DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
DIVISION OF PROCESS CONTROL ENGINEERING
DIVISION OF ECONOMIC EFFECTS RESEARCH
CONTROL OF ATMOSPHERIC EMISSIONS
IN THE WOOD PULPING INDUSTRY
FINAL REPORT
CONTRACT NO. CPA 22-69-18
MARCH 15, 1970
VOLUME
•V
-------
CONTRACTORS:
Environmental Engineering, !BC.
2324 S. W. 34th Street
Gainesville, Florida 32S01
j. E. Sirrine Company
P. 0. Box S4SS
Greenville, South Carolina 29608
SUB-CONTRACTORS:
Reynolds, Smith and Hills
P. 0. Box 4156
Jacksonville, Florida 32201
PolyCon Corporation
185 Arch Street
Ramsey, (few Jersey 07445
CONSULTANT:
Professor Donald F. Adams
Washington State University
Pullman, Washington 99163
-------
ERRATA SHEET
/\ SHOULD BE 1 I IN REFERENCE FIGURE 2-2 ENTITLED
"REGIONAL DISTRIBUTION OF SULFITE AND NSSC PULP MILLS
IN THE U.S."
SULFITE MILL SHOWN IN WESTERN NORTH CAROLINA SHOULD
BE NSSC.
-------
DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
DIVISION OF PROCESS CONTROL ENGINEERING
DIVISION OF ECONOMIC EFFECTS RESEARCH
CONTROL OF ATMOSPHERIC EMISSIONS
IN THE WOOD PULPING INDUSTRY
FINAL REPORT by
CONTRACT NO. CPA 22-69-18 E R Hendrickson, Ph. D., P. E.,
MARCH 15, 1970 Principal Investigator
VOLUME 1
J. E. Roberson, M. S., P. E.,
Sirrine Project Manager
J. B. Koogler, Ph. D., P. E.,
EEI Project Manager
ENVIRONMENTAL ENGINEERING, INC., GAINESVILLE, FLORIDA
J. E. SIRRINE COMPANY, GREENVILLE, SOUTH CAROLINA
-------
SYSTEMS ANALYSIS STUDY OF EMISSIONS ENVIRONMENTAL ENGINEERING, INC.
CONTROL IN THE WOOD PULP INDUSTRY J. E. SIRRINE COMPANY
CONSULTANTS Professor Donald F. Adams Poly Con, Inc. Gainesville, Florida • Greenville, South Carolina
15 March 1970
Mr. W. Gene Tucker
Division of Process Control Engineering
National Air Pollution Control Administration
5710 Wooster Pike
Cincinnati, Ohio 45227
Mr. F. L. Bunyard
Division of Economic Effects Research
National Air Pollution Control Administration
1033 Wade Avenue
Raleigh, North Carolina 27605
Re: Final Report, Contract No. CPA 22-69-18
Gentlemen:
Fulfilling the requirements of Contract No CPA-22-69-18,
we have prepared for NAPCA 200 copies of the final report en-
titled "Control of Atmospheric Emissions in the Wood Pulping
Industry." For ease in handling, the report has been bound in
three volumes. Each chapter is headed by a separator sheet
which contains the complete table of contents for that chapter,
and in addition each volume contains a table of contents for
all three volumes.
In accordance with your letter of 21 February 1970, we
are shipping 125 copies of the complete report to Cincinnati
and 75 copies to Raleigh.
It has been a pleasure serving NAPCA and the cause of
cleaner air. in fulfilling this contract.
Sincerely yours,
E. R. Hendrickson, Ph.D., P.E.
Principal Investigator
ERH/gea
2324 S. W. 34th Street . Gainesville, Florida 32601 •. 904/372-3318
-------
ABSTRACT
The basic objectives of this study were to make a comprehensive
and systematic evaluation of the technical and economic problems
involved in the control of airborne emissions, especially particu-
lates and gaseous sulfur compounds from the chemical wood pulping
industry; and to determine the technological gaps that need to be
filled by accelerated research and development.
Included in the scope of the work were major variations of the
kraft, sulfite, and semichemical pulping processes; the nature
and sources of emissions from each process; a review of control
hardware capabilities, efficiencies, and costs; a review of
source and ambient air sampling and analysis techniques; and an
evaluation of the overall economic impacts of air quality improve-
ment in the industry.
It is felt that several major gaps in technology have been
identified which will need to be filled before any further
great steps in progress can be taken. Brief statements of
these needed areas of research of highest priority are as
follows:
1. Develop and standardize methods and instruments for
monitoring emissions and ambient air.
2. Assess the effect of operating variables on emissions
from the kraft pulping and recovery systems.
3. Develop and standardize organoleptic techniques for
determinations of process emissions and evaluation of
ambient air quality.
4. Investigate new pulping methods which eliminate the
use of sulfur.
5. Define the mechanisms, with emphasis on transport
processes and emission interactions, which will relate
emission limitations to ambient air objectives.
6. Evaluate emissions from sources in sulfite and NSSC
mills and determine operating variables which affect
emissions.
v
-------
7. Investigate adsorption and absorption of odorous gases
and reuse of the collected material in process.
8. Determine whether TR3 is an effective measure of the
acceptability of odorous emissions from kraft mills or
must the compounds be identified more definitively.
These brief statements of needs are defined more completely and
specific projects identified.
VI
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ACKNOWLEDGMENTS
In a project of this magnitude, there are many people
other than those designated as the authors who have made
significant contributions to the Final Report.
In Environmental Engineering, Inc., Mr. Kent Withington
assembled the necessary information and prepared the first drafts
of the chapter on emissions. Dr. David T. Knuth and Mr. John Dollar
assisted with the literature search on on-going research. At
Reynolds, Smith and Hills, Mr. Lamar Russell was originally the
project engineer, but was succeeded by Mr. Leroy Doughty about the
mid-point in the project. Mr. Doughty was assisted by Mr. Robert
Clark in collecting the information about current expenditures by
the industry. Mr. Robert Clark, Mr. Forrest Dryden, and Mr. Malcolm
Steeves investigated sulfur recovery from power boilers and prepared
the drafts of that chapter. All RSH and EEI personnel participated
in the selection of a plan for projecting investment and operating
costs. Mr. Doughty of RSH was primarily responsible for this
section working with Dr. James Heaney of EEI who was responsible for
the modeling.
From the Sirrine organization, Mr. Robert Farrell prepared the
power plant energy balances assisted by Mr. H. J. Steigler. Mr.
Carlton Ranew and Mr. Peter Gombola prepared the flow diagrams
assisted by Mr. J. Don Lee, Mr. S. L. McCluskey, and Mr. J. D. Rushton.
Mr. Wells Meakin conducted the survey and prepared the preliminary
drafts on which Chapter 2 is based. Contributions to Chapters 5, 6,
and 7 were made by the EEI personnel cited above and the following
Sirrine personnel: Mr. J. H. Bringhurst, Mr. W. L. Carpenter, Mr.
M. C. Freeland, Mr. P. P. Gombola, Mr. E. C. Hartney, Mr. C. E.
Hatch, Jr., Mr. J. Don Lee, and Mr. R. C. Ranew, Mr. J. E. Roberson,
Mr. J. D. Rushton, Mr. H. A. Stokes, Mr. J. W. Stubblefield, Jr.,
and Mr. D. B. Wilson.
Consultants to the contractors included Poly Con, Incorporated,
of Ramsey, New Jersey. Mr. Jorgen Hedenhag and Mr. Samuel Jacobson
prepared much of the background information on control equipment used
in Chapters 5 and 6 and the basic cost data on control equipment used
throughout the report.
Another consultant was Professor Donald Adams of Washington
State University who prepared the material used in the chapter on
sampling and analysis.
The guidance and assistance provided by the two project officers,
Mr. W. Gene Tucker of the Division of Process Control Engineering, and
Mr. Frank Bunyard of the Division of Economic Effects Research, National
-------
Air Pollution Control Administration/ is gratefully acknow-
ledged. Mr. Tucker and Mr. Bunyard were able to furnish
information which was not readily available from other sources.
Both were of special help in polishing up the many drafts
which led to the Final Report.
Liaison was maintained throughout the project with a
committee drawn from the chemical wood pulping industry. These
gentlemen contributed information to the contractors including
otherwise unavailable cost data. Members of the pulp industry
Liaison Committee to whom great thanks are due include Dr. Herman
Amberg of Crown-Zellerbach; Mr. Richard Billings of Kimberly-
Clark; Mr. Russell Blosser and Dr. Isaiah Gellman of National
Council for Air and Stream Improvement; Dr. Loren Forman, Scott
Paper Company (Dr. Nicholas Lardieri, alternate); Mr. Matthew
Gould of Georgia Pacific; Dr. Glenn Kimble of Union Camp; Mr.
G. J. Kneeland, St. Regis; Mr. George Marsh of U. S. Plywood-
Champion; Mr. John McClintock of Weyerhaeuser; Dr. Samuel
McKibbins of Continental Can; Mr. George Rand of International;
Mr. J. T. Walker of Westvaco (Mr. Bill Wassmer, alternate);
Mr. Peter Wrist of Mead (Mr. Virgil Minch, alternate).
The typing of the many drafts and the plates for the Final
Report was done by Mrs. Peggy Bowman, Mrs. Mary Ann Hester, Mrs.
Lala Scouten, and Miss Ann Smith.
Vlll
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PREFACE
This report was prepared for the National Air Pollution
Control Administration to assist in carrying out their responsi-
bilities under the Air Quality Act of 1967. Consideration was
given mainly to the needs of the Division of Process Control Engi-
neering and the Division of Economic Effects Research. It is
probable that the information also will be used by others including
persons in the chemical wood pulping industry.
The intention was to provide a report which essentially
would specify the present status of emissions control in the industry,
indicate what additional progress could be expected by application of
existing or nearly-developed technology, and define areas of research
and development necessary for further advances in the future.
As much background explanatory material as possible was
provided. It is not necessary to be intimately familiar with the
technical aspects and economics of the industry. However, use of
the report presupposes technical knowledge of the processes used by
the industry and an appreciation of emission control technology.
It is important that the report be considered in its
entirety. It was impossible adequately to qualify all discussions
and conclusions at the place the information appears in the report.
Thus, erroneous conclusions may be drawn by taking material out of
context without a proper understanding of the background.
Costs used in the engineering estimates and calculations
were based on the price of supplies and equipment as of January
1969. Statistical data on the industry were verified as of
December 1968.
IX
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GENERAL TABLE OF CONTENTS
A Detailed Table of Contents for Each Chapter
Will Be Found on the Separator Sheet
Preceding Each Chapter
VOLUME I
Page No.
Letter of Transmittal iii
Abstract v
Acknowledgements vii
Preface ix
Chapter 1 - INTRODUCTION
Air Quality Act of 1967 1-1
General Description of Industry Studies 1-1
Objectives of This Study 1-2
Procedures for the Study 1-2
Chapter 2 - THE CHEMICAL WOOD PULPING INDUSTRY
Summary 2-1
Introduction 2-2
Economic Position 2-4
Present Geographic Distribution 2-6
Forecasts 2-9
References 2-14
XI
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Page No.
Chapter 3 - PRESENT PULPING PRACTICES
Summary 3_1
Introduction 3_2
Kraft Pulping 3-12
NSSC Pulping 3-54
Sulfite Pulping 3-62
Chapter 4 - QUANTITY AND NATURE OF EMISSIONS
Summary 4_1
Introduction 4_2
Kraft Gaseous Emissions 4_4
Kraft Particulate Emissions 4-44
NSSC Emissions 4-49
Sulfite Emissions 4-53
Auxiliary Furnace Emissions 4-59
References 4-66
Appendix A - Summary Data for Chapter 2
VOLUME II
Chapter 5 - CONTROL METHODS PRESENTLY IN USE
Summary 5-1
Introduction "" 5-3
General Description of Control Equipment 5-4
Application, Cost, and Effectiveness of Present
Control Methods 5-25
xn
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Page No,
Kraft Sources 5-33
Sulfite Sources 5-151
NSSC Sources 5-156
References 5-157
Chapter 6 - NEW DEVELOPMENTS IN CONTROL TECHNOLOGY
Summary 5_1
Introduction 5_2
General Description of Control Methods 6_2
Application, Cost, and Effectiveness of New
Control Methods 6-10
Kraft Sources 6-10
Sulfite Sources 6-40
NSSC Sources 6-42
References 6-45
Chapter 7 - CRITICAL REVIEW OF CONTROL TECHNOLOGY
Summary 7_1
Introduction 7_2
Kraft Process 7_3
Sulfite Process 7-18
NSSC Process 7-21
Chapter 8 - POWER BOILER SULFUR RECOVERY
Summary 8-1
Introduction , g_2
Flue Gas Desulfurization Technology 8-19
Kill
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Page No.
Process Feasibility Considerations 8-32
R & D Efforts 8-38
References 8-39
Appendix B - Summary Data for Chapter 8
VOLUME III
Chapter 9 - SAMPLING AND ANALYTICAL TECHNIQUES
Summary 9-1
Introduction 9-2
Kraft Sources 9-4
Sulfite Sources 9-65
NSSC Sources 9-76
References 9-77
Chapter 10 - ON-GOING RESEARCH RELATED TO REDUCTION
OF EMISSIONS
Summary 10-1
Introduction 10-2
Emissions Control Technology 10-2
Cost and Effectiveness of Emission Control 10-39
Sampling and Analytical Techniques 10-40
Control Equipment Development 10-50
Process Changes Affecting Emissions 10-54
Chemistry of Pollutant Formation or Interactions 10-57
New Pulping Processes 10-68
Control Systems Development 10-72
xiv
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Page No.
Chapter 11 - RESEARCH AND DEVELOPMENT RECOMMENDATIONS
Summary 11-1
Areas of Needed Research 11-2
Specific R S D Projects 11-6
Emission Control Technology 11-6
Cost and Effectiveness of Emission Control 11-8
Sampling and Analytical Techniques 11-9
Control Equipment Development 11-10
Process Changes 11-10
Chemistry of Pollutant Formation or Interaction 11-11
New Pulping Processes 11-12
Control System Development 11-12
Other 11-12
Chapter 12 - CURRENT INDUSTRY INVESTMENT AND OPERATING
COSTS
Summary 12-1
Introduction 12-2
Incremental Cost Categories 12-7
Chapter 13 - FUTURE INDUSTRY INVESTMENT AND OPERATING
COSTS
Summary 13-1
Introduction 13-2
Concepts for a Management Model 13-2
xv
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Page No.
Analysis of Emission Sources and Controls 13-9
Assignment of Costs 13-33
Trends in Future Capital Expenditures 13-40
References 13-49
xvi
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CHAPTER 1
TABLE OF CONTENTS
Page No.
Air Quality Act of 1967 1-1
Special Industry Studies 1-1
Objectives of the Study 1-2
Procedures for the Study 1-2
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CHAPTER 1
INTRODUCTION
1.1 THE AIR QUALITY ACT OF 1967
The Air Quality Act of 1967 builds upon the basic precepts of
the Clean Air Act of 1963 to develop a technically sound and
rational plan for improvement of air quality through application
of air quality criteria and detailed control technology. This
would be accomplished on a regional basis by a cooperative effort
on the part of the states and the Federal government. Key items
in the abatement program would include designation of air quality
control regions, publication of air quality criteria, publication
of information on available control technology, development of
air quality standards, and development of implementation plans
to meet the standards.
The basic responsibility of the National Air Pollution Control
Administration for research and development into the causes,
effects, extent, prevention, and control of air pollution was
expanded. This was necessary to provide an improved techno-
logical basis for the total program. Research and the identi-
fication of needed research were recognized as the key to
effective air quality improvement. In addition, Congress
expressed concern regarding the economic impact of implementing
the legislation. They directed that specific economic studies
be undertaken and a special report made on the costs to all
segments of the economy of carrying out the provisions of the
law.
The Air Quality Act retained many of the provisions of the Clean
Air Act and, in addition, has many important provisions not
reported here. The revisions described above, however, are
the major ones which have a bearing on the need for this study.
1.2 SPECIAL INDUSTRY STUDIES
Some of the largest manufacturing industries have some of
the most complex air quality control problems. Because of
their technical orientation, the industries have been successful
in developing new technology for solving their problems, In
addition, the technology which they have developed may be
1-1
-------
applicable to control of other sources. The Air Quality Act
imposed on NAPCA the responsibility of becoming familiar with
the technology of air pollution control, developing control
technology documents to accompany air quality criteria documents,
identifying areas of research essential to progress in carry-
ing out the provisions of the act, and assessing the economic
impact of implementing the legislation. To carry out some of
these responsibilities, the Division of Process Control
Engineering and the Division of Economic Effects Research
jointly planned and are conducting under contract, a series
of systems analysis studies of emissions control in major
industries. The study being reported is concerned with the
control of atmospheric emissions in the chemical wood pulping
industry.
1.3 OBJECTIVES OF THE STUDY
The purpose of this study was to make a comprehensive and
systematic evaluation of the technical and economic problems
involved in the control of airborne emissions, especially
particulates and gaseous sulfur compounds from the wood pulping
industry; and to determine the technological gaps that need to
be filled by accelerated research and development. Included
in the scope of the project were a consideration of major
variations of the kraft, sulfite, and semichemical pulping
processes; the nature and sources of emissions from each
process; a review of source and ambient air sampling and
analysis techniques; a review of control hardware capabilities,
efficiencies, and costs; and an evaluation of the overall
economic impacts of air quality improvement in this industry.
1.4 PROCEDURES FOR THE STUDY
The first phase of the project was concerned essentially
with compiling and presenting both statistical and technical
data about the chemical wood pulping industry. Information
was gathered on the locations, types, and capacities of all
chemical pulp mills in the United States. Projections of the
data were made through 1980 in an attempt to present a picture
of increases in capacity as well as changes in regional
distribution and predominant pulping processes of the industry.
1-2
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Surveys and critical reviews were made of ongoing research which
is related to control of atmospheric emissions and of techniques
used in the industry to monitor emissions. A major effort in
this phase was devoted to defining typical pulping processes
(flow diagrams) and preparing appropriate heat and materials
balances including identification of emissions. Confirmation
of the data developed during this phase was obtained by actual
visits to selected operating mills in various parts of the
country which had processes similar to the theoretical flow
diagrams.
A second phase involved a feasibility analysis of emissions
control technology in the industry. By appropriate modelling
based on confirmed flow diagrams, the cost and effectiveness
of emission control were evaluated for individual sources and
for entire pulping processes. New foreign and domestic develop-
ments were considered in addition to current U. S. practices.
The feasibility of sulfur recovery from utility boilers also
was investigated.
Based upon all of the preceding work, gaps in technology
were identified and recommendations made as to needed research
and development efforts. The recommendations include, but
are not limited to, the following areas:
1. The need for further development of, or clarification
of effectiveness and cost of current control technology,
2. The necessity of developing new sampling and analytical
techniques,
3. The necessity of research and development in new control
technology, and
4. Modification of current pulping processes or the
development of new processes that could lead to
reduced atmospheric emissions.
The final phase of the work was an economic study of emission
control in the pulping industry. A model was developed which
utilizing the information gathered in previous phases made
possible an estimation of the capital cost and annual operating
and maintenance costs of pollution control equipment now in
operation in the industry. A projection model was developed
to provide the capability of projecting expenditures for
achieving desired levels of emission control for a reasonable
time into the future.
1-3
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CHAPTER 2
THE CHEMICAL WOOD PULPING INDUSTRY
TABLE OP CONTENTS
Summary
Introduction
Economic Position
Present Geographic Distribution
Forecasts
Growth and Process Trends
Geographic Distribution Trends
References
Page No,
2-1
2-2
2-4
2-6
2-9
2-9
2-12
2-14
2-i
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CHAPTER 2
THE CHEMICAL WOOD PULPING INDUSTRY
SUMMARY
The pulp and paper industry is the ninth largest in the
United States, accounting for nearly four percent of the value
of all manufacturing. The per capita consumption of paper is
expected to continue to rise from the late 1969 value of 550
pounds per year.
The United States and Canada produce more than 52 percent
of the world's supply of pulp, with the U. S. in 1968 furnishing
nearly 38 million short tons. Of this amount, 32 million tons
were chemical pulp. Approximately 75 percent of this was pro-
duced by the kraft process, 9 percent by the sulfite, and 10
percent by neutral sulfite semichemical. The U. S. industry
includes more than 360 pulp mills of all types, mechanical and
chemical.
This study is concerned mainly with three types of chemical
pulping processes; kraft, sulfite, and NSSC. The geographical
distribution of the industry as of December 1968 by process and
size is shown in the chapter by maps and in Appendix A by tables.
Projections have been made of chemical pulp production by
process and region of the country through 1985. The production
of soda and dissolving pulps is expected to remain reasonably
constant. Sulfite pulp production will probably decrease slightly.
It is anticipated that NSSC production will nearly double and kraft
increase to approximately two and one-half times the 1968 figures.
By 1985, kraft and NSSC are projected to dominate chemical
pulping in the U. S. with kraft accounting for 85 percent and NSSC
9 percent of total chemical pulp production. The total production
of chemical pulp is expected to slightly more than double over the
1968 figures.
Regional distribution of pulping capacity is expected to
remain in the same relative proportions as it is today.
2-1
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2.1 INTRODUCTION
The pulp and paper industry is the ninth largest manufacturing
industry in the United States. This industry accounts for
nearly four percent of the value of all manufacturing.
Although paper is one of the oldest manufacturing industries,
it is an industry that is expanding faster than the general
economy. Consumption of paper rises with increased affluence.
The per capita consumption of paper in the U. S. is now about
550 pounds per year compared to about 412 pounds only ten years
ago. There are no signs that per capita consumption is leveling
off.
The pulp and paper industry is comprised of three distinct
segments: (1) pulp, (2) primary paper and paperboard (cardboard,
et cetera), and (3) converted paper and paperboard products.
Pulp—Most pulp is made by integrated companies and consumed
captively without moving through the marketplace. About ten
percent of the total pulp produced is, however, made by inde-
pendent pulp producers without their own paper making facilities
or by integrated companies producing surpluses for market.
About three percent of all pulp produced is consumed outside
the industry for such products as cellophane, rayon, cellulose
esters and ethers, and their derivatives. Eighty percent of
the pulp used for making paper comes from wood; about 20 percent
of the pulp is made from waste paper or such fibers as cotton and
bagasse.
Primary Paper and Paperboard—This segment of the industry produces
paper, paperboard, and building paper and board. A portion of this
production is sold directly to industrial users such as newspapers,
book publishers, and printers, or to building and other users.
Converted Paper and Paperboard Products—About 70 percent of the
primary paper production, however, is further processed by paper
converters into such products as containers, bags, sanitary tissue
products, and stationery.
Wood pulp is prepared either mechanically or chemically. In the
mechanical processes (groundwood, defibrated and exploded) wood
is shredded or separated by physical means. In the chemical pro-
cesses (kraft, sulfite, NSSC, soda, and dissolving) wood is treated
with chemical reagents which form soluble compounds with the non-
cellulosic materials, thus leaving residual cellulose. The NSSC
process involves treating the wood first with a mild chemical and
then mechanically separating the fibers.
2-2
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Data are presented in Table 2-1..which show the number of, mills
and total mill capacities for the five chemical pulping processes.
In Table 2-1, all capacities are based on air dried tons of pulp;
annual capacities are based on operating at rated capacity for
350 days per year, allowing for normal maintenance and scheduled
shutdowns. It is emphasized that these figures represent pro-
duction capability and do not portray actual production data.
TABLE 2-1
SUMMARY - U.S.A.
CHEMICAL PULP MILL CAPACITIES (UNBLEACHED)
AS OF DECEMBER 31, 1968
Process
Kraft
Sulfite
NSSC
Dissolving
Soda
TOTALS
Number
of
Mills
116
43
43
8
4
214
Capacity*
ADT/Day
87,808
10,875
10,675
4,565
570
114,473
Annual
Capacity*
Tons
30,733,000
3,799,500
3,736,500
1,600,000
200,000
40,069,000
1968
.Production
Tons
24,300,000
2,500,000
3,500,000
1,500,000
200,000
32,000,000
*These figures represent capacity and not actual production. ADT
stands for air-dried tons of unbleached pulp per day; air-dried pulp
contains 10 percent moisture.
2-3
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Three of the chemical wood pulping processes display a potential
to cause air pollution. These are the kraft, sulfite, and NSSC
processes. Collectively, these three processes account for
about 80 percent of the total wood pulp produced in the United
States.
To define the air pollution problem posed by the chemical wood
pulping industry, it is necessary to establish the geographical
distribution of existing production capacity and to identify
trends which might cause a redistribution of production capacity
in the future.
2.2 ECONOMIC POSITION
The United States pulp and paper industry includes more than 360
pulp mills of all types, mechanical and chemical. Estimates for
1967 indicate 37 companies, each with pulp and paper sales at the
manufacturer's level of at least $100 million, accounted for
$10.24 billion in sales, or 49 percent of the industry's total of
$20.88 billion.
Table 2-2 shows the wood pulp production in 1968 for the ten
leading pulp producing nations of the world (I). The other
60 pulp producing nations individually produced less than one
million tons of pulp and collectively produced 13,441,000 tons
of pulp in 1968. From these data, it can be determined that
the U. S. and Canada produced 52 percent of the world's wood
pulp in 1968. This massive capacity, coupled with the contiguous
features of the U. S. and Canada, place these countries in a
leading position in terms of production.
It is reported (2_) that North American industry is planning to
build 65 new pulp mills in the early 1970's—39 in the U. S. and
26 in Canada. It seems reasonable to conclude, therefore, that
the U. S. and Canada will remain the dominant nations in wood
pulp production at least for the next two or three decades.
2-4
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TABLE 2-2
PRODUCTION OF TEN LEADING
PULP PRODUCING NATIONS - 1968
Nation
United States
Canada
Sweden
Japan
USSR
Finland
Mainland China
Norway
France
West Germany
Million Short Tons
37.89
16.40
7.76
7.56
6.78
6.56
2.30
2.18
1.77
1.73
Data taken from Pulp and Paper: 19th Annual World Review
2-5
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2.3 PRESENT GEOGRAPHIC DISTRIBUTION
A compilation of data on current wood pulping practice in
the U. S. was begun by searching available published reports,
such as Lockwood's Directory of_ the Paper and Allied Trades,
Post's Pulp and Paper Directory, and Southern Pulp and Paper
Manufacturer's Southern Mill Directory. Information originally
tabulated included plant location, owner, pulping process
employed, rated mill capacity, type of wood pulped, and age
of original mill. These data were brought up to date based
on in-house information and available NAPCA - NCASI reports,
and communications with mill managers.
The corrected data have been tabulated and are presented in
Appendix A (Tables A-l and A-2). Using these data as a base,
two maps have been prepared to illustrate geographically the
distribution of chemical wood pulping mills throughout the
United States. These maps are presented here as Figures 2-1
and 2-2.
2-6
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CLEVELAND I PHILADELPHIA"
PITTSBUR6
• A
KRAFT MILLS
• 0-400 TPD
• 400-700 TPO
• 700-1000 TPD
• 1000-1300 TPO
• 2. -1300 TPO
REGION I
REGION H
REGION m
REGION ET
REGION Z
2-7
REGIONAL DISTRIBUTION
OF KRAFT PULP MILLS
IN THE U. S.
FIGURE 2-1
-------
CLEVELAND 1 PHILADELPHIA
PITTS BURG
INDIANAPOLIS _^/ ^ WAEHMGT9N |
h *" U 1/7 J^ X
^T^—f / /., RICHMOND
f'f • /^ '
ROANOKE
^ WINSTON
• SALEM
RALEIGH
NSSC MILLS
0- 200 TPD
200- 300 TPD
>. - 300 TPO
SULFITE MILLS
A 0- 100 TPO
A 100-200 TPD
A 200-400 TPD
A > -400 TPD
REGION I
REGION TJ
REGION IE
REGION I?
REGION Z
2-8
REGIONAL DISTRIBUTION
OF SULFITE AND NSSC PULP MILLS
IN THE U. S.
FIGURE 2-2
-------
2.4 FORECASTS
2.4.1 GROWTH AND PROCESS TRENDS
A number of forecasts have been made which attempt to portray
the future demand for wood pulp (all grades) in the United
States. These forecasts range from a low of 61 million tons
per year in 1985 as given by Forest Research Report No. 17,
1965 (3), to a high of 89 million tons per year in 1985 as
given by Resources in America, 1963 (_4) . A middle of the
road forecast has been made by the American Paper Institute.
Based on these data, plus numerous other sources, and a.
wealth of in-house knowledge, H. W. Meakin of the J. E.
Sirrine Company has projected chemical pulp production through
1985. These projections are reproduced here as Figure 2-3.
Historical data are presented in Appendix A (Table A-3).
Viewed together, these data show that through 1985, the
production of soda pulp and dissolving pulps will remain
reasonably constant; sulfite pulp production will decrease
slightly; NSSC production will nearly double, and kraft
pulp will increase to approximatley 2 1/2 times the 1968
amount.
In 1985, kraft and NSSC processes are expected to dominate
chemical pulping in the United States. Kraft production
is projected to account for about 85 percent of the chemical
(about 70 percent of total wood pulp, all grades, production),
and NSSC for about 9 percent of the total chemical pulp pro-
duction. The total production of chemical pulp is expected
to slightly more than double.
Table 2-3 has been included to summarize announced and esti-
mated expansion and phasing-out operations through 1980.
Detailed breakdowns of Table 2-3 may be found in Appendix A
(Tables A-4, A-5, A-6, and A-7).
2-9
-------
FIGURE 2-3
PROJECTION OF PRODUCTION
OF CHEMICAL PULPS IN THE U. S.
80
70
to
•z.
o
I—
£
o
co
u_
o
CO
•z.
o
60
50
40
o
o
D-
Q
LU
O
o
o;
o.
30
20
10
TOTAL
KRAFT
NSSC
SULFITE
DISSOLVING
SODA
1985
2-10
-------
TABLE 2-3
ANNOUNCED AND ESTIMATED EXPANSION , x
AND PHASING OUT PLANS THROUGH 1980 u;
Current and Planned New Plant Construction as of December 31, 1968
CAPACITY APT/DAY
Kraft
5,866 (12)
2,135 (5)
Sulfite
830 (2)
0
N5SC
750 (3)
568 (2)
New
Expansion
TOTAL 8,001 (17) 830 (2) 1,318 (5)
II. Estimate of Phased Out Operations
CAPACITY APT/DAY
Time Period
In 1968 (c)
In 1969-70
In 1970-80
TOTAL
Kraft
205
85
290
(1)
(1)
(2)
Sulfite
835
503
1,562
2,900
(5)
(3)
(17)
(25)
NSSC
235 (1)
235 (1)
Soda
60
140
200
(1)
(2)
(3)
(a) Detailed breakdowns of these data may be found in
Appendix A-
(b) Figures in ( ) indicate number of mills
(c) These capacity figures for 1968 are not included in
Table 2-1.
In addition to the current and planned new plant construction
shown above, there are at least twelve proposed or tentative
mills in the talking stage of development. These twelve mills
would, if brought to production, supply in excess of an
additional 3,000 tons per day of pulp.
2-11
-------
2.4.2 GEOGRAPHIC DISTRIBUTION TRENDS
Table 2-4 contains information which shows the regional
distribution of the industry in 1968 as well as the pro-
jected distribution in 1975 and 1980,
It appears to be the concensus of industry representatives
on the Pulp Industry Liaison Committee that the distribu-
tion of pulp production in the forseeable future (through
1985) will remain essentially as it is today. The projected
chemical pulp production shown on Figure 2-3 was, therefore,
stratified by region on the basis of this assumption.
There are several factors which influence the decision to
locate a pulp mill in a given section of the country. One
of these factors is the availability of trees to serve as
raw material. Some concern has been expressed by forestry
management people (_5_, 6_) that a tightening of the wood
supply in the South could occur in the late 1970"s. If
this were to occur, there could possibly be a shift of pro-
duction to the West and North. It is felt, however, that by
more intensified management of the better forest lands and
improved silvaculture, we can grow appreciably more wood and
thus satisfy the demands of the wood pulping industry. Thus,
it is predicted that the distribution of chemical pulp pro-
duction by regions will remain substantially as it is today.
2-12
-------
TABLE 2-4
PROJECTION OF PULP PRODUCTION BY REGION IN THE U. S.
1968 - 1980
1968
1975
1980
REGION
Kraft
Northeast
Northcentral
Southeast
Southcentral
Northwest
TOTAL
Sulfite
Northeast
Northcentral
Southeast
Southcentral
Northwest
TOTAL
NSSC
Northeast
Northcentral
Southeast
Southcentral
Northwest
TOTAL
Prod.
TPD
3,617
2,319
36,249
15,850
11,393
69,428
1,464
1,354
471
0
3,854
7,143
1,731
3,330
2,926
1,283
730
10,000
% Of
Indust.
Prod.
5.21
3.34
52.21
22.83
16.41
100.0
20.49
18.96
6.59
53.96
100.00
17.31
33.30
29.26
12.83
7.30
100.00
Prod.
TPD
5,582
3,579
55,939
24,460
17,582
107,142
1,171
1,083
377
0
3,083
5,714
2,324
4,472
3,929
1,723
980
13,428
% Growth
Over
1968
54.3
54.3
54.3
54.3
54.3
54.3
(20.0)
(20.0)
(20.0)
(20.0)
(20.0)
34.3
34.3
34.3
34.3
34.3
34.3
Prod.
TPD
6,981
4,476
69,962
30,592
21,989
134,000
1,171
1,083
377
0
3,083
5,714
2,720
5,233
4,598
2,016
1,147
15,714
% Growth
Over
1968
93.0
93.0
93.0
93.0
93.0
93.0
(20.0)
(20.0)
(20.0)
(20.0)
(20.0)
57.1
57.1
57.1
57.1
57.1
57.1
% Growtl
Over
1975
25.1
25.1
25.1
25.1
25.1
25.1
0
0
0
0
0
17.0
17.0
17.0
17.0
17.0
17.0
TPD stands for Tons Per Day
( ) Represents a decline in production
2-13
-------
2.5 REFERENCES
1. Staff, "19th Annual World Review," Pulp and Paper, 43_(7) , 7- ,
(June 25, 1969).
2. Staff, "Expansion/Modernization/Acquisition Report," Pulp and
Paper, 42_(51) , 43- , (December 16, 1968).
3. "Timber Trends in the United States," Forest Service, U. S.
Department of Agriculture, Washington, 1965.
4. "Resources in America's Future," Landsberg, Fishman and Fisher,
New York, 1963.
5. Josephson, H.R. (Director, Division of Forest Economics and
Marketing Research, Forest Service, USDA), "Availability of
Wood Supplies for the Pulp and Paper Industry," Paper presented
at 1968 Annual Meeting of Pulp and Raw Materials Division of
American Paper Institute, New York, February 20, 1968.
6. Slatin, Benjamin (Economist,API), "Future Demands for Pulp and
Paper as They Influence Pulp Wood Requirements," Paper presented
at fall meeting of the Southeastern Technical Division of the
American Pulp Wood Association, Atlanta, November 21, 1968.
2-14
-------
CHAPTER 3
PRESENT PULPING PRACTICES
TABES OF GQOTEKTS
Summary
Kraft Pulping
Kraft Flosr Diagrams
NSSC Pulping
NSSC Flow Diagrams
Sulfite Pulping
STulfite Flew Diagrams
Page No.
3-1
3-2
3-12
3-13
3-54
3-54
3-62
3-63
3-i
-------
CHAPTER 3
PRESENT CHEMICAL PULPING PRACTICES
SUMMARY
In wood pulping, cooking chemicals have rhe function of dissolving
the lignin that bonds the cellulose fiber together. Thus various
chemical processes have been developed, using acid, alkaline, or
neutral solutions, which delignify with as little destruction of
the cellulose as possible. Most of the chemical pulping processes
in use today utilize sulfur in some form in the cooking liquor.
In bringing about the solution of wood components, the sulfur combines
with constituents of the wood to produce gaseous and particulate com-
pounds which may degrade the quality of air or water if discharged
into the environment„
Three of the chemical processes (kraft, sulfite, and neutral sulfite
semichemical) account for approximately 80 percent of pulp production
in the U. S. The choice of the pulping process is determined by the
product being made, by the type of wood species available, and by econo-
mic considerations. Therefore there is not a free choice in the process
to be used. The three processes have been identified as possible
sources of particulate and gaseous emissions into the atmosphere. For
this reason they are the subject of this study.
To specifically illustrate the air pollution potentials of the industry,
flow diagrams representing pulping processes typical of mills produc-
ing the majority of the nation-s total pulp output were prepared. These
simulated flow diagrams include variations of the basic kraft, sulfite,
and NSSC processes and are prepared to feature material balances and
processes or equipment which will affect the selection of air quality
control measures. The power plant energy balances associated with
each flow diagram were also prepared to stress the air quality aspect.
Ten flow diagrams are presented for variations of the kraft process,
four for sulfite, and three for NSSC. Except for Kraft Flow Diagram
No. 10, only ^process variations utilized by a significant number of
mills have been considered =, With each flow diagram is presented infor-
mation on the typical age and location of the type of mill, general data
about the process arrangement and assumptions made, plus figures on
representative emissions from each source. The flow diagrams are
hypothetical, for use in later parts of the study, and none can
be identified with a specific mill.
3-1
-------
3.1 INTRODUCTION
Three of the chemical processes (kraft, sulfite, and neutral
sulfite semichemical) account for approximately 80 percent of
pulp production in the U. S. The choice of the pulping pro-
cess is based on a variety of factors including the product
being made, the type of wood species available, and economic
considerations. Therefore, there is not a free choice in the
process to be used. The three processes have been identified
as sources of particulate and gaseous emissions into the atmos-
phere. For this reason they are the subject of this study.
To specifically illustrate the air pollution potentials of the
industry, simulated flow diagrams representing pulping processes typical
of mills producing the majority of the nations's total pulp
output were prepared. These diagrams include modifications
of the basic kraft, sulfite, and NSSC processes and are
prepared to feature material balances and processes or
equipment which will affect the selection of air quality
control measures. The power plant energy balances associated
with each flow diagram were also prepared to stress the
air quality aspect. Thus, not all unit processes are shown
on each flow diagram and where the emissions from two unit
processes normally are discharged through the same vent,
they may be indicated as one.
Diagrams were prepared to show material balances on the basis
of one ton of unbleached air dry pulp. Except for Kraft Flow
Diagram No. 10, only process arrangements utilized by a significant
number of mills have been considered. Diagrams have not been pre-
pared for the groundwood and soda pulping processes because the
former is a mechanical process with very little or no particulate
or odorous emissions and the latter is considered obsolete. The
flow diagrams are hypothetical and none can be identified with
a specific mill.
3-2
-------
Combination boilers firing bark plus one or more fossil fuels
are common. The emissions from bark firing have been shown
separately and are estimated on the basis of debarking 100
percent of the wood supply. For mills receiving wood chips the
bark flow will be reduced in proportion to the amount of chips
received. Therefore, the oil and coal consumption must be in-
creased accordingly. Since the amount of bark burned varies
considerably from mill to mill, the emission estimates from bark
firing vary accordingly.
Boiler emissions for both coal and oil have been calculated
and are indicated on the flow diagrams. Only one set of these
emissions is applicable depending upon the particular fuel
in use. In NO case should the coal and oil emissions be
added together.
Emissions from a power boiler firing natural gas are not shown,
primarily due to lack of space. The power boiler emission when
firing natural gas is approximately the same as fuel oil in
terms of flue gas volume and weight. Of course, natural gas
has no SO or particulate emission. j
A sulfur content of two percent was selected as being a
reasonable value for both coal and oil and a value which can be
easily adjusted for any fuel analysis. See Chapter 8 for further
comments regarding fuel consumption and composition.
3.1.1 PURPOSE OF THIS CHAPTER
The purpose of this chapter is to show flow diagrams and power
plant energy balances in order to identify and quantify signifi-
cant particulate and malodorous emissions from major sources in
the pulping processes. In subsequent chapters, various pieces
of emission control equipment will be studied for these sources
with a view to analyzing the cost of this equipment versus its
effectiveness in reducing emissions. The power plant energy
balances were developed in order to determine the emissions result-
ing from the generation of the steam required for process and
electric power generation.
The quantity and concentration of emissions on all flow diagrams
are based on "annual averages" and are not intended to be
used for establishing emission standards, guides, or criteria.
3-3
-------
3.1.2 DEFINITIONS
The following definitions are provided for the benefit of those
not intimately familiar with the chemical wood pulping industry.
In some instances definitions are given because of special
meanings which a term may have in this report.
Particulate - Any material which exists as a solid in a gas
stream at duct conditions and is collected in accordance with
IGCI sampling procedures.
Trace - A quantitative expression of emissions which is less
than 0.01 pounds per ton of air dry unbleached pulp.
Standard Conditions - 29.92 inches of mercury and 70 degrees F.
Sulfidity - An expression of the percentage makeup of chemicals in
kraft cooking liquor obtained by the formula
Na S
• x 100
Na S + NaOH
where the sodium compounds are expressed as Na_O.
Yield - The percentage of a specific weight of bone dry wood that
is converted to bone dry pulp.
Weak Wash - A liquid stream in the kraft process which results from
washing of the lime mud. It is used mainly for dissolving smelt.
Smelt - The molten chemicals from the kraft recovery furnace
consisting mostly of sodium sulfide and sodium carbonate.
Oxidation Efficiency - The percentage of sodium sulfide in the kraft
black liquor which is oxidized by air introduced into the liquor.
The Na S is usually expressed in grams per liter of black liquor.
A
Roundwood - Logs as delivered to the mill with bark attached and
cut to specified lengths (up to 10 feet).
Board - A heavy sheet made with single or multiple plies of pulp
formed on a board machine such as a fourdrinier.
Linerboard - A laminated container board usually made of kraft pulp.
It consists of a base sheet which is coarse strong pulp and a top
liner sheet which is fine pulp. The top liner gives the container
board a more finished exposed sulface than the base sheet.
3-4
-------
Top Liner - A sheet, usually produced from kraft pulp, which is
added as a laminate to the base sheet to produce linerboard. The
pulp may in some cases be bleached.
Base Stock - A sheet, usually produced from unbleached kraft
pulp, formed into linerboard on a fourdrinier machine.
Corrugating Medium - A sheet, usually made from NSSC pulp,
which is corrugated to form a cushioning layer when attached
to a single sheet or between two boards. The corrugating
sheet is usually 0.009 inches thick and traditionally is
referred to as "9 point."
Bark Boiler - A combustion unit used to produce steam for
process or electrical energy which is designed to burn mainly
bark and wood residues.
Combination Boiler - A combustion unit used to produce steam
for process or electrical energy which is designed to burn
bark and at least one other fuel.
Power Boiler - A combustion unit used to produce steam for
process or electrical energy which is designed to burn oil,
coal, or gas.
Recovery Boiler - A combustion unit used to produce steam
for pulping and recovery operations, and to recover the
spent chemicals from the cooking liquor.
3.1.3 ROLE OF CHEMICALS IN PULPING
In wood pulping, cooking chemicals have the function of
dissolving the lignin that bonds the cellulose fibers
together. Ideally, the chemical process should dissolve
all of the intercellular cementing constituents and ex-
traneous materials without affecting the cellulose fibers.
Unfortunately, the ideal is never achieved. Thus, various
chemical processes have been developed' using acid, alka-
line, or neutral solutions, which delignify with as little
destruction of the cellulose as possible. All of the pulp-
ing processes of interest in this study utilize sulfur in
some form in the cooking liquor. In bringing about the
solution of wood components, the sulfur reacts with some
of the wood components to produce compounds which may de-
grade the quality of air or water if released into the
environment.
3-5
-------
During the early development stages of the wood pulp industry,
the use of chemicals was insignificant. But as new chemical
pulping techniques came into being and the need for pulp pro-
ducts increased, it created an increasing demand for chemicals.
Now the chemical requirements are such that it is an important
segment of the chemical industry.
Of the three major chemical pulping processes in use today,
the sulfite process was the first. Established in 1867, it
used a calcium base cooking acid. The raw materials, sulfur
and limestone, were inexpensive and plentiful. Pyrite, in
some areas where available, was used instead of sulfur for the
formation of sulfur dioxide. In place of limestone, some mills
preferred the milk of lime system, which can be calcium hydroxide
or a slurry of calcium carbonate.
The use of magnesium as a base for sulfite pulping has been known
since 1874. But because of the relatively high cost of the chemi-
cal make-up, magnesium oxide, it was not commercialized until
1948. It was at this time that a recovery system was developed
permitting the reuse of magnesium oxide and sulfur dioxide that is
recovered in the combustion of the spent liquor.
In 1948 a number of calcium-base mills were converted to the use
of ammonia. The higher cost of the ammonia-base over the calcium-
base is offset by a substantial increase in production because of
a 25 percent decrease in the time of a pulping cycle.
Kraft pulping came into being in 1879. It was a
modification of the caustic soda system, whereby
sodium sulfide was added to the caustic soda cooking
liquor. The introduction of the modern recovery fur-
nace in the period 1928-1934 brought about a tremen-
dous increase in the use of kraft pulp. Recovery of
cooking chemicals from kraft spent liquor is essential
for the kraft process to be cost competitive with
other processes. The recovery of chemicals is accom-
plished by spraying concentrated spent liquor into the
recovery furnace, where the organic compounds are
burned and an inorganic smelt of sodium sulfide and
sodium carbonate is formed. To make up for chemicals
lost in the operating cycle, salt cake (sodium sulfate)
is usually added to the concentrated spent liquor before it is
sprayed into the furnace.
The smelt of sodium sulfide and sodium carbonate
flows from the furnace and is dissolved in water
to form green liquor. This solution is reacted
with slaked lime (calcium hydroxide), converting the green
liquor to cooking liquor which is a solution of
sodium hydroxide and sodium sulfide. The calcium
3-6
-------
carbonate created by this reaction is settled out,
dewatered, and burned in a lime kiln. The resultant
calcium oxide is returned for reaction with the
green liquor.
NSSC pulp is produced with a neutral sulfite cooking
liquor. This liquor is prepared by reacting excess
soda ash or caustic soda with sulfur dioxide pro-
ducing a solution of pH 8 to 11. The chief use
of NSSC pulp is in the production of corrugating
medium for board grades.
3.1.4 CHARACTERISITICS OF EACH PROCESS
3.1.4.1 Kraft
The Kraft process produces a dark colored fiber. There-
fore, the market for the unbleached pulp is usually limited
to its use in board, wrapping, and bag papers. If kraft
pulp is to be used in the manufacture of fine white papers,
its fibers must be treated additionally in a bleach
plant.
Cooking chemicals (caustic soda and sodium sulfide) are
expensive to manufacture. Thus their recovery is an economic
necessity. During the recovery process, steam is produced
from the combustion of the organic materials, adding to
the economic benefits of the recovery system.
The presence of caustic soda in the cooking liquor permits
the pulping of practically all wood species. The other active
chemical, sodium sulfide, creates a chemical reaction during
cooking that imparts the strength characteristics to kraft
fibers, producing fibers that are stronger than those made
from NSSC or sulfite processes. Small amounts of sodium sulfide
react with lignin and carbohydrates in the wood to form odorous
compounds which may cause a reduction of air quality.
3.1.4.2 Neutral Sulfite Semichemical
This process is mainly used for the production of a high yield
pulp having a high crush strength, important for making corrugated
board. In addition, it utilizes hardwood species that are not
readily adaptable to the other processes. Coniferous woods are
considered less desirable for the NSSC process because of a higher
chemical consumption during cooking, high lignin content for a
given yield, and high energy requirements for refining.
3-7
-------
NSSC pulp with high yields (75 to 80 percent) is used mainly in
the production of corrugating medium and linerboard. Some is
used for blending with kraft pulp for carton board, wrapping papers,
et cetera. If cooked to a yie;d in the range of 55 to 62 percent,
NSSC pulps can be bleached and then blended with bleached sulfite
for high grade papers.
Recovery of chemicals from the spent liquor is not practiced
at the majority of mills and, therefore, may create a water
pollution problem. Incineration of the liquor may, in turn,
create an emission problem because of sulfur dioxide emission
from the incinerator and will depend on the degree of sulfur
di oxide re cove ry.
3.1.4.3 Sulfite
The sulfite pulping process dominated the commercial pulping
field from about 1890 to 1930, producing easy bleaching pulps
from non-resinous woods. The cooking chemical was calcium
bisulfite plus free sulfurous acid. The characteristics
of the pulp make it suitable for use in many grades of paper
but it is especially suitable for tissues and fine papers.
Recovery of cooking chemicals and the heat values in the
spent cooking liquors was not widespread until fairly recent
years when the older calcium base has been replaced in many
mills by a soluble base such as sodium, magnesium, or ammonium.
Sodium and magnesium bases require recovery for economic reasons,
Of the two, magnesium is more widespread in its use because
on combustion the inorganic constituents break down directly
to magnesium oxide and sulfur dioxide which can readily be
recycled. Spent liquors from ammonia base pulping may be
incinerated with recovery of most of the SO . The ammonia burns
completely to nitrogen and water vapor.
The trend toward soluble bases has improved the versatility
of the sulfite process in terms of wood species which can
be pulped; modifications of the process have led to higher
yields of pulp from wood, and recovery processes have not
only reduced water pollution, but stimulated the development
of chemical by-product opportunities unique to this process.
3-8
-------
3.1.5 FLOW DIAGRAMS AND BASIS FOR SELECTION
To describe major pulping operations, 17 basic flow diagrams,
each with a power plant energy balance, have been prepared.
These flow diagrams illustrate the majority of pulping
process variations now in use in this country. These
are as follows:
3.1.5.1 Kraft (10 Flow Diagrams)
Table 3-1 lists the significant factors which influence the
emission of air pollutants from the kraft pulping process and
the particular factors that are to be included in each of the
ten flow diagrams.
Gas flow quantities from the turpentine condenser and the
multiple effect evaporators have been assumed at 35 cubic feet
per air dry ton of pulp on all kraft flow diagrams. These may
vary between 20 cubic feet to 60 cubic feet and will depend on
individual operations of the relief lines.
For purposes of gas volume calculations, the slaker vent has
been assumed to be 40 feet high with a diameter of 24 inches
for a pulp production of 600 tons per day, giving a flow of
7,000 cubic feet per air dry ton of pulp. This may vary to a
low of 4,000 cubic feet per air dry ton. Particulate emissions
are unknown, and since most of the particulates drop!within the
mill area, this source can be considered as a mill nuisance.
3.1.5.2 Neutral Sulfite Semichemical (3 Flow Diagrams)
1. Combination of neutral sulfite semichemical and kraft
pulping (continuous digester).
2. Neutral sulfite semichemical without spent liquor recovery
(batch digesters).
3. Fluidized bed recovery process (continuous digester).
3-9
-------
TABLE 3-1
KRAFT FLOW DIAGRAM FACTORS
PULPING
OPERATION
FLOW DIAGRAM NO.
123456789 10
Batch
Digester
Continuous
Digester
Concentrated Black
Liquor Oxidation
Weak Black Liquor
Oxidation
No
Oxidation
Direct Contact
Evap . Recovery
Venturi
Recovery
Bleach Plant
No Bleaching
Lime Kiln
Moderate Collec-
tion Efficiency
Lime Kiln High
Collection Efficiency
Fluidized Bed Calcining
High Collection
Efficiency
High Solids Evapora-
tor (63% Solids)
Long Tube Vertical
Evaporators
Hardwood (H) or
Softwood (S)
Percent Yield
Product
X X X X
X X X XXX
X
X X
X X X X X X X
XXXXXX XX
X
X X X X X
X X X X X
X XXX
XX XXX
X
X
xxxxxxxxx
SSSSSSSHS S
53 45 47 47 47 45 45 46 45 47
t^tflcnw ftf o 1-3 HOW owowow >v
H-p) >•{ I— ' fl> h{ O O *1 t— ' HI— ' H f-1 H I-* O
(D (D PJ (1) (D*XJ Qj&J 0j p QJ £) 0j QJ (&
H CD O ^fP>f ffDO (DOfl>Ofl>O H
ft)
(t>
3-10
-------
3.1.5.3 Sulfite (4 Flow Diagrams)
1. Magnesium acid sulfite, with recovery (batch digesters).
2. Calcium acid sulfite, without recovery (batch digesters).
3. Magnesium bisulfite (magnefite) with recovery (batch digesters)
4. Ammonium acid sulfite, with liquor incineration (batch
digesters).
The flow diagrams have been prepared from an air quality point
of view, and are broken down only to the extent necessary to
clearly locate and identify emissions.
3.1.6 POWER PLANT ENERGY BALANCE
Power plant energy balances were developed in order to
determine the emissions resulting from the generation of
the steam required for process and electric power generation.
In order to have a common base for comparison, the balances
are based on supplying all of the specific steam and
electrical requirements for each process with no outside
purchase of either electricity or steam. Steam and
electrical usage and steam pressures have been assumed
which are representative of actual mills utilizing the
various processes. j
1
Since pulp mills must either produce dry pulp for shipment
or are part of an integrated pulp and paper operation, the
energy balances were developed to include the steam and
electric loads associated with either a paper machine or pulp
dryer. In order to give an indication of'the steam and electric
requirements of the pulp mill only, a second set of numbers
has been included on each heat balance. These pulp mill
requirements were arrived at by performing a balance without
the electric and steam requirements of a paper machine or
pulp dryer.
The amount of steam generated by the recovery boilers is
calculated based on burning the black liquor solids at an
efficiency of 60 percent. The steam generated from bark
burning is based on an efficiency of 70 percent. The remaining
steam is supplied by the power boiler(s) at an efficiency of
85 percent for coal or fuel oil. The quantity of coal or
fuel oil required for the power boiler(s) is used as a basis
to calculate the air emissions shown on the flow diagrams.
In no case should the coal and oil emissions be added
together.
3-11
-------
3.2 KRAFT
3.2.1 GENERAL DESCRIPTION OF KRAFT PROCESS
The word kraft is derived from a Swedish word which means
"strong," because kraft fibers are stronger than those
produced by either the NSSC or the sulfite processes.
The kraft process involves the cooking of wood chips
in either a batch or continuous digester, under pressure,
in the presence of a cooking liquor. The kraft cooking
liquor contains sodium hydroxide and sodium sulfide,
the hydroxide being the reagent that dissolves the lignin.
During the cooking reaction the hydroxide is consumed and
the sodium sulfide serves to buffer and sustain the cooking
reaction. At the same time, small amounts of sulfide react
with lignin in the wood giving rise to the odors characteristic
of kraft mills.
Upon the completion of the cook, the residual pressure
within the digester is used to discharge the pulp into
a blow tank. Gases and flash steam released in the tank
are vented through a condenser, where heat is recovered
and the condensible vapors removed. The noncondensible
gases, which are a source of malodors, are either con-
fined and treated or released to the atmosphere. At
the same time the pulp in the blow tank is being diluted
and pumped to washers where the spent chemicals and the
organics from the wood are separated from the fibers.
The spent chemicals and the organics, called black
liquor, are then concentrated in multiple-effect
evaporators and/or direct-contact evaporators for
subsequent burning. A solids content of 60-70 per-
cent in the black liquor is a requirement for com-
bustion in the recovery furnace.
During evaporation of the black liquor in the multiple-
effect evaporators volatile malodorous gases
are released. These gases escape where entrained gases
and vapors are drawn off by a vacuum system. In order
to eliminate the venting of these gases to the atmosphere,
they can be confined and destroyed.
3-12
-------
The black liquor may be concentrated further in a direct-
contact evaporator using hot flue gases from the recovery
furnace. These hot:gases, containing carbon dioxide,
react with sulfur compounds in the black liquor leading
to the release of hydrogen sulfide. Prior oxidation of
the black liquor wi 3.1 reduce the sulfide content of the
liquor and, hence, the amount of hydrogen sulfide released.
The concentrated black liquor is then sprayed into the
recovery furnace; where the organic content supports
combustion. The inorganic compounds, consisting of the
cooking chemicals, fall to the bottom of the furnace
where chemical reactions occur in a reducing atmosphere.
The chemicals are withdrawn from the furnace as a molten
smelt, which is dissolved in a smelt dissolving tank
to form a solution called "green liquor." The green
liquor is then pumped from the smelt dissolving tank,
treated with slaked lime, and then clarified. The
resulting liquor, referred to as "white liquor," is
the cooking liquor used in the digesters.
There are chemical losses from the kraft process, through
air emissions, mill water effluent, and with the finished
product. These losses must be made up with purchased
chemicals, usually salt cake (sodium sulfate). The[ name
"sulfate" process is derived from this make-up chemical.
3.2.2 BASIC DESCRIPTION OF KRAFT FLOW DIAGRAMS
The basic assumptions which were made in the develop-
ment of each kraft flow diagram, the diagram itself,
and the energy balance are presented on the following
pages.
3-13
-------
KRAFT DIAGRAM NO. 1
TYPICAL LOCATION
Southern United States.
TYPICAL AGE OF EQUIPMENT
Over 15 years
GENERAL
This flow diagram is based on production of base stock and
should be used with Flow Diagram No. 5/ top liner stock,
to illustrate air emissions from a linerboard pulp mill.
Flow Diagram No. 1 depicts a relatively old mill, using
batch digesters. A comparison of emissions from the lime
kiln is shown when using clean water make-up in the causti-
cizing plant versus the use of multiple-effect evaporator
combined condensate.
There are perhaps 30 to 40 mills in the United States that
are illustrated by Flow Diagram No. 1. These must be combined
with those mills represented by Flow Diagram No. 5.
EMISSIONS
The following emissions have been selected as representative,
based on the range of emissions presented in Chapter 4.
POUNDS PER AIR DRY TON OF UNBLEACHED PULP
Location
Blow Tank Accumulator
Washers and Screens
M. E. Evaporators
R. Boiler and D. c.
Evaporators
After Precipitator
Smelt Dissolving Tank
Slaker
~*2i
r 0.10
0.01
0.50
10.7
10.7
k 0.02
0
RSH,
RSR,
RSSR
2.90
0.12
0.4
1.4
1.4
0.05
0
so
£.
0
0
0
3.4
3.4
0
0
Par-
ticulate
0
0
0
81.8
9.8
4.0
Unknown
3-14
-------
KRAFT DIAGRAM NO. 1
(Continued)
EMISSIONS - Continued
H2S
1.2
0.48
0.01
RSH,
RSR,
RSSR
1.25
0.50
0.51
so2
0.1
Trace
0
Par-
ticulate
23.5
4.3
0
POUNDS PER AIR DRY TON OF UNBLEACHED PULP
Location
Lime Kiln
Lime Kiln Scrubber
Turpentine Condenser
ASSUMPTIONS
The following assumptions have been made in developing the
flow diagram:
A. PULP MILL
1. Pulp Yield = 53 Percent.
2. Cooking liquor charge per air dry ton of brown stock
equals 5,050 pounds of which 780 pounds are chemical
solids. Sulfidity equals 27 percent.
3. Black liquor solids from first stage washer equals
15 percent and from M. E. Evaporators equals 50 percent
solids.
B. RECOVERY
1. Unit operating at 15 percent excess air at economizer
outlet.
2. Particulate matter of 8 grains per SDCF leaving the
economizer.
3. Efficiency of 50 percent on particulate removal in
the direct contact evaporators.
4. Steam shatter jets utilized on smelt spouts.
5. Design efficiency of 95 percent for precipitator with
an annual average operating efficiency of 88 percent.
3-15
-------
KRAFT DIAGRAM NO. 1
(Continued)
ASSUMPTIONS - Continued
C. CAUSTICIZING
1. Lime kiln SO emission has been assumed at 0.1 pound
per air dry ton of pulp.
2. Lime kiln scrubber efficiency assumed to be 80 per-
cent on lime and 60 percent efficiency on soda.
D. POWER PLANT
1. Excess air: 30 percent for bark/ 10 percent for
oil and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjection from dust collector: 50 percent for
bark and 0 percent for coal.
4. Design efficiencies for dust collector: 80 percent
on bark and 90 percent on coal with annual operating
efficiencies of 78 percent and 88 percent, respectively.
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust
collector is 40 percent.
7. Coal firing based on pulverized coal or spreader stoker.
3-16
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
OJ
1
[11,730]
20, 700 'LBS.
£ £3
'3-' 5R
oo ^ W
^30 <&
i LHJ. .A
m ^"J
00 g^ j
£S £g " ^§
i i o> i— i m O
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DEAERATING
HEATER
l_u
0
^3 OS
?i?r
c5 g-l
M..J, TO DESUPERHEATERS
70 LBS.
[60]
SE STOCK, NC 3X OA' ION, NO BLEACHING,
PORATOnS, LIME KILN MODERATE
NCY.
s
i
^
r 700 KW-HR
b- H400]
N. CO
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CO V^/ Xl
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u- ' i — im
O _l
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80 PSIG
[
[0]
7670 LBS.
0 [2560]
£ 2560 LBS.
d g CHOI
110 LBS.
o
O3 CO
s? 1
iO KI
' ' — tn'
- . ~ o3
4 * " " y °
°J ^ [20] S^
fTl S^ 30 LBS.
165 PSIG 1 """[ '
^ ">
(II
"o
POWER PLANT AUX. ^
2800]
?800LBS
* U lOLo 1 LI
-------
KRAFT DIAGRAM NO. 2
TYPICAL LOCATION
Western United States.
TYPICAL AGE OF EQUIPMENT
Under five years.
GENERAL
Flow Diagram No. 2 contains a fluidized bed calcining system.
This flow diagram is based on production of bleached soft-
wood kraft pulp and depicts a new mill designed with emphasis
on odor abatement and reduced particulate emission. It
includes treatment of the noncondesible gases from digester
and multiple-effect evaporators with bleach plant chlorination
effluent. Flow Diagram No. 2 represents a new mill designed
for a production of 150 to 500 tons per day. • There are perhaps
two or three mills in the U. S. that are illustrated by this
flow diagram.
EMISSIONS
The following emissions have been selected as representative,
based on the range of emissions presented in Chapter 4.
POUNDS PER AIR DRY TON OF UNBLEACHED PULP
Location
Washers and Screens
BLO Tower
M. E. Evaporators
R. Boiler and D. C.
Evaporators
After Precipitator
After Scrubber
Smelt Dissolving Tank
0
0
0
1
1
1
0
2s
.08
.02
.02
.50
.50
.51
.02
RSH,
RSR,
RSSR
0.45
0.30
0.18
Trace
Trace
0.3*
0.02
so2
0
0
0
5.4
5.4
5.4
0
Par-
ticulate
0
0
0
116
3.48
1.0
1.0
3-18
-------
KRAFT DIAGRAM NO. 2
(Continued)
EMISSIONS - Continued
RSH,
RSR, Par-
H S RSSR SO,, ticulate
Location 2 2
slaker 000 unknown
Fluidized Bed Calciner unknown unknown unknown 72.0
Fluidized Bed Calciner
Scrubber unknown unknown unknown 0.7
Turpentine Condenser 0.01 0.43 0 0
*Note: This is a result of introducing the weak liquor oxidation
system off-gases into the inlet of the scrubber.
ASSUMPTIONS
The following assumptions have been made in developing the
flow diagram:
A. PULP MILL
1. Pulp Yield = 45 Percent,
2. Cooking liquor charge per air dry ton of brown stock
equals 6,996 pounds of which 996 pounds are chemical
solids. Sulfidity equals 25 percent.
3. It is assumed that there is no production of turpentine
and soap.
4. Weak liquor oxidation system ahead of the multiple-
effect evaporators. Oxidation efficiency assumed
at 99 plus percent.
B. BLEACH PLANT
1. It was assumed as a six stage bleach plant with a
chlorine emission to atmosphere of one pound per
air dry ton of pulp.
3-19
-------
C. RECOVERY
1. Unit operating at 15 percent excess air at econo-
mizer outlet.
2. Particulate matter of 8 grains per SDCP leaving
the economizer.
3. Efficiency of 50 percent on particulate removal in
the direct contact evaporators.
4. Steam shatter jets utilized on smelt spouts.
5. Design efficiency of 98 percent for precipitator with
an annual average operating efficiency of 97 percent.
6. Efficiency of 70 percent on particulate removal in the
scrubber.
D. CAU5TICIZING
1. Particulate emissions from cyclones assumed at 6 tons
per day for 165 ADT/Day unbleached pulp.
2. Scrubber efficiency assumed at 99 percent on lime.
E. POWER PLANT
1. Excess air: 30 percent for bark, 10 percent for oil
and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjection from dust collector: 50 percent for bark
and 0 percent for coal.
4. Design efficiencies for dust collector: 82 percent
on bark and 92 percent on coal with annual operating
efficiencies of 80 percen and 90 percent, respectively,
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust col-
ector is 40 percent.
7. Coal firing based on pulverized coal.
3-20
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
r-i 00
O -J
O o
CO
0$
cog
CO
00
t\>
112.470}
7,950 LBb.
USD PSIG
aoo
oj, o
O CD
i—I O
,_, g
o o
1—1
REC.
BOILER
<* >
-
COAL/OIL | BARK
COMBINATION BOILER
oc
LU
LU !
CO
o
UJ
O -J
[480]
680 IBS.
[480]
680 LBS.
05
-1
O -
rO .
DEAERATING
HEATER
[550]
850 KW-HR
eo PSIG
165 PSIG
CD O
in oo
V ~—
[600]
970 LBS.
03
So
•—'(M
POWER PLANT AUX.
[3OOO]
3000 LBS.
[MOO]
1100 LBS.
[I860]
I860 LBS.
[600]
600 LBS.
[0]
5000 LBS.
[2640]
2640 LBS.
BLEACH PLANT
-**-
DIGESTERS
WASHING
PULP DRYER
EVAPORATORS
[240]
240 LBS.
CAUSTICIZING
So
NOTES:
-**- AMPLE HOT WATER
ASSUMED TO BE AVAILABLE.
[ ] INDICATES FLOWS FOR
PULP MILL ONLY.
ALL FLOW RATES AND
KILOWATTS ARE PER TON
OF A.D. PULP.
TO DESUPERHEATERS
1160 LBS.
[800]
CONTINUOUS DlGESTERSjWEAK BLACK LIQUOR OXIDATION,
DIRECT CONTACT EVAPORATORS, BLEACHING, HIGH EFFICIENCY
LIME KILN COLLECTION.
POWER PLANT ENERGY BALANCE
KRAFT PROCESS NO. 2 *
EXHIBIT NO,
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH, EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE, FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE, S. C.
-------
KRAFT DIAGRAM NO. 3
TYPICAL LOCATION
Western United States.
TYPICAL AGE OF EQUIPMENT
Ten to 15 years with upgraded emissions control equipment.
GENERAL
This flow diagram, based on production of unbleached softwood
kraft pulp, depicts a mill designed with emphasis on odor abate-
ment. It includes incineration in the lime kiln of the non-
condensible gases, from the batch digesters and multiple-effect
evaporators. There are perhaps 4 to 6 mills in the U. S. which
are illustrated by this flow diagram.
EMISSIONS
The following emissions have been selected as representative,
based on the range of emissions presented in Chapter 4.
POUNDS PER AIR DRY TON OF UNBLEACHED PULP
Location
Accumulator
Washers and
BLO Tower
M E- Evaporators
R. Boiler and D. C.
Evaporator
After Precipitator
RSH,
RSR,
H S RSSR
0.10 3.35
:reens 0.02 0.20
0.02 0.25
:ors 0.01 0.4
D. C.
.or 5,0 Trace
.ator 5.0 Trace
so2
0
0
0
0
4.6
4.6
Par-
ti culate
0
0
0
0
106
8.50
3-22
-------
KRAFT DIAGRAM NO. 3
EMISSIONS - Continued
Location
After Scrubber
Smelt Dissolving
Tank
Slaker
Lime Kiln
Lime Kiln Scrubber
Turpentine Con-
denser
(Continued)
H2S
5.0
0.02
0
1.00
0.2
RSH,
RSR,
RSSR
Trace
0.02
0
0.6
0.30
so2
4.6
0
0
Trace
Trace
Par-
ti culate
1.7
1.0
Unknown
51
0.5
0.01
0.40
ASSUMPTIONS
The following assumptions have been made in developing the
flow diagram:
A. PULP MILL
1. Pulp Yield = 47 Percent
2. Cooking liquor charge per air dry ton of brown stock
equals 6,335 pounds of which 900 pounds are chemical
solids. Sulfidity equals 25 percent.
3. It was assumed that there is no soap skimming system
since only small quantities of soap are produced.
4. Weak liquor oxidation system ahead of the black liquor
evaporators. Oxidation efficiency was assumed at 90
percent.
3-23
-------
KRAFT DIAGRAM NO. 3
(Continued)
B. RECOVERY
1. Unit operating at 15 percent excess air at econo-
mizer outlet.
2. Particulate matter of 8 grains per SDCF leaving the
economizer,
3. Efficiency of 50 percent on particulate removal in
the direct contact evaporators.
4. Steam shatter jets utilized on smelt spouts.
5. Design efficiency of 95 percent for precipitator with
an annual average operating efficiency of 92 percent.
6. Efficiency of 80 percent on particulate removal in
the scrubber.
C. CAUSTICIZING
1. Lime kiln scrubber efficiency assumed at 99 percent
on lime and 80 percent efficiency on soda.
D. POWER PLANT
1. Excess air: 30 percent for bark, 10 percent for
oil and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjection from dust collector: 50 percent for
bark and 0 percent for coal.
4. Design efficiencies for dust collector: 82 percent
on bark and 96 percent on coal with annual operating
efficiencies of 80 percent and 95 percent, respec-
tively.
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust collector
is 40 percent.
7. Coal firing based on pulverized coal.
3-24
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
O4
I
r\)
01
[12,030]
21,000 U3b,
650°F
COAL/OIL! BARK
COMBINATION BOILER
REC.
BOILER
DEAERATING
HEATER
POWER PLANT AUX
DIGESTERS
WASHING
PAPER MACHINES
* EVAPORATORS
CAUSTIC I ZING
NOTES:
[ ] INDICATES FLOWS FOR
PULP MILL ONLY.
ALL FLOW RATES AND
KILOWATTS ARE PER
TOM OF A.D. PULP.
i-.fif'.^, nASr. STOCK, At A^ LiCUOR OXIDATION, NO BLEACHING
ONTACT EVAPORATORS, -ion LL'.'K KILN COLLECTION EFFICIENCY.
POWER PLANT ENERGY BALANCE
KRAFT PROCESS NO. 3 *
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH. EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE. FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE. S. C.
-------
KRAFT DIAGRAM NO. 4
TYPICAL LOCATION
Southern United States.
TYPICAL AGE OF EQUIPMENT
Under five years.
GENERAL
This flow diagram is based on production of kraft softwood paper
stock. It depicts a new mill designed to provide some odor
abatement, consisting of a concentrated liquor oxidation system,
a scrubber in the noncondensible gases from the black" liquor •
evaporators and a mesh pad in the dissolving tank vent. A
comparison of emissions from the lime kiln is shown when using
clean water make-up in the causticizing plant versus the use
of evaporator combined condensate. There are perhaps 10 to 20
mills in the U. S. that are illustrated by this flow diagram.
EMISSIONS
The following emissions have been selected as representative,
based on the range of emissions presented in Chapter 4.
POUNDS PER AIR DRY TON OF UNBLEACHED PULP
LOCATION
Washers and Screens
M. E. Evaporators
BLO Tower
R. Boiler and D. C.
Evaporators
After Precipitators
Smelt Dissolving Tank
Slaker
RSH,
RSR,
H S RSSR SO
;ns 0.02 0.24 0
; 0.40 0.41 0
0.02 0.31 0
C.
1.5 0.12 4.4
>rs 1.5 0.12 4.4
Tank 0.02 0.02 0
00 0
Par-
ti culate
0
0
0
106
3.18
1.0
Unknown
3-26
-------
KRAFT DIAGRAM NO. 4
(Continued)
EMISSIONS - Continued
POUNDS PER AIR DRY TON OF UNBLEACHED PULP
LOCATION
Lime KiIn
Lime Kiln Scrubber
Turpentine Condenser
ASSUMPTIONS
H2S
1.0
r 0.2
ser 0.01
RSH,
RSR,
RSSR
0.5
0.10
0.50
Par-
SO ticulate
Trace 25
Trace 0.2
0 0
The following assumptions have been made in developing the
flow diagram:
A. PULP MILL
1. Pulp Yield = 47 Percent.
2. Cooking liquor charge per air dry ton of brown stock
equals 6,189 pounds of which 889 pounds are chemical
solids. Sulfidity equals 26 percent.
3. Assumed concentrated black liquor oxidation at approximately
99 percent efficiency.
B. RECOVERY
1. Unit operating at 15 percent excess air at econo-
mizer outlet.
2. Particulate matter of 8 grains per SDCF leaving the
economizer.
3. Efficiency of 50 percent on particulate removal in
the direct contact evaporators.
4. Steam shatter jets utilized on smelt spouts.
5. Design efficiency of 99 percent for precipitator with
an annual average operating efficiency of 97 percent.
3-27
-------
C. CAUSTICIZING
1. Lime kiln scrubber efficiency assumed at 99 percent
on lime and 80 percent efficiency on soda.
D. POWER PLANT
1. Excess air: 30 percent for bark, 10 percent for
oil and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjection from dust collector: 50 percent for
bark and 0 percent for coal.
4. Design efficiencies for dust collector: 92 percent
on bark and 95 percent on coal with annual operating
efficiencies of 90 percent and 93 percent, respectively.
5. Bark is burned 24 hours per day at a controlled
rate.
6. Unburned combustible in refuse leaving the dust
collector is 40 percent.
7. Coal firing based on pulverized coal.
3-28
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
o -'
2
OC
h-LU
0$:
00
CO-J
CD
CM
I
no
CD
[9280]
18,820 LBS
650 PSIG 900 °F
[550]
850 KW-HR
23
COMBINATION BOILER
'—I l/>
O CD
1 -1
1 O
T *
•—'
-------
KRAFT DIAGRAM NO. 5
TYPICAL LOCATION
Southern United States.
TYPICAL AGE OF EQUIPMENT
Over 15 years.
GENERAL
This flow diagram is based on production of top liner stock
and should be used with Flow Diagram No. 1, base stock, to
determine air emissions from a linerboard mill. Flow Diagram
No. 5 depicts a relatively old mill, using batch digesters,
and with no provisions for odor abatement. There are perhaps
30 to 40 mills in the U. S. which are illustrated by this flow
diagram.
EMISSIONS
The following emissions have been selected as representative,
based on the range of emissions presented in Chapter 4.
3-30
-------
EMISSIONS -
KRAFT DIAGRAM NO. 5
(Continued)
Continued
POUNDS PER AIR DRY TON OF UNBLEACHED PULP
LOCATION
Accumulator
Washers and Screens
M. E. Evaporators
R. Boilers and D. C.
Evaporators 14.6
After Precipitators 14.6
Smelt Dissolving Tank 0.04
Slaker 0
Line Kiln 1.0
Line Kiln Scrubber 0.40
Turpentine Condenser 0.01
H S
2
0.12
eens 0.02
rs 0.50
RSH,
RSR,
RSSR
3.35
0.17
0.31
so.,
2
0
0
0
P ar-
ticulate
0
0
0
1.50 4.8 91.8
1.50 4.8 11.0
0.05 0 4.0
0 0 Unknown
0.6 0.1 51
0.23 Trace 10.0
0.50 0 0
ASSUMPTIONS
The following assumptions have been made in developing the
flow diagram:
A. PULP MILL
1. Pulp Yield = 47 Percent.
2. Cooking liquor charge per air dry ton of brown stock
equals 6,335 pounds of which 900 pounds are chemical
solids. Sulfidity equals 25 percent.
3. Black liquor solids from first stage washer equals 15
percent and from evaporators equals 50 percent solids,
3-31
-------
KRAFT DIAGRAM NO. 5
(Continued)
ASSUMPTIONS - Continued
B. RECOVERY
1. Unit operating at 15 percent excess air at econo-
mizer outlet.
2. Particulate matter of 8 grains per SDCF leaving
the economizer.
3. Efficiency of 50 percent on particulate removal in
the direct contact evaporators.
4. Steam shatter jets utilized on smelt spouts.
5. Design efficiency of 95 percent for precipitator
with an annual average operating efficiency of 88
percent.
C. CAUSTICIZING
1. Lime kiln SO emission has been assumed at 0.1
pounds per air dry ton of pulp.
2. Lime kiln scrubber efficiency assumed at 80 percent
on lime and 60 percent efficiency on soda.
D. POWER PLANT
1. Excess air: 30 percent for bark, 10 percent for
oil and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjection from dust collector: 50 percent for
bark and 0 percent for coal.
4. Design efficiencies for dust collector: 80 percent
on bark and 90 percent on coal with annual operating
efficiencies of 78 percent and 88 percent, respec-
tively .
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in the refuse leaving the dust
collector is 40 percent.
7. Coal firing based on pulverized coal.
3-32
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
OJ
OJ
OJ
[12,170]
21,110 LBS
650 PSIG 640 °F
COAL/OIL! BARK
— — — — — _t_
COMBINATION BOILER
DEAERATING
HEATER
DIGESTERS
WASHING
PAPER MACHINES
EVAPORATORS
CAUSTICIZING
NOTES:
[ ] INDICATES FLOWS FOR
PULP MILL ONLY.
ALL FLOW RATES AND
KILOWATTS ARE PER TON
OF A.D. PULP
70 LBS.
[70]
TOP L \EROR PAPER STOCK, BA^CH I? IGESTE RS, \J0 OXIDATION, DIRECT
CONTACT EVAPORATOR RECOVERY, \C BLEACHING, AND UME KILN
MODERATE COLLECTION EFFICIENCY.
POWER PLANT ENERGY BALANCE
KRAFT PROCESS N0.5*
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH. EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
J. E. SIRRINE COMPANY, ENGINEERS
GAINESVILLE. FLORIDA
GREENVILLE, S. C.
-------
KRAFT DIAGRAM NO. 6
TYPICAL LOCATION
Southern United States.
TYPICAL AGE OF EQUIPMENT
Five to ten years.
GENERAL
This flow diagram is based on cooking in an early design
continuous type .digester with no washing. A bleach plant is
included. The flow diagram depicts a mill with minor provisions
for odor abatement. There are perhaps 10 to 20 mills in the
U. S. that are illustrated by this flow diagram.
EMISSIONS
The following emissions have been selected as representative,
based on the range of emissions presented in Chapter 4.
POUNDS PER AIR DRY TON OF UNBLEACHED PULP
LOCATION
Washers and Screens
M. E. Evaporators
R. Boiler and D. C.
Evaporator
After Precipitators
Smelt Dissol-
Slaker
Lime Kiln
Lime Kiln Scrubber
Turpentine Condenser
RSH,
RSR,
H S RSSR
eens 0.02 0.23
rs 0.50 0.28
. C.
17.5 1.95
tors 17.5 1.95
g Tank 0.02 0.02
0 0
1.0 0.5
ber 0.40 0.20
enser 0.01 0.30
so2
0
0
5.0
5.0
0
0
Trace
Trace
0
Par-
ticulate
0
0
118
5.90
1.0
Unknown
31.5
6.3
0
3-34
-------
KRAFT DIAGRAM NO. 6
(Continued)
ASSUMPTIONS
The following assumptions have been made in developing the
flow diagram:
A. PULP MILL
1. Pulp Yield = 45 Percent.
2. Cooking liquor charge per air dry ton of brown stock
equals 8,106 pounds of which 1/150 pounds are chemi-
cal solids. Sulfidity equals 27 percent.
3. Black liquor solids from first stage washer equals
16 percent and from evaporators equals 50 percent
solids.
B. BLEACH PLANT
1. Assumed a five stage Bleach Plant with a chlorine
emission of one pound per air dry ton of pulp.
C. RECOVERY
1. Unit operating at 15 percent excess air at econo-
mizer outlet.
2. Parciculate matter of 8 grains per SDCF leaving the
economizer.
3. Efficiency of 50 percent on particulate removal in
the direct contact evaporators.
4. Steam shatter jets utilized on smelt spouts.
5, Design efficiency of 98 percent for precipitator
with an annual average operating efficiency of 95
percent.
D. CAUSTICIZING
1. Lime kiln scrubber efficiency assumed at 80 percent
or. lime and 60 percent efficiency on soda.
3-35
-------
E. POWER PLANT
1. Excess air: 30 percent for bark, 10 percent for oil
and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjection from dust collector: 50 percent for
bark and 0 percent for coal.
4. Design efficiencies for dust collector: 92 percent
on bark and 95 percent on coal with annual operating
efficiencies of 90 percent and 93 percent, respec-
tively.
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust
collector is 40 percent.
7. Coal firing based on pulverized coal.
3-36
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
O4
I
OJ
-si
[15,150]
24,860 LBS.
850 PSI6
900 °F
COAL/OIL! BARK
COMBINATION BOILER
•** AMPLE HOT WATER
ASSUMED TO BE AVAILABLE.
[ ] INDICATES FLOWS FOR
PULP MILL ONLY.
ALL FLOW RATES AND
KILOWATTS ARE PER TON
OF A.D. PULP.'
i 500 LBS.
[720]
: :CCr , NO C\ IDA- ;CN , DIRECT
, VCDERATE LIME KILN
.ECTION EFFICIENCY
POWER PLANT ENERGY BALANCE
KRAFT PROCESS NO. 6 *
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH. EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE. FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE. S. C.
-------
KRAFT DIAGRAM NO. 7
TYPICAL LOCATION
Northeastern United States.
TYPICAL AGE OF EQUIPMENT
Ten to 15 years.
GENERAL
This flow diagram is based on production of bleached stock with
cooking done in batch digesters. This flow diagram depicts the use
of a Venturi scrubber rather than the commonly used electrostatic
precipitator. A mesh pad has been assumed in the vent from the
smelt dissolving tank. There are perhaps 15 to 25 mills in the
U. S. that are illustrated by this flow diagram.
EMISSIONS
The following emissions have been selected as representative,
based on the range of emissions presented in Chapter 4.
POUNDS PER AIR DRY TON OF UNBLEACHED PULP
LOCATION
Accumulator
Washers and Screens
M. E. Evaporators
Recovery Boiler
After Venturi
Scrubber
Smelt Dissolving
Tank
Slaker
Lime Kiln
Lime Kiln After
Scrubber
Turpentine Condenser
H2S
0.12
0.01
0.50
RSH,
RSR,
RSSR
2.97
0.22
0.41
Par-
S0_ ticulate
0 0
0 0
0 0
8.0
0.4
1.4
0.02 0.02
0 0
1.0 0.6
0.23
0.01 0.50
3-38
2.3
Trace
0
47.6
0 1.00
0 Unknown
Trace 55
11.0
0
-------
KRAFT DIAGRAM NO. 7
(Continued)
ASSUMPTIONS
The following assumptions have been made in developing the
flow diagram:
A. PULP MILL
1. Pulp Yield = 45 Percent.
2. Cooking liquor charge per air dry ton of brown stock
equals 6,996 pounds of which 996 pounds are chemi-
cal soids. Sulfidity equals 25 percent.
3. Black liquor solids from first stage washer equals
15.5 percent and from M. E. Evaporators equals
50 percent solids.
B. BLEACH PLANT
1. Assumed a five stage bleach plant with a chlorine
emission of one pound per air dry ton of pulp.
C. RECOVERY
1. Unit operating at 15 percent excess air at econo-
mizer outlet.
2. Particulate matter of 8 grains per SDCF leaving
the economizer.
3. Steam shatter jets utilized on smelt spouts.
4. Design efficiency of 90 percent for Venturi scrubber
with an annual average operating efficiency of 80
percent.
5. Efficiency of 80 percent on particulate removal in
the scrubber.
D. CAUSTICIZING
1. Lime Kiln scrubber efficiency assumed at 80 percent
on lime and 60 percent efficiency on soda.
3-39
-------
KRAFT DIAGRAM NO. 7
(Continued)
E. POWER PLANT
1. Excess air: 30 percent for bark, 10 percent for
oil and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjection from dust collector: 50 percent for
bark and 0 percent for coal.
4. Design efficiencies for dust collector: 80 percent
on bark and 90 percent on coal with annual operating
efficiencies of 78 percent and 88 percent, respec-
tively.
5. Bark is burned 24 hours per day at a controlled
rate.
6. Unburned combustible in refuse leaving the dust
collector is 40 percent.
7. Coal firing based on pulverized coal.
3-40
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
§8
ID
o-
O;
C0(
CO
OJ
[19,230]
28,920 LBS.
650 PSIG
640 °F
COMBINATION BOILER
O UJ
o
I860 LBS.
c/i
^ O
-i!o
!
[8160]
MAKE-UP 9060LBS.
in
r— i_l
i i in
z
o
> i
i/i
§Q
I J CO
' 1
DEAERATING
HEATER
O
0
[750]
I050KW-HR
80 PSIG
I60PSIG
ID ID
'-'In
40 LBS.
[20]
POWER PLANTAUX.
[2900]
2900 IBS.
[3500]
3500 L6S.
[3100]
3100 UBS.
[110]
110 LBS.
BLEACH PLANT
DIGESTERS
[500]
500 LBS.
[0]
9000 LBS.
WASHING
PAPER MACHINES
EVAPORATORS
CA'JSTICIZING
NOTES:
-**• AMPLE HOT WATER ASSUMED
TO BE AVAILABLE.
L ] INDICATES FLOWS FOR
PULP MILL ONLY.
ALL FLOW RATES AND KILOWATTS
ARE PER TON OF A.O. PULP.
!§
TO DESUPERHEATERS
80 LBS.
[70]
BATCH DlC-ESTERS, NO BLACK LIQUOR OXIDATION, VENTURl RECOVERY. SOFTWOOD
BLEACHING, LIME KILN MODERATE COLLECTION EFFICIENCY.
POWER PLANT ENERGY BALANCE
KRAFT ^ROCESS NO. 7 *
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH. EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE. FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE. S. C.
-------
KRAFT DIAGRAM NO. 8
TYPICAL LOCATION
Midwestern United States.
TYPICAL AGE OF EQUIPMENT
Under five years.
GENERAL
This flow diagram is based on production of bleached hard-
wood pulp in a continuous digester. It depicts a relatively
new mill with a system for the treatment of noncondensible
gases from the digester, multiple effect evaporators and
the combined condensate from the multiple effect evaporators.
There are perhaps 1 to 4 mills in the U. S. which are illustrated
by this flow diagram.
EMISSIONS
The following emissions have been selected as representative,
based on the range of emissionspresented in Chapter 4.
POUNDS PER AIR DRY TON OF UNBLEACHED PULP
LOCATION H S
Washers and Screens 0.02
M. E. Evaporators 0.50
R. Boilers and D. C.
Evaporators 17 . 6
After Precipitator 17.6
Smelt Dissolving Tank 0.04
Slaker 0
Lime Kiln 1.0
After Lime Kiln
Scrubber 0.2
Flashsteam condenser 0.01
RSH
RSR,
RSSR
0.44
0.82
0.36
0.36
0.06
0
0.58
0.11
1.50
3-42
Par-
SO ticulate
2
0 0
0 0
7.10 120
7.1 6.00
0 4.0
0 Unknown
Trace 57
Trace 0.50
0 0
-------
ASSUMPTIONS
The following assumptions have been made in developing the
flow diagram:
A. PULP MILL
1. Pulp Yield = 46 Percent.
2. Cooking liquor charge per air dry ton of brown stock
equals 6,935 pounds of which 972 pounds are chemical
solids. Sulfidity equals 24 percent.
B. BLEACH PLANT
1. Assumed a five stage bleach plant with a chlorine
emission of one pound per air dry ton of pulp.
C. RECOVERY
1. Unit operating at 15 percent excess air at economizer
outlet.
2. Particulate matter of 8 grains per SDCF leaving the
economizer.
3. Efficiency of 50 percent on particulate removal in the
direct contact evaporators.
4. Steam shatter jets utilized on smelt spouts.
5. Design efficiency of 97 percent for precipitator with
an annual average operating efficiency of 95 percent.
D. CAUSTICIZING
1. The lime kiln scrubber has been assumed at a high
Collection efficiency/ 99 percent on lime and 80 percent on
soda.
E. POWER PLANT
1. Excess air: 30 percent for bark, 10 percent for oil
and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjection from dust collector: 50 percent for bark
and 0 percent for coal.
3-43
-------
KRAFT DIAGRAM NO. 8
(Continued)
E. POWER PLANT - Continued
4. Design efficiencies for dust collector: 92 percent
on bark and 95 percent on coal with annual operating
efficiencies of 90 percent and 93 percent, respectively.
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust collector
is 40 percent.
7. Coal firing based on pulverized coal.
3-44
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
Dspso]
23,950 LBS.
850 PSIG
900 °F
GJ
en
COAL/OIL i BARK
COMBINATION BOILER.
DEAERATING
HEATER
NOTE
-**- AMPLE HOT WATER
ASSUMED TO BE AVAILABLE.
[ ] INDICATES FLOWS FOR
PULP WILL ONLY.
ALL FLOW RATES AND
KILOWATTS ARE PER TON
OF A.D. PULP.
1480 LBS.
[8OOJ
X CONTINUOUS DIGESTERS,HARDWOOD, MO LIQUOR OXIDATION, DIRECT
CONTACT EVAPORATOR RECOVERY, FJLFACHING, AND LIME KILN HIGH
COLLECTION EFFICIENCY.
POWER PLANT ENERGY BALANCE
KRAFT PROCESS NO. 8 *
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH. EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE. FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE. S. C.
-------
KRAFT DIAGRAM NO. 9
TYPICAL LOCATION
Midwestern United States.
TYPICAL AGE OF EQUIPMENT
Under ten years.
GENERAL
This flow diagram uses equipment similar to Plow Diagram No. 8
which produces hardwood pulp, whereas No. 9 produces softwood
pulp. We have used similar flow diagrams, except for wood
species, to show the increase of emissions when cooking hardwood.
There are perhaps 30 to 40 mills in the U. S. that are illustrated
by this flow diagram.
EMISSIONS
The following emissions have been selected as representative,
based on the range of emissions presented in Chapter 4.
POUNDS PER AIR DRY TON OF UNBLEACHED PULP
LOCATION
Washers
M. E. Evaporators
R. Boiler and D. C.
Evaporator
After Precipitator
Smelt tank
Slaker
Lime Kiln
Lime Kiln After
Scrubber
Turpentine
Condenser
V
0.02
0.50
17.1
17.1
0.02
0
1.0
RSH,
RSR,
RSSR
0.22
0.39
0.24
0.24
0.02
0
0.6
Par-
SO ticulate
0 0
0 0
7.90 114
7.90 5
0 1
.70
.0
0 Unknown
Trace 55
0.2
0.01
0.11
0.35
Trace
0.50
3-46
-------
KRAFT DIAGRAM NO. 9
(Continued)
ASSUMPTIONS
The following assumptions have been made in developing the
flow diagram:
A. PULP MILL
1. Pulp Yield = 45 Percent.
2. Cooking liquor charge per air dry ton of brown stock
equals 6,996 pounds of which 996 pounds are chemical
solids. Sulfidity equals 25 percent.
B. BLEACH PLANT
Similar to Flow Diagram No. 8.
C. RECOVERY
; 1. Unit operating at 15 percent excess air at economizer
outlet.
2. Particulate matter of 8 grains per SDCF leaving the
economizer.
3. Efficiency of 50 percent on particulate removal in the
direct contact evaporators.
4. Steam shatter jets utilized on smelt spouts.
5. Design efficiency of 97 percent for precipitator with
an annual average operating efficiency of 95 percent.
D. CAU5TICI2ING
Similar to Flow Diagram No. 8
E. POWER PLANT
1. Excess air: 30 percent for bark, 10 percent for oil,
and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3-47
-------
KRAFT DIAGRAM NO. 9
(Continued)
3. Reinjaction from dust collector: 50 percent for bark
and 0 percent for coal.
4. Design efficiencies for dust collector: 92 percent on
bark and 95 percent on coal with annual operating
efficiencies of 90 percent and 93 percent, respectively.
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust collector
is 40 percent.
7. Coal firing based on pulverized coal.
3-48
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
CI5,3ICQ
24,250 I BS.
I
.£.
CD
65 G HSIG
9OO °F
COAL/01 LI BARK
COMBINATION BOILER
DEAERATING
HEATER
-**• AMPLE HOT WATER ASSUMED
TO BE AVAILABLE.
C ] INDICATES FLOWS FOR
PULP MILL ONLY,
ALL FLOW RATES AND
KILOWATTS ARE PER TON
OF A.D, PULP,
1510 LBS.
[830]
-X- CONTINUOUS DIGESTERS, SOFTWOOD, NO LIQUOR OXIPAT ION, DIRECT
CONTACT EVAPORATOR RECOVERY, BLEACHING, AND LIME KILN HIGH
COLLECTION EFFICIENCY.
POWER PLANT ENERGY BALANCE
KRAFT PROCESS NO. 9 *
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH, EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE, FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE. S. C.
-------
KRAFT DIAGRAM NO. 10
TYPICAL LOCATION
Southern United States
TYPICAL AGE OF EQUIPMENT
1969 design; 1972 start up
GENERAL
This flow diagram is based on production of unbleached
softwood kraft pulp and depicts a new mill designed with
emphasis on odor abatement and reduced particulate emission.
It includes the installation of high solids multiple effect
evaporators, resulting in the elimination of the direct
contact evaporator.
Kraft Flow Diagram No. 10 represents a new mill designed
for a production of 500 to 1000 tons per day.
EMISSIONS
Because there are no mills in the United States operating
at present without a direct contact evaporator, Flow Diagram
No. 10 illustrates an imaginary mill. Therefore, emissions
from the recovery system have been assumed.
POUNDS PER AIR DRY TON OF UNBLEACHED PULP
LOCATION
Washers and Screens
Recovery Boiler
After Precipitator
Smelt Dissolving Tank
RSH
RSR
H S RSSR SO
ins 0.02 0.24 0
>rators 0.50 0.31 0
0,10 Trace 5-0
ir 0.10 Trace 5-0
Tank Trace Trace 0
P ar-
ticulate
0
0
210
2.10
0.20
3-50
-------
H2S
0
Trace
Trace
0.01
RSH
RSR
RSSR
0
Trace
Trace
0.50
so2
0
Trace
Trace
0
Par-
ticulate
Unknown
25.0
0.20
0
EMISSIONS - Continued
IDCATION
Slaker
Lime Kiln
Lime Kiln Scrubber
Turpentine Condenser
ASSUMPTIONS
The following assumptions have been made in developing the
Flow Diagram:
A. PULP MILL
1. Pulp Yield = 47 Percent
2. Cooking liquor charge per air dry ton of brown stock
equals 6,189 pounds of which 889 pounds are chemical
solids. Sulfidity equals 26 percent.
B. RECOVERY
1. Unit operating at 15 percent excess air at economizer
outlet.
2. Particulate matter of 8 grains per SDCF leaving the
economizer.
3. No direct contact evaporators.
4. Steam shatter jets utilized on smelt spouts.
5. Design efficiency of 99.5 percent for precipitator with
an annual average operating efficiency of 99.0 percent.
3-51
-------
C. CAUSTICIZING
1. Lime kiln scrubber efficiency assumed at 99 percent
on lime and 80 percent efficiency on soda.
D. POWER PLANT
1. Excess air: 30 percent for bark, 10 percent for oil,
and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjection from dust collector: 50 percent for bark
and 0 percent for coal.
4. Design efficiencies for dust collector: 96 percent on
bark and 98 percent on coal with annual operating
efficiencies of 94 percent and 96 percent, respectively.
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust col-
lector is 40 percent.
7. Coal firing based on pulverized coal.
3-52
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
[11,170]
I943O LBS
CM
i
850 PSIG 900 °F
COAL/OIL I BARK
COMBINATION BOILER
[ ] INDICATES FLOWS FOR
PULP MILL ONLY.
ALL FLOWS AND KILOWATTS
ARE PER TON OF AD. PULP.
K70 LBS.
[610]
CONTINUOUS DIGESTERS, CONCENTRATED BLACK LIQUOR OXIDATION
DIRECT CONTACT EVAPORATOR, NO BLEACHING, HIGH EFFICIENCY
LIME KILN COLLECTION
POWER PU\NT ENERGY BALANCE
KRAFT PROCESS NO. 10*
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH, EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE. FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE, S. C.
-------
3,3 NEQTRAL SULFITE SEMICHEMICAL
3.3.1 GENERAL DESCRIPTION OF NSSC
Neutal sulfite semichemical pulping is basically a two-stage
process. It involves
1, A mild chemical treatment of the wood chips in the presence
of a neutral chemical solution within a digester and
followed by
2. A mechanical treatment, called defibering/ to disintegrate
the wood chips into pulp.
It derives its name "neutral sulfite" from the fact that the
solution containing the cooking chemicals, consisting of sodium
sulfite and sodium carbonate, is maintained above a pH of 7.0.
The name "semichemical" is given because all of the cementing
material is not completely removed by the chemical reaction and
some mechanical disintegration is required to separate the fibers.
Because some of the cementing material remains with the fibers it
follows that the "yield" for this process is higher than for a
conventional full-chemical pulping process. Semichemical pulping
may produce yields of 60 to 80 percent.
The cooking process is carried out in either batch or continuous
digesters, Steam maintains the temperature and pressure of the
cook within certain limits depending on the end use of the pulp.
During this cooking stage odorous gases are created within the
digester. At the completion of the cooking cycle, residual pressure
within the digester is used to discharge the entire contents of
the batch digester into a blow tank. Waste gases, containing
the odorous compounds formed in the digester, are usually vented
to the atmosphere.
Before the pulp fibers can be used in the production of paper
products the spent liquor must be washed from the pulp. This
washing is usually performed on multi-stage drum filters. If
a kraft system is adjoining, the NSSC spent liquor can be mixed
with the spent kraft liquor, up to a limiting percentage, and
burned in the recovery furnace. The recovered chemicals are used
entirely in the kraft system. Emissions of both sulfur dioxide and
hydrogen sulfide may be increased from the kraft recovery furnace
when NSSC liquor is added.
Besides the two above spent liquor systems, one discharging the
spent liquor to sewer and the other mixing NSSC liquor with kraft
liquor, there is a fluidized bed recovery system. This is a patented
system in which the NSSC spent liquor is oxidized in a reactor producing
a pelleted product, consisting of sodium carbonate and sodium sulfate.
3.3.2 BASIC DESCRIPTION OF NSSC FLOW DIAGRAMS
The basic assumptions which were made in the development of each
NSSC flow diagram, the diagram itself, and the energy balance are
presented on the following pages.
3-54
-------
NSSC DIAGRAM NO. 1
TYPICAL LOCATION
Southern United States
TYPICAL AGE OF EQUIPMENT
Five to ten years.
GENERAL
This flow diagram is based on delivering the NSSC spent liquor
to an adjoining kraft recovery system. The emissions shown
are those contributed by the NSSC operation only. There are
perhaps 10 to 15 mills in the U. S. illustrated by this flow
diagram.
EMISSIONS
The addition of NSSC liquor to a kraft recovery system lowers
the pH of the kraft liquor. This may result in a greater release
of SO and H S from the multiple effect and direct contact evapo-
rators .
Valid data are not available to estimate the emissions from
the NSSC process steps.
ASSUMPTIONS
The following assumptions have been made in developing the
flow diagram:
A. RECOVERY
1. Unit operating at 15 percent excess air at economizer
outlet.
2. Particulate matter of 8 grains per SDCF leaving the
economizer.
3. Efficiency of 50 percent on particulate removal in
the direct contact evaporators.
4. Steam shatter jets utilized on smelt spouts.
5. Design efficiency of 98 percent for precipitator with
an annual average operating efficiency of 95 percent.
3-55
-------
NSSC DIAGRAM NO. 1
(Continued)
B. POWER PLANT
1. Excess air: 30 percent for bark; 10 percent for oil
and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjection from dus:t collector: 50 percent for bark
and 0 percent for coal.
4. Design efficiencies for dust collector: 92 percent on
bark and 95 percent on coal with annual operating
efficiencies of 90 percent and 93 percent, respectively.
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust collector
is 40 percent.
7. Coal firing based on pulverized coal.
3-56
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
to
00
I/) -J
CD
I
01
[858O]
I6,45O LBS.
850 PSiG
900 °F
•33
cJ O
UT
I!
REC
BOILER
r-i m
O _i
iS> O
1^1 10
r ' CD
O _l
COAL /OIL I BARK
COMBINATION BOILER
O O
K) CM
a:
Q
^
3
O
[490]
930 LBS.
OLBS.
[01
[1440]
2250 LBS.
[490]
930 LBS.
[500]
800 KW-HR
[ZI50]
2150 LBS.
[500]
500 LBS.
DIGESTERS
60 PSIG
160 PSIG
DEAERATING
HEATER
in /"
s
rO
^
i—i
O to
2*3
[140]
260LBS.
in o
OJ tf>
[0]
2000 LBS.
WASHING
I5T
6000 LBS
[1300]
1500 L^
PAPER MACHINES
EVAPORATORS
0
ifl O
i—P 10
NOTES:
[ J INDICATES PLOW RATES
FOR PULP MILL ONLY.
ALL FLOW RA1 £5 AND
KILOWATTS ARE PER TON
OK A.D. PULP.
POWER PLANT AUX.
o'-J
10 DESUPERHEATERS
1020 LbS.
[340]
-V COMoiNATiCN Or NEUTRAL SULFITE SEMI-CHEMICAL
PULPING AND KRAFT PULPING.
POWER PLANT ENERGY BALANCE
N.S.S.C. PROCESS NO. I *
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH, EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE. FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE, S. C.
-------
N5SC DIAGRAM NO. 2
TYPICAL LOCATION
Southern United States .
TYPICAL AGE OF EQUIPMENT
Over fifteen years.
GENERAL
This flow diagram is based on the use of neutral sodium sulfite,
without chemical recovery. Cooking is done in batch digesters.
There are perhaps 15 to 20 mills in the U. S. illustrated by
this flow diagram.
EMISSIONS
Valid data are not available to furnish information on emissions.
ASSUMPTIONS
The following assumptions have been made in developing the flow
diagram:
A. PULP MILL
1. Pulp Yield = 77 Percent.
B. POWER PLANT
1. Excess air: 30 percent for bark, 10 percent for oil
and 20 percent for coal.
2, Bark burning equipment is a low set spreader stoker.
3. Reinjection from dust collector: 50 percent for bark
and 0 percent for coal.
4c Design efficiencies for dust collector: 82 percent on
bark and 92 percent on coal with annual operating
efficiencies of 80 percent and 90 percent, respectively.
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust collector
is 40 percent.
7. Coal firing based on pulverized coal.
3-58
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
I5.26OLBS.
Q5O PSIG
90O °F
1/5
ng
o-'
inO
CM in
"-JiM
V
Ui
to
COMBINATION BOILER
[500]
800 KW-HR
coO
60 PSIG
160 PSIG
IS
DEAERATING
HEATER
r- —
L-J(fl'
[cO
150 LBS.
39
POWER PLANT AUX.
[2100]
2IOOLBS.
S3
2o
CO O
u-J —
ID
LO]
2000 LBS..
[0]
6000 LBS.^
DIGESTERS
PAPER MACHINES
oo
TO DESUPERHEATERS
900 LBS.
[200]
BATCH DIGESTERS WITHOUT BLACK
LIQUOR RECOVERY.
POWER PLANT ENERGY BALANCE
N.S.S.C. PROCESS NO. 2*
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH, EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE, FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE, S. C.
-------
NSSC DIAGRAM NO. 3
TYPICAL LOCATION
Midwestern United States.
TYPICAL AGE OF EQUIPMENT
Ten to fifteen years.
GENERAL
This flow diagram is based on the use of neutral sodium sulfite
with chemical recovery by the fluidized-bed process. Cooking
is done in batch digesters. There are perhaps 2 to 4 mills
in the U. S. which are illustrated by this flow diagram.
EMISSIONS
Valid data are not available to present information on
emissions except as shown on the flow diagram.
ASSUMPTIONS
The following assumptions have been made in developing the flow
diagram:
A. PULP MILL
1. Pulp Yield = 77 Percent.
B. POWER PLANT
1. Excess Air: 10 percent for oil and 20 percent for coal.
2. Reinjection from dust collector: 0 percent.
3. Design efficiencies for dust collector: 96 percent on
coal with annual operating efficiency of 95 percent.
4. Coal firing based on pulverized coal.
5. Roundwood is not debarked. Bark goes to the digester
with the wood.
3-60
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
850 PSIG
900
in -
CM o
cr
UJ
CD
OJ
I
CD
[500]
800KW-HR.
DEAE RATING
HEATER
33
[1800]
1800 LBS.
[180]
300 LBS.
[500]
,500 LBS.
[0]
|60
[aooo]
_
§8
'-'00
7?
8
DIGESTERS
WASHING
PAPER MACHINES
EVAPORATORS
)(*-
POWER PLANT AUX.
[ ] INDICATES FLOWS FOR
PULP MILL ONLY.
ALL FLOW RATES AND
KILOWATTS ARE PER TON
OF A.D. PULP.
POWER PLANT ENERGY BALANCE
N.S.S.C. PROCESS NO. 3 *
EXHIBIT NO.
* FLUIDIZEO-BED RECOVERY PROCESS.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH, EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE. FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE, 5. C.
-------
3.4 SULFITE
3,4.1 GENERAL DESCRIPTION OF SULFITE PROCESS
Sulfite pulping is an acid chemical method of dissolving the
lignin that bonds the cellulose fibers together. Many of the
older mills use a sulfurous acid - calcium bisulfite solution
for the cooking acid. Calcium-base spent liquor, because of
problems associated with evaporation and chemical recovery, is
discarded and may result in water pollution problems. In order
to overcome the problem of water pollution several other acid
bases have been developed, the most important being sodium,
magnesium, and ammonium.
Because sulfite pulp is used in a wide variety of end products,
operations will vary considerably between mills. These products
can include pulp for making high grade book and bond papers,
tissues, for combining with other pulps, and for making dissolving
pulp for producing cellophane, rayon, acetate, films, and others.
The pulping operation involves cooking the wood chips in the
presence of an acid within a digester. The heat required for
cooking is produced by the direct additipn of steam to the digester
or by the steam heating of the recirculated acid in an external
heat exchanger. The cooking liquor, or acid, is made up of sulfurous
acid and a bisulfite of one of the four above blses. The sulfurous
acid is usually produced by burning sulfur or pyrites and absorbing
the SO in liquor. Normally, part of the sulfurous acid is converted
to the base bisulfite to buffer the cooking action. During the
cooking action, it is necessary to vent the digester occasionally
as the pressure rises within the digester. These vent gases contain
large quantities of sulfur dioxide and, therefore, are recovered
for reuse into the cooking acid.
Upon completion of the cooking cycle the contents of the digester,
consisting of cooked chips and spent liquor, are discharged into a
tank. During this operation some water vapor and fumes escape to
the atmosphere from the tank vent. The pulp then goes through a
washing stage, where the spent liquor is separated from the fibers.
The washed pulp is either shipped or kept within the plant for
further processing.
3-62
-------
The spent liquor that was washed out of the pulp can be
discarded or, as an alternative, can be concentrated by
evaporation and run through a recovery cycle. The concen-
trated liquor is sprayed into a furnace where the organic
compounds are burned. The residual inorganic compounds
may be collected and reused in the manufacture of cooking
acid.
3.4.2 BASIC DESCRIPTION OF SULFITE FLOW DIAGRAMS
The basic assumptions which were made in the development
of each sulfite flow diagram, the diagram itself, and the
energy balance are presented on the following pages.
3-63
-------
SULFITE DIAGRAM NO. 1
TYPICAL LOCATION
Western United States.
TYPICAL AGE OF EQUIPMENT
Over fifteen years.
GENERAL
Sulfite Flow Diagram No. 1 is based upon the use of magnesium
acid sulfite with chemical recovery. Cooking is done in batch
digesters. There are perhaps 3 to 6 mills in the U. S. which
are illustrated by this flow diagram.
EMISSIONS
Because of the possible variations in this process arrangement,
valid data are not available to provide ranges of emissions.
ASSUMPTIONS
The following assumptions have been made in developing the
flow diagram:
A. PULP MILL
1. Pulp Yield = 43 Percent.
2. Cooking Acid: Combined SO = 1.2 Percent
Free SO_ =7.3 Percent
Total SO =8.5 Percent
B. POWER PLANT
1. Excess Air: 30 percent for bark, 10 percent for oil
and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjection from dust collector: 50 percent for bark
and 0 percent for coal.
4. Design efficiencies for dust collector: 82 percent on
bark and 92 percent on coal with annual operating
efficiencies of 80 percent and 90 percent, respectively.
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust collector
is 40 percent.
7. Coal firing based on pulverized coal.
3-64
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
OJ
I
CO
en
[I4,490J
20,04 OLBS.
850PSIG 300°F
COM BIN ATI ON BOILER
DEAERATING
HEATER
BLEACH PLANT
•**•
DIGESTERS
WASHING
PULP DRYER
EVAPORATORS
SLAKER
•**- AMPLE HOT WATER
ASSUMED TO BE AVAILABLE.
[ ] INDICATES FLOW RATES
FOR PULP MILL ONLY.
ALL FLOW RATES AND
KILOWATTS ARE PER TON
OF A.D. PULP.
I400LBS.
[1070]
* BATCH DIGESTERS, MAGNESIUM ACID SULFITE
WITH CHEMICAL RECOVERY AND BLEACH PLANT.
POWER PLANT ENERGY BALANCE
SULFITE PROCESS NO. I *
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH, EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE. FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE. S. C.
-------
SULFITE DIAGRAM NO. 2
TYPICAL LOCATION
Western United States.
TYPICAL AGE OF EQUIPMENT
Over 15 years.
GENERAL
Sulfite Flow Diagram No. 2 is based on the use of calcium acid
sulfite, without chemical recovery. Cooking is done in batch
digesters. There are perhaps 15 to 25 mills in the U. S. which
are illustrated by this flow diagram.
EMISSIONS
Because of the possible variations in this process arrangement,
valid data are not available to provide ranges of emissions.
ASSUMPTIONS
The following assumptions have been made in developing the
flow diagrams:
A. PULP MILL
1. Pulp Yield = 45 Percent
2. Cooking Acid: Combined SO = 1.25 Percent
Free SO,, = 7.00 Percent
Total SO = 8.25 Percent
B. POWER PLANT
1. Excess air: 30 percent for bark, 10 percent for oil
and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjecti.on from dust collector: 50 percent for bark
and 0 percent for coal.
4. Design efficiencies for dust collector: 82 percent on
bark and 92 percent on coal with annual operating
efficiencies of 80 percent and 90 percent, respectively.
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust collector
is 40 percent.
7. Coal firing based on pulverized coal.
3-66
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
6OO PSiG
66O °F
O -1
O O
OLU
05
tog
CO
OJ
I
COAL/OIL! BARK
COMBINATION BOILER
o
DEAERATING
HEATER
[600]
II CO KW-HR
[1000]
1000 LBS
60 PSIG
160 PSIG
O o
in
•39
o o
o o
[4500]
4500 LBS.
BLEACH PLANT
O
O
80 LBS.
[20]
00
DIGESTERS
[o]
7500 LBS.
PAPER MACHINES
POWER PLANT AUX.
NOTES-.
•KX- AMPLE HOT WATER
ASSUMED TO BE AVAILABLE.
[ ] INDICATES FLOWS FOR
PULP WILL ONLY.
ALL FLOW RATES AND
KILOWATTS ARE PER TON
OF A.D. PULP.
TO DESUPERHEATERS
240 LBS.
[180]
BATCH DIGESTERS, CALCIUM ACID SULFITE
WITHOUT CHEMICAL RECOVERY BLEACH PLANT.
POWER PLANT ENERGY BALANCE
SULFITE PROCESS NO. 2 *
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH, EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE, FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE. S. C.
-------
SULFITE DIAGRAM NO. 3
TYPICAL LOCATION
Western United States
TYPICAL AGE OF EQUIPMENT
Converted to magnesium base within the past five years.
GENERAL
Sulfite Flow Diagram No. 3 is based on the use of magnesium
bisulfite liquor (Magnefite), with chemical recovery. Cooking
is done in batch digesters. There are perhaps 2 to 4 mills
in the U. S. which are illustrated by this flow diagram.
EMISSIONS
Because of the possible variations in the process arrangement,
valid data are not available to provide ranges of emissions.
ASSUMPTIONS
The following assumptions have been made in developing the flow
diagram:
A. PULP MILL
1. Pulp Yield = 50 Percent
2. Cooking Liquor: Combined SO = 2.5 Percent.
Free SO,, = 2.5 Percent
Total SO = 5.0 Percent
B. POWER PLANT
1. Excess Air: 30 percent for bark, 10 percent for oil
and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3, Reinjection from dust collector: 50 percent for bark
and 0 percent for coal.
4. Design efficiencies for dust collector: 82 percent
on bark and 92 percent on coal with annual operating
efficiencies of 80 percent and 90 percent, respectively.
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust
collector is 40 percent.
7. Coal firing based on pulverized coal.
3-68
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
[I3.79OJ
I9,350LBS.
850PSIG 900 °F
in
I—(CD
O-i
r- O
o ro1
tn
i-a:
CD
REC
BOILER
i—I CO
O -I
£•£
I—I CO
O-i
in o
COAL/OIL [ BARK
°3
£o
~CD
__ V_
'-'VO
OJ
COMBINATION BOILER
o -1
Cl o
DEAERATING
HEATER
8
^L O
BLEACH PLANT
**-
DIGESTERS
PULP DRYER
EVAPORATORS
SLAKER
** AMPLE HOT WATER
ASSUMED TO BE AVAILABLE.
[ ] INDICATES FLOW RATES
FOR PULP MILL ONLY-
ALL FLOW RATES AND
KILOWATTS ARE PER TON
OF A.D. PULP.
TO DESUPERMEATERS
I230LBS.
[910]
BATCH DIGESTERS, MAGNESIUM BISULFITE (MAGNEFITE),
WITH CHEMICAL RECOVERY AND BLEACH PLANT.
POWER PLANT ENERGY BALANCE
SULFITE PROCESS NO. 3 *
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH, EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE. FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE, S. C.
-------
SULFITE DIAGRAM NO. 4
TYPICAL LOCATION
Western United States.
TYPICAL AGE OF EQUIPMENT
Over 15 years.
GENERAL
Sulfite Flow Diagram No. 4 is based on the use of ammonium
acid sulfite, with liquor incineration. Cooking is done
in batch digesters. There are perhaps 1 to 4 mills in the
U. S. which are illustrated by this flow diagram.
EMISSIONS
Because of the possible variations in this process arrangement,
valid data are not available to provide ranges of emissions.
ASSUMPTIONS
The following assumptions have been made in developing the
flow diagram:
A. PULP MILL
1. Pulp Yield = 50 Percent
2. Cooking Acid: Combined SO = 1.0 Percent
Free SO = 7.0 Percent
Total SO = 8.0 Percent
B. BLEACH PLANT
Assumed as a three stage bleach plant.
C. POWER PLANT
1. Excess air: 30 percent for bark, 10 percent for
oil and 20 percent for coal.
2. Bark burning equipment is a low set spreader stoker.
3. Reinjection from dust collector: 50 percent for bark
and 0 percent for coal.
4. Design efficiencies for dust collector: 82 percent
on bark and 92 percent on coal with annual operating
efficiencies of 80 percent and 90 percent, respectively.
5. Bark is burned 24 hours per day at a controlled rate.
6. Unburned combustible in refuse leaving the dust collector
is 40 percent.
7. Coal firing based on pulverized coal.
3-70
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
34,340 LB:
600 PSIG 68O °F
OJ
•m
COMBINATION BOILER
» BLEACH PLANT
in
S3
DEAERATING
HEATER
POWER PLANT AUX.
TO DESUPERHEATERS
DIGESTERS
**
PAPER MACHINES
EVAPORATORS
**• AMPLE HOT WATER
ASSUMED TO BE AVAILABLE.
[ ] INDICATES FLOWS FOR
PULP MILL ONLY.
ALL FLOW RATES AND
KILOWATTS ARE PER TON
OF A.O. PULP.
I-LIQUOR INCINERATION
WITHIN THE COMBINATION
BOILER.
260 LBS.
[220]
BATCH DIGESTERS, AMMONIUM ACIDSUFITE, WITHOUT
CHEMICAL RECOVERY, BLEACHING, AMMONIUM LIQUOR
INCINERATION BLEACH PLANT.
POWER PLANT ENERGY BALANCE
SULFITE PROCESS NO. 4 *
EXHIBIT NO.
SYSTEMS ANALYSIS STUDY OF
EMISSIONS CONTROL IN THE WOOD PULPING INDUSTRY
CONTRACT NO. CPA 22-69-18
FOR
DEPARTMENT OF HEALTH, EDUCATION AND WELFARE
CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE
NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
ENVIRONMENTAL ENGINEERING, INC.
GAINESVILLE, FLORIDA
J. E. SIRRINE COMPANY, ENGINEERS
GREENVILLE, S. C.
-------
CHAPTER 4
QUANTITY AND NATURE OF EMISSIONS
TABLE OF COKTEMTS
Summary
Introduction.
Kraft Gaseous Emissions
General
Recovery Furnace
Direct Contact Evaporator
Digester Relief and Blow
Lime Kiln
M. E. Evaporator
BEO Tower
Stock Washer
Smelt Dissolving Tank
Kraft Particulate Emissions
General
Recovery Furnace and DCE
Eime Kiln
HSSC Emissions
Sulfite Emissions
Auxiliary Furnace Emissions
Summary of Emission Data
Review of Emission Standards
References
Page No.
4-1
4-2
4-4
4-4
4-8
4-19
4-24
4-30
4-32
4-37
4-40
4-42
4-44
4-44
4-44
4-46
4-49
4-53
4-59
4-61
4-64
4-66
4-i
-------
CHAPTER 4 .
QUANTITY AND NATURE OF EMISSIONS
SUMMARY
The control of gaseous and particulate emissions from the
various processes in chemical wood pulping requires an under-
standing of the quantity and nature of the compounds involved.
This information is limited. The largest amount of data is
available for the kraft process. Because of the numerous
variables which affect emissions, it is virtually impossible
to give more than a broad range of values without monitoring
specific sources in individual mills.
For each pulping process considered in this study, both gaseous
and particulate emissions are discussed. The nature and effects
of the compounds of interest are discussed briefly. Then for
each source, where the information is available, the theory
of production is discussed, the operating and process variables
which affect emissions are described, an assessment of the
relative importance of the process as a source is made, ranges
of emissions for major compounds are cited, and an attempt is
made to estimate the lowest emission which can be attained by
optimum operation. There are numerous gaps in this format
simply because the necessary information was not available.
4-1
-------
4.1 INTRODUCTION
Planning for the control of gaseous and particulate
emissions from various processes requires an understanding
of the quantity and nature of the compounds involved.
Although the wood pulping industry has been engaged in
research efforts with respect to its air quality improve-
ment programs for many years, valid information on emissions
is rather sparse. The condition is due in part to slow
development of dependable analytical techniques. In many
instances, the low concentrations of gases are near the
limit of resolution of most standard analytical techniques.
The largest amount of information on emissions is available
for the various modifications of the kraft process.
4.1.1 SOURCES OF DATA
Information on the chemical nature and formation of
particulate emissions from various pulping operations
has been known for some time and is readily available
in the literature. Only in recent years, however, have
definite studies been made to explain the production and
identify more than broad categories of gaseous emissions.
Although the recent literature contains some data of
this nature, much information had to be obtained by
direct communication.
Quantitative emission data were obtained from the literature,
from in-house studies, and by direct communication.
4.1.2 LIMITATIONS OF DATA
Attempting to set forth specific quantitative values for
emissions from a process as complicated as chemical wood
pulping involves considerable risk. Process and operating
variables may have profound and sometimes unknown effects
on emissions. Wide and relatively rapid fluctuations may
occur in some operating variables and in emissions. A
number of combinations of unit processes is possible in
a mill to produce the same end result. The nature and
manner of operation of each unit process has an effect on
the emissions from every other unit process. In addition,
unit processes frequently are modified from their original
design.
4-2
-------
Only the main compounds of interest have been monitored
although numerous others may be present. Reliable
analytical techniques are not available for all compounds
of interest. Even in those instances where so called reasonably
reliable sampling and analytical techniques have been
in use for some time, the actual procedure selected will
influence the apparent concentration.
For these reasons it is virtually impossible to give
more than a broad range of values without monitoring
specific sources in specific mills.
4.1.3 BENEFITS TO BE OBTAINED BY MONITORING SOURCES
Only by monitoring individual sources in specific mills
can reasonably reliable values be obtained for the range
of concentration for compounds of interest. Procedures
for such monitoring and the limitations of the procedures
are discussed in Chapter 9. Variations in emissions
need to be correlated with operating variables.
It must be realized that reliable sampling and analytical
procedures are not available for all sources and all
compounds which may be of interest. Despite the limitations
of existing analytical procedures, monitoring of individual
sources as an operational guide may result not only in
reduced emissions but in increased efficiency of operation.
4-3
-------
4.2 GASEOUS EMISSIONS FROM THE KRAFT PROCESS
4.2.1 GASEOUS EMISSIONS FROM THE KRAFT PROCESS - GENERAL
The characteristic kraft mill odor is principally due to the
presence of a variable mixture of hydrogen sulfide, methyl
mercaptan, dimethyl sulfide, and dimethyl disulfide. All of
these gases contain sulfur, which is a necessary component of
the kraft cooking liquor. Hydrogen sulfide, methyl mercaptan,
dimethyl sulfide, and dimethyl disulfide are referred to as
reduced sulfur compounds, and the latter three gases are usually
described as organosulfur compounds.
Hydrogen sulfide emissions are derived from breakdown of the
weak base, sodium sulfide, which is the characteristic of kraft
cooking liquor. It may also be generated by improper operation
of a recovery furnace. Methyl mercaptan and dimethyl sulfide
are formed in reactions with the wood component lignin.
Dimethyl disulfide is formed through the oxidation of mercaptan
groups derived from the thiolignins.
A great deal of variability exists in the published values
of the odor thresholds for these sulfur gases, as can be seen
in Table 4-1. The detection of these gases by the olfactory
senses is obviously a highly individualistic determination.
Table 4.2 presents some of the physical properties of these
sulfur gases.
Sulfur Dioxide (SO_) _ .. _ . , . . . ,_, ,
2 . Sulfur dioxide emissions in the kraft
process result from oxidation of reduced sulfur compounds. A
potential source of sulfur dioxide is the recovery boilers,
where reduced sulfur gases present can be oxidized in the
furnace atmosphere.
Sulfur dioxide is a mildly acidic gas and is readily absorbed
by the alkaline black liquor in the direct contact evaporator.
The mechanism is an acid-base reaction:
SO + 2NaOH £• Na SO + HO Eq. 4.la
4U ^i J ^
Na SO + SO + HO J 2NaHSO Eq. 4.1b
This reaction will, of course, result in a lowering of the pH
of the liquor, because of the reduction in free alkali.
4-4
-------
TABLE 4-1
ODOR THRESHOLDS OF KRAFT MILL GASEOUS
SULFUR COMPOUNDS IN AIR
ppm (by volume)
Sulfur Dioxide 1.0-5.0 (2)
Hydrogen Sulfide 0.0085 (_!) ,
Methyl Mercaptan 0.0021 (2) ,
Dimethyl Sulfide 0.0001 (2),
0.0047 (2), 0.0009 (4)
0.040 (3), 0.0006 (_4)
0.0036 (3), 0.0003 (4)
TABLE 4-2
CHARACTERISTICS OF KRAFT MILL GASEOUS
SULFUR COMPOUNDS
Compound
Characteristic
Odor
Explosive Limits (air)
Color Lower Upper
Sulfur Dioxide
Hydrogen Sulfide
Methyl Mercaptan
Dimethyl Sulfide
strong, suffocating none
rotten eggs none
rotten cabbage none
vegetable sulfide none
Not-explosive
4.3% 46% (5)
3.9% 22% (6)
2.2% 9% (6)
4-5
-------
The principal potential sources of sulfur dioxide in the kraft
mill are the power boilers and the recovery furnace. Emissions
from the power boilers depend upon the type of fuel and the
sulfur content of the fuel. With a 2 percent sulfur fuel oil,
the sulfur dioxide emissions range from 12 - 43 Ib/ADT of pulp;
for a 2 percent sulfur coal, the emissions range from 15 - 57
Ib/ADT of pulp. The sulfur dioxide emissions from the recovery
furnace range from 0.5 - 15 Ib/ADT of pulp.
Hydrogen Sulfide (HS) . TT , -,,-.-,. ^ i_i -j-
2 Hydrogen sulfide is a feebly acidic gas
which partially ionizes in aqueous solution. The ionization pro-
ceeds in two stages with the formation of hydrosulfide and, with
increasing pH, sulfide ions
H S + HS~ + H+ + S~ + 2H+ Eq. 4.2
increasing pH ->•
Black liquor contains a high concentration of dissolved sodium
sulfide in strongly alkaline solution. If the pH were depressed,
the sodium sulfide would hydrolyze to sodium hyrosulfide and
below pH 8 appreciable unionized hydrogen sulfide would form as
the reaction equilibria in Eq. 4.2 moves from right to left. Shih
(28) reports that at a pH of about 8.0, most hydrogen sulfide forms
hydrosulfide ions, so in normal black liquor conditions, there is
very little dissolved hydrogen sulfide in the liquor.
Due to the equilibrium between the hydrosulfide ion and water
vapor, hydrogen sulfide gas can be stripped from black liquor at
steam vents. There could be, therefore, a problem in the evapo-
rator areas of the kraft mill.
Hydrogen sulfide is formed in the recovery furnace in the reducing
atmosphere found in the lower sections, as the sulfur containing
compounds from the black liquor are volatilized and reduced. How-
ever, in normal furnace operation the hydrogen sulfide oxidizes to
sulfur dioxide (which is largely absorbed within the furnace) in
the combustion sections before the exhaust gases leave the
furnace.
Hydrogen sulfide generally represents the largest gaseous emission
from the kraft process. Two of the most effective means for reduc-
ing the hydrogen sulfide emissions from kraft mills are black liquor
oxidation and maintaining tight control of critical process operating
variables.
4-6
-------
Methyl Mercaptan (MeSH). Methyl mercaptan is a reduced sulfur
compound which is formed during the kraft cook by the reaction
of hydrosulfide ion and the methoxy-lignin component of the
wood (8) :
Lignin-OCH + HS~ * MeSH + Lignin-cf Eq. 4.3
Methyl mercaptan will also dissociate in an aqueous solution to
methyl mercaptide ion. Shah (9) has reported that this dis-
sociation is essentially completed above a pH of 12.0:
MeSH + OH •«- MeS~ + HOH Eq. 4.4
Methyl mercaptan will, therefore, be present in low concentra-
tions as a dissolved gas in the black liquor. As the pH decreases,
the equilibrium shown above shifts to the left and MeSH gas is
evolved.
Methyl mercaptan is primarily emitted from the digester relief and
blow where it is formed, and from the brown stock washers where
the pH of the liquor drops below the equilibrium point. Its
emission1 decreases as its residual concentration in the liquor
diminishes.
Dimethyl Sulfide and Dimethyl Disulfide (MeSMe, MeSSMe). Dimethyl
sulfide is primarily formed through the reaction of methyl mercaptide
ion with the methoxy-lignin component of the wood (8). It does not,
however, dissociate as hydrogen sulfide and methyl mercaptan do:
Lignin-OCH + MeS~ -»• Lignin-0 + MeSMe Eq. 4.5
Dimethyl sulfide may also be formed by the disproportionation of
methyl mercaptan. At normal liquor temperatures (150 - 200°F) it
is highly volatile.
Dimethyl disulfide is formed by the oxidation of methyl mercaptan
throughout the recovery system, especially in oxidation towers.
Dimethyl disulfide has a higher boiling point than any of the
other compounds and its retention in the liquor is therefore greater
than the other organosulfur compounds.
4MeSH + O + 2MeSSMe + 2H O Eq. 4.6
4-7
-------
4.2.2 GASEOUS EMISSIONS FROM THE KRAFT RECOVERY FURNACE
4.2.2.1 Formation of Gaseous Pollutants
The purposes of burning concentrated black liquor
in the kraft recovery furnace are: the recovery of
sodium and sulfur, the production of steam, and the
disposal of unwanted dissolved wood components in
the liquor. In most instances, liquor of 62% solids
content or greater will burn in a self-supporting
combustion. Sodium and sulfur can be recovered in
the form of sodium sulfide and sodium carbonate.
The recovery furnace theoretically is divided into
three sections: the drying and pyrolysis zone,
the reducing zone, and the oxidizing zone. The
black liquor is intorduced to the furnace through
spray guns located in the drying zone. The
heat in the furnace is sufficient to immediately
evaporate the remaining water from the liquor and
to cause the organic solids within the liquor to under-
go pyrolysis. Pyrolysis is defined as the chemical
change brought about by the action of heat upon a
substance.
Pyrolysis occurs in the drying zone of the furnace.
The drying zone of most recovery furnaces is in a
combined oxidation and reduction state because of
the manner in which the primary air is introduced
into the furnace. Forced draft fans force the primary
air into the furnace through the air ports located
around the perimeter of the furnace at the level of
the drying zone.
It is felt that sulfur which exists in organic substances
undergoing pyrolysis in the oxidizing atmosphere will
usually be oxidized to form nonvolatile sulfur radicals
such as sulfite, thiosulfate, and sulfate (10). These
non-volatile sulfur radicals in the form of sodium salts
will fall into the reducing zone of the furnace, although
small particles may be carried out of the furnace by the
draft of the fan.
4-8
-------
Flue
Gas
Air
Black Liquor
Air-
OXIDIZING
X
DRYING
X
REDUCING
Smelt
FIGURE 4-1 SHOWING THE PRINCIPAL SECTIONS AND LOCATIONS OF
AIR INLETS FOR A TYPICAL RECOVERY FURNACE
4-9
-------
Conversely, sulfur which exists in organic substances under-
going pryolysis in a reducing atmosphere/ may form volatile
reduced sulfur compounds (10). These gases flow into the
upper regions of the furnace.
These proposals exist only as theory, and much work remains
to be done in understanding the mechanism of pyrolysis of
black liquor before these theories can be regarded as correct.
The sodium salts of the oxidized sulfur compounds which have
fallen into the reducing zone along with the carbon ash residue
will undergo reduction to sodium sulfide and sodium carbonate.
Carbon dioxide and carbon monoxide are gaseous by-products
of these reduction processes. The fused sodium sulfide and
sodium carbonate are withdrawn and mixed with water in the
smelt tank to form green liquor.
The total reduced sulfur (TRS) gases and the carbon monoxide
which are drawn into the oxidizing zone of the furnace should
undergo oxidation to sulfur dioxide, carbon dioxide, and water
This oxidation will>be carried to completion-if proper conditions
of temperature, excess oxygen, residence time and turbulence
are provided. When these conditions do not exist, complete
oxidation will not occur and the reduced sulfur compounds will
escape from the furnace.
4.2.2.2 Effect of Operating Variables upon Emissions from the
Recovery Furnace
There are many operating variables which have been shown to
affect the emissions from a kraft recovery furnace. Several
of those which are considered to be the most important and
which are understood the best are: the rate at which black
liquor is fired into the furnace, the ratio of secondary
air to the black liquor firing rate, the percent excess oxygen
in the furnace flue gas, black liquor spray droplet size, and
turbulence within the recovery furnace.
Several authors have identified the relationship which
exists between the firing rate of a furnace and the
gaseous emissions (10, 11, 12, 13). Figure 4-2 shows
the relationship between the firing rate and the
hydrogen sulfide emissions from a particular recovery
furnace. The hydrogen sulfide emissions gradually
increase until a sharp upward break occurs. The
point at which this sharp increase occurs is primarily
dependant upon the capacity of the forced draft fan.
-------
FIGURE 4-2
THE EFFECT OF OVERLOADING A KRAFT RECOVERY
FURNACE UPON HYDROGEN SULFIDE EMISSIONS
600 - •
400 • -
200 '
100
120
PERCENT OF RATED CAPACITY
4-11
140
-------
The other operating variables discussed in this section are
important in determining the rate at which the emissions
will increase with overloading.
The I.D. fans installed on a furnace are usually conser-
vatively designed and can handle small increases in the
black liquor firing rate which are required during peak
loading. However, a point will be reached when the fan
is at its limiting capacity and it will no longer be
able to provide sufficient oxygen to oxidize the rising
gases (10). In addition, secondary air will not be introduced
at a rate sufficient to provide adequate mixing to thoroughly
oxidize the gases. Increasing the capacity of the fan will
not solve the problem totally. As the air flow within the
furnace is increased, carry-over of black liquor droplets will
occur. These particles will burn in the upper sections
of the furnace, generating excessive heat which may result in
superheater tube failure.
The increased hydrogen sulfide emission of an overloaded
furnace is therefore partially caused by the poor gas flow
characteristics and lack of oxygen within the oxidizing zone
of the furnace, both of which are required to maintain minimum
emissions.
It has also been shown that to maintain minimum reduced
sulfur emissions from a recovery furnace the percent of
excess oxygen in the recovery flue gas must be maintained
above a minimum level (10). The presence of sufficient
excess oxygen does not, however> insure minimal emissions
unless certain conditions exist in the furnace: the
efficient mixing of the available oxygen with the combustible
material, a temperature high enough to provide rapid chemical
reaction, and sufficient residence time to allow oxidation
to occur. Murray and Rayner (10) have experimentally
determined in the laboratory the relationship between the
percent excess oxygen in the flue gas and the hydrogen
sulfide emissions as shown in Figure 4-3. Thoen (13) has
also derived similar relationships, but the percent excess
oxygen required for a particular furnace must be experimentally
determined for each case. Most authors have reported that
minimum TRS emissions occur when oxygen in the flue gas from
the recovery furnace is about 2.5 - 4.0 percent by volume.
4-12
-------
FIGURE 4-3
THE EFFECT OF RESIDUAL OXYGEN IN THE FLUE GAS
UPON HYDROGEN SULFIDE EMISSIONS
600 . .
400
J
\
3.
u
u
D
S
200. .
CORRELATION COEFFICIENT = 0.606
2.0
2.5 3.0 3.5
OXYGEN IN FLUE GAS (%)
4-13
4.0
4.5
-------
The ratio of the secondary air flow rate to the black liquor
firing rate is also an important variable. At the ratio which
yields the lowest emissions, the excess oxygen requirement
is usually satisfied (10, 13). Murray and Rayner's relation-
ship of this ratio versus the hydrogen sulfide emissions is
shown in Figure 4-4. Results by other authors show that the
secondary air should amount to about 30 - 40 percent of the
air supplied to the furnace.
Thoen (13) has reported that when black liquor is sprayed
into the furnace in small drops there exists a tendency for
the solids to be carried up to the oxidizing zone immediately,
whereas larger spray droplets will fall to the bottom of the
furnace. When black liquor is carried to the upper zones it
will burn slowly/ yielding excessive amounts of heat which
will overheat the boiler. The products of combustion will
then be swept out of the furnace before they can be oxidized
and emissions of TRS gases will be increased. Thoen has
given TRS emission values (Table 4-3) for "coarse" and
"fine" sprays which show about a 1000 percent increase between
the two. Unfortunately the sizes of the coarse and fine spray
droplets were not reported, but the nozzle sizes, line pressures
and temperatures corresponding to the coarse and fine spray
conditions are shown in Table 4-3. The size of the spray
droplets can be controlled by the temperature and pressure
of spraying the liquor and by the type of spray nozzles.
The turbulence created by the introduction of the secondary
air is of great importance. Turbulence creates thorough
mixing and thus more efficient oxidation of the gases. A
well designed introduction system for the secondary air
will provide a high degree of turbulence while imparting
no vertical velocity to decrease residence time. The more
common methods of injection are horizontally and tangentially
arranged inlet ports.
The channeling of the reducing atmosphere into the upper
regions of the furnace has two effects. First it allows
an increased period of contact between sulfur containing
organic solids and the reducing atmosphere which will lead
to further reduced sulfur emissions. Secondly, it will
decrease the efficiency of the oxidizing zone of the furnace.
Channeling can be easily controlled by proper introduction
of secondary air to create turbulence to mix the oxygen
with the reducing atmosphere.
4-14
-------
FIGURE 4-4
THE EFFECT OF THE SECONDARY AIR/BLACK LIQUOR FIRING
RATE RATIO UPON HYDROGEN SULFIDE EMISSIONS
600 - •
400
en
a.
EL.
h
en
200 -.
CORRELATION COEFFICIENT = 0.755
•4-
2.4
2.8 3.2
SECONDARY AIR TO FURNACE (Ibs./lbs. solids)
4-15
3.6
-------
To date it has not been shown experimentally that there is
a relationship between the sulfide ion concentration in the
black liquor and the quantity of gaseous emission of any
compound from the recovery furnace itself. Thus any decrease
in emissions from the furnace itself while burning oxidized
black liquor as opposed to unoxidized liquor is purely
coincindental. The effect of oxidized and unoxidized liquor on
reduced sulfur emissions shows up in the direct contact evapo-
rator following following the recovery furnace, where emissions
will be decreased if the liquor is oxidized.
Th,e wide variety of recovery furnace designs makes it impossible
to present data which can be considered to be typical for
every furnace. The data and figures presented in this section
are given to show trends which have been observed on selected
furnaces.
TABLE 4-3
THE EFFECT OF SPRAY SIZE ON SULFUR
GAS EMISSIONS FROM A KRAFT RECOVERY
FURANCE*(13) (USING UNOXIDIZED BLACK LIQUOR)
Flue Gas Concentration (ppm)
SO H S MeSH MeSMe MeSSMe
Coarse Spray 2.120.02 0 0 0
Fine Spray 10.70 2.40 0.12 0 0.03
*These data are representative of a particular furnace only.
Note: Coarse Spray - No. 4 Nozzle at 17 psi and 240°F
Fine Spray - No. 2 Nozzle at 17 psi and 245°F
4-16
-------
4.2.2.3 Relative Importance of the Recovery Furnace
The importance of the kraft recovery furnace as a source
of emissions is dependent upon the operation of the furnace
itself. As has been described in this section, there exists
an optimum set of operating conditions for each furnace
which will result in the reduction of the emissions of
reduced sulfur compounds to a negligible level. If the
furnace is operated at conditions other than optimum,
the quantity of emissions will increase as the divergence
from the optimum condition, increases. The kraft recovery
furnace may then become the major source of sulfurous
emissions in the mill.
4.2.2.4 Ranges of Emissions of Gaseous Sulfur Compounds
The importance of the operating variables has been
determined. In general, recovery furnaces are rarely
operated under optimum conditions. The ranges of emissions
in Table 4-4 typify the emission ranges for kraft recovery
furnaces operating under non-optimum conditions. Variances
from these ranges may occur if the furnace is operated
under severe operating conditions. Operation under optimum
conditions is discussed in the following section.
T A B L E 4-4
APPROXIMATE RANGES OF EMISSIONS FROM KRAFT
RECOVERY FURNACES
(Before the Direct Contact Evaporator)
lb/ADT Of pulp
Sulfur Dioxide 10.0 - 15.0
Hydrogen Sulfide 1.0 - 5.0
Methyl Mercaptan 0.01- 0.10
Dimethyl Sulfide 0.01- 0.02
Dimethyl Disulfide 0.01- 0.02
4-17
-------
4.2.2.5 Emissions Under Optimum Conditions
A kraft recovery furnace which is operated at optimum
operating conditions which have been individually
determined for the furnace in question can be expected
to emit negligible amounts of gaseous sulfur compounds.
In his study of the effects of operating conditions
upon emissions from the furnace, Theon (13) , operated
a recovery furnace under optimum conditions for a
24 hour period, and obtained the results in Table 4-5.
TABLE 4-5
KRAFT RECOVERY FURNACE
EXTENDED OPERATION AT OPTIMUM CONDITIONS* (13)
(24hr)
(load-116% design)
ppro v/v %
Periodic Samples SO H s RSH RSR RSSR O CO CO
1 0.04 0000 3.1 15.6 0
2 0.07 0000 4.4 15.4 0
3 0.04 0000 4.4 15.4 0
4 0.01 0000 4.8 15.4 0
5 0,08 0000 2.1 16.4 0
*35% secondary air at 180 ft/sec; coarse black liquor spray.
Note: (1) 0 indicates concentration less than detection limits of
analytical equipment.
(2) Work currently under way indicates the sulfur dioxide
concentrations presented in this table may be low due
to the limitations of the analytical techniques used.
4-18
-------
4.2.3 GASEOUS EMISSIONS FROM THE DIRECT CONTACT EVAPORATOR
2.3.1 Formation of Gaseous Pollutants
Gaseous emissions from the direct contact evaporator are caused
by the stripping of the dissolved gases from the black liquor by
the furnace flue gases. This occurs when a concentration differ-
ence exists between the actual concentration of the gases in the
flue gas and the equilibrium concentration which is consistent
with the temperature and pH of the liquor (14). In black liquor,
the dissolved hydrogen sulfide and methyl mercaptan are normally
low, as discussed in Section 4.2.1. However, the absorption of
carbon dioxide and sulfur dioxide from the flue gas reduces the
pH of the liquor causing an increase in the concentrations of
these dissolved gases. This point will be elaborated upon shortly.
Dimethyl sulfide and dimethyl disulfide usually have low residual
concentrations in the unoxidized liquor and their emission from
this source is characteristically low. The concentrations of these
two gases in oxidized liquor is usually slightly higher (especially
dimethyl disulfide) and the emissions may be slightly greater than
for unoxidized liquor.
The absorption of carbon dioxide and sulfur dioxide takes place
according to the straightforward acid-base equilibrium reactions:
OH + C0 H H+ + C0= Eq. 4.7
OH + .S02 H H+ + S03= Eq. 4.8
In the case of black liquor, the carbonate and sulfite ions are
both stronger acids than hydrosulfide and mercaptide 'ions and will
displace the latter ions from the liquor. The acid hydrogen ions
formed by the absorption of these gases will enter into competitive
reactions between hydrosulfide, mercaptide and hydroxide ions in
the liquor:
H + HS~ + H2S* Eq' 4'9
H' 4- RS~ J RSHt Eq. 4.10
HT + OH~ + HO Eq. 4.11
In actuality, all three reactions take place. The proportion of
the ion which enters into each reaction will depend upon the
relative strengths of the negative ions listed and the concentra-
tions of the ions .
4-19
-------
Most of the hydrogen ion will probably react with the
hydroxide ion to lowejT the pH of the solution. This
shift in equilibrium Will cause an increase in the
dissolved concentration of hydrogen sulfide and methyl
mercaptan gases in th.0 liquor, and the reactions which
take place in Eq. 4-9 and 4.10 will tend to increase
emissions from the evaporator. The escaping vapor may
also serve as a vehicle for hydrogen sulfide and methyl
mercaptan stripping.
4.2.3.2 Effect of Operating Variables Upon Emissions from the
Direct Contact Evaporator
For a given concentration of a dissolved gas in the
black liquor, there exists an equilibrium concentration
of that compotuxd in trie gas above the liquor, which is
consistent with the temperature and the pressure of the
system. According to the principles of mass transer, a
transfer of mass froiti the liquor to the gas phase will
occur if the concentration of the gas is lower than the
equilibrium concentration.
Conversely, mass transfer will occur from the gas to the
liquor if the concentration in this gas phase is greater
than the equilibrium concentration.
Murray and Eayner (13) have developed a mathematical model
which approximates the actual conditions for hydrogen
sulfide transfer- Their formula shows that the equilibrium
concentration, of hydrogen sulfide above the liquor is de-
pendent upon the sulfide ion concentration and the pH of the
liquor. The mathematical model for the mass transfer of
hydrogen sulficle is Dependent upon this equilibrium concen-
tration and the concentration of hydrogen sulfide in the
entering gas stream as well as the gas flow rate. Tables
4-6 and 4-7 show the effect of pH and sulfide concentration
upon the emission of hydrogen sulfide from the direct contact
evaporator. The datei are taken from the pilot plant work
under controlled conditions•
A similar mathematical model could be developed for methyl
mercaptan. Dimethyl sulfide and dimethyl disulfide do not
dissociate in blacK liquor and their removal from the liquor
is a function of their vapor pressures and the temperature
of the liquor, rathet than a function of the pH.
4-20
-------
TABLE 4-6
THE EFFECT OF CHANGING THE pH OF THE BLACK LIQUOR
ON HYDROGEN SULFIDE EMISSIONS DURING DIRECT
CONTACT EVAPORATION (14)
(Pilot Plant Study)
12.59
12.33
12.07
Na S Cone
in Black
Liquor
(g/i.)
14.2
18.3
15.3
H S Cone
in Recovery
Furnace
Flue Gases
(ug/l.)
16
41
36
H S Cone
in Contact
Evaporator
Exit Gas
(yg/1.)
53
185
273
Change in H i
Across Contact
Evaporator
(P/I.)
r
37
144 ;
237
TABLE 4-7
THE EFFECT OF CHANGING THE SODIUM SULFIDE CONCENTRATION BY
OXIDATION ON THE EMISSION OF HYDROGEN SULFIDE DURING
CONTACT EVAPORATION (14)
(Pilot Plant Study)
Na S Cone
in Black
Liquor
PH (g/1.)
11.85 28.4
20.2
Zero
12.30 33.3
18.3
Zero
H S Cone
in Recovery
Furnace
Flue Gases
(yg/i.)
204
Zero
74
32
41
14
H S Cone
in Contace
Evaporator
Exit Gas
(yg/1.)
580
216
50
295
186
'10
Change in H S
Across Contact
Evaporator
(w/i.)
376
216
- 24
263
145
- 4
4-21
-------
It should be noted that if black liquor oxidation is
performed to a residual sulfide concentration of less
than 0.1 gm/liter, the pH of the liquor is no longer
a factor in emissions from the direct contact evaporator.
4.2.3.3 Relative Importance of the Direct Contact Evaporator
The significance of the direct contact evaporator as
an emissions source is dependent upon the residual
sodium sulfide concentration and the pH of the black
liquor being handled. Hydrogen sulfide emissions have
been observed to increase rapidly with increasing
sodium sulfide residual concentrations in black liquor.
High sodium sulfide concentrations in black liquor may
result in the direct contact evaporator becoming a
major source of emissions. When emissions are high,
the hydrogen sulfide emissions may be decreased by
maintaining a higher pH.
Complete oxidation (99+ percent) of kraft black liquor
to produce a negligible sodium sulfide concentration
will virtually eliminate the direct contact evaporator
as a major emission source within the kraft mill.
4.2.3.4 Ranges of Emissions of Gaseous Sulfur Compounds
Because of the importance of the sodium sulfide con-
centration upon the emission of hydrogen sulfide and
methyl mercaptan, ranges of emissions for both oxidized
and unoxidized liquor have been tabulated. The ranges
of emissions in Table 4-8 represent the sum of the
recovery furnace and direct contact evaporator contri-
butions, and do not separate the increase in emissions
across the direct contact evaporator from the portion
that may enter with the recovery furnace gases.
4.2.3.5 Emissions under Optimum Conditions
From the very low reduced sulfur emissions from a
modern recovery furnace operated under optimum con-
ditions, it is concluded that the emissions from a
direct contact evaporator are primarily dependent
upon the degree of black liquor oxidation. At 99+
percent oxidation efficiency, the emissions should be of the
be of the order of 0.5 Ib/ADT.
4-22
-------
If high residual sulfide concentrations remain in the
liquor during evaporation, the emissions can be controlled
to a limited extent by maintaining the pH as high as is
feasible.
TABLE 4-8
APPROXIMATE RANGES OF EMISSIONS FROM THE DIRECT
CONTACT EVAPORATOR
UNOXIDIZED LIQUOR OXIDIZED LIQUOR
•(Ib/ADT) (Ib/ADT)
Sulfur Dioxide 2.0 - 8.0 2.0 - 8.0
Hydrogen Sulfide 5.0-30.0 0.10-2.0
Methyl Mercaptan 0.50 - 2.50 0.05 - 0.25
Dimethyl Sulfide 0.10 - 0.30 0.01 r 0.10
Dimethyl Disulfide 0.10 - 0.40 0.01 - 0.20
4-23
-------
4.2.4 GASEOUS EMISSIONS FROM THE DIGESTER RELIEF AND BLOW
4.2.4.1 Formation of Gaseous Pollutants
In a digester, chips are treated with predetermined quantities
of alkali, in the form of caustic sulfide liquors, and subjected
to heat and pressure to separate fibrous constituents of wood
by dissolving the nonfibrous constituents (15). Digester "relief
is an essential part of [Batch] digester operation; it is done
for four purposes: circulation, control of cooking, reduction
of digester pressure before blowing and removal of air. . .(16)."
In some cases the gases which are relieved from the digesterlnay
be vented to a turpentine recovery system where the crude turpen-
tine is condensed. Noncondensibles in the relief gases will
pass through the turpentine condenser and are a possible source
of emissions at this point unless further processing of them
is arranged. When a turpentine recovery system is not used,
the relief gases are sent to a heat recovery system, after
which the noncondensible gases represent a potential emission
problem. When the cook is completed, the contents of the
digester are blown into the blow tank by the pressure within
the digester. "The contents are blown tangentially into the
top of the blow tank, the stock dropping into the tank and the
steam and gases escaping from the top vent (IT)." The steam
and gases pass through a heat accumulator from where they may
be emitted to the atmosphere.
The hydrolytic equilibria for the sulfide ions in the kraft
liquor are:
S - + HOH £1 HS~ + OH~ Eq. 4.12
HS~ + HOH +2 H S -f OH~ Eq. 4.13
While previous work indicates that in kraft pulping, the
equilibrium for Equation 4.13 lies almost completely to the
left, reliable values for the equilibrium constant for Equation
4.12 are not available. However, K.. is known to be large, and
it is proper to express the total sulfur in the liquor as
hydrosulfide ion (HS~) (8).
The demethylation of lignin is believed to be accomplished
by a nucleophlic attack by the hydrosulfide ions upon the
methoxyl group of the lignin. In a consecutive bimolecular
reaction the mercaptide ion attacks another methoxyl group
and yields dimethyl sulfide (8).
4-24
-------
Lignin-OMe + HS -»• MeSH + Lignin-O Eq. 4.14
MeSH + OH~ -> Mes" + HOH Eq. 4.15
Lignin-OMe + MeS~ ' "*" MeSMe + Lignin-O~ Eq. 4.16
Thus since the methyl mercaptan concentration increases as
a consequence of the reaction in Eq. 4.14, the rate of reaction
4.16 likewise increases, which tends to deplete mercaptan by
conversion to dimethyl sulfide.
Ultimately, a steady state condition may be reached at which
the mercaptan is formed and depleted at equal rates, and its
concentration will remain constant. On the other hand the
rate of dimethyl sulfide formation should be zero at the
outset of the cook and gradually increase, approaching a steady
rate of formation at steady state condition (see Figure 4-5) (8).
There are some side reactions which can occur during a cook.
One is the oxidation of methyl mercaptan to dimethyl disulfide (8):
2RSH + 1/2 0 -»• RSSR + HO Eq. 4.17
It is conceivable that by eliminating oxygen from the system, this
side reaction producing a malodorous gas could be suppressed.
Another side reaction which may be significant is the dispropor-
tionation of methyl mercaptan to dimethyl sulfide and hydrogen
sulfide (8) . This reaction has been found to have a slow
but significant rate:
2RSH -»• RSR + H S Eq. 4.18
4J2.4.2 The Effect of Operating Variables Upon Emissions
McKean, Norwicki and Douglass have stated that minimum black
liquor recycle, short duration cooks, low cooking liquor
sulfidity and high residual alkali will help yield minimal
emissions from the kraft digester. However these authors differ
in their opinion of the effect of temperature in the digester
upon emissions.
In the following paragraphs the relationships between various
operating variables and emissions are discussed. It must be
remembered, however, that practical verification has not been
reported in many instances between the relationships established
and variations in pulp quality produced under these conditions.
In other words, it frequently is not possible to optimize operating
conditions to produce minimum emissions and still produce pulp
of the desired quality.
4-25
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en
a)
r-l
O
e
o
M
EH
EH
3
8
FIGURE 4-5
THE RATE OF FORMATION OF METHYL MERCAPTAN AND
DIMETHYL SULFIDE DURING DIGESTION AT 180° C
0.014--
0.012..
0.010'•
RSR
0.008
0.006
0.004
0.002-
RSH
TIME (hours)
4-26
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Effect of Wood Species on Odor Formation. Investigations into
the quantitative amounts of.gaseous products from the digesters
have indicated that the amounts of TRS produced from hardwood
cooks are greater than those produced from softwood cooks under
the same conditions (T, 8). In the case of hardwoods, there is
an initial rapid rate of production of malodors that ultimately
approaches a constant rate that is about 10 percent greater
than softwoods. As a result, a 4-hour hardwood cook will produce
about 30 percent greater quantity of odorous compounds than
a softwood cook (7_, 8) . The production of a greater quantity
of odorous compounds indicates that the syringyl methoxyls
from hardwoods react 10 percent faster than quaiacyl methoxyls
which are found in the softwoods (T_, 8) .
Rate of Mercaptide Ion Attack on Lignin Methoxyl. Two hypothe-
ses have been formed to account for the slow initial rate of
dimethyl sulfide formation. The first is that as the pulping
proceeds the transfer of lignin into the soluble phase from
the solid phase would enhance the accessibility of the lignin
to mercaptide ion attack. However, this hypothesis has been
partially disproved by showing that carbohydrate-free lignin
preparations, which would have better accessibility, still suffer
from slow initial attack by mercaptide ions (8).
The second hypothesis is accounted for by purely chemical
factors. The structural changes which take place in the
lignin to cause solubilization during pulping, cause severe
degradation to lower weight fragments. It may, therefore, be
expected that these changes would effect the methoxyl reactivity (8)
Temperature Dependance of Reactions. Experimental laboratory
investigation has derived the activation energies for the principle
reactions occuring during pulping (7_) . The activation energies
for the odor forming reactions (Eq. 4.14 and 4.16) are 7.6 and
11.3 kcal/mole, while the activation energy of the delignification
has been estimated to be about 30 kcal/mole.
By inspection of the Arrhenius equation, which describes the
temperature dependence of the rate constant, it appears that
an increase in temperature will accelerate the delignification
reaction while having only a moderate effect upon the odor
forming reactions.
Thus, for example, if the cooking temperature were raised
from 160 to 190°C the rate of delignification would be increased
by a factor of 10 while the odor forming reaction rate would
be increased by a factor of about 2.3. Thus for the same
amount of delignification the odorous compounds formed during
the 190°C cook would be only one-fourth of the amount produced
at 160°C.
4-27
-------
It is worth noting that at elevated temperatures the formation of
odorous gases (see Eqs. 4.14 and 4.16) takes place at a greater
rate. The practice of blowing a digester at the earliest time
which is consistant with the pulp quality desired is practiced for
economic reasons. However, 'the importance of practicing this
proceedure from an emissions standpoint can be seen in the previous
example.
A continuous digester can eliminate these problems because the
temperature of the pulp can be raised and lowered quickly, and
the dissolved lignins can be removed before they enter the
activated forms which eventually cause odors.
The Effect of Sulfidity. Because of the ionic equilibrium between
sulfide ions and hydrosulfide ions, a higher liquor sulfidity will
result in higher hydrosulfide ion concentrations. The net result
will be a greater formation of methyl mercaptan by the reaction
shown in Equation 4.14.
The higher hydrosulfide ion concentrations will also result in
greater hydrogen sulfide emissions created by steam stripping,
although this problem appears to be of less importance than the
additional methyl mercaptan formation mentioned previously. In
general, higher sulfidities will result in greater losses of
reduced sulfur compounds.
The Effect of pH. The pH of the cooking liquor has an effect upon
the emission of hydrogen sulfide and methyl mercaptan, as discussed
in Section 4.2.1. Because methyl mercaptan is readily evolved at
a pH below about 12, it is desirable to maintain a high residual pH
after the cook to minimize this volatilization. A high pH, however,
will not prevent the stripping of these gases (7). The feasibility
of controlling the pH in this instance is controversial.
Heat Accumulator Size. In cases where direct contact heat accumulators
are used, the volume of water through which the digester blow gases
pass in the heat accumulator has a great effect upon the emissions of
two of the reduced sulfur gases. Hydrogen sulfide and methyl mercaptan
have limited solubilities in water (0.035 Ib/gal and 0.187 Ib/gal
respectively at 70°F) , and the greater the volume of water through
which the noncondensible gases pass, the greater the absorption of
them will be.
4-28
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4.2.4.3 Relative Importance of the Digester Relief and Blow
Emissions
The digester relief and blow may be the largest source
of organosulfur emissions within the kraft mill. This
is because these compounds are primarily formed in the
digesters and the first opportunity for stripping from
the liquor is at this point. At process points beyond
this the residual organosulfur compounds will be stripped
to a lesser extent.
The digester is a relatively minor source of hydrogen
sulfide emissions when compared with the recovery furnace,
direct contact evaporators, multiple effect evaporators,
and the lime kilns. Sulfur dioxide emissions are almost
negligible from the digester blow and relief.
4.2.4.4 Ranges of Emissions from the Digester Relief and Blow
Taking into account the variability of the operating
conditions, the ranges of emissions for gaseous sulfur
compounds from batch digesters are listed in Table 4-9.
Emission data from continuous digesters are not currently
available and the emissions from such equipment must not
be considered identical to batch digester emissions.
TABLE 4-9
APPROXIMATE RANGES OF EMISSIONS FROM THE DIGESTER
RELIEF AND BLOW
lb/ADT
Sulfur Dioxide Trace - 0.01
Hydrogen Sulfide 0.01 - 0.12
Methyl Mercaptan 0.02 - 0.40
Dimethyl Sulfide 0.40 - 2.5
Dimethyl Disulfide 0.20 - 1.50
4-29
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4.2.5 GASEOUS EMISSIONS FROM THE LIME KILN SYSTEM
4.2.5.1 Formation of Gaseous Pollutants
There is little published information concerning gaseous
emissions from the lime kiln. It has been considered to be
a minor source of sulfur gases and thus few studies have been
made.
Possible sources of sulfur compounds into the kiln system
include the fuel used to fire the unit, residual concen-
trations of reduced sulfur compounds in the lime mud, non-
condensible gases burned in the kiln, and scrubbing liquor
used in the kiln scrubbers.
Taylor theorizes (19) that a part of the gaseous reduced
sulfur emissions from the kiln will depend upon the residual
concentration of the reduced sulfur compounds and sodium
sulfide concentration in the lime mud. Thus the thoroughness
of washing the mud to remove these residual concentrations
could greatly affect the emissions. .Unfortunately no
quantitative data exists on the residual concentration and
emission relationship. The mechanisms by which reduced sulfur
compounds may be produced and their subsequent conversion
are unknown.
Combustion of the noncondensible reduced sulfur compounds
resulting from other processes in the lime kiln has been
used with considerable success. In the hot end of the kiln,
these gases as well as those mentioned in the previous para-
graph are subjected to temperatures in the range of 1500-1800°F.
Under these conditions, with sufficient excess oxygen, oxidation
of the reduced sulfur gases takes place with a high degree of
efficiency. The critical temperature and oxygen ranges are
unknown.
Sulfur dioxide which would be a gaseous product of such
oxidation reactions as well as of the fuel oil combustion
will be subject to immediate chemical absorption by the
calcium carbonate or oxide. The scrubbers used on all kiln
systems also are effective gas removal devices. Very
little sulfur dioxde is emitted from the kiln system for
this reason.
4-30
-------
Taylor (19) has observed that where scrubbing liquor
containing sulfides, such as weak wash, filtrates or
evaporator condensates from unoxidized black liquor,
is used in the lime kiln scrubbers hydrogen sulfide,
methyl mercaptan, dimethyl sulfide and dimethyl disulfide
may be stripped. He noted that evaporator condensates
from well-oxidized weak black liquor do not result in
any significant increase in odor level.
4.2.5.2 Effect of Operating Variables upon Emissions
Data on this are not available.
4.2.5.3 Relative Importance of Lime Kiln System Emissions
Data not available
4.2.5.4 Ranges of Emissions from the Lime Kiln System
Warther and Amberg (27) have reported a range of
0.01 - 0.83 Ib/ADT of total reduced sulfur emissions
from the lime kilns of four different pulp mills.
More complete data are not now available although work
is currently under way to determine such information.
~ ->
4.2.5.5 Emissions Under Optimum Conditions
Data not available.
4-31
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4.2.6 GASEOUS EMISSIONS FROM THE MULTIPLE EFFECT EVAPORATOR
4.2.6.1 Formation of Gaseous Pollutants
Concentration of black liquor from 13 - 16 percent solids
to 48 - 55 percent is almost always carried out with a
multiple effect evaporation system. A multiple effect
evaporator arrangement serves as an economical means for
accomplishing this because in general one pound of steam
will evaporate four to five pounds of water. Usually,
five or six evaporation units (effects) make up the system.
Each effect consists of a vapor head and a heating element.
Hot vapors from the vapor head of a previous effect pass
to the heating element of the following effect. The
effects are operated at successively'lower pressures
which causes a decrease in the boiling point of the liquor.
Vapors after'the final effect are condensed'in a condenser
rapidly enough to maintain a high vacuum. A typical
multiple effect evaporator is shown in Figure 4-6.
The emissions from the multiple effect evaporators are
noncondensible reduced sulfur gases which are vaporized
or stripped during the boiling. These noncondensible
gases, with vapors created during boiling, pass to the
heating element of the following effect. In order to
eliminate an accumulation of noncondensible gases in the
heating element each heating element is provided with a
gas vent. The vents from the heating elements that are
under a pressure greater than atmospheric are vented to
its vapor head. The vents from the heating elements
under a vacuum are usually valved to a common header
going directly to either a barometric or surface condenser.
With a barometric condenser in use a limited quantity of
hydrogen sulfide and methyl mercaptan gases are soluable
in the water spray. The condensate will then become a
potential water pollution problem. A small steam jet is
used to remove noncondensible gases. If a surface condenser
is used the noncondensible gases are separated from the
condensibles. A small steam jet is used to remove the
noncondensible gases.. It is these noncondensible gases that
create the problem of air pollution from multiple effect
evaporators.
The reduced pressure in the latter effects will result in
a higher evolution of the reduced sulfur compounds. This
increased evolution and the steam stripping of the reduced
4-32
-------
45 psi
product
•*
vapor
f
Vapor Hd.
250° F
16 psig
Heating
Element
s
1
-
1
i
*
i
I
i
condensate
non-c
water, i
•Cond.
{ 1 f 1
-------
sulfur compounds are responsible for the emissions from
the multiple effect evaporators. The steam stripping
will be enhanced by the creation of foam within the
evaporator tubes, because the foam will present a greater
interfacial surface area for stripping.
4.2.6.2 Effect of Operating Variables Upon Emissions
Because emissions from the evaporators are caused by
the steam stripping of reduced sulfur compounds and
by the direct volatilization of these compounds, the
sulfidity and the pH of the liquor will tend to be
controlling factors in the quantity of gases emitted.
The effects of these variables have been discussed in
Section 4.2.1 and 4.2.3.
If weak black liquor oxidation has been performed, the
emissions will be reduced because of the removal of
the reduced sulfur compounds.
An important factor entering into the quantity of
emissions from the evaporators when unoxidized black
liquor is being processed, appears to be the type of
condenser utilized. Harding (20) presented data on
the emissions using two different types of condensers.
These data are presented in Table 4-10.
Barometric condensers provide a reduction in the emission
of reduced sulfur gases, but provide a contaminated conden-
sate which may pose a water pollution problem. These
reduced sulfur gases which have been scrubbed may be
stripped from the condensates if the condensates are later
used in the process.
Surface condensers provide a more efficient means for
the collection and later destruction of the noncondensible
gases.
4-34
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TABLE 4-10
GASEOUS EMISSIONS FROM MULTIPLE EFFECT EVAPORATORS (20)
(lb/ADT)
Condenser Type H S RSH RSR RSSR
Surface 4.80 1.44 0.35 0.62
Barometric (with loss at
noncondensible jet) 0.04 0.03 0.04 0
Barometric (losses from
hot well) 0.13 0.20 0.14 0.02
4.2.6.3 Relative Importance of the Multiple Effect Evaporator
Noncondensible emissions from multiple effect evaporators
are low volume/ highly concentrated streams, and represent
a major emission source within a kraft mill. Although
black liquor oxidation may reduce the emissions significantly,
the concentrations of reduced sulfur gases is such that
further processing of the noncondensible gases is required.
Overloading the evaporators should not increase the emissions
from the evaporator per evaporated pound of solids introduced.
4.2.6.4 Ranges of Emissions from the Multiple Effect Evaporators
TABLE 4-11
APPROXIMATE RANGES OF EMISSION FROM THE
MULTIPLE EFFECT EVAPORATORS
Oxidized Black Liquor Unoxidized Black Liquor
(lb/ADT) (lb/ADT)
Sulfur Dioxide 0.01 0-0.01
Hydrogen Sulfide 0.01-0.02 0.10-3.0
Methyl Mercaptan 0.10-0.30 0.10-1.50
Dimethyl Sulfide 0.05-0.15 0.05-0.08
Dimethyl Disulfide 0.05-0.15 0.01-0.02
4-35
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4.2.6.5 Emissions Under Optimum Conditions
Because of the wide variation in the design of multiple
effect evaporators (i.e., the number of effects, type
of evaporator use, feed locations, steam characteristics,
and the variety of condensers utilized) the variability
of conditions makes it impossible to define an optimum
set of conditions for which to predict emissions.
4-36
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4.2.7 GASEOUS EMISSIONS FROM THE BLACK LIQUOR OXIDATIOft TOWER
4.2.7.1 Formation of Gaseous Pollutants
Black liquor oxidation accomplishes the goal of converting
the volatile reduced sulfur compounds of the black liquor
to non-volatile or less volatile states. Thus the sulfide
ions of the liquor are converted to thiosulfate ions, and
the organosulfur compound are oxidized to dimethyl disulfide.
Oxidation units come in a wide variety of styles, some of
the more common styles are thin film towers, packed towers,
and bubble trays. All oxidation units attempt to provide
intimate contact between liquor and air while providing
ease of handling black liquor.
Gaseous emissions from the oxidation tower are created by
the stripping of the reduced sulfur compounds from the
liquor by the air passing through it. Comparatively large
volumes of dimethyl disulfide are emitted from this source,
which may be explained by three factors. The first is the
residual concentration of dimethyl disulfide in the liquor,
the second is the fact that the methyl mercaptan and dimethyl
sulfide are oxidized to dimethyl disulfide in the liquor,
and the third is that methyl mercaptan and dimethyl sulfide
which have been stripped into the gas may be oxidized in the
gaseous states to dimethyl disulfide. Because dimethyl
disulfide is the least volatile form of the organosulfur
compounds present in the liquor, it would be preferable to
accomplish the oxidation of the organosulfurs to dimethyl
disulfide as quickly as possible to retain as much of the
sulfur in the oxidation tower as possible.
4.2.7.2 Effect of Operating Variables Upon Emissions
The changes in operating variables which may favorably effect
emissions from the oxidation tower may also have a detrimental
effect upon the efficiency of the black liquor oxidation.
However, there has not been enough work done in this area
to discuss these effects thoroughly. It has been established
that the temperature of the liquor must be held above about
160°F in order to prevent formation of elemental sulfur.
Higher temperatures could result in a more efficient oxidation
operation (power requirements, as well as overall efficiency),
however, a higher temperature would mean greater volatility
4-37
-------
of the reduced sulfur compounds/ and hence greater
emissions. Another variable would be the air flow rate
through (or over) the liquor. (From a given flow rate of
air the effect of increasing the flow rate of air upon
the oxidation efficiency and the emissions is not established.)
Black liquor oxidation is designed to decrease the emissions
from the direct contact evaporator. For this reason the
effects of the variables mentioned above upon the emissions
from the oxidation tower must be balanced against the effect
that a greater oxidation efficiency might have upon the
emissions from sources effected by liquor oxidation. In
other words, a slight increase in emissions from the oxidation
tower created by conditions necessary for more efficient
oxidation might result in a decrease in emissions throughout
the mill of significantly greater magnitude. However, this
balance must be studied in much greater detail on individual
plants before any quantitative relationship can be developed.
In oxidation towers where oxidation is not completed to a
high percentage (99+ percent), the residual reduced sulfur
gases may be stripped from the liquor by the gases being
passed through it. In a two stage oxidation system, the
first stage would involve such a case.
4.2.7.3 Relative Importance of the Oxidation Tower
The organosulfur emissions from the oxidation tower, particu-
larily the dimethyl disulfide emissions rank as the third
largest source of emissions of this type behind the digester
relief and blow, and the multiple effect evaporators. The
emission of hydrogen sulfide and sulfur dioxide emissions
from this source is negligible and the oxidation tower as
a unit is considered a small source of atmospheric emissions.
4-38
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4.2.7.4 Ranges of Emissions from the Oxidation Towers
TABLE 4-12
APPROXIMATE RANGES OF EMISSION FROM OXIDATION TOWERS
(lb/ADT)
Sulfur Dioxide 0.00 - 0.01
Hydrogen Sulfide 0.01 - 0.02
Methyl Mercaptan 0.05 - 0.10
Dimethyl Sulfide 0.02 - 0.08
Dimethyl Disulfide 0.05 - 0.15
4.2.7.5 Emissions Under Optimum Conditions
This information is not available at the present time.
4-39
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4.2.8 GASEOUS EMISSIONS FROM THE STOCK WASHERS
4.2.8.1 Formation of Gaseous Pollutants
Emissions from the brown stock washers arise primarily
from the vaporization of the volatile reduced sulfur
compounds. There are no chemical reactions which take
place. However, there is a shift in the equilibrium for
hydrogen sulfide and methyl mercaptan. Since the washer
water has approximately a neutral pH, the dilution of the
liquor by the water will cause a lowering of the pH to
approximately 10.0. This pH is below the equilibrium
point for methyl mercaptide ion and results in a correspond-
ing shift to methyl mercaptan gas„ The lower pH will
also cause an increase in the concentration of dissolved
hydrogen sulfide. However the equilibrium point of H S
( 8.0) will not be reached.
It is therefore reasonable to expect a large proportion
of the emissions from the washers to be methyl mercaptan.
4.2.8.2 Effect of Operating Variables Upon Emissions
: There are no well defined relationships for the effect
of operating variables upon ..emissions from the washers,
but several operations can be discussed quantitatively.
The amount of air drawn over the stock washers will affect
the emissions because greater air flows will present greater
driving forces for the mass transfer of the dissolved gases
into the surrounding atmosphere.
The temperature of the water is also important because the
volatility of the hydrogen sulfide and methyl mercaptans
increases with temperature. The pH of the water also affects
the emissions as previously discussed. The turbulence of the
mixing of pulp and washer water may cause increased interface
between the atmosphere and the liquid resulting in additional
volatilization.
The thoroughness with which the liquor is removed in the first
stage washer is important. If the liquor is efficiently removed
in the first stage, the pH of the resulting weak liquor may
remain sufficiently high to limit hydrogen sulfide emissions.
There would also be less liquor in the remaining stages.
4-40
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4.2.8.3 Relative Importance of the Emissions from the Stock Washers
The emissions from the stock washers are extremely low in
all cases with the possible exception of methyl mercaptan.
4.2.8.4 Ranges of Emissions from the Stock Washers
TABLE 4-12
APPROXIMATE RANGES OF EMISSIONS FROM THE BROWN STOCK WASHERS
lb/ADT
Sulfur Dioxide 0.01 - 0.02
Hydrogen Sulfide 0.01 - 0.12
Methyl Mercaptan 0.10-0.25
Dimethyl Sulfide 0.01 - 0.02
Dimethyl Disulfide 0.01-0.02
4.2.8.5 Emissions Under Optimum Conditions
The data are not available at present.
4-41
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4.2.9 GASEOUS EMISSIONS FROM THE SMELT DISSOLVING TANK
4.2.9.1 Formation of Gaseous Pollutants
The gaseous emissions from the smelt dissolving tank
are reduced sulfur compounds. Because the organosulfur
compounds could not exist in the smelt at the smelt
temperature, their presence in the vent gases must be
accounted for by the introduction from outside sources.
One such source might be the drafting of gases from the
reducing zone of the furnace through the smelt spout of
the furnace into the smelt tank. The natural draft of
the smelt tank might cause a sufficient draft upon the
furnace gases to pull these through a partially filled
spout. Another source of organosulfur compounds might
be the water used for smelt dissolving. In some instances,
condensate water bearing these compounds is introduced
to the causticizing system by way of the lime kiln
scrubber and subsequently reach the smelt tank. A study
of the water cycle from the scrubber will show that a
portion of these condensates may eventually enter the
smelt tank (see Kraft Flow Diagrams, Chapter Three) where
the temperature would be favorable for volatization.
However, the effect of such condensates in the smelt
tank is believed to be very small.
Of course the chemical equilibrium of sulfide ion created
by the dissociation of sodium sulfide, will create a
condition for hydrogen sulfide emission resulting from
stripping.
4.2.9.2 Effect of Operating Variables upon Emissions
Because the smelt tank is essentially an uncontrolled
reaction vessel, there are no operating variables which
can effect the emissions. However, proper design of the
smelt spout could alleviate some of the emissions resulting
from gases drawn from the recovery furnace.
4.2.9.3 Relative Importance of the Smelt Tank
The smelt tank is a minor source of emission of all gaseous
compounds emitted from the kraft recovery system.
4-42
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4.2.9.4 Ranges of Emissions from the Smelt Tank
TABLE 4-14
APPROXIMATE RANGES OF EMISSIONS FROM THE SMELT TANK
(lb/ADT)
Sulfur Dioxide 0
Hydrogen Sulfide 0.02 - 0.05
Methyl Mercaptan 0.02 - 0.05
Dimethyl Sulfide 0.01 - 0.02
Dimethyl Disulfide 0.0 - 0.01
4.2.9.5 Emissions Under Optimum Conditions
The data are not currently available.
4-43
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4.3 PARTICULATE EMISSIONS FROM THE KRAFT PROCESS
4.3.1 PARTICULATE EMISSIONS FROM THE KRAFT PROCESS - GENERAL
Particulate emissions from the kraft process occur primarily
from the recovery furnace, the lime kiln, and the smelt
dissolving tank. They are caused mainly by the carry-
over of solids plus the sublimation and condensation of
inorganic chemicals. The sublimation and condensation
normally produces a fume. Little information is avaialble
on the actual range of particle sizes from these sources,
especially in the recovery furnace when agglomeration tends
to occur readily. In addition, particulate emissions occur
from combination and power boilers.
4.3.2 PARTICULATE EMISSIONS FROM THE RECOVERY FURNACE AND DIRECT
CONTACT EVAPORATORS
4.3.2.1 Particulate Formation
Particulate emissions from the recovery furnace and direct
contact evaporator complex consist primarily of sodium sulfate,
and sodium carbonate. These emissions may result from both
of the processes previously described. The high flue gas
velocity may cause the carry-up of small droplets of black liquor
which have been sprayed into the furnace. These droplets should
burn in the oxidizing zone, but some of them may escape from
the furnace.
The inorganic sodium salts which are found in particulate
emissions from the furnace may be carried up by the furnace
draft or may be formed in a vaporization - condensation
process.
There are no particulates contributed by the direct contact
evaporator. In fact, the evaporator may serve as a particu-
late reduction device, the method of reduction depending upon
the type of evaporator in use.
4.3.2.2 Effect of Operating Variables Upon Emission
The portion of the sodium salt particles created by
the sublimation-condensation process is not controllable
because the initiating step, sublimation, takes place on
the smelt pile where control is virtually impossible.
4-44
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The portion of the particulate emissions which are
attributable to the carry-up of black liquor solids is
controllable to a small extent. The amount of solids
carried up by the induced draft is dependent upon the
spray droplet size and the vertical velocity in the
furnace (see Section 4.2.2.2). Thus a large spray
"droplet size will reduce the carry-up of solids within
the furnace. '
Once in the oxidizing zone of the furnace, the solids
will burn to gaseous and solid." products. The solid
products will initially consist of sodium sulfate,
sodium carbonate, and organic solids. The sodium
carbonate may react with the flue gas sulfur dioxide
and oxygen to form additional sodium sulfate. The
extent of this conversion will depend upon the sulfur
dioxide concentration in the gas.
The organic solids will undergo a combustion-oxidation
reaction. In most instances the oxidation will not be
100 percent efficient and some carbon residue will escape
from the furnace. The operating conditions of temperature,
percent excess oxygen, turbulence, and residence time will
affect the efficiency of this reaction.
As mentioned in the previous section, the particulate
concentration may be reduced when the flue gas passes
through the direct contact evaporator. In a cascade
evaporator a high flue gas velocity will provide a greater
impingement rate for the particulates than a lower velocity.
A Venturi evaporator can actually serve as a particulate
scrubber.
Particulate emissions from the recovery furnace-direct
contact evaporator complex are dealt with more effectively
with particulate control devices such as electrostatic
precipitators and Venturi scrubbers. It would be more
advantageous to control furnace operating conditions to
minimize gaseous emissions rather than particulate emissions,
Although most conditions resulting in reduced gaseous
emissions also serve to reduce particulate emissions.
4-45
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4.3.2.3 Relative Importance
The kraft recovery furnace is the largest source of
particulate emissions in the pulping system. Particulate
control devices currently in use remove 80 - 99 percent
plus of the particulates from the flue gas.
4.3.2.4 Ranges of Emissions
The range of particulate emissions from the recovery furance
and direct contact evaporator (cascade and cyclone) is 75 -
125 Ib/ADT without control devices. Using a 90 percent
venturi evaporator scrubber after the furnace, the particulate
emissions are in the range of 2- - 40 Ib/ADT.
4.3.2.5 Emissions Under Optimum Conditions
These data are not currently available.
4.3.3 PARTICULATE EMISSIONS FROM,THE LIMg KILN
4.3.3.1 Particulate Formation
Particulate emissions from the lime kiln consist of the
sodium salts, calcium carbonate, calcium sulfate, calcium
oxide, and insoluble ash. The presence of the sodium salts
may be accounted for by the sublimation-condensation process
described in Section 4.3.2.1 and by dust entrainment within
the kiln. However, neither calcium carbonate, nor calcium
oxide will vaporize at temperatures within the kiln and
the presence of calcium carbonate and calcium sulfate must
be explained by the entrainment of the calcium carbonate
and calcium oxide. The particles of calcium oxide may
react with either the carbon dioxide or sulfur dioxide within
the kiln to yield the appropriate calcium salt. Calcium
carbonate may react with the sulfur dioxide and then oxygen
to yield calcium sulfate.
4-46
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CaO + C02 CaC03 Eq. 4.19
CaO + SO CaSO Eq. 4.20
£• *J
CaCO3 + S02 CaS03 + CO Eq. 4.21
CaS03 + 1/20 CaS04 Eq. 4.22
The presence of the ash may stem from the burning of the
fuel oil in the kiln.
4.3.3.2 Effect of Operating Variables upon Emissions
Other than controlling the rate of material output there
appears to be no way of controlling the particulate emission
for the lime kiln through manipulation of operating
variables.
4.3.3.3 Relative Importance of Lime Kiln Particulate Emissions
The particulate emissions from the lime kiln (before the
control equipment) are about one-fourth, the emissions from
recovery furnace but are still significantly large. However,
the relatively low gas flow rates through the lime kiln
allow installation of moderately priced high efficiency
wet scrubbers which can reduce particulate emissions to
low levels. At the present time, most lime kilns are
equipped with wet scrubbers whose efficiencies range from
80 - 99 percent on the calcium salts. The particulate
emissions from the lime kilns whose scrubber efficiencies
are in the lower part of the range may be significant.
4.3.3.4 Ranges of Emission from the Lime Kiln
The range of particulate emission from the lime kiln
before the particulate control equipmentis 20 - 65
Ibs/ADT.
4.3.3.5 Emission Under Optimum Conditions
These data are not currently available.
4-47
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4.3.4 PARTICULATE EMISSIONS FROM THE SMELT DISSOLVING TANK AND
SLAKE TANK
The range of particulate emissions from the smelt dissolving
tank and slake tank are of a low magnitude (1.0 - 4.0 Ib/ADT
and 4.0 - 6.0 Ib/ADT respectively). The emissions are primarily
caused by the entrainment of large particles in the vent gases.
Because of the violent reactions taking place in each of these
tanks, it is reasonable to expect that the turbulence of the
dissolving water will splash water droplets containing both
dissolved and undissolved inorganic salts above the surface.
Here, because of the high temperature of the vent gases, the
water may evaporate leaving the solid particles in suspension
above the liquid. These particles may be carried out by the
vent gases if they are not of sufficient weight to drop back
into the liquid.
4-48
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4o4 NSSC PROCESS - GENERAL
"As in the acid suliite process, neutral sulfite pulping
depends on sulphonatio.i and hydrolysis of tne lignin to
softer, the rigid matrix in which the wood fibers are
bound together. Since suiphonation takes place slowly
and to a land.red extent, involving "A" groups cf lignin
only, high temperatures in the range of 160 to ISO'C
are required to complete the reaction, within a reasonable
time. Although the dissolution of the lignin is described
as a two-stage process-sulphonation followed by hydrolysis-
soiubilization begins quite soon, since some of the lignin
molecules- are small enough to dissolve immediately on
suiphonation, in contrast to the ^arge molecules which
must hydrolyze before they can pass into solution"(21) .
"In semichemical pulping perhaps one-half or less of the
total lignin is removed. In preparing bleachable pulps,
it is not economical to cook much below a lignin content
of 10 percent in the pulp because cooking time, carbohydrate
loss, and chemical requirement increase disproportionately.
Although the neutral character of the liquor is a handicap
in suiphonation, it is beneficial insofar as it reduces
loss of carbohydrate by hydrolysis. This contributes to
the exceptionally high yield and strength of NSSC pulps"(21).
Because of the difference in the chemical attack on the lignin
using sulfite liquors, such compounds as methyl mercaptan
and dimethyl sulfide are not formed during digestion. The
NSSC process should therefore be free from these odorous
compounds. In addition, the absence of sulfide ions from
the cooking liquor will virtually eliminate hydrogen sulfide
as a possible emission,
NSSC pulp mills handle the spent cooking liquor in a variety
of manners. Many NSSC mills are located on the same property
as kraft mills. In these instances the spent cooking liquor
can be mixed with the kraft black liquor and serve as make-
up chemicals for the kraft processc A process similar to this
is shown in the NSSC Flow Diagram No, 1 located in Chapter 5.
It is possible to recover some of the chemicals from the
smelt tank to provide fresh cooking liquor for the NSSC
pulping although this is not shown -
4-'i9
-------
Another method of handling the spent cooking liquor is to
simply discharge the liquor to settling ponds/ soil filtration
or aeration units without an attempt to recover the chemicals.
Such a system obviously will cause stream pollution. In
the system shown in NSSC Flow Diagram No. 2, a percentage
of the spent liquor is mixed with the fresh cooking liquor
while the remaining spent liquor is discharged to the sewer.
For NSSC mills which do not have kraft recovery systems
available, the chemicals of the spent liquor may be
recovered in a fluidized bed reactor in the form of sodium
sulfate and sodium carbonate. A fluidized bed recovery
system is shown in NSSC Flow Diagram No. 3.
In each of the spent liquor handling systems mentioned above
cooking liquor must be prepared from fresh chemicals. There
are two methods available for the preparation of fresh liquor.
One is to mix soda ash and sodium sulfite together with the
proper amount of water. Spent cooking liquor may be used
to provide some of the chemicals and water.
Another method is to burn raw sulfur to sulfur dioxide in
a sulfur burner and subsequently absorb the SO in an absorp-
tion tower using a soda ash solution for an aqueous medium.
Atmospheric emission sources from an NSSC mill are limited
to SO. absorption towers, blow pits, spent liquor evaporators,
and fluidized bed reactors. In the case of spent liquor
recovery in a kraft mill recovery system, the NSSC liquor
will have an effect upon the emissions from the kraft recovery
system. Each of these sources will be discussed in the
following sections.
The quantities of atmospheric emissions from the NSSC emissions
sources are unknown at the present time and subsequent discussions
deal with qualitative aspects of emissions from the NSSC systems
only.
4-50
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4.4.1 GASEOUS EMISSIONS FROM THE NSSC PROCESSES
4.4.1.1 Sulfur Dioxide Absorption Tower
Sulfur dioxide absorption towers generally are counter-
current packed towers using sodium carbonate (soda ash)
as the absorbing medium. The chemical absorption takes
place according to the following reaction:
2 Na + C03 = +SO2 -»• 2 Na+ + S0~ + CO f Eq. 4.23
This reaction will lead to the emission of carbon dioxide.
Sulfur dioxide may also be absorbed in water according
to the following reaction:
HOH + SO2 -> 2 H+ + SO~ Eq. 4.24
Nearly total absorption of sulfur dioxide in the tower is
feasible in a properly designed and operated tower. The
quantity of sulfur dioxide emitted from the tower will
depend upon the efficiency of operation. Quantitative data
of the emission of sulfur dioxide is therefore dependent
upon the design and operating conditions of the individual
towers.
4.4.1.2 Blow Pit
When the cooked pulp is blown into the blow pit, large
amounts of steam and gases escape from the pulp and spent
liquor. Sulfur dioxide seems to be the major gaseous
emission from the blow pits . Recently, recovery systems
have been installed to recover- the sulfur dioxide from
the blow pit gases . Installations in NSSC mills have been
of individualistic design but all installations are based
upon the absorption of sulfur dioxide by wet scrubbing
either in the vent stack or by routing the gas through
an SO absorption tower. Again the efficiency of operation
will dictate the quantity of sulfur dioxide emissions from
the blow pit.
4.4.1.3 Fluidized Bed Reactor
Fluidized bed reactors have been developed for NSSC mills
which do not have kraft mill recovery facilities for
disposing of their spent liquors. Fluidized beds can
4-51
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accomplish the complete oxidation of organic wood constituents
in the liquor yielding gaseous products of carbon dioxide, water,
and minute traces of other organic compounds. Recovery of
the cooking chemicals is in the form of sodium sulfate and sodium
carbonate. These chemicals may be reused as kraft mill make-up
chemicals. The ratio of sodium sulfate to sodium carbonate
products may be controlled by the operating conditions in the
fluidized bed.
In principle the spent cooking liquor is concentrated to
approximately 30-40 percent solids and is sprayed into the
top of the bed. As the liquor falls and comes into contact
with the rising gases evaporation occurs. The temperature
of the gases above the bed is approximately 800-1000°F.
The partially dried liquor will either fall onto the bed
or deposit on rising entrained dust particles and become
thoroughly dried. As these particles grow they become too
heavy to become entrained and will stay on the bed. Entrained
particles which escape the reactor are collected in suitable
mechanical dust collectors and are returned to the bed.
At the temperatures found above the bed, essentially none of
the organic chemicals will undergo oxidation. The temperature
of air supplied to the bed is approximately 1100-1200°F, while
the bed temperature is in the range of 1200-1400°F, slightly
higher than the air supplied because of the exothermic
reactions taking place.
Under normal operating conditions atmospheric emissions
from a fluidized bed reactor with dry and wet mechanical
control devices are low. However, data on the actual
emissions are not currently available.
4.4.1.4 Recovery in Kraft Systems
Precise data are not available on the effect which mixing spent
NSSC liquor with kraft black liquor has upon the emissions from
kraft recovery units from the point at which they are mixed up
to and including the recovery furnace. However, the greatest
effect that the mixing will have is to lower the pH of the
kraft liquor. Section 4.2 details the importance of maintaining
a high residual pH of the kraft black liquor during the recovery
process. The effect of this mixing must be studied in greater
detail.
4-52
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4.5 EMISSIONS FROM THE SULFITE PROCESS
4.5.1 EMISSIONS FROM THE SULFITE PROCESS - GENERAL
There are four classes of sulfite pulping liquors: acid
sulfite, bisulfite, neutral sulfite, and alkaline sulfite.
Table 4-15 gives the predominant cooking chemical and
initial pH of each of the classes. These two variables
determine which class of sulfite pulping that a particular
mill practices.
Calcium, sodium, magnesium, and ammonia are the four base
chemicals around which the sulfite processes have been
designed. At a pH below 6, it is proper to represent the
sulfite in the cooking liquor as hydrosulfite ion (HSO ]_
while above this pH it is represented as sulfite ion(SO_).
The calcium and sulfite combination is insoluble in aqueous
solution of pH above 2. Hence, calcium sulfite cooking
liquors are limited to the acid sulfite processes. Magnesium
sulfite is soluble in solutions whose pH is below 7 (approxi-
mately) , and it may be used in acid sulfite, bisulfite, and
over the lower end of the neutral sulfite range of pH.
Ammonium sulfite is soluble in solutions of a pH below 9
(approximately), while sodium sulfite is soluble over the
entire range of pH. The desired range of pH for the cooking
liquor will dictate the type of cooking chemicals which can
be used.
As in the kraft pulping process, the objective of the sulfite
cook is to dissolve the lignin in a wood chip and leave a
fiber group which may be dispersed into an aqueous suspension
suitable for paper making. The method of attack by sulfite
liquors on lignin is different than the kraft liquor chemical
attack. The sulfite and neutral sulfite processes involve
lignin sulphonation, acid hydrolysis, and acid condensation (22)
In sulfite cooking, the products of lignin-sulfite reactions
do not produce volatile reduced sulfur compounds such as
methyl mercaptan and dimethyl sulfide.
Sulfur dioxide is the principle atmospheric emission from
the sulfite processes. The main causes of SO release are
stripping by gas streams and volatilization during periods
of high liquor temperature. Hydrogen sulfide emissions are
possible during recovery of the spent liquors if the recovery
system is not maintained under proper oxidizing situations.
4-53
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TABLE 4-15
PREDOMINATE CHEMICALS AND pH
OF SULFITE COOKING LIQUORS (23)
Approximate
Predominate Chemical initial pH
Name in Cooking Liquor at 25°C
Acid sulfite H->s°o + XHSO 1-2
^ J .J
Bisulfite XHSO 2-6
Neutral sulfite XSO + XCO 6-9+
•3 j
Alkaline sulfite XSO + XOH 10+
4.5.2 GASEOUS EMISSIONS FROM SULFITE PROCESSES
4.5.2.1 Gaseous Emissions from Absorption Towers
Industrial absorption towers for sulfite processes are usually
packed towers or Venturi absorbers. In the case of packed towers,
sulfur dioxide gas is introduced in the bottom of the tower
while a corbonate solution of the desired base (sodium, etc.) is
introduced at the top of the tower. In the case of calcium, lime-
rock (CaCO ) is introduced as packing into the tower. Sulfur
dioxide reacts with water to yield an acidic solution.
v
acidic '
2H+ + SO~ -> H+ + HSO~ -*• H SO -> HO + SO Eq. 4.25
j X^ J * ^ J ^" £t f+
, basic
v
Carbonate in solution will undergo an adjustment in equilibrium
as the hydrogen ion concentration increases. The result is the
production of carbon dioxide gas.
CO~ + H+ J CO \ + HO Eq. 4.26
This reaction depletes the concentration of hydrogen ion
and tends to maintain a constant pH.
Acid fortification towers are absorption towers. Weak cooking
liquor is passed through the tower for the purpose of absorbing
additional sulfur dioxide. This replenishment of sulfite in the
liquor offsets the sulfite lost through mill emissions as sulfur
dioxide or combined in lignosulphonic acids in the pulping process.
4-54
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Sufficient data are not available to adequately determine
a range of sulfur dioxide emissions for gas absorption
towers. The quantity of sulfur dioxide gas delivered
to the absorption tower will depend upon the desired
pH and strength of-inorganic chemicals in the cooking
liquor. Currently available data show that the sulfur
dioxide emissions from the absorption tower are in the
range of 15-20 Ib/ADT before secondary scrubbing of
the overhead gases.
4.5.2.2 Gaseous Emissions from Digester Relief and Blow Gases
Gaseous sulfur dioxide emissions from digester relief
and blow gases stem from the temperature increase of
the cooking liquor. Gases in general become less soluble
in aqueous solutions during temperature rises. Sulfur
dioxide is such a gas. Temperatures in the digester
may range from 120°C to 180°C. When relief lines are
opened and the pressure within the digester is relieved
large quantities of sulfur dioxide will be emitted with
the escaping steam.
There are three methods of discharging the-digester; hot
blowing, cold blowing, and flushing. In a hot blow, the
pressure in the digester is relieved to a predetermined
level and the contents are then blown into a blow pit.
In cold blowing, the pressure in the digester is relieved
to a low level and the contents are then pumped into a
dump tank below the digester. Spent liquor is introduced
into the bottom cone of the digester to reduce pulp
consistency and aid discharge.
In the flushing system, after the digester has been relieved,
spent liquor or hot water is pumped into the digester for
several minutes at a high rate. The blow valve is then
opened and the pulp is discharged while the flushing liquid
continues to enter the digester.
The three types of digester discharge affect the amount
of sulfur dioxide which is emitted to the atmosphere.
Gases which leave the digester during relief are sent
4-55
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to the accumulators where they fortify the cooking liquor.
The gases which pass through the accumulators are sent
to other areas in the process where they may be absorbed.
However, blow tanks and dump tanks are usually vented
to the atmosphere. Gases carried from the digester to
these tanks may therefore be sources of emissions. Recent
installation of gaseous control devices on blow pit gases
will reduce these emissions.
A review of the digester discharge systems shows that for
the hot blow style the pressure is only partially relieved
before the blow is made. The digester gases which were not
relieved will be sent to the blow pit during the blow.
Significant quantities of sulfur dioxide are therefore
emitted in this style of discharging if no recovery is
practiced.
In the cold blow and flushing style of discharging the digester,
the pressure is almost fully relieved, and the relief gases
are routed to the accumulators. That fraction of the gases
which remains in the digester may then escape from the system
when the pulp is discharged to the dump tanks. Table 4-16
shows what ranges of sulfur dioxide emissions might be
expected from the blow pit vent stack.
TABLE 4-16
APPROXIMATE EMISSIONS FROM BLOW PIT OR DUMP TANK VENTS
(WITHOUT SCRUBBING)
Blow Pit 100 - 150 Ib/ADT
Dump Tank 10-25 Ib/ADT
4.5.2.3 Gaseous Emissions During The Recovery of Spent Cooking
Liquors
Practices in the recovery of the base used in pulping
differs widely from mill to mill, as researchers find
more effective methods of chemical reclamation. Because
of the variety of chemical and physical properties
exhibited by the base chemicals, calcium, sodium,
magnesium, and ammonia, different processes have been
developed to satisfy the handling and recovery problems
peculiar to each base. In some instances no attempt
is made to recover the chemical or sensible heat of the
spent liquors, or in some cases only the heat is recovered.
4-56
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The four sulfite processes presented in the flow
diagrams located in Chapter 3 represent the four
most widely used processes and the attendant recovery
systems. They will be the recovery processes which
will be discussed primarily in this section.
"In the case of calcium base liquors the scaling of
evaporator surfaces, the need for all stainless-
steel equipment, the relatively low value and the
chemical complexity of the resultant smelt, and
the difficulty with fly ash" (24) have led to
the common practice of simply disposing of the spent
liquors by a convenient means and making no attempt
to recover the heat or chemicals. Sulfite mills
which incorporate these processes usually utilize
sulfur dioxide absorption towers in conjunction with
a sulfur burner as shown in Sulfite Plow Diagram
No. 2. The digester relief gases also may be routed
through the accumulator tanks for recovery of sulfur
dioxide. Gases vented to the accumulators are further
routed through the acid-making system to recover as
much SO as possible. Spent liquors which are disposed
of by means of a sewer may present severe water
pollution hazards.
Spent "liquor from several magnesium sulfite processes
can be burned in a simple heat- "arid chemical-recovery
system in which the inorganic salts break down into
magnesium oxide -and sulfur dioxide. These chemicals
can then be recombined directly to produced magnesium
bisulfite acid for cooking" (25). Sulfite Flow
Diagrams No, 1 and 3 show variations of such a process.
A thorough discussion of the recovery process principles
may be found in "The Pulping of Wood" (25).
The sulfur dioxide produced in the recovery furnace is
carried out and through a dust collector before entering
the direct contact evaporator. These evaporators are
designed to prevent absorption of the SO in the evaporating
liquor, so that all SO may be sent to the absorption
tower.
4-57
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The venturi absorption towers absorb the sulfur dioxide
with a solution of magnesium hydroxide. Sulfur dioxide
enters the towers from the recovery furnace as well as
from the fortification towers, and/or the digester.
Magnesium hydroxide readily absorbs the sulfur dioxide.
Absorption efficiencies of the venturi absorption systems
range from 95 - 98+ percent. Sulfur dioxide emissions
from the absorption system range from 10 - 25 Ib/ADT
of pulp.
"At present there is no process in commercial operation
for the recovery of pulping chemicals from ammonium-base
spent cooking liquors" (26). Many ammonium acid sulfite
mills simply incinerate their waste liquors in combination
boilers to recover the heating value of the liquor. Such
a system is demonstrated in Sulfite Flow Diagram No. 4.
Sulfur dioxide emissions from such incinerators are in the
range of 250 - 500 Ib/ADT.
Sulfur trioxide emissions from recovery furnaces and
incinerators are possible if close control is not taken
over the excess oxygen in the flue gases as well as its
temperature. A common means for controlling SO_ formation,
other than oxygen control, is the use of cooling towers
which cool the sulfur dioxide below the temperature required
for conversion to sulfur trioxide. Quantitative data of
the emission of sulfur trioxide are not available.
4.5.2.4 Emissions from Multiple-Effect Evaporators
Multiple-effect evaporators which concentrate spent liquors
are a source of sulfur dioxide emissions. Such emissions
are evolved because of the high temperature and low pressure
conditions in the effects. The type of condenser has an
effect on the sulfur dioxide emissions. Adequate contact
between the sulfur dioxide and the cooling water will remove
a large portion of the gas.
Sulfur dioxide emissions from the multiple effect evaporators
are in the range of 5 - 10 Ib/ADT of pulp.
4-58
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4.6 AUXILIARY FURNACES
The atmospheric emissions of sulfur dioxide and fly ash
from auxiliary furnaces are directly dependent upon the
amount of sulfur bearing fuels which are burned in the
furnace. The amount of energy which must be provided
by the auxiliary furnaces is directly dependent upon
the total energy requirements of a mill and the amount
of this energy which can be furnished by the recovery
system. This energy demand on the auxiliary furnace
is highly individualistic for each pulp and paper mill.
A common source of fuel for auxiliary furnaces is wood
bark. Bark has a heating value of approximately
4,500 BTU/lb., and is readily available in mills which
use roundwood. Bark burning produces very little
sulfur dioxide; approximately 1 Ib.SO /1000 Ibs. bark.
Fly ash from bark burning is in the range of approximately
10 - 20 Ib. ash/1000 Ibs. bark.
Fuel oil is another common fuel used in auxiliary furnaces.
Fuel oil contains varying percentages of sulfur which forms
sulfur dioxide in the oxidizing atmosphere of the furnace.
Fuel oil has a heating value of approximately 19,000 BTU/lb.
The quantity of sulfur dioxide formed in the combustion
of fuel oil, assuming efficient combustion, depends mainly
upon the sulfur content of the oil, which is usually in
the range of 1 - 6 percent. A convenient formula for
determining the amount of sulfur dioxide produced in the
combustion of fuel oil is:
pound SO formed _ pounds sulfur 2 pounds SO 1nnn
_ ^ —~ X ^ X J-U \J \J
1000 ; r:— , — :: r, •= ' ., ,.
pounds oil burned pound fuel oil pound sulfur
The fly ash formation of fuel oil ranges from 0.9 - 1.0 Ibs.
ash/1000 Ibs oil.
Coal is another fuel used in auxiliary furnaces. Coal has
a heating value of 14,000 BTU/lb. Like fuel oil, the sulfur
content of coal is usually in the range of 1 - 6 percent.
The quantity of sulfur dioxide formed in the combustion of
coal may be found by using the equation shown above. The
fly ash produced by burning coal is higher than that of fuel
oil, and is in the range of 60 - 80 lbs/1000 Ib coal.
Natural gas is another fuel which is now being used to a
limited extent for auxiliary furnaces. Its heating value
is 1,000 BTU/ft . The sulfur and ash content of natural
gas may be considered negligible.
4-59
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Table 4-17 summarizes the data.
TABLE 4-17
SULFUR DIOXIDE AMD FLY ASH PRODUCTION FROM THE COMBUSTION
OF ASSORTED FUELS IN AN AUXILIARY FURNACE
SO Fly Ash
(lb/1000 Ibs fuel) (lb/1000 Ibs fuel)
Bark 1.0 - 1.5 10 - 20
Oil (2% S) 40 0.9 - 1.0
Coal (2% S) 40 60 - 80
Natural Gas Trace Trace
Because of the varied power requirements placed upon the auxiliary
furnaces by the assorted pulping and paper making systems, it
is beyond the scope of this chapter to attempt to give emissions
of sulfur dioxide and fly ash from the auxiliary furnaces in
terms of pounds per air dry ton of pulp. However the flow diagrams
and the associated heat and energy balances presented in Chapter
3, may give the reader an idea of the energy requirements placed
on the auxiliary furnace. The flow diagrams show how these
requirements can be satisfied using the fuels discussed here, and
the emissions of sulfur dioxide and fly ash which might result.
4-60
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4.7 SUMMARY OF EMISSION DATA
Table 4-18 summarizes the approximate ranges of emissions for
the principle gaseous sulfur compound-and particulate emissions
from the kraft pulping and recovery system. Table 4-19 summarizes
the approximate ranges of sulfur dioxide and fly ash formation
in the combustion of fuels in the auxiliary furnaces.
Because of the variety and complexity of the pulping and
recovery systems used in the sulfite and NSSC processes,
a meaningful table cannot'- be presented here. The reader is
referred to the flow diagrams in Chapter Three to obtain the
emissions of a particular system.
4-61
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i
(T>
to
TABLE 4-18
SUMMARY OF EMISSION DATA - KRAFT PROCESS
(Emissions in Ib/ADT)
Digester Relief & Blow
Brown Stock Washers
Oxidation Towers
so2
T - 0.01
0.01 - 0.02
0 - 0.01
Multiple Effect Evaporators OX. 0.01
UNOX. 0 - 0.01
Direct Contact Evaporators OX. 2.0-8.0
UNOX. 2.0 - 8.0
Recovery Furnace 10 - 15
Smelt Tank 0.0 - 0.01
Lime Kiln DATA
0.01 -
0.01 -
0.01 -
0.01 -
0.10 -
0.10 -
5.0 -
1.0
0.02
NOT
MeSSMe
0.20 - 1.50
0.01 - 0.02
Particulate
; MeSH MeSMe
0.12 0.02 - 0.40 0.40 - 2.5
0.12 0.10 - 0.25 0.01 - 0.02
0.02 0.05 - 0.10 0.02 - 0.08 0.05 - 0.15
0.02 0.10 - 0.30 0.05 - 0.15 0.05 - 0.15
3.0 0.10 - 1.50 0.05 - 0.08 0.01 - 0.02
2.0 0.05 - 0.25 0.01 - 0.10 0.01 -'0.20 75-125(cascade)
20-40 (venturi)
- 30.0 0.50 - 2.50 0.10 - 0.30 0.10 - 0.40 75-125(cascade)
20-40 (venturi)
- 5.0 0.01 - 0.10 0.01 - 0.02 0.01 - 0.02
- 0.05 0.02 - 0.05 0.01 - 0.02
0 - 0.01 1.0 - 4.0
AVAILABLE - TRS - 0.01 - 0.83
20 - 65
-------
TABLE 4-19
SUMMARY OF SULFUR DIOXIDE-AND FLY ASH FORMATION
IN AUXILIARY FURNACE COMBUSTION
SO Fly Ash
(lb/1000 Ib fuel) (lb/1000 Ib fuel)
Bark 1.0 - 1.5 10 - 20
Fuel Oil (2% sulfur) 40 0.9-1.0
Coal (2% sulfur) 40 60 - 80
Natural Gas Trace Trace
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4.8 REVIEW OF EMISSION STANDARDS APPLICABLE TO PULP MILLS
A variety of emission regulations is in effect in many city, county,
regional, and s tate abatement areas in the U.S. In addition to
general nuisance provisions, specific emission limitations are
in effect on particulates, individual gaseous compounds, and classes
of compounds. Some of these limitations, such as. emissions of
particulates, sulfur dioxide, hydrogen sulfide, arid total reduced
sulfur compounds (TRS) may be applied to chemical pulp mills.
In some localities an attempt is made to apply to pulp mills the
process weight table originally developed in Los Angeles County.
This is an inappropriate application of the process weight table
which was developed for and applied to the metallurgical industry.'.
The process weight concept represents the state of the art on
emissions control from metallurgical processes. The nature and
size range of particulates, as well as the characteristics of the
processes themselves, are vastly different from the recovery and
calcining operations involved in chemical pulping.
As of late 1969, in states where pulp mills are located, regulations
specific to pulp mills were to be found in Washington, Oregon, and
Humboldt County, California. In all cases the rules are applicable
to kraft mills only.
Provisions of the Washington and Oregon regulations are identical
with respect to emission limitations. All limitations are stated
per ton of air dry pulp produced. Principal provisions of the
regulations include:
(a) TRS Compounds from the recovery furnace: No
more than 2 pounds per ton (1972) reduced to
no more than 1/2 pound per ton by 1975.
(b) Noncondensible gases from the digesters and
multiple effect evaporators: Collected and
burned in the lime kiln or proven equivalent.
(c) Particulates from the recovery furnace: No
more than 4 pounds per ton.
(d) Particulates from lime kiln: No more than
1 pound per ton.
(e) Particulates from smelt tank: No more than
1/2 pound per ton.
4-64
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The principal provisions of the Humboldt County regulations
specific to pulp mills include:
(a) TRS compounds from any single emission point:
No more than the total daily weight calculated
by the formula:
- 2
TRS (pounds per day) = 0.012 (H )
s
where H, is the height in feet of the emission
point above mean ground elevation.
(b) Total maximum allowable monthly TRS emissions
to the atmosphere: No more than one pound
per ton of dry wood charged into the [pulping]
process.
(c) Maximum allowable ground level concentration of
TRS, expressed as H»S: No more than 0.03 ppm
for no longer than 60 minutes.
In Washington and Oregon (29) the regulations were developed in
cooperation with representatives of the kraft pulping industry.
The most important sources of odors and paocticulates weze
identified, the state of the art in emissions control was
determined, and developments in new technology were assessed.
The regulations consider best available technology and uniqueness
of process.
The states of Washington and Oregon presently are developing
regulations for atmospheric emissions from sulfite mills.
By mid-1970, Air Quality Regions called for by the Air Quality
Act of 1967 will be designated in all of the states. The
criteria and control documents for SO and particulates have
been published by NAPCA. Thus more stringent SO and particulate
emission standards would appear inevitable under this program.
Present plans by NAPCA call for publication of some 35 criteria
documents (including one for odors) by 1975. Application of
emission standards in the states should follow within about 15
months of publication.
4-65
-------
4.9 REFERENCES
1. CederLSf, R., Edfor, M. L., Friberg, L., Lindvall, T., Nordisk
Hygenish Tidskrfit 46, 51, (1965).
2, Leonardia, G. , Kendall, D., Barnard, N., "Odor Threshold Determinators
of 53 Odorant Chemicals" J. APCA 19 (2), 91-5, (1969).
3. Young, F. A., Adams, D. R., Sullivan, Dobbs, "The Relationship
between Environmental-Demographic Variables and Olfactory Detection
and Objectionability Thresholds" to be published in Perception and
Ps chophysics.
4. "Handbook of Air Pollution" U. S. Department of H.E.W., P.H.S.,
Bureau of State Services. Division of Air Pollution, Cincinnati,
Ohio.
5• "The Merck Index" 8th Edition, Merck and Co., Inc., Rahway,
N. J., 1968.
6. Douglass/ I. B., "Some Chemical Aspects of Kraft Odor Control",
J. APGA 18 (8)/ 543, (1968)
7. McKean, W. R., Hrutfiord, B. F., Sarkanen, K. V., "Effect of
Kraft Pulping Conditions on the Formation of Methyl Mercaptan
and Dimethyl Sulfide," TAPPI, 50_ (8) , 400-05, (1968)
8. McKean, W. R., Hrutfiord, B. F., Sarkanen, K. V., "Kinetic Analysis
of Odor Formation in the Kraft Pulping Process," TAPPI, 48_ (12) ,
699-703, (1965).
9. Shih, T. T., Hrutfiord, B. F., Sarkanen, K. V,, Johanson, L. N.,
"Methyl Mercaptan Vapor-Liquid Equilibrium in Aqueous Systems
as a Function of Temperature and pH'," TAPPI, 5£ (12), 634-8, (1967).
10. Murray, F. E., Rayner, H. B., "The Emission of Hydrogen Sulfide
from Kraft Recovery Furnaces," Pulp and Paper Magazine of Canada,
69_ (5) , 71-4, (1968) .
11. Blosser, R. O., Cooper, H. B., Megy, J. A., Duncan, L., Tucker,
T. w., "Factors Affecting Gaseous Sulfur Emissions in the Kraft
Recovery Furnace Complex," Paper Trade Journal 153 (21), 58-59,
(1969) .
4-66
-------
12. Harding, C. I., Landry, J. O., "Future Trends in Air Pollution
Control in the Kraft Pulping Industry," TAPPI, 4_9_ (8), 61-7a,
(1966).
13. Thoen, G. N., DeHaas, G. G., Tallent, R. G., Davis, A. S., "The
Effect of Combustion Variables on the Release of Odorous Sulfur
Compounds from a Kraft Recovery Unit," TAPPI, 5.1 (8), 329-33,
(1968).
14. Murray, F. E., Rayner, H. B., "Emission of Hydrogen Sylfide
from Kraft Black Liquor during Direct-Contact Evaporation,"
TAPPI, 48_ (10), 588-92, (1965).
15. "The Pulping of Wood," MacDonald, R. G., Volume I, Second
Edition, McGraw Hill Book Company, New York, (1969).
16. Ibid, page 455.
17. Ibid, page 478.
18. McKean, W. T., Hrutfiord, B. F., Sarkanen, K. V., "Kinetics
of Methyl Mercaptan and Dimethyl Sulfide Formation in Kraft
Pulping," TAPPI, _51 (12), 564-7, (1968).
19. Taylor, C. E., "Lime Kilns and Their Operation," in Atmospheric
Emissions from Sulfate Pulping, (E. R. Hendrickson, Editor),
April 1966.
20. Harding, C. I., "Source Reduction in the Pulping Industry,"
presented at the Fifth Annual Sanitary and Water Resources
Engineering Conference, Vanderbilt University, June 2-3, 1966.
21. "The Pulping of Wood," MacDonald, R. G., Volume I, Second
Edition, McGraw Hill Book Company, New York, 1969, page 227-29.
22. Ibid, page 61.
23. Ibid, page 278.
24. Ibid, page 324-5.
25. Ibid, page 341-3.
4-67
-------
26. Ibid, page 341.
27. Warther, J. F., Amberg, H. R., "The Status of Odor Control in the
Kraft Pulp Industry," presented at National AIChE Meeting, Portland,
August 1969.
28. Shih, T. T., Hrutfiord, B. F., Sarkanen, K. V., Johanson, L. N.,
"Hydrogen Sulfide Vapor-Liquid Equilibrium in Aqueous Systems As
A Function of Temperature and pH," TAPPI, 50_ (12), 630-4, (1967) .
29. Hildebrandt, P. W., Droege, H., and Stockman, R. L., "Development
of Regulations for Atmospheric Emissions from Kraft Pulp Mills,"
presented at National AIChE Meeting, Atlanta, February 1970.
4-68
-------
APPENDIX A
Appendix A consists of seven tables. Table A-l summarizes
the number of pulp mills and pulp production by process for each
state.
Table A-2 presents specific data for each mill within a
given state. The pulp tonnage listed in the columns headed
Unbleached (Unbl.) is the total tonnage of all air dry pulp pro-
duced at a mill by~ a particular pulping process. The tonnage
listed in the columns headed Bleached (Bl.) is that portion of
the total tonnage which is bleached and is expressed in finished
bleached tons. For example:
Kraft
County Owner Unbl. Bl.
Little River Nekoosa-Edwards 430 400
Paper Company
means that the entire output of 430 unbleached tons was probably
used to produce 400 finished bleached tons. Since a shrinkage
(pulp loss) of approximately 5-10 percent is experienced from
unbleached to finished bleached pulp, this should be a reasonable
assumption
Jesup Wayne ITT, Rayonier 675 675
means that the mill reported the same tonnage for unbleached and
bleached. These tonnages have been tabulated as received from the
mill; whereas, in actual practice there should be a difference
between the two numbers.
Mill age has not been included in these tabulations since many
of the older mills have been modified to such an extent that the
original mill age has little relation to the technological age of
the mill.
Table A-3 contains detailed historical data presented in
support of Figure 2-3.
Tables A-4 through A-7 present detailed data in support of
Table 2-3.
A-l
-------
TABLE A-l
SUMMARY OF CHEMICAL WOOD PULP MILLS IN U. S.
AS OF DECEMBER 1968
>
LOCATION
STATE
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
District of Columbia
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
NUMBER OP PULP MILLS AND PULP CAPACITY IN AIR DRY TONS PER DAY
NO
12
-
1
7
5
9
11
1
_
-
_
9
6
1
2
2
4
KRAFT
AD TPD
9,470
-
320
3,820
2,015
8,710
12,235
840
_
-
_
7,966
2,505
740
-
440
575
4,405
SULFITE
NO. AD TPD
-
2 1,340
-
-
-
1 375
- -
-
_ _
- -
_ _
-
4 1,290
-
-
1 168
1 135
-
SODA
NO. AD TPD NO.
_
_
_ _ _
_ _
- -
_
- - 2
- -
— — 2
- 1
- - 1
- - 4
w _ 0
_ _
1 54
- 3
- - 2
_ _
NSSC
AD TPD
-
-
-
-
-
-
600
-
370
110
200
915
360
-
-
770
360
-
1,200
-------
TABLE A-1 (Continued)
KRAFT SULFITE SODA NSSC
STATE NO. AD TPD NO. AD TPD NO. AD TPD NO. AD TPD
Nebraska __ __ __ __
Nevada -- __ __ __
New Hampshire 1 615 2 205 - 2 445
New Jersey __ __ __ __
New Mexico -- -- -- - -
New York 1 205 2 160 1 155 4 611
North Carolina 4 4,440 - - - - 2 570
North Dakota -- -- -- - -
Ohio 1 652 - - - - 2 790
Oklahoma - - - - - 1 420
Oregon 6 4,745 5 765 - 1 250
Pennsylvania 5 1,235 2 350 1 86 1 385
Rhode Island -- -- -- - -
South Carolina 4 4,860 - - - - 2 725
South Dakota -- __ -_ - -
Tennessee 2 1,220 - - 1 275 2 309
Texas 5 3,780 - - - -
Utah -- -- -- --
Vermont -- __ _- - -
Virginia 4 4,000 - - - - 4 1,110
Washington 8 5,560 12 4,515 - - 3 510
West Virginia -- -- - - - -
Wisconsin 4 1,255 11 1,552 - 2 865
Wyoming - - - - ~~ ~~
TOTAL 116 87,808 43 10,875 4 570 43 10,675
-------
TABLE A-2
SUMMARY OF CHEMICAL WOOD PULP MILLS IN EACH STATE
AS OF DECEMBER 1968
LOCATION
KIND OF PULP MILLS AND AD: TPD CAPACITY
TYPE WOOD
I
J^
SOFT-
KRAFT SULFITE SODA NSSC WOOD
CITY
Brewton
Coosa Pines
Demopolis
Jackson
Mahrt
Mobile
Mobile
Montgomery
Naheola
Selma
COUNTY
Escambia
Talladega
Marengo
Clarke
Russell
Mobile
Mobile
Autauga
Choc taw
Dallas
OWNER
Container Corp.
of America
Kimberly-Clark
Corp.
Gulf States
Paper Corp.
Allied Paper, Inc.
Georgia Kraft Co.
International
Paper Co. , Sou.
Kraft Div.
Scott Paper Co.
Union Camp Corp.
American Can Co.
Hammermill
Paper Co.
Unbl.
900
630
400
520
900
1050
1400
870
970
430
Bl. Unbl. Bl. Unbl. Bl. Unbl.
ALABAMA
400
630
375
475
0
450
1300
0
900
400
Bl. %
75
64
60
40
90
77
73
93
60
75
HARD-
WOOD
%
25
36
40
60
10
23
27
7
40
25
Pine Hill
Wilcox
MacMillan
Bloedel
United, Inc.
900
95
-------
TABLE A-2 (Continued)
KRAFT
SULFITE
SODA
NSSC
SOFT- HARD-
WOOD WOOD
CITY
Tuscaloosa
TOTAL ALABAMA
Ketchikan
Sitka
COUNTY OWNER Unbl. Bl. Unbl. Bl . Unbl. Bl. Unbl. Bl. %
Tuscaloosa Gulf States 500 0 90
Paper Corp.
Unbleached = 9470 000
Of Which Bleached = 4930
NUMBER OF MILLS 12 0 0 0
ALASKA
Ketchikan Pulp Co. 740 620 100
Alaska Lumber 600 500 100
& Pulp Co. , Inc.
%
10
0
0
TOTAL ALASKA
Unbleached
Of Which Bleached
NUMBER OF MILLS
1340
1120
-------
TABLE A-2 (Continued)
KRAFT
SULFITE
SODA
NSSC
SOFT- HARD-
WOOD WOOD
CITY
Snowf lake
TOTAL ARIZONA
Ashdown
Camden
Crossett
Morrilton
Pine Bluff
Pine Bluff
COUNTY OWNER
Navajo Southwest Forest
Industries, Inc.
Unbleached =
Of Which Bleached
NUMBER OF MILLS
Little River Nekoosa-Edwards
Paper Co.
Ouachita International
Paper Co . ,
Sou. Kraft Div.
Ashley Georgia-Pacific
Corp. , #1 Mill
#2 Mill
Conway Arkansas Kraft
Corp.
Jefferson Dierks Paper Co.
Jefferson International
Paper Co . ,
Sou. Kraft Div.
Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl. %
ARIZONA
320 65 100
320 0 0 0
65
1000
ARKANSAS
430 400 65
700 0 93
640 120 100
200 200 0
350 0 88
200 0 100
1300 1170 70
%
0
35
7
0
100
12
0
30
TOTAL ARKANSAS
Unbleached
Of Which Bleached
NUMBER OF MILLS
3820
1890
,7.
Q-
-------
TABLE A-2 (Continued)
CITY
Anderson
Antioch
Antioch
Fairhaven
Samoa
KRAFT SULFITE
COUNTY OWNER Unbl. Bl . Unbl. Bl .
CALIFORNIA
Shasta Kimberly-Clark 165 150
Corp.
Contra Costa Fibreboard Corp. 500 160
Contra Costa Fibreboard Corp. 250 0
Humboldt Crown Simpson 550 500
Pulp Co.
Humboldt Georgia-Pacific 550 500
Corp.
TOTAL CALIFORNIA Unbleached = 2015 0
Fernandina
Beach
Fernandina
Foley
Of Which Bleached = 1310
NUMBER OF MILLS 5 0
FLORIDA
Nassau Container Corp. 825 0
of America
Nassau ITT Rayonier 375 375
Taylor The Buckeye 950 860
SOFT- HARD-
SODA NSSC WOOD WOOD
Unbl. Bl. Unbl. Bl. % %;
100 0
100 0
85 15
100 0
100 0
0 0
0 0
95 5
100 0
85 15
Cellulose Corp.
-------
TABLE A-2 (Continued)
CO
CITY COUNTY
Jacksonville Duval
Jacksonville Duval
Palatka Putnam
Panama City Bay
Pensacola Escambia
Port St. Joe Gulf
TOTAL FLORIDA
KRAFT SULFITE
OWNER Unbl. Bl. Unbl. Bl .
FLORIDA (Continued)
Alton Box 675 0
Board Co.
St. Regis 1300 0
Paper Co.
Hudson Pulp & 950 400
Paper Corp.
International 1410 735
Paper Co. ,
Sou. Kraft Div.
St. Regis Paper 300 260
Co. - West Mill
St. Joe Paper Co. 1700 500
Unbleached = 8710 375
Of Which Bleached = 2755 375
NUMBER OF MILLS 9 1
GEORGIA
SOFT- HARD-
SODA NSSC WOOD WOOD
Unbl. Bl. Unbl. Bl. % %
90 10
60 40
60 40
50 50
88 12
90 10
0 0
0 0
Augusta
Richmond
Brunswick Glynn
Continental Can
Co., Inc.
Brunswick Pulp
& Paper Co.
750 700
1290 1195
60
61
40
39
-------
TABLE A-2 (Continued)
CITY
COUNTY
Cedar Springs Early
Cedar Springs Early
Jesup
Macon
Port
Wentworth
Riceboro
Rome
St. Marys
Savannah
Savannah
Valdosta
Wayne
Bibb
Chatham
Liberty
Floyd
Camden
Chatham
Chatham
Lowndes
TOTAL GEORGIA
OWNER
Great Northern
Paper Co.
Great Northern
Paper Co.
ITT Rayonier, Inc. 675
Georgia Kraft Co.
Continental Can
Co., Inc.
Interstate Paper
Corp.
Georgia Kraft Co.
Gilman Paper Co.
Union Camp Corp.
Union Camp Corp.
Owens-Illinois
Inc.
KRAFT SULFITE
Unbl. Bl. Unbl. Bl.
GEORGIA (Continued)
1700 0
675 675
875 0
625 0
450 0
1500 0
900 350
2700 0
770 0
SOFT-
SODA NSSC WOOD
Unbl. Bl. Unbl. Bl. %
99
300 0 0
90
85
95
95
90
80
95
300 0 0
95
HARD-
WOOD
%
1
100
10
15
5
5
10
20
5
100
5
Unbleached
Of Which Bleached
NUMBER OF MILLS
= 12,235
2,920
600
11
-------
TABLE A-2 (Continued)
KRAFT SULFITE
CITY COUNTY OWNER Unbl. Bl. Unbl. Bl .
IDAHO
Lewiston Nez Perce Potlatch Forests, 840 800
Inc.
TOTAL IDAHO Unbleached = 840 0
Of Which Bleached = 800
NUMBER OF MILLS 1 0
> INDIANA
H
O
Carthage Rush Container Corp.
of America
Terre Haute Vigo Weston Paper
S Mfg. Co.
SOFT- HARD'
SODA NSSC WOOD WOOD
Unbl. Bl. Unbl. Bl. % %
100 0
0 0
0 0
120 0 0 100
250 0 0 100
TOTAL INDIANA
Unbleached
Of Which Bleached
NUMBER OF MILLS
0
0
0
0
0
0
370
2
-------
TABLE A-2 (Continued)
CITY
Fort Madison
TOTAL IOWA
1
j
j
Hawesville
TOTAL KENTUCKY
COUNTY OWNER
Lee Consolidated
Packaging Corp.
Unbleached =
Of Which Bleached
NUMBER OF MILLS
Hancock WesCor Corp .
Unbleached =
Of Which Bleached =
NUMBER OF MILLS
SOFT- HAR&
KRAFT SULFITE SODA NSSC WOOD WOOD
Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl. % %
IOWA
110 0 0 100
000 110
0
0001
KENTUCKY
200 0 0 100
000 200
0
0001
-------
TABLE A-2 (Continued)
SOFT- HARD-
CITY
Bastrop
Bastrop
Bogalusa
Bogalusa
H Elizabeth
NJ
Hodge
Hodge
Pineville
Port Hudson
St. Francis-
ville
Springhill
COUNTY
(Parish)
Morehouse
Morehouse
Washington
Washington
Allen
Jackson
Jackson
Rapides
E . Baton Rouge
West Feliciana
Webster
KRAFT SULFITE
OWNER Unbl. Bl . Unbl. Bl.
LOUISIANA
International Paper
Co., Sou. Kraft Div.
Bastrop Mill
International Paper 1200 1100
Co., Sou. Kraft Div.
Louisiana Mill
Crown Zellerbach 1350 140
Corp.
Crown Zellerbach
Corp.
Calcasieu Paper 250 0
Co . , Inc .
Continental Can 500 0
Co . , Inc .
Continental Can
Pineville Kraft 850 0
Corp.
Louisiana Forest 550 510
Products Corp.
Crown Zellerbach 550 500
Corp.
International 1650 1000
SODA NSSC WOOD
Unbl. Bl. Unbl. Bl. %
485 0 0
45
99
150 0 0
90
100
200 0 0
100
15
60
70
WOOD
%
100
55
1
100
10
0
100
0
85
40
30
Paper Co.,
Sou. Kraft Div.
W. Monroe
Ouachita
Olinkraft, Inc.
1066
77
23
-------
T A B'L E A-2 (Continued)- .
CITY
W. Monroe
W. Monroe
TOTAL LOUISIANA
Augusta
Cumberland
Mills
East
Millinocket
Jay
Lincoln
KRAFT SULFITE
COUNTY OWNER Unbl. Bl. Unbl. Bl.
LOUISIANA (Continued)
Ouachita Olinkraft, Inc. 1066 0
Ouachita Olinkraft, Inc.
Unbleached = 7966
Of Which Bleached = 3250
NUMBER OF MILLS 9 0
MAINE
Kennebec Statler Tissue 125 125
Corp .
Cumberland S. D. Warren Co. 270 250
Penobscot Great Northern
Paper Co.
Franklin International '525 470
Paper C,o.
Penobscot Lincoln Pulp 225 210
SOFT- HARD-
SODA NSSC WOOD T-70OD
Unbl. Bl. Unbl. Bl. % %
77 23
80 0 0 100
915
0
0 4
85 15
30 70
160 0 0 100
65 35
0 100
-------
TABLE A-2 (Continued)
CITY
Millinocket
Old Town
Old Town
Rumford
Wins low
Woodland
Woodland
TOTAL MAINE
Luke
KRAFT SULFITE SODA NSSC
COUNTY OWNER Unbl . Bl. Unbl. Bl. Unbl . Bl. Unbl . Bl.
MAINE (Continued)
Penobscot Great Northern 500 0
Penobscot Penobscot Co. 375 350
Penobscot Penobscot Co. 215 200
Oxford Oxford Paper Co. 560 525
Kennebec Scott Paper Co. 450 415
Washington Georgia-Pacific 550 500
Corp.
Washington Georgia-Pacific 200 0
Corp.
Unbleached = 2505 1290 0 360
Of Which Bleached = 2305 740 0
NUMBER OF MILLS 64 02
MARYLAND
Allegany West Virginia 740'. 740
Pulp & Paper Co.
SOFT- HARD-
WOOD WOOD
% %
100 0
10 90
100 0
35 65
75 25
70 30
0 100
30 70
TOTAL MARYLAND
Unbleached
Of Which Bleached
NUMBER OF MILLS
740
740
-------
TABLE A-2 (Continued)
KRAFT
SULFITE
SODA
NSSC
Ostego
Allegan
Corp.
Menasha
170
0'
SOFT HARB
WOOD WOOD
CITY COUNTY
Lawrence Essex
TOTAL MASSACHUSETTS
Of
I
Ul
Detroit Wayne
Filer City Manistee
Filer City Manistee
Muskegon Muskegon
Ontonagon Ontonagon
OWNER Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl.
MASSACHUSETTS
Oxford Paper Co. 54 50
Unbleached =00 54 0
Which Bleached = 50
NUMBER OF MILLS 001 0
MICHIGAN
Scott Paper Co.* 168 168
Packaging Corp. 200 184
of America
Packaging Corp. 375 0
of America
S. D. Warren Co. 240 225
Hoerner Waldorf 225 0
% %
0 100
90 10
50 50
0 100
36 64
0 100
100
TOTAL MICHIGAN
Unbleached
Of Which Bleached
NUMBER OF MILLS
440
168
409
168
0
0
770
3
*Shut down in 1969
-------
TABLE A-2 (Continued.)
SOFT- HARD-
CITY
Cloquet
Cloquet
Grand Rapids
International
Falls
St. Paul
KRAFT SULFITE SODA NSSC WOOD
COUNTY OWNER Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl. %
MINNESOTA
Carl ton The Northwest 325 305 60
Paper Company
Sub. of Potlatch
Forests, Inc.
Carlton The Northwest 135 125 10
Paper Company
Sub. of Potlatch
Forests, Inc.
Itasca Blandin Paper Co. 50 50 0
Koochiching Boise Cascade 250 250 50
Corp.
Ramsey Hoerner Waldorf 310 0 0
Corp.
WOOI
%
40
90
100
50
100
TOTAL MINNESOTA
Unbleached =
Of Which Bleached =
NUMBER OF MILLS
575 135
555 125
2 1
360
50
MISSISSIPPI
Monticello
Lawrence
St. Regis Paper
1690
100
-------
TABLE A-2 (Continued)
KRAFT SULFITE SODA NSSC
SOFT- HARD-
WOOD .WOOD
CITY COUNTY OWNER Unbl. Bl . Unbl. Bl . Unbl. Bl. Unbl. Bl. % '% -
MISSISSIPPI (Continued)
Moss Point Jackson International 730 660
Paper Co.
Sou. Kraft Div.
Natchez Adams International 1000 1000
Paper Co.
Sou. Kraft Div.
> Vicksburg Warren International 985 300
M Paper Co.
^ Sou. Kraft Div.
TOTAL MISSISSIPPI ' Unbleached = 4405. 0.0 0
Of Which Bleached = 1960
NUMBER OF MILLS 4 000
MONTANA
Missoula Missoula Hoerner Waldorf 1200 250
Corp.
55 45
19 81
85 15
100 0
TOTAL MONTANA
Unbleached =
Of Which Bleached =
NUMBER OF MILLS
1200
250
-------
TABLE A-2 (Continued)
KRAFT
SULFITE
SODA
NSSC
00
CITY COUNTY
Berlin Coos
Berlin Coos
Groveton Coos
Groveton Coos
Lincoln Grafton
TOTAL NEW HAMPSHIRE
Deferiet Jefferson
Glens Falls Warren
Lyons Falls Lewis
Mechanicville Saratoga
OWNER Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl.
NEW HAMPSHIRE
Brown Company 615 500
Brown Company 220 0
Groveton Papers Co. 115 105
Groveton Papers Co. 225 0
Franconia Paper 90 90
Corp.
Unbleached = 615 205 445
Of Which Bleached = 500 195 0
NUMBER OF MILLS 12 2
NEW YORK
St. Regis Paper Co. 100 60
Finch, Pruyn & 237 178
Co. , Inc.
Georgia-Pacific Corp. 120 120
West Virginia 184 158
Norfolk
Pulp & Paper Co.
St. Lawrence Northland Paper
SOFT-
WOOD
35
0
100
0
100
60
100
0
0
0
100
HARD-
WOOD
65
100
0
100
0
0
100
100
100
-------
TABLE A-2 (Continued)
CITY
North
Tonawanda
Plattsburgh
Ticonderoga
i
H
VO
KRAFT SULFITE SODA NSSC
COUNTY OWNER Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl.
NEW YORK (Continued)
Niagara International 155 155
Paper Co.
Clinton Georgia Pacific 70 0
Corp.
Essex International 205 190
Paper Co.
SOFT- HARD-
WOOD WOOD
% %
0 100
0 100
0 100
TOTAL NEW YORK
Unbleached
Of Which Bleached
NUMBER OF MILLS
205
160
155
611
190
60
155
456
-------
TABLE A-2 (Continued)
KRAFT
SULFITE
SODA
NSSC
SOFT- HARD-
WOOD WOOD
CITY COUNTY
Canton Haywood
Plymouth Washington
Plymouth Washington
Riegelwood Columbus
Roanoke Rapids Halifax
Sylva Jackson
TOTAL NORTH CAROLINA
Of
OWNER Unbl. Bl. Unbl. Bl. Unbl .
NORTH CAROLINA
U.S. Plywood - 1290 1290
Champion Papers ,
Inc.
Weyerhaeuser Co. 1180 450
Weyerhaeuser Co.
Riegel Paper Corp. 1070 1000
Hoerner Waldorf 900 0
Corp.
The Mead Corp.
Unbleached = 4440 0
Which Bleached = 2740
NUMBER OF MILLS 4 1
Chillicothe Ross
Circleville Pickaway
Coshocton Coshocton
TOTAL OHIO
Of
OHIO
The Mead Corp. 652 600
Container Corp.
of America
Stone Container
Corp .
Unbleached = 652 0 0
Which Bleached = 600
NUMBER OF MILLS 1 0
Bl. Unbl. Bl. % %
60 40
80 20
300 0 0 100
50 50
88 12
270 0 0 100
570
0
0 2
0 100
240 0 0 100
550 0 0 100
790
0
0 2
-------
TABLE A-2 (Continued)
CITY
Broken Bow
TOTAL OKLAHOMA
i
j
j
Albany
Coos Bay
Gardiner
Jordan Cove
KRAFT SULFITE SODA NSSC
COUNTY OWNER Unbl. Bl . Unbl. Bl. Unbl. Bl. Unbl. Bl.
OKLAHOMA
McCurtain Dierks Forests, Inc. 420 0
Unbleached =0 0 0 420
Of Which Bleached = 0
NUMBER OF MILLS 00 01
OREGON
Linn Western Kraft 500 0
Corp.
Coos Coos Head 90 0
Timber Co.
Douglas International 545 0
Paper Co.
Coos Menasha Corp. 250 0
SOFT- HARD
WOOD WOOD
% %
100 0
100 0
100 0
100 0
0 100
-------
TABLE A-2 (Continued)
NJ
CITY
Lebanon
Newberg
Oregon City
St. Helens
Salem
Springfield
Toledo
Wauna
TOTAL OREGON
KRAFT SULFITE SODA NSSC
COUNTY OWNER Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl.
OREGON (Continued)
Linn Crown Zellerbach . 105 0
Corp.
Yarnhill Publishers'
Paper Co .
Clackamas Publishers' 170 100
Paper Co.
Columbia Boise Cascade 800 650
Corp.
Marion Boise Cascade 220 210'>
Corp.
Lane Weyerhaeuser 1150 0
Corp.
Lincoln Georgia Pacific 950 0
Corp.
Clatsop Crown Zellerbach 800 550
Corp.
Unbleached = 4745 ' 765 0 250
Of Which Bleached = 1200 310'- 0
NUMBER OF MILLS 65 01
SOFT- HARD-
WOOD WOOD
% %
100 0
100 0
100 0
100 0
100 0
100 0
100 0
85 15
-------
TABLE A-2 (Continued)
10
CITY COUNTY
Erie Erie
Johns onburg Elk
Johnsonburg Elk
Lock Haven Clinton
Mehoopany
Roaring Blair
Springs
Spring Grove York
Tyrone Blair
Williamsburg Blair
KRAFT SULFITE SODA NSSC
OWNER Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl.
. . PENNSYLVANIA
Hammermill Paper 385 385
Co.
New York & Penn- 170 160
sylvania Co., Inc.
New York & Penn- 110 110
sylvania Co . , Inc .
Hammermill Paper 86 80
Co.
Charmin Paper "" 240 240
Products Co.
Combined Paper 195 180
Mills, Inc.
P. H. Glatfelter 550 500
Co.
Westvaco 160 152
Westvaco* 160 0
SOFT-
WOOD
%
0
0
100
0
0
50
50
30
0
HARD'
WOOD
%
100
100
0
100
100
50
50
70 -
100
TOTAL PENNSYLVANIA
Unbleached
Of Which Bleached
1235
350
86
385
992
350
80
385
*Shut down in 1969
-------
TABLE A-2 (Continued)
SOFT- HARD-
CITY
Catawba
Charleston
Florence
Georgetown
Georgetown
Hartsville
TOTAL SOUTH
KRAFT SULFITE SODA NSSC
COUNTY OWNER Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl.
SOUTH CAROLINA
York Bowaters Carolina 860 860
Corp .
Charleston Westvaco 1850 0
Florence South Carolina 600 0
Industries, Inc.
Georgetown International 1550 340
Paper Co . ,
Sou. Kraft Div.
Georgetown International 325 0
Paper Co . ,
Sou. Kraft Div.
Darlington Sonoco Products 400 0
Co.
CAROLINA Unbleached = 4860 0 0 725
Of Which Bleached = 1200 0
NUMBER OF MILLS 4 0 02
WOOD WOOD
% %
88 12
80 20
90 10
79 21
0 100
0 100
-------
TABLE A-2 (Continued)
CITY
Calhoun
Counce
Harriman
Kingsport
Knoxville
KRAFT SULFITE SODA NSSC
COUNTY OWNER Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl.
TENNESSEE
McMinn Bowaters Southern 520 490
Paper Corp.
Hardin Tennessee River 700 0
Pulp & Paper Co .
Roane The Mead Corp. 190 0
Sullivan The Mead Corp 275 260
Knox Southern Extract 119 0
Co.
SOFT- HARD-
WOOD WOOD
% %
100 0
91 9
0 100
0 100
0 100
TOTAL TENNESSEE
Unbleached
Of Which Bleached
NUMBER OF MILLS
1220
275
309
490
260
-------
TABLE A-2 (Continued)
CITY
Evadale
Houston
Lufkin
Mulford
I
o$?asadena
TOTAL TEXAS
Big Island
Covington
Covington
KRAFT SULFITE SODA NSSC
COUNTY OWNER Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl.
TEXAS
Jasper Eastex, Inc. 1200 1000
Harris Southland Paper 450 100
Mills, Inc.
Angelina Southland Paper 325 300
Mills, Inc.
Orange Owens-Illinois 1000 0
Inc.
Harris U. S. Plywood 805 805
Champion Papers , Inc .
Unbleached = 3780 0 0 0
Of Which Bleached = 2305
NUMBER OF MILLS 50 00
VIRGINIA
Bedford Owens-Illinois , Inc. 450 0
Alleghany Westvaco 950 850
Alleghany Westvaco 270 0
SOFT- HARD-
WOOD WOOD
% %
58 42
100 0
100 0
100 0
70 30
0 100
34 66
0 100
-------
TABLE A-2 (Continued)
CITY
Franklin
Hopewell
Hopewell
Lynchburg
West Point
to
TOTAL VIRGINIA
Anacortes
Bellingham
COUNTY
Isle of Wight
Prince George
Prince George
Campbell
King William
KRAFT SULFITE SODA NSSC
OWNER Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl.
VIRGINIA (Continued)
Union Camp Corp. 1100 940
Continental Can 900 0
Co. , Inc.
Continental Can 200 0
The Mead Corp. 190 0
The Chesapeake 1050 0
Corp. of Virginia
SOFT- HARD
WOOD WOOD
% %
43 57
100 0
0 100
0 100
88 12
Unbleached = 4000 0 0 1110
Of Which Bleached = 1790 0
NUMBER OF MILLS 40 04
WASHINGTON
Skagit
Whatcom
Scott Paper Co. 135 135
Georgia Pacific 530 500
5 95
100 0
Corp.
-------
TABLE A-2 (Continued)
CITY
COUNTY
OWNER
KRAFT
Unbl. Bl.
SULFITE
Unbl.
Bl.
Camas
Camas
Cosmopolis
Everett
Everett
Everett
Everett
Hoquiam
Longview
Longview
Longview
Longview
Longview
Millwood
Port Angeles
Port Angeles
Clark
Clark
Grays Harbor
Snohomish
Snohomish
Snohomish
Snohomish
Grays Harbor
Cowlitz
Cowlitz
Cowlitz
Cowlitz
Cowlitz
Spokane
Clallam
Clallam
WASHINGTON (Continued)
Crown Zellerbach 780 780
Corp.
Crown Zellerbach
Weyerhaeuser Co.
Scott Paper Co.
Simpson Lee 85 80
Paper Co.
Weyerhaeuser Co. 440 400
Weyerhaeuser Co.
ITT Rayonier,Inc.
Longview Fibre Co. 1800 400
Longview Fibre Co.
Weyerhaeuser Co. 695 650
Weyerhaeuser Co.
Weyerhaeuser Co.
Inland Empire
Fibreboard Corp.
ITT Rayonier, Inc.
420
488
850
400
400
850
360
545
310
545
425
42
70
450
400
20
65
450
SOFT-
SODA NSSC WOOD
Unbl. Bl. Unbl. Bl. ' V
100
100
90
100
0
85
100
100
100
140 0 0
91
100
230 0 100
100
95
100
HARD-
WOOD
' "% '
0
0
10
0
100
15
0
0
0
100
9
0
0
0
5
0
-------
TABLE A-2 (Continued)
SOFT- HARD-
CITY
Port Towns end
Tacoma
Vancouver
Wallula
> Wallula
to
VD
TOTAL WASHINGTON
COUNTY OWNER
Jefferson Crown Zellerbach
Corp.
Pierce St. Regis Paper
Co .
Clarke Boise Cascade
Corp.
Walla Walla Boise Cascade
Corp.
Walla Walla Boise Cascade
Corp.
Unbleached =
Of Which Bleached
NUMBER OF MILLS
KRAFT SULFITE SODA NSSC
Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl.
WASHINGTON (Continued)
420 0 " ~"
930 145
200 185
410 0
140 0
5560 4515 1 510
2375 4260 0
8 12 03
WOOD WOOD
% %
100 0
100 0
100 0
100 0
100 0
-------
TABLE A-2 (Continued)
CITY
Apple ton
Brokaw
Green Bay
Green Bay
Green Bay
Kaukauna
Marinette
Mosinee
Nekoosa
Oconto Falls
Park Falls
COUNTY
Outagamie
Marathos
Brown
Brown
Brown
Outagamie
Marinette
Marathon
Wood
Oconto
Price
OWNER
Consolidated
Papers, Inc.
Wausau Paper
Mills Co.
American Can Co.
Charmin Paper
Products Co.
Green Bay
Packaging , Inc .
Thilmany Pulp
& Paper Co.
Scott Paper Co.
Mosinee Paper
Mills Co.
Nekoosa-Edwards
Paper Co.
Scott Paper Co
Kansas City
SOFT-
KRAFT SULFITE SODA NSSC WOOD
Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl. %
WISCONSIN
165 155 100
155 145 15
155 145 0
130 123 100
250 0 0
380 90 100
55 50 100
175 0 80
340 315 75
115 110 80
115 110 67
HARD-
WOOD
%
0
85
100
0
100
0
0
20
25
20
33
Peshtigo
Port Edwards
Marinette
Wood
Star Co.
Badger Paper
Mills, Inc.
Nekoos a-Edwards
Paper Co.
100
235
90
225
75 25
0 100
-------
TABLE A-2 (Continued)
SOFT- HARD-
CITY
Rhine lander
Rothschild
Tomahawk
Wisconsin
Rapids
TOTAL WISCONSIN
KRAFT SULFITE SODA NSSC
COUNTY OWNER Unbl. Bl. Unbl. Bl. Unbl. Bl. Unbl. Bl.
WISCONSIN (Continued)
Oneida St. Regis Paper Co. 217 200
Marathon American Can Co. 217 200
Lincoln Owens-Illinois 615 0
Inc.
Wood Consolidated 360 333 67
Papers , Inc .
Unbleached = 1255 1552 0 865
Of Which Bleached = 738 1463 0
NUMBER OF MILLS 4 11 02
WOOD WOOD
% %
100 0
0 100
0 100
33
-------
T A B L E A-3
ANNUAL PRODUCTION AND CONSUMPTION OF CHEMICAL WOOD PULPS
IN U.S.A.
1937 - 1967
MILLIONS OF TONS OF PULP
Year
1937
1940
1945
1950
1953
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
Kraft
2.1
3.7
-
7.5
9.4
11.3
12.1
11.9
12.3
13.8
14.6
15.4
16.3
17.5
20.1
21.5
22.4
22.8
Sulfite
1.8
2.3
-
2.4
2.3
2.6
2.7
2.6
2.4
2.5
2.6
2.6
2.6
2.7
2.7
2.7
2.8
2.7
NSSC
0.1
0.2
-
0.7
1.0
1.4
1.5
1.6
1.6
1.9
2.0
2.4
2.5
2.6
2.7
2.9
3.2
3.3
Dissolving
0.4
0.3
-
0.5
0.7
1.0
0.9
1.0
0.9
1.1
1.1
1.2
1.3
1.4
1.5
1.5
1.5
1.4
Soda
0.5
0.5
-
0.5
0.4
0.4
0.5
0.4
0.4
0.5
0.5
0.4
0.4
0.4
0.2
0.2
0.2
0.2
Total
Production
Chemical
Pulps
4.9
7.0
9.3
11.6
13.8
16.7
17.7
17.5
17.6
19.8
20.7
22.0
23.1
24.6
27.2
28.8
30.1
30.4
Year
1937
1940
1945
1950
1953
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
Net
Imports
1.9
0.6
4.1
2.0
1.7
1.3
1.4
1.2
1.4
1.6
1.0
1.0
1.3
1.0
1.0
1.4
1.5
1.2
Consumption
Chem. Pulps
6.8
7.6
10.4
13.6
15.5
18.0
19.1
18.7
19.0
21.4
21.7
23.0
24.4
25.6
28.2
30.2
31.6
31.6
Consumption
Per Capita - Pounds
105
115
151
180
194
218
226
210
216
240
240
250
261
271
295
310
320
318
Source: U. S. Bureau of Census
U. S. Pulp Producers Association
American Paper Institute
A-32
-------
TABLE A-4
CHEMICAL WOOD PULP MILLS
SUPPLEMENTARY DATA
CURRENT AND PLANNED NEW PLANT. CONSTRUCTION
AS OF DECEMBER 31, 1968
CJ
00
State
Alabama
Alaska
Arkansas
Florida
Idaho
Kentucky
Louisiana
Maine
Minnesota
New York
Owner
New - N
Exp. — E
U.S. Plywood-Champion
Papers
U.S. Plywood-Champion
Papers
Georgia-Pacific Corp.
Potlatch Forests, Inc.
Container Corp. of America
Potlatch Porests, Inc.
Westvaco
Western Kraft Corp.
Boise Cascade Corp.
Great Northern Paper Co.
Northwest Paper Co.
Finch, Pruyn & Co., Inc.
International Paper Co.
N
N
Kind of Pulp S Capacity - AD Tons/Day
Kraft Sulfite NSSC
500 Bl.
600
E
N
E
E
N
N
N
E
E
N
N
425 Bl
400 Bl
550
220
600 Bl
200 Bl
600
250 Bl
510 Bl
510 Bl
350
480
Date on
Stream
1970
1973
1970
1971
1969
1970
1969
1970
1969
1971
1970
1970
-------
TABLE A-4 (Continued)
w
North Carolina
Oregon
Pennsylvania
South Carolina
Tennessee
Texas
Virginia
Washington
West Virginia
Georgia-Pacific Corp,*
Weyerhaeuser Corp
American Can Company
Hammermill Paper Co.
Kimberly-Clark Corp.
Inland Container Corp.
International Paper Co,
Union Camp Corp.
ITT Rayonier, Inc.
Milburn Corp.
TOTAL - AD TONS PER DAY
TOTAL - AD TONS PER YEAR - 350 DAYS
N
N
N
E
N
N
N
E
N
N
2
600 Bl.
300 Bl.
300 Bl.
650 650 Bl.
600 Bl.
300 Bl.
7,605
,662,000
200 1969
1970
1969
200 Bl. 1970
-
300 1970
1971
1970
-
250
830 1,300 = 9,735 Gra
290,000 455,000 = 3,407,000
* Plans shelved in 1969
Source: Paper Trade Journal
Pulp & Paper
February 3, 1969
December 16, 1969
-------
TABLE A-5
Ul
Ul
Location
South Carolina
Wyoming
Florida
Minnesota
Mississippi
Minnesota
Arizona
Texas
Texas
Missouri
Oklahoma
Michigan
CHEMICAL WOOD PULP MILLS
SUPPLEMENTARY DATA
PROPOSED AND TENTATIVE NEW MILLS
AS OF DECEMBER 31, 1968
Owner
Tenneco Co.
State
Great Northern Paper Co.
Boise Cascade Corp.
Columbia Pulp & Paper Co.
Minnesota International
Pulp & Paper Co.
Ponderosa Paper Products,
Sabine Pulp s Paper Co.
Texas Newsprint Co.
Delta-New Madrid Paper Corp.
Dierks Forests, Inc.
Oxford Paper Co.
New - N
Exp'.-v E
N
N
N
N
N
N
Inc. N
N
N
p. N
N
N
TPD
-
500
300
500
350
-
-
-
300
-
-
400
Kind
Kraft
Bl. Kraft
Bl. Kraft
Kraft
Kraft
Newsprint
Sulfite
Bl. Kraft
Newsprint
Newsprint
-
Bl. Kraft
Stage
Study
Study
Study
Study
Deferred
Study
Planned
Planned
Study
Study
Proposed
Deferred
Source: Paper Trade Journal
Pulp & Paper
-------
TABLE A-6
CHEMICAL WOOD PULP MILLS
SUPPLEMENTARY DATA
ESTIMATE OF PHASED OUT OPERATIONS
1968 THROUGH 1970
MILLS CLOSED DOWN
In 1968
(Tonnages not included in 1968 Mill Capacities)1
Location
Sulfite
Soda
Kraft
NSSC
Maine
Minnesota
Oregon
Wisconsin
New York
Wisconsin
AD Tons per
May
Early
May
June
Total
350 Day
1968
1968
1968
1968
1968
1968
Year
125
180
210
130
190
835
292,000
60
(Tonnage
60
21,000
replaced by new kraft mill)
0 0
0 0
In 1969 and 1970 (Tonnages included in 1968 Mill Capacities)
Michigan May 1969
New York (1970)
Minnesota 1970
Washington Feb. 1969
New York 1969
Total
Ad Tons per 350 Day Year
168
(To be replaced by 205
New Mill)
135
200
(To be replaced
by MgO)
235
503
176,000
0
0
205
72,000
235
82,000
Maine
Note:
Source:
In 1969 - A 500 TPD Sulfite Sodium Base Mill will be converted
to Magnesium Base.
Probably other Sulfite Mills using Sodium and Calcium Base
Processes will convert to other Processes, but announcements
have not been made up to this time.
This study (Meakin)
A-36
-------
TABLE A-7
CHEMICAL WOOD PULP MILLS
SUPPLEMENTARY DATA
ESTIMATE OF PHASED OUT OPERATIONS
1970 TO 1980
State
Mas s achus e tt s
New Hampshire
New York
Oregon
Pennsylvania
Washington
Wisconsin
Number
Mills
1
2
2
2
2
3
7
Process and AD Tons per Day
Kraft Sulfite Soda NSSC
54
205
160
195
110 86
85 112
780
Total
AD Tons per .
350 Day Year
19
85
30,000
1,562
547,000
140
49 ,-000
A-37
------- |