most mills are recovery boiler limited, and therefore do
not have the capacity for additional solids load to recovery. This is not the case
CONFIDENTIAL 65
- VON
at Canton, and it is expected that the incremental solids load can be handled with
minimal capital cost. There is, however, an incremental load in white liquor use
to produce low kappa pulps, which may require concurrent investment in the
causticizing and lime kiln area.
Although the benefits are listed in the table separately for hardwood or softwood
pulp, it is assumed that a single cooking system would be installed to replace all
of the existing batch digesters at the mill.
The key benefits to Canton for replacement of the cooking system is:
Significant decrease in steam use
Significant increase in pulp strength
Minimizing the peak steam demand in cooking
Lower kappa variability (lower standard deviation)
More uniform pulp quality
Lower rejects
Reduced bleach chemical consumption
Reduced effluent outfall
Increased yield
Modern cooking systems to practice extended delignification can be either
continuous digesters (Kvaerner and Ahlstrom) or displacement batch (GL&V,
Valmet, and Lenzing). All of the benefits listed above apply to both technologies,
although continuous or batch technology may have an advantage in any specific
mill and application. The major differences between the two technologies as it
applies to the Canton mill are as follows:
Continuous digesters require significantly less space for installation
Displacement batch digesters have a significant advantage in quality
(minimum off-quality pulp) for a mill that produces both hardwood and
softwood pulp.
CONFIDENTIAL 66.
CONVERSION TO TWO STAGE
OXYGEN DELIGNIFICATION
CONFIDENTIAL 67
- IGIN
Conversion to Two Stage Oxygen Delignification
The design of commercial oxygen delignification stages has evolved significantly
since its introduction in the 1970s. Most new installations are operated at
medium consistency, with the majority of the operating installations being single
stage with nominally 60 minutes retention time. Recently, two stage oxygen
delignification systems have become well accepted in the industry, especially for
softwood pulps. In addition to bleach chemical cost savings, environmental
benefits can be achieved due to the lower kappa number entering the bleach
plant.
Hardwood Pine
Current Kappa
To OZ 15.4 25
To Bleach Plant 10.1 14.3
Delignification, % 34% 42.8
2-Stage 02 kappa 9.1 12
0 Kappa 1.0 2.3
Delignification 41% 52%
Color
Current#/Day 14,270 10,830
Reduction % 10% 16%
Reduction #/Day -1,430 -1,730
Impact
Water Use N/C N/C
Effluent Flow N/C N/C
AOX kg/t -0.06 -0.115
Toxicity N/C N/C
Temperature N/C N/C
Pulp Quality/Viscosity Potential improvement Potential improvement
Impact on Operating Cost -0.1% CI02 -0.23% CIOZ
-0.1% NaOH -0.23% NaOH
+Steam +Steam
+Power +Power
+02 chemicals +Oz chemicals
Commercial Experience High High
Operating Cost decrease decrease
Capital Cost Moderate Moderate
CONFIDENTIAL 68
-- - - V
iGnt
The conversion to a two stage oxygen delignification system requires an upgrade
to the pressure capability of the medium consistency pump feeding a new reactor
vessel. The new reactor vessel will be sized for 15-30 minutes retention time,
and will be a straight walled cylindrical upflow vessel, similar to the existing
oxygen reactors in the mill. A second point of addition of steam, oxygen, and
alkali, with their associated controls will be necessary. A simplified schematic of
this conversion is shown on the next page.
The implementation of a second oxygen reactor ahead of the existing oxygen
reactor is simple in principle, but particularly on the softwood line, installation
may be very difficult due to space constraints. On the softwood side, it may be
necessary to install a second medium consistency pump due to a potential
remote location of the new first stage oxygen reactor.
The capital cost for implementation of this technology is estimated to be $1.5-2
million for the hardwood line, and $2-3 million for the softwood side.
From an operating standpoint, this conversion will result in the following changes:
Increased steam use
Increased oxygen and alkali use
Increased power use (pump and mixers)
Increased maintenance costs
Lower kappa to the bleach plant
Reduced bleach chemical costs
Reduced environmental impact
Increased solids load to recovery
There are a number of commercial installations of two stage oxygen systems in
North America, with at least two operating on hardwood pulp and at least 7
operating on softwood pulp. Generally, it is difficult to justify the second oxygen
reactor on hardwood pulp, as the incremental kappa number reduction is quite
small. This makes this technology commercially demonstrated, and operating
mills can be visited to verify applicability to the Canton Mill.
CONFIDENTIAL 69
Retrofit of a Single Stage Oxygen Delignification System to a Two Stage System
60 Min.
Reactor
Discharger
Pul in 10-30 Min.
P
Pre- Reactor
NaOH, >
F— LP Steam 1 '
�w
ti NaOHs
I
pwr r
<bFl 02 wY...
02 I
r Steam _
u.
I Med % HI-Shea
HI-ShearrM
I Mixer I Mixer Blowtank
MP Steam
CONFIDENTIAL 70
G St
CONVERSION TO ZD STAGE
CONFIDENTIAL 71
Conversion to ZQ Stage
Ozone gas has been known to be a very powerful delignification and bleaching
agent. A key barrier to its commercialization has been the loss in viscosity when
applying large quantities of ozone on pulp. More recently, ozone in combination
with chlorine dioxide in the first stage of bleaching has been commercialized.
The use of a low quantity of ozone in a position in the fiberline with relatively high
residual lignin avoids this barrier, as viscosity losses are very low. The
application of ozone significantly decreases the active chlorine demand, and
reduces environmental impact.
Hardwood Pine
Kappa to Bleach Plant 10.1 14.3
Kappa factor(KF) 0.30 0.25
Repl. Ratio - #CI02/#03 1-2.5 (1.7) 1-3.4 (1.7)
03 required #/T 6 6
C102 current use 1.1% = 22 #/t 1.4% = 24 #/t
Reduction in C102 use -10.3 #/t —10.3 #/t
Future C102 use 11.7 #/t 17.7 #/T
Future kappa factor 0.152 0.162
NaOH current use 1% = 20 #/t 2.2% = 44#/t
Reduction in NaOH in Eo -2#/t -4 #/t
Added NaOH for ZD stage +2#/T +2 #/t
Net NaOH reduction 0 -2 #/t
-H2SO4 use N/C N/C
Color
Current#/Day 14,270 10,830
Potential Reduction % 25%* 20%**
Future Reduction #/Day -3550 #/Day -2760 #/Day
Impact
Water Use N/C N/C
Effluent Flow N/C N/C
AOX kg/t -0.27 -0.27
Toxicity N/C N/C
Temperature N/C N/C
Pulp QualityNiscosity N/C N/C
Commercial Experience Moderate Moderate
Operating Cost decrease decrease
Capital Cost Moderate/High** Moderate/High**
CONFIDENTIAL 72
V GLA
* Color reduction for the hardwood line is generally based on published data
from Domtar at Espanola, Ontario, Canada; however, this is a unique
installation which requires consideration before making projections for other
installations:
1. Domtar produces birch pulp, known to be very difficult to bleach, requiring
a high kappa factor (0.40-0.45).
2. The replacement ratio at Domtar has been reported to be as high as 3.4,
however actual projections from laboratory studies show a more realistic
replacement ratio for design is 1.7.
Data on birch pulp at 9.5 kappa showed the following:
ODEoD color= 16 #/t
O(DZ)EoD color = 12 #/t
Reduction = 25%
Therefore, color reduction for Canton hardwood is predicted to be 25%,
although this could be higher in commercial operation, if Domtar type results
are achieved.
** Color reduction projections for the softwood line needs to take into
consideration the recycle of filtrates due to the BFR® process. Estimated
reduction:
D1 = 7020 #/Day at 25% reduction = 5265 #/Day (1755 #/Day reduction)
Eop = 2690 #/Day at 15% reduction = 2287 #/Day ( 403 #/Day reduction)
D, = 1120 #/Dav at 0% reduction = 0 #/Day ( 0#/Dav reduction)
10,830 #/Day at overall reduction of 20%, or 2760#/Day reduction
*** The capital cost of the system could be "moderate' or "high", depending on
whether an ozone generation system is purchased. There is a possibility that
a gas supplier would be willing to enter into a long term contract for providing
ozone "over the fence". In this case, we estimate that the fiberline equipment
may be installed for $0.8-$1.2 million; however, the added cost for the
installation of an ozone generation system is likely to be in the range of $4-5
million.
The addition of ozone to the first bleaching stage at Canton will have a major
impact on chlorine dioxide use in the first stage. The major benefits reported at
Domtar, for the conversion of the hardwood line only to ZD technology are:
Reduced bleaching cost while increasing final brightness
Reduced DCM extractives in the pulp
Reduced pulp TOX content
No impact on pulp strength or viscosity
Reduced AOX, COD, and color in effluent
CONFIDENTIAL 73
tlGO/
Although all of these benefits should be realized at the Canton mill as well, the
absolute magnitude of the impact of this change will need to be projected based
on detailed laboratory evaluations.
The fiberline equipment required for installation of ozone in the first bleaching
stage is:
Ozone pulp mixer
Ozone reactor
Ozone gas separator
Ozone destruct unit (may be near fiberline or near ozone generator)
In addition, the sulfuric acid delivery system must be reviewed to assure
homogeneous mixing of the acid with the pulp for good pH control, and the
medium consistency pump will likely need to be upgraded or replaced to provide
sufficient pressure to feed the ozone mixer and reactor.
It is technically feasible to install an ozone stage on either or both the hardwood
and softwood lines at Canton. The space requirement for equipment is small, so
it is likely a location for the mixer, reactor, and gas separator can be located in
close proximity to the existing D, towers. A general schematic of the fiberline
equipment required is shown on the next page.
To support this installation, an ozone generation system must be installed. This
must include multiple ozone generators, oxygen gas supply, power supply,
chilled water supply, ozone gas compressor, and ozone destruct unit, and
oxygen plant.
In conjunction with this installation, and as ozone gas is a "new" chemical to be
used in the mill, safety procedures must be developed, and adequate alarms and
interlocks must be installed to prevent dangerous concentrations of ozone gas
being emitted to the atmosphere.
The key issue for commercial installation at Canton is power use.
Incremental power required for fiberline = 400-500 HP (300-375 kW)
Power required for ozone generation = 69-81 kWh/t
Hardwood line only = 53,000-62,000 kWh
Softwood line only = 45,000-53,000 kWh
Thus the incremental power load at the mill site-will be 2.5-2.9 MW for the
hardwood line and 2.3-2.6 MW for the softwood line.
There are currently at least 5 "ZD" installations operating, with several additional
systems currently being installed. These systems are operating on hardwood,
CONFIDENTIAL 74
vGIN
softwood, and eucalyptus pulps. It is possible for the Canton team to visit
commercial installations to determine the viability of this technology for the
Canton mill.
CONFIDENTIAL 75
IN GN
Ozone Reactor
Gas to Destruct
0
Gas Separator
Compressed
Ozone
1 ! Pulp to C102 Tower
CONFIDENTIAL 76
V GB
CONVERSION OF Eo/Eop STAGES
TO (PO)/PHT STAGES
CONFIDENTIAL 77
V G1N
Conversion of Eop Stages to Hot Peroxide Stages
The use of a small quantity of hydrogen peroxide in the first oxidative extraction
(Eo) stage has been well established in the industry to reduce chlorine dioxide
use and overall bleach chemical cost. Recently, some mills have incorporated
more aggressive peroxide stages in this, and other positions in the bleach plant
for dramatic reductions in chlorine dioxide use. Although, as far as we know,
this technology has not to date been deployed for color reduction, we believe it
has good potential for low cost retrofit of this stage to reduce color at the Canton
mill.
Hardwood Pine
Current
Kappa to Bleach Plant 10.1 14.3
Kappa Factor (KF) 0.3 0.25
Potential KF future 0.15 0.13
Chemical Use Impact
H2O2/ton 16 16
Repl. Ratio#act.Cl/#HZOZ 1.9 2.2
Added NaOH +10#/t +10#/t
Added 02 +0#/t +0#/t
Added MgSO4 2-4#/t 2-4#/t
Color
Current#/Day 14,270 10,830
Reduction, % 33% 26%
Reduction, #/Day -4700 -2800
Impact
Water Use N/C N/C
Effluent Flow N/C N/C
AOX kg/t -0.3 -0.36
Toxicity decrease decrease
Temperature increase increase
Pulp Quality/viscosity N/C N/C
Commercial Experience Moderate Moderate
Operating Cost increase increase
Capital Cost (PO)/PHT Moderate/Low Moderate/Low
Although this technology has not yet been applied for color reduction, there is
substantial laboratory data that supports a significant decrease in color using this
technology. Most data is on non-oxygen pulps, but shows reduction in total
bleach effluent color in the range of 25 and 45% for softwood and hardwood
pulps, respectively for the use of 10 #H2O2/ton addition. Data on oxygen pulps,
although limited, suggests a reduction of greater than 35% can be achieved with
CONFIDENTIAL 78
vGLAI
this technology. A very recent study shows the conversion of an EoP to a PHT
stage on softwood pulp resulting in a total bleach color reduction of 60% when
the peroxide charge is increased form 12 #/t to 24 #/t (+12 #/t). For Canton, we
suggest the total peroxide use of 16 #/t, which is an increase of 16 #/t on
hardwood, and an increase of 10 #/t on softwood. This will allow a 50%
reduction in kappa factor in the D, stage, thus reducing Di stage color
significantly. Based on these peroxide applications, we project a reduction in
color from the Eo/EoP stages of 45% for hardwood and softwood. The net
reduction in total effluent color will be 33% and 26% for hardwood and softwood,
respectively. These reductions need to be confirmed by laboratory studies.
There are two technologies that can be implemented to achieve the benefits of
increased peroxide use in the Eo stage. There is significant commercial
experience with the use of the (PO) stage technology. This technology is very
similar to an oxygen delignification stage, where the pulp is treated in a
pressurized upflow tower for 1-3 hours at relatively high temperature (>900C). An
alternative technology has been developed, in which high temperature is applied
only in the first 10-20 minutes, after which, the pulp is discharged to an
atmospheric retention tower. This concept is shown on the next page.
The implementation of a (PO) stage in the Canton mill will be a relatively high
capital cost project, and will be difficult, especially on the hardwood side due to
the space requirements for the (PO) reactor. For simplicity, we will describe an
overview of the system changes required to implement PHT technology at the
Canton mill. It should be recognized, however, that (PO) technology is currently
operating on hardwood, softwood, and eucalyptus pulps in mills today, while
there is no "true" PHT stage in operation to date. All installations that have the
mechanical configuration of the PHT technology, are unable to operate at the
specified time, temperature, and/or pressure.
The implementation of the PHT technology requires the following steps:
1. Upgrade or replacement of the medium consistency pump feeding
the stage
2. Addition of steam sparger and/or steam mixer to add steam to the
pulp to achieve a temperature of 195-205°F (90-951C), along with
piping and controls for"addition of medium pressure steam to this
stage
3. Replacement of the current upflow tube with a pressurized upflow
tube designed for 10-20- minutes retention time
4. Upgrade or installation of new magnesium preparation and delivery
system
5. Upgrade or installation of new hydrogen peroxide delivery system
6. Upgrade or maintenance of Eo mixer
CONFIDENTIAL 79
IvGIN
The implementation of the PHT technology in the softwood line should be
relatively easy, due to the available space around the existing Eo tower;
however, the opposite is true for the hardwood line. It is likely that the new
upflow tube for the hardwood line would need to be constructed in place, which
will dramatically increase the cost of the installation. In either case, we anticipate
the cost of the conversion to PHT technology may be in the range of $1 million,
while the conversion to (PO) technology is likely closer to $2 million.
This technology is one that could be tested at mill scale at the Canton mill using
existing equipment, even with its limitation in retention time. For such a trial to be
valid, a means to add magnesium, sufficient quantities of hydrogen peroxide, and
a means to increase the temperature to 195-205OF is necessary. Laboratory
studies could then be used to predict the benefit of increased retention time in
the upflow tube.
CONFIDENTIAL 80
e
V GIW
Upflow Section:
Pressurized: 4 bar
Temperature: 90 - 130°C Downflow Section:
Atmospheric Condition
Temperature: 95 - 98°C
Pump
Mixer
CONFIDENTIAL 81
VGU/
IMPLEMENTATION OF THE BFR° PROCESS
ON THE HARDWOOD LINE
CONFIDENTIAL 82
VGIN
Implementation of the BFR° Process on the Hardwood Line
The BFR® Process has been commercialized on the pine line at Canton, and it is
the only commercial installation of its type in the world. It seems clear that this
technology can also be applied to the hardwood line, but at a very high capital
cost and significantly increased operating cost.
Hardwood
Color
Current#/Day 14,270
Reduction, % 38
Reduction, #/Day -5400
Impact
Water Use, gal/ton 0*
Effluent Flow, gal/ton -2200
AOX, kg/t -0.16
Toxicity N/C
Temperature increase
Pulp QualityNiscosity N/C
Commercial Experience Low
Operating Cost increase
Capital Cost Very High
* Condensate use will be reduced by the amount of bleach filtrate used on the
oxygen washers. The use of treated mill water will not be affected.
The color reduction for this technology is achieved by recycling filtrate back to
recovery versus sewering the entire flow from the D, and Eop stages. The
projection of color reduction is based on the results achieved on the softwood
side when this process was incorporated on that fiberline.
The incorporation of this technology will require a new Metals Removal Process
(MRP), a new or an upgrade of the existing Chlorides Removal Process (CRP),
and an upgrade to the evaporators. It is uncertain how the purge from the CRP
will need to be changed to manage chlorides in the recoveryprocess. It is likely
that the purge flow will need to be increased, which will increase the color
discharged due to this stream. This increase will offset whatever color reductions
are achieved in the bleach plant effluent.
The BFR® process is estimated to require a capital cost of about $25 million, and
will result in operations and maintenance cost increase of about$3-5/ton.
CONFIDENTIAL 83
CONVERSION TO TOTALLY
CHLORINE FREE (TCF) BLEACHING
CONFIDENTIAL 84
gVGLN
Conversion to Totally Chlorine Free (TCF) Bleaching
There are 22 TCF (kraft hardwood, softwood, eucalyptus and sulfite pulps)
bleach plants operating in the world today. Most of these mills operate a TCF
sequence only to satisfy market demand; otherwise they operate an ECF or
"ECF-Light" sequence. Experience is acceptable quality on kraft hardwood
pulps (5 operating) with mixed results on kraft softwood pulps (7 operating). The
major issue in commercial operation is the operating cost and flexibility to
achieve consistent final brightness and quality.
Hardwood Pine
Kappa to Bleach Plant 10.1 14.3
Final Brightness, %ISO 87 86
Bleach Chemical, #/ton
Q DTPA 4 4
PHTH2O2 30 40
NaOH 30 40
MgSO4 10 10
DTPA 4 4
Z H2SO4 15 15
03 6 6
P H2O2 24 30
NaOH 24 30
MgSO4 10 10
DTPA 4 4
Color
Current#/Day 14,270 10,830
Reduction, % 90% 90%
Future Reduction, #/Day -12,850 -9,750
Impact
Water Use, gal/ton -2400 -2400
Effluent Flow, gal/ton -1900 -1900
AOX kg/t Reduced to background Reduced to background
level level
Toxicity Associated with metals Associated with metals
purge stream i purge stream
Temperature increased increased
Pulp QualityNiscosity reduced reduced
Commercial Experience Low
Operating Cost increase
Capital Cost Very High
CONFIDENTIAL 85
vGIN
The sequence selected as an example is the (A or Q)EopZQ(PO or PHT)
sequence. This sequence is generally regarded as a conservative design
sequence that is easily retrofitted into an existing four stage bleach plant. In the
case of Canton, which operates a three stage bleach plant with a pre-washer, the
first stage (A or Q) would need to be performed in the existing brown stock high
density storage.
The steps required for commercial implementation at Canton are the following:
1. Conversion of the brown stock high density storage tower to serve
as an A or Q stage
2. Conversion of the D, and D2 stages to P/Eop and (PO)/PHT stages
3. Conversion of the Eo/Eop stage to a ZQ stage
4. Reconfiguration of piping and control schemes
5. Addition of oxygen plant and ozone generation facility
Several issues that will be important to consider for this implementation at
Canton are:
1. There will continue to be an effluent flow necessary for metals
removal, and this purge is likely to be in the range of 500-1000
gal/ton on each line.
2. There is a possibility that the existing BFR® process may be able to
serve this purpose on the pine line; alternatively, this process may
be shut down to reduce operating cost.
3. There will be a significantly higher energy load for TCF bleaching
due to the high temperature peroxide stage(s), potential cooling
required for the ozone stage, and the added ozone stage.
4. Space must be made available for the oxygen plant and the ozone
generation facility.
5. Pulp Quality will be adversely affected; it is uncertain whether the
pulp properties that may be achieved can be suitable for production
of the paper and paperboard grades manufactured at Canton.
5.1 The viscosity of the final pulp will likely be reduced by about
15%.
5.2 There is a potential loss in tear strength, which will be
directly related to the amount of ozone applied in the ozone
stage.
5.3 TCF pulps will require optimization of refining strategy in the
stock preparation area.
5.4 The final pulp will have a higher kappa number.
CONFIDENTIAL 86
AEoPZEQPHT (or "QPZP") Bleach Plant
NaOH ° o
0 0 ° ETA
Eop PHT
90°C 110°C/
A Q 98*C
60T 70°C
4 414A1 RIO-
HzSOa NaOH 03 NaOHOZ ❑
Oz A HZp2 Eoa O rza
N PHT
Oz a EDTA
Acid Purge
CONFIDENTIAL 87
APPENDICES
CONFIDENTIAL 88
GUt
APPENDIX 1
CONFIDENTIALITY AGREEMENT
CONFIDENTIAL 89
CONFIDENTIALITY AGREEMENT
BETWEEN BLUE RIDGE PAPER PRODUCTS INC.,
CLEAN WATER FUND OF NORTH CAROLINA (on behalf of the
"Environmental Coalition on BRPP"),
LIEBERGOTT & ASSOCIATES CONSULTING, INC.,
AND GL&V PULP GROUP, INC.
Blue Ridge Paper Products Inc., with offices at Main Street, Canton, NC, 28716, Clean Water
Fund of North Carolina, with offices at 29% Page Street, Asheville, NC 28801, Liebergott &
Associates Consulting, Inc., with offices at 5825 Shalom Avenue, Suite 802, Cote St. Luc,
Quebec, Canada H4W 3A5, and GL&V Pulp Group, Inc., with offices at 150 Burke Street,
Nashua, NH 03060, USA, (hereinafter collectively referred to as "Parties"), desire to enter into
an Agreement which allows them to execute a Bleach Environmental Process Evaluation and
Report.
WHEREAS, Liebergott & Associates Consulting Inc. and GL&V Pulp Group, Inc., desire to
perform a Bleach Environmental Process Evaluation and Report for compensation, and
WHEREAS, Blue Ridge Paper Products Inc. and Clean Water Fund of North Carolina and the
Environmental Coalition on BRPP, desires that Liebergott & Associates Consulting Inc. and
GL&V Pulp Group, Inc., perform a Bleach Environmental.Process Evaluation and Report, and
WHEREAS, in the course of the execution of this Evaluation, it will be necessary for Blue
Ridge Paper Products Inc. disclose to the other Parties to this Agreement sensitive and
confidential business and technical information,
THEREFORE, the parties agree as follows:
1. The Parties may have disclosed or may disclose information and may have loaned or may
loan material and documents to the other Parties containing certain confidential informa-
tion and other technical and business information and material concerning and/or
embodying the technical and financial operation of the Pulp and Paper Manufacturing
Facility at Canton, NC, (hereinafter referred to individually and collectively as the In-
formation"), which may be made available by written and/or verbal communication, as well
as by visual observation and shall be presumed to be confidential.
2. The Parties agree not to communicate the disclosed Information to any third party who is
not a signatory to this Agreement, without the prior written authorization of the party
furnishing such Information, and shall not use the Information nor circulate it within their
own organizations except in connection with activities arising out of this Agreement.
3. The Clean Water Fund of North Carolina certifies that it has the authority to enter into this
Agreement on behalf of the "Environmental Coalition on BRPP", and agrees that it will
have in place, prior to any disclosure of any Information, a Confidentiality Agreement with
obligations at least as strong as the obligations in this Agreement.
4. The obligations set forth in Paragraph 2 hereof shall terminate with respect to any
particular portion of the Information when the receiving Party can document that:
a) it was in the public domain at the time of its receipt from a Disclosing Party;
b) it entered the public domain through no fault of the Receiving Party subsequent to the
time of its receipt from a Disclosing Party;
c) it was in the Receiving Party's possession free of any obligation of confidence at the
time of its receipt from a Disclosing Party, and was not previously acquired directly or
indirectly from another party to this Agreement; or
d) it was rightfully communicated to the Receiving Party by a third party, free of any
obligation of confidence, subsequent to the time of its receipt from a Disclosing Party.
5. All materials including, without limitation, samples, documents, drawings, models,
apparatus, sketches, designs, and lists furnished to a Receiving Party by a Disclosing
Party and which contain Information, shall remain the property of the Disclosing Party and
shall be returned to the Disclosing Party promptly at its request with all copies made
thereof.
6. This Agreement is effective commencing on April 01, 2001, and the Parties obligations
under this Agreement shall expire on March 31, 2006.
7. Nothing in this Agreement shall give any Party the right to use the Information of the
Disclosing Party in processes or systems, or to manufacture, or have manufactured,
processes, systems, equipment or parts utilizing the Information.
8. This Agreement shall be constructed and enforced in accordance with the laws of the
S to of KM lCOtG3l, United States of America. /�, /
L ��Na�' h Carolina �1/�$�rLs /U/ JlC T�17.��0 � kks y/Lma/
Rie�'a er Product, Inc. Liebergo &Associat s Consulting Inc.
i
By: By: r!
Title: /floor /fir r/ls Title: I
Date: ///19,Q// aS� �p7/ Date: Y b b
Clean W er Fund of No h Carolina GL&V Pulp Group, Inc.
B . By: A lJ
Title: x-c • W , Title: Iwc /Aa1OEM'
Date: � ?,&D Z Date: 13 -,VA 41
V
APPENDIX 2
STUDY PARTICIPANT RESUMES
j
CONFIDENTIAL 93
vGIN
NORMAN LIE13ERGOTT Ph.D.
Norman Liebergott was formerly. a Senior Scientist at the Pulp and Paper Research
Institute of Canada (Paprican). He is presently the President of Liebergott & Associates
Consulting Inc. and a Special Consultant to Paprican and many pulp and paper
companies in the world. Dr. Liebergott is also an adjunct professor of the Department of
Chemical Engineering at McGill University, Montreal, Quebec, teaching in a Master and
Ph.D program in bleaching of chemical wood pulps and non wood pulps, as well as
mechanical and secondary fibre pulps. During his 45 years of service to the pulp and
paper industry Dr.Liebergott has distinguished himself as a leader in pulp bleaching
processes. His contributions include instrumental work using oxygen, alkali and peroxide
to decrease and/or eliminate the use of chlorine and chlorine-containing chemicals in the
bleaching sequence of chemical pulps. His work in this area has centred on developing,
implementing, and promoting the oxygen-alkali delignification, activated oxygen
delignification, oxygen-peroxide re-enforcement of the alkali extraction stage and ozone
and per-acid delignification and oxidative bleaching processes. He also has been
conducting research on sulphite, kraft, kraft AQ-polysulphide pulping. Dr. Liebergott has
developed bleaching techniques using reducing and oxidizing chemicals to enhance the
pulp properties of mechanical and secondary fibre pulps.
Dr. Liebergott has been involved with over 200 different mills in helping them to better
control the bleaching process and to meet environmental regulations. His research in the
area of pulp bleaching processes and environmental control has earned him 39 patents
and he has published over 100 scientific articles. He has reported his work at over 150
scientific meetings and has been invited to numerous mills in Canada, United States,
South Africa, Chile, Argentina, Brazil, Russia and China to provide technical assistance.
Over the past several years he has been contracted by different mills to audit the mills
by undertaking an evaluation of the bleach plant lines, chemical usage and procedures
used by these mills in their bleach plants as well as updating the knowledge of bleach
plant operators by providing in-house bleaching technology training
Dr. Liebergott has been awarded two Weldon medals and the Douglas Jones
Environmental Award from the Canadian Pulp and Paper Association and the Russel O.
Blosser Best Paper Award from the Environmental Conferences of the Technical
Association of the pulp and paper industry, as well as the Pulp Manufacturers Division
Award and the CFC Ritter prize. He also received Paprican's President's Citation Award.
In 1991 he was named a Technical Association of Pulp and Paper Industry (TAPPI)
Fellow.
In the community service area, for the past 28 years Dr. Liebergott was elected as a
school board commissioner and has served as either chairman of the Council of
Commissioners or the Executive Committee of the Laval, North Island and Laurenval
School Boards. In appreciation for his many years of devoted service for his support for
the staff, and for his value for public education and the love of children he was recently
honoured with the Laurenval School Boards "Distinguished Service Awards" in the field
of public education.
CONFIDENTIAL 94
VGBI
Lewis D. Shackford
Vice President
GL&V Pulp Group. Inc.
Education
B.S. Chemical Engineering with minor in Paper Engineer, Magna Cum Laude
University of Lowell (formerly Lowell Technological Institute), Lowell, MA
Professional Engineering
Licensed Professional Engineer, State of New Hampshire (#5823)
Affiliations
TAPPI Member(Alkaline Pulping Committee since 1973, Brown Stock Washing
Subcommittee member since 1981; Pulp Manufacture Division Officer since 1996,
currently Chairman)
CPPA, APPITA, ABTCP, AIChE, NSPE
Summary of Experience
Experienced in performing tasks, and/or leading engineers or scientists, as individuals or
as teams, towards goals to improve organizations' financial results. Nearly 25 years'
experience in pulp mill fiberline systems design and operation, with particular expertise
in the areas of pulping, washing, delignification, bleaching, industry and regulatory
trends, and emerging process technology. Strong background in proposal preparation,
presentation, and benefits analysis for conventional or advanced machinery and
technology. Negotiation of agreements for technical and business cooperation and
management of agreements with alliance partners has been a key responsibility.
Extensive experience in commercialization of new product and process technology, and
process risk management. Extensive experience in preparing and presenting technical
reports on process design and optimization, technical and business process training,
and technical papers for industry conferences. Numerous mill process start-ups and
optimization efforts have been undertaken with successful results. General knowledge
in woodyard operations, recycled fiber, stock preparation, power/recovery and effluent
treatment.
Typical Proiect Experiences
Leadership of machine and process design for an innovative pulp washer, supervision of
installation, and leadership of the start-up and optimization efforts (Southeast U.S. mill).
CONFIDENTIAL 95
- - VGB/
Evaluation of the operations of a multiple line kraft mill (several brown stock washing
lines and bleaching lines), and development and presentation of strategy to optimize
financial results in the mill (Southeast U.S. mill).
Participation in high and medium consistency ozone bleaches pilot plants and
commercial installations' start-up and optimization (six occasions U.S. and Canada).
Start-up and optimization of the first integrated medium consistency oxygen
delignification system in North America (Mid-West U.S. mill).
Optimization of two stage medium consistency oxygen delignification system (B.C.,
Canada mill).
Development of recommended technical strategy for achieving compliance with USEPA
Cluster Rule (several U.S. mills).
Optimization of brown stock washing bleaching (plants and unit operations) in numerous
American mills.
Other Experience and Contributions
Continuing Education — "The Professional Manager" and "Managing Business
Strategies"—Indiana Executive Program, Bloomington, Indiana.
Numerous publications and presentations in the fields of pulp cooking and washing, ECF
and TCF bleaching, and issues regarding the closure of mill filtrate cycles to approach
TEF operation. List available on request.
Patents -4 U.S. issued, 7 pending (32 global issued or pending)
TAPPI Pulp Manufacture Division Leadership and Service Award Recipient, 1995.
TAPPI Short Course Contributor since 1979
Brown Stock Short Course (Chairman and Instructor), Bleach Plant Operations
Short Course (Instructor), Improving Screening and Cleaning Efficiencies Short
Course, Oxygen Delignification Symposium (Paper Presenter), Mixing
Symposium
CONFIDENTIAL 96
vGIN
William J. Miller
Process Manager
Chemical Pulping
GL&V/ IMPCO-JONES Inc.
Education
Bachelor of Science, Pulp and Paper Science and Engineering, S.U.N.Y College of
Environmental Science and Forestry at Syracuse University, Syracuse NY 1972.
Professional Activities
TAPPI member since 1982
Member TAPPI Bleaching Committee 1992- present
Instructor for TAPPI B.P.O.S. 1991 -present
Presentedrinstructed in ABTCP, Miller Freeman, PIMA, and TAPPI conferences.
Named to "Finest Faculty" of TAPPI instructors for 1996
Summary of Experience:
Over twenty five years of technical and production experience in pulping and bleaching.
Expertise in applying practical research to mill operations.
Extensive experience in mill operations, operator training, system start-ups and
optimization
Development of business plans, based on industry trends
Process areas of expertise include: oxygen delignification, bleaching systems, washing
systems; Kraft recovery liquor cycles.
1988-present: GL&V/Impco-Jones, Inc., Nashua. N.H.
Process Manager-Chemical Pulping
Primarily responsible for the development, marketing and performance of pulp bleaching
process equipment and systems, including oxygen delignification, chlorine dioxide,
reinforced extraction, ozone and hydrogen peroxide systems. This involves equipment
and process development, business planning, directing operator tr is ping, process and
equipment start-ups, planning and conducting process optimization. Recent projects
include bringing economical equipment (TRI-PhaseTM mixer) and process solutions to
the marketplace for achieving "Cluster Rule" compliance levels.
CONFIDENTIAL 97
vGLAI
1988-present: GLBV/Impco-Jones, Inc., Nashua. N.H. (continued)
Other responsibilities include:
Fiberline system design, environmental impact and process
guarantees
World wide technical sales support
Brownstock and post oxygen washing systems
ECF bleach plant conversions and optimization
Presenter/Trainer for industry seminars and conferences
Process consulting and troubleshooting for customer mills
1972-1988 Technical and production supervisory positions for two major pulp/paper
companies. Experience included:
Evaporator/Recovery boiler operations and maintenance
--- ----Recausticizing operations, maintenance and upgrades
Bleach plant, brownstock system start ups and optimization
Chemical manufacturing and handling, including R-3 and R-8 CI02 start
ups and optimizations
All aspects of operator training, including safety sessions and
Involvement Teams
Publications
"Effect of Entrained Black Liquor Solids on Medium Consistency Oxygen
Delignification", TAPPI 74(2) 117 (1991)
"Effect of Kraft Pulping on Oxygen Delignification Kinetics", TAPPI 82(10) (1999)
Patents
US Patent No. 5,916,415, "Oxygen Delignification of Medium Pulp Slurry", (1999)
CONFIDENTIAL 98
APPENDIX 3
GLOSSARY OF TERMS
f
CONFIDENTIAL 99
- � VGLAI
Active Cl2 —The expression used in oxidative bleaching technology to express
concentration of different oxidizing agents in terms of chlorine oxidation equivalents.
ADMT—Air Dry Metric Tons (pulp) - Refers to the weight of dry pulp/paper in equilibrium
with the atmosphere. Though the amount of moisture in dry pulp/paper will depend on
the atmospheric condition of humidity and temperature, as a convention, 10% moisture
is assumed in air dry pulp/paper.
AOX — Adsorbable Organic Halides — A measure that describes the total amount of
organochlorine (reported as Cl) in effluent.
BOD — Biochemical Oxygen Demand —When effluent containing biodegradable organic
matter is released into a receiving water, the biodegradation of the organic matter
consumes dissolved oxygen from the water. The BOD of an effluent is an estimate of the
amount of oxygen that will be consumed in 5 days following its release into a receiving
water; assuming a temperature of 20°C.
CPPA—Canadian Pulp and Paper Association
COD — Chemical Oxygen Demand — measures the oxygen equivalent of the organic
matter content of a sample that is susceptible to oxidation by a strong chemical oxidant.
Delignification — The removal of lignin, the colored material that bonds wood fibers
together, during the chemical pulping process.
ECF— Elemental Chlorine Free (bleaching) - ECF papers are made exclusively with pulp
that uses chlorine dioxide rather than elemental chlorine gas as a bleaching agent. This
virtually eliminates the discharge of detectable dioxins in the effluent of pulp
manufacturing facilities.
Exotherm -A chemical reaction giving off heat.
ISO— Intemational Standards Organization, unit of measure for bleaching (%)
Kappa Factor — Ratio of equivalent chlorine bleaching chemicals applied to the lignin
content of the pulp in the Do bleaching stage.
Kappa Number—A term used to define the lignin content in pulp.
NCASI —National Council for Air and Stream Improvement
TCF — Totally Chlorine Free (bleaching) - Totally chlorine free applies to virgin fiber
papers that are processed with a bleaching sequence that includes no chlorine or
chlorine derivatives.
Transition metals— noted for their variability in oxidation state, these metals differ from
other metals in that their valence electrons are in more than one shell. Interfere with
efficiency of certain oxidative bleaching chemicals.
TSS—Total Suspended Solids—the portion of total solids retained by a filter.
Viscosity — A measurement of the degree of polymerization of the pulp's cellulose,
which is an indicator of pulp strength.
Conversions:
To convert m3 to gal, multiply by 264.2
CONFIDENTIAL 100,
APPENDIX 4
TECHNICAL OVERVIEW OF
BLUE RIDGE PAPER PRODUCTS INC
CONFIDENTIAL 101
EVOLUTION OF FIBERLINES
Blue Ridge Paper Products
Canton, North Carolina
HARDWOOD FIBERLINE (PAST) .
• 7 - 3300 cubic feet batch digesters
• 2 - Brownstock washer lines
— Vacuum washers
• Two stage fine screen room
• 2 - Bleach lines
— CEHD (Low Brightness)
— CEHHD (High Brightness)
HARDWOOD LINE SCHEMATIC
PRE 1993
Brownstock Washing Screening
Knotting
0
FInbleache
Storage C E
Centricleaners
D
High
® ® Hardwoo
H H 7 (b I
4211)
Centricleaners
TOD
Low
® ® ardwoo
OPERATING CONDITIONS
HARDWOOD (PAST)
• 650 ADBT/Day
• Digester K# = 10.0
• CEK = 4.0
i Final Quality
— 80 & 82 ISO Brightness
— 10 cps Viscosity
— 20+ Dirt count
SOFTWOOD FIBERLINE (PAST)
• 11 - 3300 cubic feet batch digesters
• 1 - Brownstock washer line
— Vacuum washers
• Two stage fine screen room
• 2 - Bleach lines
— CEHDH (Low Brightness)
— CEHHDH (High Brightness)
SOFTWOOD LINE SCHEMATIC
PRE 1992
Brownstock Washing Screening
C E
nbleach d
Storage
® C E
JACentricleaners
PD HrHh
Centricleaners
H PD HLow
Pine
OPERATING CONDITIONS
SOFTWOOD (PAST)
• 900 ABDT/Day
• Digester K# = 21 .0
• CEK = 6.0
• Final Quality
— 80 & 82 ISO Brightness
— 13 cps Viscosity
— 20+ Dirt Count
i
HARDWOOD FIBERLINE
(PRESENT)
• 9 - 3300 cubic feet batch digesters
• Two stage Knotting
• Vacuum Washers
• 1 - Brownstock washer line
— 4 Stage -Pre 02 - 3 Stage Post 02
• Four stage pressurized fine screening
• 1 - Medium Consistency Bleach line
— OD100TMEoD
HARDWOOD LINE SCHEMATIC
PRESENT
Pre Oxygen Washers 02 Reactor
Post Oxygen Washers
Knotting
Blow Screening
Tank
Pre-Bleach
Washer D1 Washer Eo Washer D2 Washer
D1 Eo D2
Y C
OPERATING DESIGN
HARDWOOD PRESENT
• 765 ADBT/Day
• Digester K# = It.0
• 02 K# = 6.5
• CEK = 2.4
• Final Quality
— 86\IS0 Brightness
— 18 cps Viscosity
— 3 Dirt count
SOFTWOOD FIBERLINE
(PRESENT)
® 9 - 3300 cubic feet batch digesters
• Two stage Knotting
® Compaction Baffle Washers
• 1 - Brownstock washer line
— 3 Stage Pre 02 - 3 Stage Post 02
• Four stage pressurized fine screening
• 1 - Medium Consistency Bleach line
— OD100TMEopD
SOFTWOOD LINE SCHEMATIC
PRESENT
Washer/Decker
02 Reactor
Pre-02 Washers
Knotting Post 02 Washer Brown
Screenin Stock
i-Densi
® ®'
Pre,-Bleach
Washer Dl Washer Eo Washer I D2 Washer
Bleached
D1 Eo D2 Hi-Densi
Storage
OPERATING DESIGN
SOFTWOOD (PRESENT)
• 655 ADBT/Day
• Digester K# = 17.5
• 02 K# = 10.5
• CEK = 2.2
• Final Quality
— 86 ISO Brightness
— 15.5 cps Viscosity
— 3 Dirt Count
CANTON MILL SECONDARY
EFFLUENT
ENVIRONMENTAL PERFORMANCE
Pre - Modernization Post - Modernization
• Effluent Flow • Effluent Flow
— 45 MGD — 29 MGD
• Effluent Color Effluent Color
— 115 kg/tonne of — 30 - 35 kg/tonne of
pulp
Pulp Effluent BOD
• Effluent BOD — 0.5 - 1.0 kg/tonne of
— 1.6 kg/tonne of pulp pulp
Canton Mill Secondary Effluent Color
Annual Average
400000
350000
300000
ea 250000
200000
s.
0
0 150000
U
100000
50000
0
1988 1989 1990 1991 1992 1993
SOFTWOOD LINE SCHEMATIC
PRE 1992
Brownstock Washing Screening
E
NCC
nbleach d Fl
Storage
® qC E
Centricleaners
H H D H
High
\ ® Pine
�Centricleaners
IH TD HLow Pine
i
OPERATING CONDITIONS
SOFTWOOD (PAST)
• 900 ABDT/Day
• Digester K# = 21 .0
• CEK = 6.0
• Final Quality
— 80 & 82 ISO Brightness
— 13 cps Viscosity
— 20+ Dirt Count
HARDWOOD FIBERLINE
(PRESENT)
• 9 - 3300 cubic feet batch digesters
• Two stage Knotting
• Vacuum Washers
• 1 - Brownstock washer line
— 4 Stage Pre 02 - 3 Stage Post 02
• Four stage pressurized fine screening
• 1 - Medium Consistency Bleach line
— OD100TMEoD
r -
i
HARDWOOD LINE SCHEMATIC
PRESENT
Pre Oxygen Washers 02 Reactor
Post Oxygen Washers
Knotting
0
Blow Screening
Tank
Pre-Bleach
Washer D1 Washer Eo Washer D2 Washer
Dl Eo D2
e o
OPERATING DESIGN
HARDWOOD (PRESENT)
• 765 ADBT/Day
• Digester K# = 11.0
• 02 K# = 6.5
• CEK = 2.4
• Final Quality
i
— 86\IS0 Brightness
— 18 cps Viscosity
— 3 Dirt count
SOFTWOOD FIBERLINE
(PRESENT)
• 9 - 3300 cubic feet batch digesters
• Two stage Knotting
Compaction Baffle Washers
1 - Brownstock washer line
— 3 Stage Pre 02 - 3 Stage Post 02
Four stage pressurized fine screening
• 1 - Medium Consistency Bleach line
— OD100TMEopD
SOFTWOOD LINE SCHEMATIC
PRESENT
Washer/Decker
02 Reactor
Knotting Pre-02 Washers Post 02 Washer Brown
Screenin Stock
i-Densi
Pre?Bleach
Washer DI Washer Eo Washer D2 Washer
Bleached
D1 Eo D2 Hi-Densi
Storage
OPERATING DESIGN
SOFTWOOD (PRESENT)
• 655 ADBT/Day
• Digester K# = 17.5
• 02 K# = 10.5
• CEK = 2.2
• Final Quality
— 86 ISO Brightness
— 15.5 cps Viscosity
— 3 Dirt Count
CANTON MILL SECONDARY
EFFLUENT'
ENVIRONMENTAL PERFORMANCE
Pre - Modernization Post - Modernization
• Effluent Flow • Effluent Flow
— 45 MGD — 29 MGD
• Effluent Color • Effluent Color
— 115 kg/tonne of — 30 - 35 kg/tonne of
pulp
pulp Effluent BOD
• Effluent BOD 0.5 - 1.0 kg/tonne of
— 1.6 kg/tonne of pulp pulp
Canton Mill Secondary Effluent Color
Annual Average
400000
350000
300000
ea 250000
200000
0
c 150000
U
100000
50000
0
1988 1989 1990 1991 1992 1993
SOFTWOOD LINE SCHEMATIC
PRE 1992
Brownstock Washing Screening
C E
nbleach d
Storage
® rci E
Centricleaners
H H T[D H
High
Pine
Centricleaners
H D H
Low
® Pine
OPERATING CONDITIONS
SOFTWOOD (PAST)
• 900 ABDTlDay
• Digester K# = 21 .0
• CEK = 6.0
• Final Quality
— 80 & 82 ISO Brightness
— 13 cps Viscosity
— 20+ Dirt Count
HARDWOOD FIBERLINE
(PRESENT)
• 9 - 3300 cubic feet batch digesters
• Two stage Knotting
• Vacuum Washers
• 1 - Brownstock washer line
— 4 Stage Pre 02 - 3 Stage Post 02
• Four stage pressurized fine screening
• 1 - Medium Consistency Bleach line
— OD100TMEoD
HARDWOOD LINE SCHEMATIC
PRESENT
Pre Oxygen Washers 02 Reactor
Post Oxygen Washers
Knotting
0
Blow Screening
Tank
Pre-Bleach
Washer D1 Washer Eo Washer D2 Washer
DI Eo D2
a o
3 F
ii
OPERATING DESIGN
HARDWOOD (PRESENT)
• 765 ADBT/Day
• Digester K# = 11.0
• 02 K# = 6.5
• CEK = 2.4
• Final Quality
— 86\IS0 Brightness
— 18 cps Viscosity
— 3 Dirt count
SOFTWOOD FIBERLINE
(PRESENT)
• 9 - 3300 cubic feet batch digesters
• Two stage Knotting
• Compaction Baffle Washers
• 1 - Brownstock washer line
— 3 Stage Pre 02 - 3 Stage Post 02
• Four stage pressurized fine screening
• 1 - Medium Consistency Bleach line
— OD100TMEopD
SOFTWOOD LINE SCHEMATIC
PRESENT
Washer/Decker
02 Reactor
Knotting Pre-02 Washers Post 02 Washer Brown
Screenin Stock
i-Densi
Storage
Pre Bleach
Washer D1 Washer Eo Washer D2 Washer
Bleached
Hi-Densi
DI Eo D2
Storage
® '1
OPERATING DESIGN
SOFTWOOD (PRESENT)
• 655 ADBT/Day
• Digester K# = 17.5
• 02 K# = 10.5
• CEK = 2.2
• Final Quality
— 86 ISO Brightness
— 15.5 cps Viscosity
— 3 Dirt Count
CANTON MILL SECONDARY
EFFLUENT
ENVIRONMENTAL PERFORMANCE
Pre - Modernization Post - Modernization
• Effluent Flow • Effluent Flow
— 45 MGD — 29 MGD
• Effluent Color Effluent Color
— 115 kg/tonne of — 30 - 35 kg/tonne of
pulp
pulp • Effluent BOD
• Effluent BOD — 0.5 - 1.0 kg/tonne of
— 1.6 kg/tonne of pulp pulp
Canton Mill Secondary Effluent Color
Annual Average
400000
350000
300000
ee 250000
b
200000
0
0 150000
U
100000
50000
0
1988 1989 1990 1991 1992 1993
SOFTWOOD FIBERLINE (BFRTM)
• Demonstration of Bleach Filtrate
Recycle (BFRTM)
— Chloride Removal Process
— Metals Removal Process
— Closure of first two bleach stages
BFR CONCEPT FLOWSHEET
BLACKfit isC ORIIE 4„}
Q RECOVERY I �RMOVAU` ��LIQUOR ESP
EVAPS BOILER '°EROCESS 110
Cl & K
CAUSTICIZING
WATER
WOOD COOKING/ PULP
D EO D
WASHING/ OXYGEN
SCREENING DELIG.
� �RMOA sZ Ca &
PfRO��ES�' M
FILTRATE RECYCLING SCHEME
TO DECKER
FILTRATE TANK I
I HOT WATER
r - - - - - - - - - - - - - i ,
I WHITE-
, WATER
I 1 I I
I I 1
I I I
I I I
I , I D1 EOP D2
I I 1
I I 1
1 I I
I I I
I
I
I \ 1
I
L — — — — — — — — asr,t #
-
TO
DECKER TO BLEACHED
L _ _ _ METALS HIGH DENSITY
SHOWERS PURGE STORAGE
FIBERLINE OPERATION WITH
BFRTM
• Reduced bleach plant effluent from
19 m3/tonne to 6 m3/tonne
• Increased operating cost ^40 %
• No serious scaling issues to date
• No detected change in corrosion
OTHER IMPROVEMENTS
• Spill Control and Collection
— Installed new sump collection systems
— Improved planning during outages
• Hardwood Filtrate Recycle
— Recycling �20 % of Eo filtrate
— Evaluating D100 filtrate reuse
CANTON MILL SECONDARY
EFFLUENT ENVIRONMENTAL
PERFORMANCE
Post - Modernization BFRTM Operation
• Flow - 29 MGD • Flowl - 29 MGD
• Color - 30 - 35 • Color - 20 - 25
kg/tonne of pulp kg/tonne of pulp
• BOD - 0.5 - 1.0 • BOD - 095 - U
kg/tonne of pulp kg/tonne of pulp
• AOX - 0. 13 - 0.22 AOX - 0.04 - 0. 12
kg/tonne of pulp kg/tonne of pulp
Canton Mill Secondary Effluent Flow
Annual Average
50.00 45.06 44.68
45.00 -- 42.67 -- -- - -
A 40.00 - ------
o. 35.00 - - 32.72
30.00 - - 7.27 27.58 27,36
-25� ��� 2 .50 24.67
25.00 - -- -- -
c 20.00 -- -- - - - --
15.00 - - - - -- --
3 10.00 -- --- -- - - - - - -
w 5.00 - - - - -- - - - --- -
0.00
Canton Mill Secondary Effluent Color
Annual Average
4009000 -
350,000 - -
3009000 - -
2509000 - -
2009000 -
�, 1509000 - -
0
c 1009000 - -
509000 - -
00 00 C\ 01 C1 01 C1
C1 C1 C1 C1 C1 C1 CIN
Canton Mill Secondary Eiffluent BOD
Annual Average
2.50 -
2.00 1.92 -
1.65
C
1.50 - 1-34
A1.00 - -- --o:7s-._
O 0.62 0.68 0• 0.67 0.63 -
0.46 0.44
0.50 -- ------ -- -
0.00 -
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000
Canton Mill Secondary Effluent COD
Annual Average
50.00 - 44.00
40.00 - --35:28----- ._ . ---- ---- - ._
C
0 30.00 -- ------ -
22.00
A 20.00
® 12.28 10.59 9.70
8.40
U 10.00 - -- - --
0.00 --
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000
Canton Mill Secondary Effluent AOX
Annual Average
0.20 -
0.17
0.15
a 0.15 — --- -- --
0.11
0.09 0.09 0.10
0.10 — -- ------ -
�C
0.05 — ----
0.00
1995 1996 1997 1998 ' 1999 2000
I
T=nba
- 8om!mnd{m pue ialrwunul J
8umpuudnepwloleau!-q I
svog!p—lgsn-p 9uw4 -]sw pmongrye 7a pmou-SOZ
moo nsu aye 8owldapSpew "ism p;uoug M w Ie°ou- mJ ssaaod uo-pp am,ba'Aetq o
u!g�pinom aulagas siyl T mJ—oos f go-ppe agnbw Sett' v
'%SZ
'YS o7 OZ Aq assalw!m S1a101(SQ.0
mlw an!lel!m!sse papaw aql"811 OZ Ag---q m4mm(ScauD gH1wp;,gO=.plmmm0O1u3 T
ws lou mm—u 21wOg8nO108mI 'm!s uo Peel TUQp -parbw SPHOS Page !p 1c1MUM
uo puq lw!aylnsu!m anp Sq sasaaop moo nnu a Pjf anP Iwmbv m!s umgsumop -p 8om!uwdm;pull amenu!au1 T -pmnbal v4s vo pull lwug!nsv!m
•0!ty aql plmb-m!s umansumoa ro 8ompumd ne peloT--,ut -P 'a1!s as Pull!]wuglnsu!Oq -p pam,bai 2OS unagsumad -
.algel!ane s!umm swan saumasy •aumi •lumapnf8ouoouaw •al!s uo pull lw!og!nsm m -p peon!-m!s umagn-op -a
'(Ivsanni%OESZ)Sawpgp puod F-!nb-mp u!rile-tq m uo pxN s!vmox;d psou- applmbmal!smeagsimod v •a1!s uo pull]wugp,su! -ammumpwl 2mmowl
,lueld lwugeag mp ry ou-m!w lm!)!Ugrs a uk,lln=U uea uoq. 4Redo uownpalm!oJ - On anp p-ba7 al!s umansumoa —goofgo m!oo ana. pull sa!gnoWr.p 9unesado
ssoa>e uownpw lolw qyZ a o8rpm lamol yanw a papajqm nylyd 'swmpuw ltonory mrys 7uaudipnf 8uuaau!8w m Sl!pgeu!m anp pmwpuge o1 anp suo_gelado amyl Pwopuege
_ 11.qsp1nOw,I=9UPUXUm;U)mmM +a7ema0 Pw RId3 A9 volp mjw lwngla paleag m sasea,u m SBgouyay nq/Faun paix,puoa ve uo paseq s lwapd pmou- -snunmiw p5 Jo 7a8teJ lolw w 8uw!yae sEn mq!tIa¢J ylo ill 18lauta1 1qw SBolouyam!enw-uo!w add
cpxm m Sumo=—uoiw saursy ga'wsv an!swln uy-q anpu Son n.golougm sue, naaq annq sism m!!d ON •q AvpgWw uoganpw"1oo-q Jo aige&—!s!--A luxmeaq 'q "J 7wugwn auyl a!eas-!Inj -Jo-pw ve slum!¢8uu;-n SIMd ' I
I
l0W UOVIBO 11M umuej a,p of relnu! -nnu mp Jo,(needle 1m. wme,ayl m1e1. _ 'm}y umnuJ MP m"Lngu '0!W WN omUT3 a p olue!!m!s -0gq ualue0 mp(O-mmgs
atp m jelmus uogeagdde vemJ ao-ge,!ldde ua mJ smue!p ism aMel!"m OT uo wilm 1, -m!w uogogdde vemJ svoq¢Ogsu! uoq®gdde ve mJ suone!P�v! amu¢O aql m ue1!m!s uogeaydde ve mJ wgdgdde ue mJ - uopm!!dde ue mJ suoue!lelsu! I,
mopipgsv!Iepuawmoa amouy oN •e lu! a uo umoull ON aeou-IOU swp ASolouyam S!g]. pnataunum amoral oN �..umoun ON •e suogelpgsm;�w umouDI ON -¢ p;.�umoml ON M p'!atwvuw umoua ON -e SHRSSI
000'ISI'IIS 000'01•I'8ES .000'68L't4£S 000'68Z66S 000'89L'641S ; 000'£OZ'06S 000'688'09S 000'ELE'LSS LSOO 7VJ1dV3 OH.LVMS3
ESO'LEI'ZS EZL'Lte9'9S tovtLC13 L48'068'1ZS 0600V8ZS 8Z5'898'ZIS EZ5'Ih£'61S IIOVLW9ZS LSOOONLLVKHdO
1Vf1NNV OH.LVMLSH
SIDM N070O OS
ON ON SHA S3A Sad ON ON ON - HAURDVA'LLNaMSNOOO.L
AJJ'H9V OHIVNJ_gNOWHO
061 9E (Sinn=aloJaq)80Z IZ Ot 46 I£ I£' n!ug 101aa'N0700.I.PI3nim
3OV1mV'IV:uHHOHm
ago a slum Jolaa'dorim ltaf173d8
06Z 179 (8u.raw. J q)81E ZE 91 6S1 t'9 19 PflVirAM'IMJ1.M03M I
%001 %58-08 VIN °/A6 %96 %09-O9 %06-08 %06-08 `V''Bgvavo
NOI.LDncr"N010J
SM9010NH331 WAOMH HO100 AO.LN3NSS3SSV I00Z 30 AUVLaAMS 1-I 211 V.L
eurlareo yyoN Voluso
'aul slanllard Jaded 86P21 anlH _
luewssGWV Aftoug3a1 IVAOWB2l MOD IooZ �E
I
2001 Color Removal Technology Assessment
Blue Ridge Paper Products hic.
Canton,North Carolina
TABLE 1-1 SUMMARY OF 2001 ASSESSMENT OF COLOR REMOVAL TECHNOLOGIES
NEW
COLOR REDUCTION
CAPABILITY 80-900/6 80-90% 50-WI 95% 90% N/A 80.85% ]00%
THEORETICAL MAXIMUM 64 64 159 16 32 318 fore rmpn 64 290
EFFLUENT COLOR,color units 8)
THEORETICAL AVERAGE .31 31 94 IO 21 208(before tni)rinp�' 36 190
EFFLUENT COLOR,color wits -
DEMONSTRATED ABILITY
TO CONSISTENTLY ACHIEVE NO NO NO YES YES YES NO NO
50 COLOR UNITS
' ESTIMATED ANNUAL $26,407,504 S19,341,523 $12,868,528 528,304,090 521,890,847 54,374,404 $6.647,723,.
OPERATING COST $2,137,053
ESTIMATED CAPITAL COST S57,373,000 $60,994,000 $40,203,000 =$149,768,000 $9912891000 S34,789,000 $38,140,000 $11,151,000
ISSUES a No(mown commercial L No(mown co mnereial s. No(mown mnmietcial installations a. No Inrowm commercial a. No known cornmeircial L This technology does not remove L No(mown commereial No known commercial installations
installations form application installations for an application for an application similar to the Canton installations for an application installations for an application color It relies on the assimiktive installations for an application foran application sbailar to the
similar to the Canton MiLL similar to,the Canton Mill. Mill. ifinilar to the Canton Mill. siimbrtD the Cantou Mill. :olor capacity of the river similar to the Canton Mill. Canton Mill.
1 _ Plants using alum as an end-of- _ Fullsak lime treatment for b. Treatment process is incapable of b.Color reduction capability b. No pilot tests have been b.This technology is very sensitive .An extensive research b. Assures color remaining in waste-
ipe color removal feCbhWlogy cobr removal a other facilities was achieving color target of 50 color mits. removal percent is based on an conducted using this technology. in increases in treated effluent color effort by EPRI and Bowater waterfteatrnent influent would still
abandoned those,operations due to abandoned doe to inability to gmeeringjudgmet. and/ordroughtconditioars. Either achieved a much lower undergo a 25%color reduction across
operatingilifficultiesand aebimc cokrobjective a Downstream site required don to - c.Color reduction capability tordition can result in a significant he mamerd plan
inconsistent performance. insufficient land on site. c. Downstream site uucd due removal
req percent is based on an increase in the required pond efficiency(25-30%removal).
Downstream site required due to insufficient lard on site, wring judgment volume. a Assmrrs excess steam¢available
i c. Dowustreamsite required due Do msuffideot land on site, it. Incinerator and air permitting a Downstream site required at the Mill.
bo insufficient land on site required. L Ittimvatorand airpermitting d. Downstream site required don c.If the river Bow decreases by due to in a frcient land on
d. Efuent total dissolved solids insufficient hnd out site. 13%(drought),the river will not site
d. Effluentmmldisolvedsolids LIDS)Merely to unease by20to ve the needed assimilative color' .
t (TDS)Irkelytoinaracby20to 5%. capacity-
25%.
a. May require adds process for d. This scheme would result in
e May rectum,add-on process for IDS removal at additional cost. nearly depleting the rives flew
TDS removal at additional cost. during drought conditions
f. incinerator and air permitting '
f. Incinerator and au permitting required.
required.
I
� 1
I 1
I
1 '
7