Energy E fficiency in the Pulp Paper Industry th EDphasis on eveloping … · 2016. 7. 8. · pour...
Transcript of Energy E fficiency in the Pulp Paper Industry th EDphasis on eveloping … · 2016. 7. 8. · pour...
WORLD BANIK TECHNICAL PAPER NUMBER 34
Energy E fficiency in the Pulp Paper Industryth EDphasis on eveloping Countries
Andrew J. Ewing
l 4 0, f
Pub
lic D
iscl
osur
e A
utho
rized
Pub
lic D
iscl
osur
e A
utho
rized
Pub
lic D
iscl
osur
e A
utho
rized
Pub
lic D
iscl
osur
e A
utho
rized
Pub
lic D
iscl
osur
e A
utho
rized
Pub
lic D
iscl
osur
e A
utho
rized
Pub
lic D
iscl
osur
e A
utho
rized
Pub
lic D
iscl
osur
e A
utho
rized
WORLD BANK TECHNICAL PAPERS
No. 1. Increasing Agricultural Productivity
No. 2. A Model for the Development of a Self-help Water Supply-Program
No. 3. Ventilated Improved Pit Latrines: Recent Developments in Zimbabwe
No. 4. The African Typanosomiases: Methods and Concepts of Controla:id Eradication in Relation to Development
(No. 5.) Structural Changes in World Industry: A Quantitative Analysisof Recent Developments
No. 6. Laboratory Evaluation of Hand-operated Water Pumps for Usein Developing Countries
No. 7. Notes on the Design and Operation of Waste Stabilization Pondsin Warm Climates of Developing Countries
No. 8. Institutioni Building for Traffic Management
(No. 9.) Meeting the Needs of the Poor for Water Supply and Waste Disposal
No. 10. Appraising Poultry Enterprises for Profitability: A Manualfor Investors
No. 11. Opportunities for Biological Control of Agricultural Pestsin Developing Countries
No. 12. Water Supply and Sanitation Project Preparation Handbook: Guidelines
No. 13. Water Supply and Sanitation Project Preparation Handbook: Case Studies
No. 14. Water Supply and Sanitation Project Preparation Handbook: Case Study
(No. 15.)Sheep and Goats in Developing Countries: Their Present andPotential Role
(No. 16.)Managing Elephant Depredation in Agricultural and Forestry Projects
(No. 17.)Energy Efficiency and Fuel Substitution in the Cement Industrywith Emphasis on Developing C.ountries
No. 18. Urban Sanitation Planning Manual Based on the Jakarta Case Study
No. 19. Laboratory Testing of Handpumps for Developing Countries:Final Technical Report
No. 20. Water Quality in Hydroelectric Projects: Considerations for Planningin Tropical Forest Regions
( ) Indicates number assigned after publication.
(List continues on the inside back cover)
WORLD BANK TECHNICAL PAPER NUMBER 34
Energy Efficiency m the Pup d Paper pdustwith Emphasis on Develop"g Cotn est
Andrew J. Ewing
The World BankWashington, D.C., U.S.A.
Copyright (© 1985The International Bank for Reconstructionand Development/THE WORLD BANK
1818 H Street, N.W.Washington, D.C. 20433, U.S.A.
All rights reservedManufactured in the United States of AmericaFirst printing February 1985
This is a document published informally by the World Bank. In order that theinformation contained in it can be presented with the least possible delay, thetypescript has not been prepared in accordance with the procedures appropriate toformal printed texts, and the World Bank accepts no responsibility for errors. Thepublication is supplied at a token charge to defray part of the cost of manufacture anddistribution.
The World Bank does not accept responsibility for the views expressed herein, whichare those of the author(s) and snould not be athibuted to the World Bank or to itsaffiliated organizations. The findings, interprelations, and conclusions are the resultsof researdc supported by the Bank; they do not necessarily represent official policy ofthe Bank. The designations employed, the presentation of material, and any maps usedin this document are solely for the convenience of the reader and do not imply theexpression of any opinion whatsoever on the part of the World Bank or its affiliatesconceming the legal status of any cotmtry, territory, city, area, or of its authorities, orconcerning the delimitation of its boundaries or national affiliation.
The full range of World Bank publications, both free and for sale, is described in theCatalog of Publications; the continuing research program is outlined in Abstracts ofCurrent Studies. Both booklets are updated annually; the most recent edition of each isavailable without charge from the Publications Sales Unit, Department T, The WorldBank, 1818 H Street, N.W., Washington, D.C. 20433, U.S.A., or from the EuropeanOffice of the Bank, 66 avenue d'I6na, 75116 Paris, France.
Andrew J. Ewing is a consultant to the World Bank.
Library of Congress Cataloging in Publication Data
Ewing, Andrew J., 1942-Energy efficiency in the pulp and paper industry with
emphasis on developin?g countries.
(World Bank technical paper, ISSN 0253-7494 ; no. 34)1. Paper industry--Energy consumption. 2. Paper
industry-,-Developing countries--Energy consumption.3. Pulpwpod industry--Energy consumption. 4. Pulpwoodindustry-LDeveloping countries--Energy consumption.I. Title. II. Series.HD9820.5.E95 1985 333.79 85-3264ISBN 0-8213-0515-8
ABSTRACT
The production of paper is relatively energy-intensive: one ton
of paper requires energy e(quivalent to about three quarters of a ton of oil
in industrialized countries, and as much as 2-3 times this figure in
developing countries. Although about one half of this energy requirement
may be met by burning the waste products of the industry, the balance must
be purchased.
Faced with sharply rising energy costs in the 1970s, producers in
the industrialized countries have shown that energy consumption in paper
production can be substantially reduced, and that improving the efficiency
of waste recovery can further decrease the requirement for purchased
energy. The wide,range of measures discussed in this paper include steps
to improve internal energy efficiency through a variety of measures such as
improved housekeeping, process modification, and water re-use, steps to
improve waste utilization, and cogeneration. Preliminary analyses of the
costs and benefits of such measures are included.
The paper also describes the particuar technical and other
constraints which have so far tended to limit the introduction of similar
energy-saving techniques in the pulp and paper industries of many
developing countries. Proposals are included for policy and other measures
which could be introduced to stimulate improvements to energy efficiency in
these situations.
iv -
CONDENSE
L'industrie du papier est assez grosse consomnatrice de'6nergie
pour une tonne de papier, il faut 1'equivalent 6nerg6tique d'environ trois
quarts de tonne de p6trole dans les pays industrialis6s et deux a trois
fois ce chiffre dans les pays en d6veloppement. La combustion des dechets
industriels satisfait environ la moiti6 de ce besoin 6nerg6tique, mais le
solde doit etre achet6.
Devant la hausse en fleche des coats de 1'6nergie dans les
annees 70, les producteurs dans les pays industrialis6s ont montre que
1'on peut sensiblement r6duire la consommation d' energie dans la produc-
tion de papier et qu'en ameliorant la recup6ration des dechets, on peut
diminuer encore les achats d'6nergie. Cette 6tude e,. .mine toute une s6rie
de mesures susceptibles d'am6liorer 1'efficacite 6nerg6tique interne,
notamment des ameliorations dans 1'exploitation interne, des changements
dans les proc6d6s de fabrication, la r6utilisation de 1'eau, des am6liora-
tions dans l'utilisation des dechets et la cog6n6ration. On y trouve
aussi des analyses pr6liminaires des coats et avantages de ces mesures.
L'6tude.d6crit 6galement les problmes particuliers9 techniques
et autres, qui ont jusqu'a. present frein6 l'adoption de moyens similaires
d'economiser l'energie dans l'industrie de la pate et du papier dans de
nombreux pays en developpement. Elle contlent aussi des propositions de
politique gen6rale et autres mesures que l'on pourrait adopter dans ces
cas-Ia pour amnliorer le rendement 6nerg6tique.
EXTRACTO
La produccion de papel requiere un uso relativamente ih.tensivo de
energia: una tonelada de papel demanda el equivalente de aproximadamente
tres cuartos de tonelada de petr6leo en los paises industrializados, y
hasta dos a tres veces esta cantidad en los paises en desarrollo. Aunque
alrededor de la mitad de este requerimiento puede satisfacerse quemando
los productos residuales de la industria, el resto debe comprarse.
Frente al rapido aumento de los costos de la energia que se produjo
en el decenio de 1970, los productores de los paises industrializados han
demostrado que es posible reducir sustancialmente el consumo para la
produccion de papel y que mejorando la eficiencia de la recuperaci6n de
residuos se puede disminuir auin mas la necesidad de comprar energia. Las
numerosas medidas que se examinan en este trabajo comprenden algunas para
aumentar la eficiencia energ6tica interna mediante mejores m6todos de
conservaci6n, modificaci6n de los procesos y reutilizaci6n del agua, pasos
para mejorar la utilizaci6n de residuos, y cogeneraci6n. Se incluyen
tambien analisis preliminares de los costos y beneficios de dichas medidas.
En el informe se examinan asimismo las limitaciones t6cnicas y de
otro tipo que hasta la fecha han tendido a limitar la introducci6n de
tecnicas similares para el ahorro de energia en las industrias de la pasta
y el papel de muchos paises en desarrollo. Se presentan propuestas
relativas a politicas y otras medidas que podrian adoptarse para estimular
una mejor eficiencia energ6tica en estas situaciones.
- vi -
ABBREVIATIONS AND ACRONYMS USED
API - American Paper Institutebdkg - bone dry kilogramsFAD - Food and Agriculture Organization of the United NationsGJ - gigajoules (109 joules)kcal - kilocalorieskg - kilogramskgoe - kilograms of oil equivalentkWh - kilowatt hoursm - cubic metersmtoe - million tons of oil equivalentMWI - megawatt hoursOECD - Organization for Economic Cooperation and DevelopmentSEE - State Economic EnterpriseSEKA - Turkish SEE with responsibility for paper productiont - tonstoe - tons of oil equivalenttpd - tons per daytpy - tons per year
ENERGY CONVERSION FACTORS
1 toe 1 107 kcal- 35.5 GJ- 4.26 MWh
- vii -
TABLE OF CONTENTS
SUIMMARY ix
I. INTRODUCTION ................. . ................. 1
II. THE PULP AND PAPER INDUSTRY ................................. 4
Paper Production and Consumption ....................... 4Technical Characteristics of thae Industry ............. 6
Pulp Mills ............................. 7Chemical Pulping ................................. 8
Mechanical Pulping.................... ......... 9
Combination Chemical anc Mechanical Pulping ........ 10
Paper Mills ......................................... 11Integrated Pulp and Paper Mills ........................ 13
III. ENERGY CONSUMPTION IN PULP AND PAPER PRODUCTION ............ 14
Global and National Statistics ......................... 14
National Studies .......................... .......... 16United States ...................................... 17
Japan ......................................... 18
Sweden ........................................... 18Developing Country Experience ..................... 19
General Assessment .............................. 22
IV. IMPROVING ENERGY EFFICIENCY .................... (, ....... 24
Basis of Analysis ............................... ....... 24Base Specific Energy Consumption............................. 25
Improvements in Energy Efficiency .......... ............ 28Internal Energy-Saving Measures ............... 28Improved Waste Utilization ................ 34
Cogeneration ................................. 40
General Assessment .* ........... . .... .. . . . ........... . 42
V. THE DEVELOPING COUNTRY SITUATION .......................... 44
Comparison of Energy Consumption .................. 44Principal Reasons for Lower Energy Efficiency in
Developing Countries ...... ........................... 44Plant Size *o........................... ...... 44
Design Technology ........... .................... 46Operational Environment ..................... 48Operational Management and Personnel ...... 49
General Assessment .......... * . .....* ................. 49
- viii -
VI. IMPROVING ENERGY EFFICIENCY IN THE PULP AND PAPERINDUSTRIES OF DEVELOPING COUNTRIES ......................... 51
Approach .......................................... * 51
Policy Considerations .................................. 52Sectoral Initiatives ................................... 56
Sector Planning .................................. 56Dissemination of Information ....................... 57
Mill-Specific Activities ............................... 58
VII. CONCLUSIONS AND RECOMMENDATIONS ....................... 60
Conclusions ........................................... 60Recommendations ................................. 61
ANNEXES
I Selected References ............................... 63
4-1 Energy Consumption in Unit Processes ...................... 65Introduction .............................................. 65Wood Preparation e .. . . e..e *-*.................. .. .. .- 65Pulping and Washing ............................ ........ 67Kraft Pulping .......................................... 67Thermo-mechanical Pulping ........................... 68
Bleaching ................................. 69Pulp Drying ............................................. 70Chemical Recovery .................................. 71Stock Preparation ......... ................................ 72Paper Machines ........................................ 73Total Energy Consumption .................................. 73
4-2 Energy Balance at Low Internal Energy EfficiencyTable 1 - Bleached Kraft Pulp Mill ................. ..... 75Table 2 - Linerboard Mill *........................... 76Table 3 - Newsprint Mill .......................... 77
4-3 Energy Balance at High Internal Energy Efficiency ... . . 78(Tables 1-3)
4-4 Energy Balance with Efficient Waste Recovery and HighInternal Energy Efficiency . ....................... .... 81(Tables 1-3)
4-5 Energy Balance with Cogeneration, Efficient WasteRecovery, and High Internal Energy Efficiency . ......... 84(Tables 1-3)
5 Short- and Long-Term Energy Efficiency Improvement Activities 87Short-term Measures .................................. 87Long-term Measures ........................................ 89
- ix -
SUMMARY
1. The objectives of this paper are first, to quantify the
consumptioni of energy in the production of paper; second, to compare the
consumption of energy in the paper industries of industrialized and
developing countries; third, to show the extent and nature of energy
savings which have been achieved in the industrialized countries; and
fourth, to suggest some preliminary approaches to encourage the transfer of
energy-saving technology to the paper industries of developing countries.
2. The production of paper is relatively energy intensive: one ton
of paper requires energy equivalent to approximately three quarters of a
ton of oil (toe) in industrialized countries, and typically double this
figure in developing countries. Although as much as one half of this
energy requirement is supplied by burning waste products of the industry,
the balance--about 70-75 million toe annually--must be purchased.
3. The paper industry produced about 170 million tons of paper and
paperboard in 1982, and output has been expanding rather steadily at an
average rate of about 4% annually over the past two decades. More than 85%
of both production and consumption is in the industrialized countries but
rates of growth are higher in developing countries, and this trend will
continue because of the generally more favorable conditions for producing
fibrous pulping material.
4e Paper production is normally a two-step process in which first,
the fibrous raw material is converted into pulp, and second, the pulp is
x
converted into paper. Pulping processes range from chemical to mechanical,
with very wide variations in the equipment and energy requirements.
Paper-making is more standardized, but there are still signific4knt
differences in the types of equipment to produce different grades of paper,
and in the level of plant sophistication, which will also lead to big
variations in energy requirements.
5. In the OECD countries, the paper industry consumed 58 million toe
of purchased energy in 1981, or about 7% of total industrial energy
consumption. In terms of its importance as an energy consumer, the paper
industry thus ranks below the steel (174 million toe), chemical
(123 million toe) and petrochemical (122 million toe) industries, but
slightly above the cement industry (49 million toe).
6. Efforts to reduce energy consumption for paper production in the
industrialized countries have been measurably successful over the past
decade. For example, the total amount of energy consumed per ton of paper
produced has declined by about 10% in the US. More importantly, the amount
of purchased energy consumption has declined, by about 28% in the US, 22%
in Japan, and 20% in Sweden (where energy consumption is already very low).
7. Similar statistics showing energy efficiency improvement over
time are not readily available from developing countries. In a few
countries (such as Brazil), energy efficiency is comparable to, if not
better than, the levels found in industrialized countries. More typically,
however, total energy consumption, and purchased energy requirements, are
substantially higher in developina countries,
- xi -
8. The impressive achievements in improving energy efficiency in
industrialized countries have come about as a result of activities in three
main areas:
(a) reductions in actual energy consumption at the point of use
together with improved energy re-use and recovery;
(b) increases in the amount of energy generated internally from
waste; and
(c) cogeneration of electric power and low pressure steam.
9. By properly applying these principles to the design of new
plants, f or some grades of paper it is possible to reduce purchased energy
requirements almost to zero. Even in existing plants, a substantial part
of the potential energy savings can be achieved. Returns on investments
for the smaller types of in-plant improvements are very high and often
exceed 100%. For the larger investments, returns of 20-30% are quite
realistic, which is more than the industry recovers from investments in
paper production facilities.
10. Developing countries striving to reduce energy consumption in
paper millk face many problems which' aa ra not normally found in the
industrialized countries. Principal among these are small plant size, the
design technology employed, the operational environment and the skill level
of the operational management and personnel. Not only must these issues be
- xii
properly addressed when designing energy efficiency improvement programs
for the paper industries of developing countries, but it must be realized
that they will inevitably limit the level of achievement.
11. Despite the problems, there is a great deal of scope for
improving energy efficiency in the paper industries of many developing
countries. Such improvement requires that issues be addressed at three
levels:
(a) a review of national policies to identify and modify those which
encourage inefficient energy use by the industry, and introduce
others which would encourage improved energy efficiency;
(b) initiatives at the sector level to improve energy-efficient
sectoral planning, and to collect information and publicize the
nature and extent of the benefits to be had through improving
energy efficiency; and
(c) the development c. ;ill-specific action programs beginning with
an energy audit which would identify specific short-term and
longer-term actions leading to improved energy efficiency.
12. Because it is already involved in aiding the development of the
pulp and paper industries in a number of countries, both through direct
lending and through local financial institutions, the World Bank is well
suited to help with the planning for and implementation of such programs.
I. INTRODUCTION
1.01 Paper production is energy intensive: the production of a ton of
paper requires, on the average, energy equivalent to about three quarters
of a ton of oil.l/ Overall, about one half of this energy requirement is
generated internally with steam raised in boilers fired with bark, other
wood waste and residual cooking liquor (black liquor). Electric power may
also be generated internally in steam-driven turbines, or in a few
situations, in captive hydro-electric installations. The balance of the
energy required must normally be purchased in the form of electricity or
fossil fuels.
1.02 According to OECD statistics, paper producers in the OECD
countries purchased a total of 58 millio"n toe of energy in 1981, or about
6.5% of the total OECD industrial energy consumption. In terms of total
purchased energy consumption, the paper industry ranks behind only the iron
and steel, chemical and petrochemical industries in terms of importance as
a consumer of industrial energy. Energy is one of the most important cost
factors in the production of paper: for some grades, the cost of energy
may exceed the cost of raw materials.
1,03 Under these circumstances it is not surprising that considerable
effort has b,een directed, first to reducing overall energy consumption in
1/ Steel production is similarly energy-intensive, consuming about0.6-1.0 toe per ton of product. Cement is less so: about 0.1-0.2 toeper ton.
-2-
pulp and paper mills, and second to reducing purchased energy requirements
by increasing the amount of energy produced internally from residual
materials. Most of this activity has been in the industrialized countries
where technology and capital required to implement energy efficiency
projects are more readily available.
1-04 This paper brings together some of the significant volume of
material concerned with improving energy efficiency in the paper industry.
The specific references which have been utilized are listed in Annex I.
The objectives are first, to qujantify the consumption of energy in the
production of paper, second, to compare t.he consumption of energy in the
paper industries of industrialized and developing countries, third, to show
the extent and nature of energy savings which have been achieved in the
industrialized countries, and fourth, to suggest some preliminary
approaches to encourage the transfer of energy-saving technology to the
paper industries of developing countries. The paper is a desk review which
indicates the magnitude of the problems and the nature of the possible
solutions. Implementing such solutions in a specific country situation
would require an analysis of that situation as both the paper industry and
the energy supply picture vary considerably from country to country.
Implementing solutions in a particular mill situation should be done in the
context of an overall program of efficiency improvement.
1.05 The arrangement of the paper is as follows, Chapter II provides
some background information about the paper industry followed by a review
of recent experience concerning the consumption of energy in the industry
(Chapter III), as a prelude to utilizing case studies to detail the kinds
of activities which are being undertaken to improve energy efficiency
(Chapter IV). Chapter V discusses the particular problems which relate to
energy efficiency improvement in developing countries, and Chapter VI
suggests an approach to initiating an energy assessment program for the
pulp and paper industry in developing countries. Some supporting
statistical information, and the more detailed technical data, are
contained in Annexes which support the main text. The overall conclusions
and recommendations of the study are contained in Chapter VII.
4 -
II. THE PULP AND PAPER INDUSTRY
Paper Production and Consumption
2.01 World production of paper 2/ in 1982 amounted to
170 million tons, which was produced in an estimated 6,000 mills located in
90 countries representing all types of economic systems and all levels of
economic development (Refs 2, 3). As shown in the following table, paper
production has been growing steadily over the past 20 years. The average
rate of increase is slightly less than 4% annually over the period.
Table 2-1
World Production of Paper(million tons)
Year Production
1961 781966 1051971 1301976 1491981 170
Source: Refs 2, 3.
2.02 Both the production and the consumption of paper are concentrated
in the industrialized countries. Country statistics for 1982 are
summarized according to economic groupings in the following table:
2/ The term "paper", unless otherwise specified, includes paper andpaperboard.
-5-
Table 2-2
World Paper Production and Consumption inEconomic Groupings of Countries (1981)
PerApparent Capita
Pro- Net Con- Popu- Con-duction Imports sumption lation sumption- ------(million tons) ----- (million) (kg/cap)
IndustrializedCountriesNorth America 70.1 (4.9) 65.2 257 254.0Western Europe 43.8 (2.3) 41.5 351 118.0Oceania 2.1 0.4 2.5 18 139.0Other 18.4 - 18.4 147 125.0
DevelopingCountriesAfrica 0.4 0.5 0.9 385 2.3Latin America 7.6 1.8 9e4 375 25.1Middle East 0.9 1.0 1.9 226 8.4Asia 5.7 1.9 1.6 1,253 6.1
Centrally PlannedEconomiesAsia 5.5 0.6 6.1 1,097 5.6Eastern Europe & USSR 13.4 (0.1) 15.3 406 38.0
World Total 169.9 (1.1) 168.8 4,515 37.0
Source: Refs 2, 3. Numbers may not add up due to rounding and reportingdiscrepancies.'
2.03 Although the above figures clearly show the dominance of the
industrialized countries in both the production (about 88% of the world
total) and the consumption (85%) of paper, production and consumption in
the developing countries are growing at a significantly faster rate as
shown in the following table:
-6-
Table 2-3
Comparison of Growth Rates in Paper Production andConsumption in Developing and Industrialized Countries
Average Annual Rate of Growth (%)Production Consumption
1961-70 1971-80 1961-70 1971-80
Industrialized Countries 5.6 2.8 505 2.8Developing Countries 7.4 7.3 7.5 6.0
World 5.7 3.2 5.7 3.2
Source: Derived from Ref 2.
Technical Characteristics of the Industry
2.04 Paper production is normally a two-step process in which first,
the fibrous raw material is converted into pulp, and second, the pulp is
converted into paper. Plants in the pulp and paper industry may thus be
(i) pulp mills, which produce pulp as an end product for shipment to other
paper-producing plants; (ii) paper mills which produce paper and board from
purchased pulp, and sometimes from recycled waste paper, or
(iii) integrated pulp and paper mills which combine the features of both
(i) and (ii). Although there is a wide variety of paper grades produced,
and a number of different processes for pulp and paper production, certain
common unit processes are found in all integrated plants. These include
fibrous raw material preparation, pulping and paper-making. Other unit
processes which may be incorporated are chemical recovery, which recovers
the chemicals used in pulping for re-use, and usually generates steam as a
by-product, and bleaching, where the pulp is bleached prior to being
converted into paper. In some plants bleaching chemicals may be produced
on-site which can have a significant effect on energy consumption.
-7
2.05 In order to facilitate subsequent discussion on energy
consumption and energy conservation, the following paragraphs briefly
describe the technical principles of the main types of pulp and
paper-producing plant.
Pulp Mills
2.06 All pulp mills share the characteristic of starting with some
cellulose-containing fibrous raw material and breaking it down by chemical
or mechanical means, or a combination of these processes, into a pulp which
can be delivered to a paper mill. At the end of the pulping process, the
pulp is a suspension of fibrous material in water. Non-integrated "market"
pulp mills usually dry the pulp to facilitate handling and reduce freight
costs, and then ship it in baled form to the paper mill. However in some
instances, even market pulp may be pumped in slush form to a nearby paper
mill, or shipped in a partially dried condition.
2.07 Pulp mills can be subdivided into categories according to their
fibrous raw material, and according to the chemical, mechanical or
combination of processes which they utilize. As these factors have a
marked impact on the amount and type of energy used to produce pulp, it is
appropriate to briefly describe the most important materials and processes.
2.08 Most pulp for paper-making is produced from wood (about 94% of
total world pulp production, or 130 million tons in 1982). Almost any type
-8-
of wood can be used for the production of chemical and semi-chemical pulp,
but there are limitations on the wood species which can be used to make
mechanical pulp. Of the non-wood fibers, which were used to produce
approximately 8 million tons of pulp in 1982, the most important are rice
straw and sugarcane bagasse. Other fibrous .*xaterials used for paper pulp
production on a small scale include wheat seraw, cotton waste, jute, flax,
reeds and kenaf.
Chemical Pulping
2.09 As noted above, pulping processes may be subdivided into chemical
processes, mechanical processes and combinations of these two. By far the
most important is chemical pulping, accounting for more than 70% of all
paper-pulp production. The principal feature of a chemical process is a
heated pressure vessel called a digester, into which the fiber is
introduced along with the chemicals. The purpose is to dissolve
non-cellulosic components of the fibrous raw material (primarily lignins)
into the aqueous phase. After the pulp is removed from the digester it is
washed to remove the dissolved chemicals. Digesters ma.y operate on a
continuous batsis or in batches. After washing, the pulp may be further
refined by screening and bleaching, according to the ultimate end-use
requirements. Depending on the degree of cooking and subsequent treatment,
and to some extent on the fibrous raw material, the yield of chemical pulp
will vary between 40% and 50% of the bone dry weight of input fiber.
-9-
Mechanical Pulping
2.10 About 22% of the pulp used for paijer production is produced by
mechanical pulping processes. In purely mechanical processes, the raw
material is broken down by physical means into an aqueous susperisiop of
fibrous particles. In the oldest, and still the most widely used process,
short pulpwood logs (billets) are pressed against a large revolving
grindstone and literally ground into a pulp. The cellulose fibers are to
some extent damaged by this process, and the pulp also contains most of the
non-cellulosic component of the pulpwood raw material. For these reasons,
groundwood pulp has a much lower strength than chemical pulp. However the
yield is much higher, typically between 90% and 95% on a bone-dry weight
basis.
2.11 A more recent development in mechanical pulping is the use of
refiners to break down wood particles into fibers by forcing them between
rotating steel plates with a variety of surface configurations. Refiner
groundwood pulp has superior strength characteristics to those of stone
groundwood pulp, although the power consumed to make a ton of pulp is
significantly higher. This process uses wood particles (chips and sawdust)
rather than logs, which may be an advantage if pulpwood is only available
in this form (e.g., waste from a sawmill), or a disadvantage if logs have
to be chipped, requiring additional equipment and power. By using steam
from the refiners to pre-steam chips, so-called thermo-mechanical pulp can
be produced which again has certain superior characteristics to ordinary
refiner groundwood pulp.
- 10 -
2.12 As with chemical pulp, mechanical pulp can be further treated by
screening, or chemically to improve brightness, depending on the ultimate
end-use.
Combination Chemical and Mechanical Pulping
2.13 There is a wide spectrum of processes which use a combination of
chemical and mechanical means to produce pulp. Nearest to the chemical end
of the spectrum are the semi-chemical processes which use digesters as for
full chemical pulping, but generally uso less chemicals and steam, and
follow the digesting process with a heavy refining stage. Semi-chemical
pulp is produced at higher yields than full chemical pulp, and uses less
quantities of chemical. However, while eminently suitable for certain
grades of paper, such as corrugating medium, semi-chemical pulp is costly
to bleach, and of generally lower strength. Moreover the recovery of
chemicals for re-use is more difficult.
2.14 These mixed chemical and mechanical processes offer some very
specific advantages in terms of product characteristics for certain
end-uses. They are generally characterized by higher yield and lower
chemical costs than full chemical pulping, and better strength
characteristics than full mechanical pulping. Recent improvements to the
chemi-mechanical pror-ess in particular have led to the production of a.
superior pulp which is receiving attention as a lower-cost alternative to
full chemical pulp for certain applications. Nevertheless because their
end-uses are rather specific, they represent less than 8% of total world
pulp production and this.proportion is unlikely to increase substantially
in the foreseeable future.
Paper Mills
2.15 Paper mills produce paper from pulp. Most paper mills either
produce their own pulp, or purchase pulp produced by one of the methods
described above, but about 25% of the fiber used for paper-making is
recycled waste paper. The paper-making process differs considerably
according to the type of paper to be produced but certain basic elements
are common to all types of paper.
(a) Stock Preparation. This stage of the process will vary according
to (i) the form and type of pulp, and (ii) the type of paper to
be produced. If pulp is procured in dried, baled form the bales
must be broken down and the pulp slushed into a suspension in
water. If waste paper is used, it will normally require cleaning
and de-inking as well as slushing. Stock preparation normally
also includes refining to achieve the proper fiber
characteristics for the grade of paper to be produced, screening
to remove foreign material, and cleaning to remove sand.
Chemicals, dyes and fillers such as clay may be added during
stock preparation to impart specific characteristics to the
paper.
- 12 -
(b) Forming. The fibers must be formed into a sheet and this is
normally accomplished by starting with a very dilute suspension
(usually less than 1 part of fiber to 200 parts of water--a
consistenicy of less than 0.5%), and either discharging it onto a
travelling wire screen where water is removed by gravity and
suction, or picking it up on a travelling felt blanket to which
suction is applied. After forming, the consistency of the sheet
is typically in the range of 15-20% fiber.
(c) Pressing. More moisture is removed by pressing the sheet betwreen
pairs of rollers. The sheet is normally carried through the
rollers on a felt to support it and to help carry away the water
which is pressed out. Vacuum may be applied to further
facilitate water removal. After pressing, the dryness of the
sheet would normally be 35-45%.
(d) Drying. After pressing, the sheet is dried, normally by
supporting it on a felt and carrying it around a number of
steam-heated drums. Surface characteristics may be imparted to
the sheet by drying the sheet directly on a large, surfaced,
steel drying cylinder, or by pressing the sheet between steel
rollers. The sheet may also be coated or treated with chemicals
(such as rosin size) to obtain specific surface properties.
After drying, the sheet is normally wound on to reels at the end
of the paper machine.
- 13 -
(e) Finishing. Paper machine reels are usually rewound into small
reels of widths determined by the end use. Other finishing
operations may include cutting sheets of specific sizes. The
degree of finishing varies widely according to the product and
the ultimate end use.
Integrated Pulp and Paper Mills
2.16 Most paper is produced in integrated mi~lls which combine both a
pulp mill and a paper mill as described above. Paper production in
non-integrated mills is normally on a relatively small scale (from 10 tpd
to 100 tpd in industrialized countries, and generally smaller in developing
countries). Such mills tend to be located near large cities, and to use
purchased pulp or waste paper, or a combination of the two.
2e17 Integrated mills are more typically located close to the source
of the fibrous raw material. In industrialized countries they are normally
in the size range of 500-1,000 tpd or even larger. In developing
countries, depending on local situations, they tend to be smaller.
Non-integrated mills tend to produce more specialized grades such as
tissue, writing paper, and boards with a high waste paper component.
Integrated mills tend to produce bulk grades for shipment in reels such as
newsprint, sack kraft paper and linerboard.
-14-
III. ENERGY CONSUMPTION IN PULP AND PAPER PRODUCTION
Global and National Statistics
3.01 As noted in Chapter I, the pulp and paper industry is a
significant consumer of energy. In the OECD countries .s a group, the
industry ranks below iron and steel, chemicals and petrochemicals, and
slightly above cement, in terms of its share of industrial energy
consumption. Relevant statistics are presented in the following table.
Table 3-1
Energy Consumption in the OECD (1981)(mtoe)
Elec-Oil Solid Gas tricity Total %
Total Commercial Energy 1,435 233 537 397 2,602 100Of which:
Consumption in Industry 289 191 236 174 890 34Of which:Iron & Steel 14 108 28 24 174 7Chemicals 26 6 61 30 123 5Petrochemicals 110 - 8 4 122 5Paper a/ 18 6 16 19 58Cement 15 21 4 9 49 2
a/ Purchased energy only, which represents about one half of the energyconsumed by the paper industry.
Source: Refs 4, 5.
3.02 Total production of paper and paperboard in the OECD in 1981 was
133*5 million tons so that energy equivalent to 0.43 tons of oil was
purchased for each ton of paper produced. Although national averages mask
15 -
changes in grade composition which can have a major effect an unit energy
consumption, it is interesting to compare the proportion of energy used for
pulp and paper production in selected OECD countries, and also the apparent
unit energy consumption per ton of paper produced.
Table 3-2
Purchased Energy Consumption by the Pulp and PaperIndustry in Selected OECD Countries
1981 Purchased Energy ConsumptionAll Industry Pulp & Paper
Country (mtoe) (mtoe) (%) (toe/t paper)
Canada 56.8 4.6 8.1 0.34USA 360.0 24.2 6.7 0.43Japan 132.4 6.5 4.9 0.38Finland 8.8 3.4 38.6 0.55France 49.1 1.9 3.9 0.36Italy 41.3 1.7 4.1 0.34Sweden 12.2 5.0 41.0 0.82UK 43.7 1.9 4.3 0.56
All OECD 889.9 58.0 6.5 0.43
Source: Ref 4.
3.03 Once again it must be pointed out that comparisons within this
table must be undertaken very carefully. First there may be reporting
inconsistencies, in particular related to the energy which is generated
internally. Second, whereas overall in the OECD the production of pulp and
of paper are more or less in balance, there are big variations from country
to country. Those countries which import a substantial proportion of the
pulp they use to make paper (such as Italy) will show a low apparent energy
consumption per ton of paper. Those countries which produce substantially
more pulp than paper (such as Sweden) will show high figures. Third, those
- 16 -
countries which produce a substantial proportion of mechanical pulp will
show higher average unit energy consumption.
3.04 Some attempts have been made to make inter-country comparisons of
OECD data more meaningful by comparing the structure of national pulp and
paper industries (the relative proportions of mechanical pulp, chemical
pulp, market pulp and paper and board production) with specific fuel and
energy consumption. In one study (Ref 15), the results of multiple
regression analyses of this type are presented, and statistically
significant equations are developed which show that the main determinant of
electrical energy consumption is the proportion of mechanical pulp
produced, while the main determinants of fuel consumptior are the
proportion of chemical pulp produced and the amount of self-generated
electricity. While these findings are reasonable, the coefficients derived
could not be interpreted in meaningful physical terms, and the authors of
the referenced study concluded that regression analysis was of limited
value in making inter-country comparisons of specific energy consumption in
the pulp and paper industry.
National Studies
3.05 More interesting statistical information is found in national
studies of energy consumption in the paper industry which have been
undertaken by or on behalf of various national associations or consulting
engineering companies. In particular, since the rapid escalation in energy
prices which began in the early 1970s, various studies showing the impact
- 17 -
of energy saving efforts have been published. The following paragraphs
present achievements in this area for three selected major pulp- and
paper-producing countries.
United States (Ref 6)
3.06 Between 1972 and 1982, total energy consumption dropped from
0.82 toe to 0.74 toe per ton of paper and dried pulp produced, a reduction
of 10%.3/ During the same period, purchased energy consumption dropped
from 0.48 toe to 0.35 toe per ton of paper and dried pulp produced, a
reduction of 28%. After making adjustments for differences in capacity
utilization, fuel mix and energy use for environmental control over the
period, API has estimated that the actual reduction in purchased energy use
per ton was 35%. The study on which these result§ were based covered 380
pulp, paper and paperboard mills, operated by 106 companies, which in 1982
accounted for 93% of the industry's production.
3.07 The study contains an extensive list of the measures for
improving energy efficiency which have led to the reductions noted. These
fall broadly into three groups: (i) fuel switching (primarily from fossil
fuels to wood fuel); (ii) process changes and improvements (including, in
particular, increased cogeneration, and the replacement of inefficient
equipment with new, more efficient units); and (iii) in-process energy
conservation.
3/ The selection of the denominator (paper and dried pulp production) inthe equation to determine unit energy consumption introduces somepossibility for double-counting and lower unlt energy consumption.
presumably the statistics from within countries are on a consistentbasis, but this remains a source of possible variation when comparing
statistics from one country with another.
- 18 -
Japan (Ref 8)
3.08 Between 1973 and 1982, purchased energy cohsumption dropped from
0.59 toe to 0.46 toe per ton of paper and paperboard production, or a
reduction of 22%. The referenced study gives examples of energy-saving
through specific measures during the period 1979 to 1981, and groups them
according to specific types of energy savings defined in Japan's "Energy
Conservation Act'. During this period the most important energy-saving
measures were found to be as follows:
Table 3-3
Relative Importance of Energy-Saving Measures
in Japan's Pulp and Paper Industry, 1979-81
Measure % of Total Savings
Rationalization of heating, cooling & heat transfer 28.8
Rationalization of conversion of electricity
into power, heat, etc. 27.6
Reutilization of waste heat 21.4
Rationalization of heat conversion into power, etc. 12.1
Other 10.1
100.0
Source: Ref 8.
Sweden (Ref 9)
3.09 Intra-mill comparisons undertaken from time to time have rather
clearly demonstrated that the Scandinavian pulp and paper industry has
consistently been more energy-efficient than its North American
couinterpart. Many of the energy conservation techniques now being applied
in North American mills were developed in Swedish and Finnish mills and
- 19 -
were in use there even before the early 1970s. For this reason, and
because of changes in the product mix, there has been little recent
discernible improvement in Sweden in the overall unit consumption of energy
in pulp and paper production, which was at a level of approximately
0.51 toe per ton of paper produced and dried pulp exported in both 1973 and
1979. However with increased use of waste fuels, and expanded
cogeneration, the purchased energy fell from 0.26 toe to 0.21 toe per ton,
a reduction of almost 20%.
Developing Country Experience
3.10 Unfortunately the detailed statistical information required to
evaluate trends in energy conservation over time in developing countries is
not readily accessible. A few countries, such as Brazil, have highly
developed industries, with large, modern mills, and a significant stake in
export markets. Since 1977, efforts in the Brazilian pulp and paper
industries have been directed towards reduction in fuel oil consumption, by
increasing the use of wood fuel, and by using electrical energy where this
alternative is feasible. Purchased energy consumption by Brazil's industry
is only about 0.33 toe per ton of paper and market pulp which is comparable
to levels in OECD countries. This low level is at least in part because
the Brazilian industry is one of the leaders in efforts to increase the
extraction of logging wastes (small wood, branches, etc.) which are
- 20 -
nonnally left in the forest but which can be brought to the mill, chipped
and burned with other waste wood to reduce purchased oil requirements.4/
3.11 Unfortunately, many of the characteristics of the Brazilian
industry--relatively new, relatively large integrated mills with a high
level of foreign participation--are not generally found in the pulp and
paper industries of developing countries, and the Brazilian experience
cannot usually be replicated. More typically, mills are smaller, older,
and often built with very little attention to energy efficiency. A
selection of reported energy consumption figures for a few developing
countries where recent information has been published is presented in
summary form in the following table.
4/ Unlike bark removed from the pulpwood used in the mill, there aresignificant extraction, transportation and preparation costsassociated with utilizing forest wastes. One Brazilian source(Ref 11) estimates that fuelwood from the forest actually costs 10-20%more than pulpwood, but is still only about 40% of the cost of oil.
- 21 -
Table 3-4
Energy Consumption in Pulp and Paper Millsin Selected Developing Countries
Coverage Average EnergyNo. of % of Total Consumed (toe/t)
Country Mills Production Purchased Total
Colombia 4 80 0.75 1.09Turkey' 7 89 0.99 n.a.India 4 13 1.72 2.42Pakistan 5 90 1.22 1.29Indonesia 15 38 0.72 1.09Thailand 1 25 0.44 0.55
Average a/ 0.83 / 1.17
OECD 0.43 0.65b/
a/ Weighted according to production from sampled mills in each country.b/ Based on statistics from Japan, Sweden and the USA.
Source: Refs 1, 13, 14, 16, 18.
3.12 As noted in the discussion concerning the intra-country
comparison for industrialized countries (para 3.03) care must be taken in
interpreting these data. In some countri's, for example, a substantial
part of the fiber-furnish for paper-making is waste paper (domestic and
imported)1which means that much of the energy has been consumed elsewhere.
In Indonesia and Thailand, substantial quantities of imported pulp are
utilized with a similar lowering effect on national energy consumption. It
is noteworthy that in India, which imports very little pulp, and utilizes
relatively little waste paper for paper-making, unit energy consumptions
are the highest among the countries tabulated. Although the data is
incomplete, it suggests that on average, paper production in developing
countries consumes about twice as much energy as in industrialized
countries. In some countries, at least in the mills included in the
samples, apparent energy consumption is substantially higher.
-22-
General Assessment
3.13 From the foregoing it can be concluded, first, that in the
industrialized countries, efforts to reduce energy consumption by the paper
industry over the past decade have been measurably successful. Although
statistics from only 3 countries have been presented, the,se countries
produce over 77 million tons of paper, or more than 44% of total
world production. The indicated savings in purchased energy in these
countries alone, as a result of measures taken over the past decade, amount
to about 10 million toe per year at 1982 production levels. For the
industries themselves, this represents a reduction in costs equivalent to
about US$25 per ton, or 4-5% of the end value of the product.5/ It can be
concluded that the incentive created by higher energy costs has been rather
effective in improving energy efficiency in the industrialized countries.
3.14 The second conclusion to be drawn from the material contained in
this chapter is that with the notable exception of a few countries such as
Brazil, energy consumption in the paper industries in developing countries
is usually substantially higher--double, on the average, in the countries
where information is available--than in the industrialized countries.
Based on a differential in purchased energy of about 0.4 toe (Table 3-4),
this represents a competitive disadvantage of about US$80 per ton of paper
purchased. In some countries the differential energy consumption is
substantially higher than 0.4 toe, and the competitive disadvantage
correspondingly worse.
5/ Assuming energy costs US$200 per toe, and paper has a value ofUS$500-600 per ton,
- 23 -
3.15 Although there are clearly deficiencies in the aggregated
information, there can be little doubt that the principal problem in this
field is one of wastage of energy, not lack of information. Of the 36
mills from which energy consumption data has been used in preparing
Table 3-4, all but 12 purchased at least i'O% more energy than the OECD
average. The 12 low energy-consumers were all simple non-integrated mills
using purchased pulp or waste paper which means merely that much of the
energy was expended at another site.
- 24 -
IV. IMPROVING ENERGY EFFICIENCY
Basis of Analysis
4.01 In the preceding chapter, it was demonstrated that efforts over
the past decade to improve the energy efficiency of the pulp and paper
industries of the United States, Japan and Sweden have been measurably
successful. Similar results would be found in analyzing the industries in
most other paper-producing industrialized countries. These results have
been achieved not by radical changes in process technology, but ge.nerally
as a result of a large number of relatively small steps taken at the
individual plant level. Because of wide variations from plant to plant, it
would not be appropriate in this paper to attempt to provide a detailed
catalogue of all the measures which can contribute to improved energy
efficiency.
4.02 As an alternative, the approach taken is to demonstrate, by means
of hypothetical mill cases, backed up by specific examples, the nature and
extent of the improvements which can be achieved in the three major areas
for enhancing energy efficiency, namely:
(a) internal energy-saving measures, including direct energy
conservation at-the point of use, and in-process waste heat
recovery;
- 25 -
(b) improved utilization of waste materials for fuel, in particular
wood wastes and waste cooking liquor (black liquor); and
(c) cogeneration of steam and electric power whereby electricity can
be produced efficiently in back-pressure turbines, the exhaust
steam from which is used in the process.
4.03 To examine the potential for improvement in different processes
and plants, three typical mill configurations have been used, producing,
respectively, bleached kraft pulp, linerboard and newsprint. The capacity
in each case is 250,000 tpy, which is a typical size of such plants in
industrialized countries. As a starting point it has been assumed that the
plants have been built using the technology of the 1960s and early 1970s,
which implies incorporation of some of the more straightforward 4--plant
energy-saving and waste heat recovery systems.
Base Specific Energy Consumption
4.04 Because of the wide range of reported energy consumption in the
various unit processes, even in mills with essentially the same equipment
and product mix, the selection of base specific energy consumption is
somewhat arbitrary. Annex 4-1 presents a range of reported data from a
variety of sources for each of the process stages in the typical mill
configurations to be evaluated, and gives the basis for the selection of
the base figt're in each case. The selected typical base-case data are
summarized in the following table:
- 26 -
Table 4-1
Typical Process Energy Consumption in the Productionof Selected Pulp and Paper Grades a!
Bleached Kraft Pulp Linerboard NewsprintElec- Elec- Elec-
Thermal trical Thermal trical Thermal trical(GJ/ton) (kWh/ton) (GJ/ton) (kWh/ton) (GJ/ton) (kWh/ton)
WoodPreparation 0.1 65 0.1 55 0.1 45
Pulping &Washing 3.5 120 3.0 210 - 1,710
Bleaching 5.0 190Pulp Drying 3.6 160 - - - -StockPreparation - 240 100
Paper-making - - 6.5 190 5.8 250ChemicalRecovery 5.2 75 4.2 65 - -
Miscellaneous 1.1 130 1.2 140 1.0 100
Total 18.5 740 15.0 900 6.9 2,205
a/ For mills built with 1960s technology and thus no out-of-the-ordinAryenergy saving or heat recovery systems.
Source: See Annex 4-1.
4.05 The bleached kraft pulp mill and the linerboard mill would almost
invariably incorporate a chemical recovery boiler, which typically could
deliver about 13.0 GJ per ton of pulp and 11.0 GJ per ton of paper to the
two plants, respectively. Even with 1960s technology, such plants would
incorporate heat recovery systems on the digesters and paper machines (or
pulp dryers), and be designed to re-use certain waste water streams to
improve energy efficiency. For the base-case situation, it has been
assumed that wood waste is not collected and burned, and that electric
power is not generated in the plant, but many mills of this era dli adopt
- 27 -
these practices.6 / If no other measures were taken to conserve energy or
to generate energy internally, the energy balance for each plant would be
as detailed in Annex 4-2. The purchased energy requirement, and the
approximate unit cost of energy per ton of product (assuming oil at US$200
per ton and electric power at US$0.03 per kWh) would be as follows:
Table 4-2
Energy Requirements and Costs in the Productionof Selected Pulp and Paper Grades
Bleached Kraft Linerboard Newsprint
Total Energy Consumed (k-oe/ton) a/ 786 709 723Purchased Oil (kg/ton)
Lime Kilns c/ 60 50Steamp. Generation 120 135 205
Purchased Power (kWh/ton) 740 900 2,205Total Purchased Energy (kgoe/ton) a/ 354 396 723Energy Cost (US$/ton) b/ 58 64 107
a/ Power converted to oil at 4.26 kWh/kgoe, and thermal energy at33.5 GJ/ton.
b/ Oil assumed to cost US$200 per ton; power to cost US$0.03 per kWh.c/ Lime kilns in the kraft chemical recovery system are almost invariably
fueled with oil or natural gas.
Source: Energy Balances, Annex 4-2.
4.06 As noted above, these levels of purchased energy requirements
were typical in mills built in the industrialized countries in the 1960s
and early 1970s. Also as noted, with the incentive generated by rapidly
increasing oil prices, advances on three major fronts--reduction in process
energy requirements, improved waste utilization as fuel, and internal power
generation--have led to significant reductions in these requirements. The
following paragraphs discuss the potential benefits which could be achieved
in these areas.
6/ In Sweden in 1973, for example, it is reported that bark was burned,and back-pressure power generated, at about 50% of the theoreticallyobtainable levels (Ref 7). In most other countries the figures wouldbe lower.
- 28 -
Improvements in Energy Efficiency
Internal Energy-Saving Measures
4.07 In a typical pulp and paper plant, there are numerous
possibilities for reducing energy requirements at the point of use, and for
re-using energy by re-using heated effluent streams either directly or in
heat exchangers. These systems can most easily be incorporated in designs
for new plants, but in many instances can be added subsequently. Some of
these direct measures to reduce energy requirements at the point of use in
the major process areas are:
(a) Wood Handling
(i) whole log chipping;
(ii) mechanical instead of hydraulic barking;
(iii) belt insteed of pneumatic conveying; and
(iv) plant location to reduce handling distances.
(b) Chemical Pulping
(i) continuous instead of batch processes;
(ii) indirect rather than direct heating;
- 29 -
(iii) increased liquor strength; and
(iv) high consistency pulp washing.
(c) Bleaching
(i) high consistency bleaching and washing.
(d) Pulp Drying and Paper-making
(i) closed circulating water systems; and
(ii) high efficiency of mechanical water removal (forming and
pressing).
(e) General
(i) good insulation;
(ii) plant layout to reduce pumping distances;
(iii) minimization of water use; and
(iv) properly designed and efficient motors, pumps, fans and
agitators to reduce electrical consumption.
- 30 -
4.08 The extent to which these measures can be applied to reduce
direct energy consumption will vary widely from mill to mill, but the
difference between an efficient and an inefficient mill in this respect
would normally amount to about 10% of thermal energy and 5% of electrical
energy.
4.09 More substantial inroads into process energy requiretaents can be
made by installing and operating efficient heat recovery systems. A
typical pulp or paper mill will utilize 60-160 cubic meters of process
water for every ton of product, depending on the products and processes.7/
This water enters the mill at ambient temperature (say 10-150C, although
considerably colder during winter in northern climates) and leaves as
effluent with a temperature of 25-35%C. A substantial part of'the energy
used in a pulp and paper-mill is eventually lost in the effluent. The
amount of heat lost can be reduced by reducing the volume of w4ter (by
recycling and re-using effluent streams), and by using hot effluents to
heat incoming process water. Similarly, heat recovery systems can be
installed on the substantial emissions of hot vapors from such unit
processes as the digester system, the chemical recovery system, a
thermo-mechanical pulping plant, and the paper machine or pulp dryer.
7/ Water consumption may be considerably higher in older mills wherelittle attention was paid to minimizing consumption or maximizingrecycling. At the other end of the scale, it is possible to designvirtually "closed" mills with very little process water make-up. Thecapital cost of a closed mill may be as much as 10% higher than thatof a conrventional mill, however, and certain process probl: ms mayoccur as a result of build-ups of impurities in the system. Becauseof these costs and problems, only one such mill has actually beenbuilt and operated.
- 31 -
4.10 Depending on the degree of heat recovery in the original design,
the potential fo- further energy savings with heat recovery systems is
substantial, ranging from levels of about 10% in such processes as the
chemical recovery system and a thermo-mechanical pulp plant, to 20% in a
chemical pulping plant, and to 50% in a bleach plant. Taken together, for
the three illustrative mill configurations, the in-plant measures to reduce
energy consumption and to recover energy would reduce the requirements for
purchased energy from the levels shown in Table 4-2 to the figures in the
following table. Details of the energy balance in this case are provided
in Annex 4-3.
Table 4-3
Energy Requirements and Costs After Internal Energy Saving Program
BleachedKraft Pulp Linerboard Newsprint
Total Energy Consumed (kgoe/ton) 603 594 642Purchased Oil (kg/ton)
Lime Kilns 55 50 -Steam Generation - - -
Purchased Power (kWh/ton) a/ 550 855 2,095Total Purchased Energy (kgoe/ton) 184 281 642Enetgy Cost (US$/ton) 27 42 93
a! In the case of the bleached kraft pulp mill, it has been assumed thatsurplus steam from the recovery boiler would be used to generateelectric power in a condensing turbine, thereby reducing purchasedpower requirements. Details are in Annex 4-3.
Source: Energy Balances, Annex 4-30
4.11 Comparing the total energy consumed with base-case volumes in
Table 4-2, it can be seen that the overall reduction which could
theoretically be achieved by these measures amounts to 23% for the bleached
kraft mill, 16% for the linerboard mill and 11% in the newsprint millo The
actual reductions in total energy consumption in the United States between
- 32 -
1972 and 1982 was about 10% (para 3.06), suggesting that there may be scope
for further improvements in this area, particularly as old plant is
replaced with new equipment designed with more attention to energy
conservation. The reduction in purchased energy which could be achieved
with these in-plant measures averages almost 30% compared with actual
achievements of 35% in the USA (para 3.06), 22% in Japan (para 3.08), and
20% in Sweden (para 3.09).
4.12 The capital investments required to achieve the projected savings
from internal measures will differ substantially from mill to mill and as
noted above would likely be significantly more in a retro-fitting situation
than in a new plant. The measures would likely consist of a number of
relatively minor modifications such as piping changes, addition of heat
exchangers, insulation improvement, and the modification of electrical
drives. Comparing Tables 4-2 and 4-3, the indicated saving projected from
such measures ranges from US$14 per ton of newsprint, to US$31 per ton of
bleached kraft pulp. Based on an annual production of 250,000 tons, this
represents from US$3.5 million to US$7.8 million per year in each plant.
Capital costs estimated for such an imprecisely defined group of projects
must be equally imprecise: however individual project components are
likely to be in the tens of thousands, or in a few cases hundreds of
thousands of dollars. In some cases, where perhaps changes in operating
techniques are all that would be required, no investment would be necessary
to deliver significant benefits. A complete program of such internal
efficiency improvements for a large and complex mill would not likely cost
in excess of US$3--5 million, indicating rather high potential rates of
return.
- 33 -
4.13 The costs and benefits from programs of internal efficiency
improvement have been detailed in some published information from the Japan
Paper Association (Ref 8), based on a survey of Japanese mills, which
groups a number of projects of this type and shows the total capital cost
and the total energy saving. The annual savings expressed as a percentage
of investment cost from these data is exceptionally high.
Table 4-4
Japan - Costs and Benefits from SelectedInternal Energy Saving Projects (1976-78)
Investmentat 1983 Annual Energy Saving
prices a/ Total b/No. of (US$ Power Fuel (US$ ROI c/
Type of Project Cases million) (MWh) (toe) million) (x)
Heat Recovery fromHot Effluent 47 1.7 (1,560)d/ 40,000 8.0 370
Heat Recovery fromExhaust Steam 73 2.4 730 66,000 13.2 450
Improvements inMachine OperatingEfficiency 45 0.4 69,800 600 2.2 450
Motor CapacityAdjuistments 58 0.7 40,500 330 1.3 85
Paper MachinePress DrainageImprovement 55 3.6 10,300 23,700 5.5 53
a/ Converted from Japanese yen at Y 295 = US$1, the average exchange ratefrom 1976 to 1978, and brought to 1983 prices using the index ofconsumer prices for industrial countries (Ref 12).
b/ Calculated using prices of US$200/ton for oil and US$0.03/kWh forelectric power.
c/ Calculated as 100 x (Annual Saving/Investment).d/ Increased power consumption.
Source: Ref 8.
4.14 The very high indicated rates of return are probably at least in
part an indication of low efficiency before the measures were taken. Ekono
- 34 -
(Ref 10), while commenting on the difficulty of evaluating the
profitability of energy-related -rojects because of the complex
interrelationships which are involved, has estimated that the ratio between
first year savings and total investment is typically about 40% for projects
which lead to a saving in process heat, and 50% for projects which save
power. In the same paper, Ekono cites a specific case where the rate of
return for an energy-saving project was of the order of 100%.
4.15 Despite the difficulties inherent in identifying precisely the
benefits to be obtained from improved internal energy efficiency, it can be
concluded that the first steps in such programs are likely to be highly
profitable, requiring only small investments which lead to substantial
energy savings. As mills become more efficient, the marginal benefits
decline, but may still be substantial.
Improved Waste Utilization
4.16 In kraft mills, there is typically scope for improving the output
of steam from the recovery boiler for each ton of pulp produced. This can
most effectively be actomplished before the mill is built by appropriately
designing the recovery furnace to incorporate adequate furnace capacity to
ensure complete combustion and a high furnace/boiler efficiency.8 /
Maintaining a high solids content in the black liquor fired to the furnace
is another method of improving furnace efficiency which may require
8/ Steam production from an overloaded kraft recovery boiler may be asmuch as 30% less per unit of solids fired than in a properly designedand efficiently operated furnace.
- 35 -
modifications to black liquor heating and pumping systems to handle liquor
of higher viscosity. Proper combustion conditions are essential, as with
aay boiler, but adjustments must be made taking into account the needs of
the cheriical recovery process which requires a reducing atmosphere in the
lower parts of the furnace, and the corrosion problems which may be
encountered with low stack temperatures.
4.17 The output from a kraft recovery furnace depends on the raw
material ,.eing pulped and the grade of pulp being produced.9/ For
bleachable grades, typical actual figures are of the order cf 12 GJ/ton of
pulp z.:oduced while wit.h a modern, high-efficiency furnace, a figure of
.14-16 GT/Lon should te feasible, an improvement of 17-33%. According to
. i4.tiStIc CS(Ref 2), the actual industry-wide improvement in steam
t.-i-.' ' ;t ion from waste liquc)r between 1972 and 1982 averaged about 10%, as a
* .: of a combiration of improvements in existing equipment,
a.cements, and the irstallation of new,high-efficiency units. For the
hypothetical mill.5s exatmired in this study, an improveinent of 15% to the
ba£se output figures has been assumed,
The setond major possibility for ..proved was,t. utilization is
tht kcotb;nxstion of waoodl waste (primarily berk) in a specially designed
boiler. As furtci.j detailed in Aninax 4-1, some 15-25% of the volume of
log!3 enterAu) & pj3) and pApr.r mill is bark ancG fines 17lich cannot be used
fOrx pulp`I'g. In ;it Wt i,Ltih purcliase chips produc.ed as waste in sawmills,
thJ a' vol,inie muay be reduc! ii, but there is ar inc.rcaoed trend towards
9/ Uigl-er y:LeId PlJ g:tve less crgarxic waste and consequently thepotenitial -or ste<am producti:xni is -educed.
-36-
transporting wood waste from sawmills to pulp and paper mille, and
recovering residues from logging operations, so that the amount of
wood-waste fuel available may exceed the theoretical quantity available
from the wood actually pulped. In the US, between 1972 and 1982, the
proportion of the total energy requirements of the pulp and paper industry
supplied by wood waste increased from 7% to 14% (Ref 6). In Sweden, based
on some analysis of "model mills" (Ref 7), the theoretical proportion of
total energy supplied by internally generated wood waste is
of the order of 16-18%. Actual levels were only about 6% in 1973, but had
more than doubled by 1979. In addition to providing facilities fox the
combustion of wood waste for steam production, part of the improvement has
been achieved by taking measures to reduce the moisture content of wood
fuel (in some cases by drying with waste heat), and otherwise to improve
boiler efficiency.
4.19 For the typical mills included in this analysis, the impact of
burning wood waste on the energy balance has been incorporated based an the
waste which would be generated from the mill's own pulpwood requirements.
The effect of improved waste utilization (increased recovery boiler
efficiency and wood waste utilization) on the balance for each of the mills
is detailed in Annex 4-4 and summarized in the following table:
-37-
Table 4-5
Energy Requirements and Costs after Internal SavingProgram and Efficient Waste Recovery
BleachedKraft Pulp Linerboard Newsprint
Total Energy Consumed (kgoe/ton) 603 594 642Purchased Oil (kg/ton)
Lime Kilns 55 50 -Steam Generation - 90
Purchased Power (kWh/ton) 175 670 2,095Total Purchased Energy (kgoe/ton) 96 207 582Energy Cost (US$/ton) 16 30 81
Source: Energy Balances, Annex 4-4.
4.20 It can be seen that under the conditions of efficient waste
recovery, both the linerboard and bleached kraft pulp mills are more thluan
self-sufficient in thermal energy and must purchase fuel only to meet. the
needs of the lime kilns.10/ For the energy balances for these cases, it
has been assumed that the excess thermal energy would be converted to
electric power in a condensing turbine, and this power used in-plant to
reduce the requirement for purchased power. In practice, of course, it is
more efficient to use excess heat to produce electric power in a
back-pressure turbine and the effects of this measure are discussed below.
4.21 The investment costs involved in achieving the benefits to be had
from improved waste utilization will vary substantially from case to case.
Raising the solids content of black liquor to achieve higher steam
production, and modifying equipment as required to handle the higher
viscosity liquor, may be a relatively straightforward procedure in existing
mills. According to the Japan Paper Association, 18 such projects carried
10/ Some mills are experimenting with coal and gasified wood as fuel forlime kilns and further advances in this respect may be anticipated.
38 -
out between 1976 and 1978 cost some US$700,000 (adjusted to 1983 prices)
and led to annual savings in energy costs of the order of more than
US$2.5 million annually. However, the full benefits to be gained from the
efficient combustion of black liquor can normally only be achieved by
proper adjustment of combustion conditions and this cannot normally be
achieved in situations where a recovery furnace is undersized for current
production rates. For new installations, however, it is clearly profitable
to pay for additional recovery boiler capacity: for a 250,000 tpy bleached
kraft pulp mill, 10% additional recovery capacity in a new recovery furnace
would cost approximately US$2 million. This extra capacity would lead to
an improvement of about 10% in the recovery of heat from waste liquor, the
annual saving in fuel would represent about 360,000 GJ. If oil is being
consumed, this would represent a saving of about US$2 million annually,
indicating a return of 100% of the capital cost in one year of operation at
full production.
4.22 In the case of wood waste, it is possible to convert oil-fired
boilers for the direct combustion of solid fuels but under these
circumstances, it is necessary to dry and pulverize the fuel which would
normally involve additional equipment and cost. More usually, to achieve
the beniefits of wood waste combustion, it is necessary to build a properly
designed solid fuel boiler, which typically would have the capacity to burn
coal as well as wood. Such boilers can be (and usually are) incorporated
in the designs for new mills, or can be added to an existing mill with a
minimum of process disturbance. A recent summation of such installations
in North America covering start-ups in the period 1982-85 (Ref 11) showed
- 39 -
21 new wood or wood/coal installations in the US, and 6 in Canada. The
total cost of these installations is estimated at about US$1,300 million.
Steam production totals some 5,000 tons per hour, The cost of producing
this much steam from oil would be about US$600 million annually. If wood
waste can be considered to be of no cost, or at least at a cost which is
not higher than its cost of disposal by other means, the annual saving as a
result of these installations represents about 45% of the investment cost.
In fact most of these boilers will burn coal as well as wood so the saving
attributable to the combustion of wood alone would be somewhat less.
4.23 For the hypothetical mills in the case studies, approximate rates
of return can also be estimated:
Table 4-6
Waste Wood Utilization Costs and Benefitsfor Typical Mill Installation
Energy Saving b/Boiler Annual
Cost (US$Capacity a/ (US$ Unit million ROI
Mill (t/hr) million) (US$/ton) per year) )
Bleached Kraft Pulp 40 12 15 3.8 32Linerboard 30 10 12 3.0 25Newsprint 30 10 12 3.0 25
a/ To match internally generated waste wood as detailed in the millbalances (Annex 4-4).
b/ Assuming wood waste at zero net cost replaces oil at US$200 per ton,
Source: Based on Energy Balances in Annex 4-4.
- 40 -
Cogeneration
4.24 Because of the balance between steam and power consumption, most
integrated pulp and paper mills offer excellent possibilities for reducing
purchased energy requirements by generating electric power in-planlt in
turbines which exhaust steam at pressures suitable for process use. The
opportunities for this are greatest in mills with chemical pulping
processes, where the consumption of thermal energy is higher, and less in
mills -such as a newsprint mill) with mechanical pulping, which consumes
relatively large amounts of electric power. For the three illustrative
mill cases, it has been assumed that each mill would install back-pressure
turbines to the extent that their respective processes could utilize
exhaust steam. To complete the balances, it has been assumed that any
additional excess heat would be converted to condensing power. Finally, it
has been assumed that if there is a potential for generating electric power
in excess of the mill's own requirements, the excess could be sold at a
price of US$0.025 per kWh. Balances for each of these cases are presented
in Annex 4-5 and summarized in the following table:
Table 4-7
Energy Requirements and Costs after Internal SavingProgram and Waste Recovery Program with Cogeneration
BleachedKraft Pulp Linerboard Newsprint
Total Energy Consumed (kgoe/ton) 643 622 677Purchased Oil (kg/ton)
Lime Kilns 55 50Steam Generation - 15 125
Purchased Power (kWh/ton) (305) 180 1,800Total Purchased Energy (kgoe/ton) (16) 107 422Energy Cost (IJS$/ton) 1 18 79
Source: Energy Balances, Annex 4-5.
- 41 -
4.25 With cogeneration, the bleached kraft pulp mill is
self-sufficient in electrical as well as thermal energy (except for lime
kiln oil), and has a surplus of electrical power for sale. In the
linerboard mill, modest amounts of both oil and electric power are still
required, while the newsprint mill inevitably must still purchase the bulk
of its electric power.
4.26 To determine the benefits of installing back-pressure turbines in
a pulp and paper mill, proper accounting of the effects of the new
installation on both the steam and power balances of the mill must be
carried out in order to determine properly the benefits which accrue. In
the balances for the three typical mill installations, this has been done.
By choosing appropriately sized turbogenerators to meet the needs of each
case, and assuming approximate capital costs, the indicative returns from
such investments can be estimated.
Table 4-8
Cogeneration Costs and Benefits for Typical Mill Installations
Energy SavingTurbogenerator Annual
Cost (US$Size (US$ Unit million ROI
Mill (MW) million) (US$/ton) per year) (%)
Bleached Kraft Pulp 25 13.0 15 3.8 32Linerboard 20 10.0 12 3.0 39Newsprint 10 3.5 12 0.5 15
Source: Based on energy balances presented in Annex 4-5.
42
4.27 Somewhat higher figures are reported by other saurces. Ekono
(Ref 10) estimated first-year savings from increased back-pressure power
generation in existing mills to be 57% of the total investment. Japanese
experience in the period 1979-81 (Ref 8) suggests that 62 projects costing
some US$10 million in total (adjusted to 1983 prices) aimed at the
"rationalization of heat conversion into power", led to savings in energy
equivalent to about US$4.4 million annually, or 44% of the capital cost.
These figures could be higher than those quoted in Table 4-8 because to
some extent they likely include modifications to existing operations rather
than new turbogenerators. Also, as previously noted, the benefits to be
obtained from one type of energy conservation project depend on the
efficiency of the systems already in place.
General Assessment
4.28 The preceding analysis has used model mills and actual reported
experience to describe both qualitatively and quantitatively how
energy-efficiency improvements are being effected in the pulp and paper
industry at the mill level. The analysis has also demonstrated, at least
in general terms, the order of the magnitude of the investment costs
involved and of the savings which could be achieved. Although the results
will differ markedly from mill to mill, the indicated annual savings from
the types of energy-efficiency improvement examined range from about 20% to
over 100% of the total investment cost, The highest returns come from the
simplest projects, particularly in mills which are initially the most
inefficient in terms of their use of energy. The larger investments which
43 -
are required to improve waste utilization, such as wood-burning boilers, or
to effect cogeneration, yield generally lower rates of return, but still at
levels (20-30%) which should prove attractive, particularly in an industry
where returns from investment in pulp and paper production itself seldom
reach these levels.
4.29 The next chapter discusses the particular situations which tend
to pr-evail in the pulp and paper industries of developing countries, and
the nature and extent of improvements which can be considered in such
cases.
- 44 -
V. THE DEVELOPING COUNTRY SITUATION
Comparison of Energy Consumption
5.01 As noted in Chapter II, approximately 15 million tons or about 9%
of the world's paper is produced in developing countries. Although
statistical information covering all countries is not available, there is
information from important developing-country paper producers which
suggests rather conclusively that the proportion of energy consumed by the
industry in developing countries is substantially higher
(paras 3.11-3.12). The variation in reported energy consumption from mill
to mill is significant both in developing and industrialized countries, but
with a few notable exceptions (such as Brazil), the available information
generally supports the observation that total energy consumption and
purchased energy consumption in developing countries may average about
double the figures found in the industrialized countries. The financial
implications depend on the source and cost of the energy which must be
purchased (India, for example, has generally adequate supplies of rather
low-cost coal). Nevertheless, energy is typically a much more significant
cost factor in paper production in developing countries. Some of the more
obvious reasons why this is so are discussed in the following paragraphs.
Principal Reasons for Lower Energy Efficiency in Developing Countries
Plant Size
5.02 The annual capacity of the average paper mill in Scandanavia and
the USA is of the order of 100,000 tons. In Latin America, the average
- 45 -
capacity is about 18,000 tons; in Africa (excluding South Africa), 9,000
tons; and in Asia (excluding Japan), 5,000 tons.e1 1 While the unit energy
requirraments for actual chemical and physical processes--pulping,
bleaching, drying--do not change with plant size, the effect of
inefficiencies in a smaller plant are significantly magnified. Some
published information on the effect of plant size on energy consumption (in
industrialized countries) is illuminating. A study of Canadian paper mills
(reported in Ref 15) plots steam consumption against plant capacity.
Although there is considerable scatter in the data, the results indicate
that average steam consumption per ton of paper in a plant of 30,000 tons
annual capacity is approximately double that in plant of 150,000 tons
capacity. Another regression analysis (reported in Ref 16) also shows
considerable scatter but suggests a more modest 30% decrease in specific
energy consumption with a five-fold increase in mill-size. The latter
study also examined the effect of capacity utilization on energy
consumption, and determined that a mill operating at 70% of capacity would
utilize at least 10% more energy per ton than the same mill operating at
90% of capacity. Since developing country mills are often operating at
relatively low rates of capacity utilization, this factor alone can
contribute to higher specific energy use.
5,03 The problem of small mill size is one which cannot readily be
overcome and it would be unrealistic to suppose that a 1,000 tpy plant in a
developing country could ever hope to match the specific energy consumption
of a 250,000 tpy plant In an industrialized country. In the case of very
-1/ Derived from Ref 3.
- 46 -
small plants, even the cost of a study to improve energy efficiency may be
disproportionately high in relation to the potential benefits.
5.04 Apart from plant size per se, the relatively small size of many
plants in developing countries forces designers to adopt different
technical solutions which are frequently inefficient from an energy
conservation point of view. Probably the most serious of these is the
omission of chemical recovery systems in small chemical pulp mills.
Chemical recovery is normally not incorporated in plants of less than
20,000 tpy annual capacity, or when it is, it is often of a type which
utilizes none or only a part of the waste heat for the generation of
steam. Thus while the paper industry in industrialized countries can
generate more than 50% of its energy requirements from waste, including
waste liquor, the possibilities in developing countries are substantially
less. Of some 110 integrated pulp and paper mills in India, less than
20 have recovery systems. Of five integrated plants in Indonesia, two have
chemical recovery systems, but with limited heat recovery capacity (Ref
17). Another effect of small size is to render inappropriate some of the
best solutions for improving energy efficiency, including bark-burning and
back-pressure power generation, as these may not be economic on a very
small scale.
Design Technology
5.05 Paper plants in developing countries are often sold as a turnkey
package where one of the principal considerations is the initial capital
- 47 -
cost. Since a package oil-fired boiler is cheaper than a combination
boiler which can burn waste wood, the former will often be specified even
if the return of the additional investment for the latter is attractive.
Efficient in-plant water and heat recovery systems require additional
capital investment, which can readily be justified on the basis of energy
savings, but which may not be included if the turnkey contractor's primary
objective is to reduce costs, Diesel-powered generating sets are normally
cheaper than steam turbogenerators with back-pressure capability. The
process-control equipment required to monitor and fine-tune an efficient
operation may not be necessary just to produce paper, and is frequently
omitted. When capital cost is the primary consideration in selecting a
pulp and paper plant, it is inevitable that some of the additional
equipment which could readily be justified on the basis of its potential
for reducing energy consumption will not be included.
5.06 The specification of equipment for a paper plant in a developing
country may also be less energy-efficient as a result of efforts to utilize
appropriate technology. Variable speed electrical drives can significantly
reduce electric power consumption in some applications but they are usually
more complicated to operate and maintain, and may be excluded on these
grounds. Designing boilers to operate at high steam pressures is
energy-efficient, but such equipment requires more sophisticated water
treatment, and is susceptible to failure due to deficiencies in control in
this area. To some extent, at least, the search for appropriate technology
is not always compatible with the goal of energy efficiency and the pulp
and paper plants in developing countries tend to be less energy efficient
as a result.
- 48 -
Operational Environment
5.07 Managers of paper plants in developing countries must face
internal and external problems which are not normally encountered in
industrialized countries, and these may often lead, directly or indirectly,
to reduced energy efficiency. Internally, the most frequent problem of
this type will involve an equipment breakdown, the spare parts for which
may take weeks or months to procure. Under these circumstances,
extraordinary measures may be required to keep the plant in operation, such
as bypassing a heat-recovery system, or otherwise operating parts of the
plant in an energy-inefficient manner.12/
5.08 External factors can lead to similar problems. Failures in the
local electrical distribution system may force a plant to rely on standby
diesel generators which are relatively high-cost producers of electric
power. Boilers which may be designed to burn coal may be forced to use
standby oil supplies if there are problems with coal deliveries due to
mining or transportation problems. Another type of external factor relates
to energy pricing policies. In Egypt, Burma and Indonesia, for example,
energy has long been available at less than import parity prices, which has
discouraged building and operating plants to be energy efficient. Even
12/ The author has encountered two cases recently where steam-turbineswere out of commission for more than six months while the rotors wereshipped back to the suppliers for re-machining.
- 49 -
when energy prices are increased (as in Indoresia in 1982, for example),
the legacy of inefficiently designed plants remains.13/
Operational Management and Personnel
5.09 With numerous exceptions, managerial and operating personnel in
developing countries may be frequently less concerned and aware of the
implications of their operating techniques. This may in part be due to a
lower level of education and technical sophistication, particularly at the
operating level. Also, the pulp and paper industries of developing
countries are often in the public sector, where there may frequently be
less material incentive to seek improvements in energy efficiency. In a
recent symposium on Energy Conservation in the Pulp and Paper Industry,14/
delegates from most of the developing countries participating (India,
Indonesia, Nepal, Pakistan, Sri Lanka, Thailand and the Republic of Korea),
cited a lack of awareness of mill personnel as being one of the major
barriers to be overcome in efforts to improve energy efficiency in pulp and
paper mills in their countries.
General Assessment
5.10 This brief review of the energy situation in the pulp and paper
industry in developing countries has discussed some of the major reasons
13/ This is not just a developing-country problem. The movement towardsimproving energy efficiency may have been slower in the US and Canadathan in some other industrialized countries because of partialcontrols on energy prices.
14/ Held in Japan, June 1983.
- 50 -
why the consumption of energy in the production of paper is generally
double that of industrialized countries. Some of these reasons relate to
problems which can only be overcome within the context of the overall
development of the country, and the type of industrial restructuring which
inevitably accompanies such development. Others however can be immediately
faced at the sector and plant level, with the potential for dramatic
savings in energy leading to significant sectoral and national impact.
5.11 The next chapter outlines some approaches which could be
considered to identify and support programs and projects aimed at trying
to reach this potential.
- 51 -
VI. IMPROVING ENERGY EFFICIENCY IN THE PULP AND PAPER
INDUSTRIES OF DEVELOPING COUNTRIES
Approach
6.01 Previous chapters have described the extent to which energy
efficiency can be improved in the pulp and paper industry, and the
particular problems which face the industry in developing countries.
Although improved energy efficiency must ultimately be achieved at the
individual plant level, it is essential to begin with a broader approach
which considers the policy and institutional environment within which the
industry operates in a particular country, in order to identify the
incentives which will stimulate the desired activities to improve energy
efficiency. Second, since the energy efficiency of this sector is
determined to a large extent by its structure, some consideration of
overall sectoral planning and objectives, to ensure that energy efficiency
is taken into account, is required. Active participation by the industry
at this stage of the process is essential. The sector-wide approach is
also the right level at which to establish guidelines, and to disseminate
the technical information necessary for planning and preparing
energy-efficiency projects. Only when these vital two first steps--policy
establishment and sectoral objective-setting--have been accomplished, is it
realistic to expect much success in implementing the third and critical
step of in-plant energy-efficiency improvement.
6.02 It could be argued that this proposed broad top-down approach is
too centrally planning oriented to be effective; that improvements in the
- 52 -
industrialized countries have been achieved largely at the corporate level,
under the sole impetus of increased energy prices. This argument ignores
the vastly different competitive situation among producers in the
industrialized countries, and the particular situations which more
generally prevail in the developing world. In the industrialized
countries, for example, there are frequently a number of strong domestic
producers competing with each other, and relatively free imports of pulp
and paper from external sources. In developing countries, there is usually
a much lesser number of smaller plants, often inefficient, which require
tariff or other forms of protection both to justify their establishment and
to maintain their operation in the face of international competition. The
different situation requires a different approach, even though the ultimate
objectives may be the same.
6.03 The following paragraphs discuss the factors at the policy,
sector and plant levels, which should be considered in establishing a plan
for improving energy efficiency in a specific developing country situation.
B. Policy Considerations
6.04 It is axiomatic that in a free-market economy, the proper pricing
of all inputs and outputs would eventually force pulp and paper producers
to either come close to matching their international competitors'
production efficiency, including energy efficiency, or to go out of
business. Unfortunately, the situation in most developing countries is so
far removed from this long-term goal that unacceptable hardship would be
- 53 -
imposed on existing producers if such a course were to be followed
immediately, and it is unrealistic to suppose that much progress in
improving energy efficiency in developing countries in the short term will
be obtained by increased competition among domestic producers or from
imports. A brief description of the situation in two countries where the
Bank is active in the pulp auA paper sector--Indonesia and Turkey--provides
useful illustration of this point.
6.05 In Indonesia, up to 1973 the pulp and paper industry consisted of
seven mills, all in the public sector, of which two dated to the
pre-Independence era and five were built in the 1960s. Since 1973, in
conjunction with dynamic growth throughout the industrial sector, some 25
new mills have been built. A slumber of factors contributed to this
development:
(a) Market Opportunity. Demand for paper was expanding rapidly, and
in the early 1970s the domestic industry could supply only about
15% of this demand;
(b) Government Policy. The economic climate improved after 1967, and
industrial livcenses were granted freely to both domestic and
private investors for the establishment of paper mills;
(c) Tariff Protection. Tariff protection on some grades of paper
ranged up to 60%. It is noteworthy that the expansion, of
domestic production has been greatest in the grades with the
highest level of import duty; and
- 54 -
(d) Low Energy Costs. Until January 1982, petroleum-based fuels
in Indonesia were priced at about 45% of import parity prices.
6.06 This set of circumstances led to rapid expansion of the industry,
but generally in the form of small non-integrated mills with an
exceptionally low degree of energy efficiency. The Government has
recognized this problem (which applies not only to the paper industry) and
reduced the subsidy on energy prices in January 1982 and again in January
1983. Reductions in import duties are proposed. These steps will force
many of the existing producers to adopt measures to improve their.
efficiency and this restructuring should eventually lead to a much stronger
and more viable sector. The Bank is taking an active role in assisting in
this respect by financing a restructuring study which should help
individual mills to ad3ust to the new regime. Efforts to help stimulate
improvements in energy efficiency are an important part of this study.
6.07 In Turkey, in a move aimed at increasing the efficiency of State
Economic Enterprises (SEEs), the Government has removed most of the price
controls and subsidies which had hitherto supported and encouraged some
rather inefficient operations. Although these policies are admirable, they
have led to considerable hardship in many SEEs, including SEKA (the Turkish
state enterprise for pulp and paper production), and it is useful to
examine how such enterprises can restructure themselves to face the new
environment in which they operate, and in particular the extent to which
improvements in energy efficiency can be instituted to assist in this
respect.
- 55 -
6.08 SEKA produced slightly more than 400,000 tons of market pulp and
paper in 1982. Energy costs were about US$215 per ton of production, or
more than double the OECD average. SEKA's loss for that year was
equivalent to about US$46 million, or $115 for every ton of production.
Similar (or higher) losses are projected for the years after 1982. A
significant part of these losses is due to financial charges, so it would
be simplistic to attribute the poor financial performance to energy
inefficiency alone. Nevertheless, high energy costs are a major
contributing factor to SEKA's continuing operational loss and, more
importantly, improved energy efficiency could contribute substantially to
the company's recovery.
6.09 Some guidelines for appropriate policies to stimulate
energy-efficiency can be developed from the foregoing. In particular,
-Ace the efficiency of the industry must be measured by its ability to
coimpete with imports, almost all of which come from the industrialized
countries, any internal pricing or protection policies must be designed to
discourage the establishment and operation of inefficient producers. In
addition, financial incentives can be offered to encourage producers to
adopt energy-effiAent techniques. Specifically:
(a) Energy prices should be set at close to import parity prices or
opportunity costs;
(b) The prices of other inputs, and product prices, should not be set
in such a way as to enable inefficient producers (including
- 56
energy-inefficient producers) to continue to operate profitably;
and
(c) Tax incentives and credit facilities could be offered to
stimulate necessary investments in equipment designed to reduce
energy consumption. 15/
Incentives, including investment tax credits, tax exemptions, and
accelerated depreciation have been adopted in various mixes in a number of
developed countries in Europe and North America to promote energy
conservationi programs (Ref 19). These incentives, plus import duty
exemptions, also in various combinations, have begun to be employed in
developing countries such as Portugal, Turkey, Indonesia, Philippines and
India, although in most instances, policy formulation is in the early
stages of development.
Sectoral Initiatives
Sector Planning
6.10 While it is not necessarily appropriate to prepare a detailed
plan for the development of the pulp and paper sector in order to begin to
15/ Although proper energy pricing should alone be sufficient to encourageimproved energy efficiency, there are strong indications that in
Japan, Canada and the US, incentives have accelerated the rate at
which energy-saving projects have been implemented. The necessityfor, and nature of specific incentives for a particular case can only
be developed on the basis of specific national policies andobjectives.
- 57 -
seek improvements in energy efficiency, it is important to understand the
necessity to direct sectoral growth towards a structure which is efficient
in its use of energy. Inevitable, this suggests development along certain
well-established liInes:
(a) Integration, Integrated pulp and paper mills are significantly
more efficient than non-integrated mills and offer enhanced
opportunities for waste utilization and cogeneration,
(b) Mill Size. Larger mills are more energy-efficient than smaller
units. In this respect, sectoral growth as a result of the
expansion of existing opterations should be preferred over the
establishment of new mills.
(c) Raw Materials and Process Selection. Raw material selection
is usually based on availability, and process selection on the
raw material and the proposed product specification. Introducing
energy considerations may modify the selection of the optimum
plant in these respects.
Dissemination of Information
6.11 Most couintries with an established pulp and paper industry also
have producers' associations which regularly confer on matters of
industry-wide concern. Such associations offer an excellent opportunity
for stimulating discussion and disseminating information concerning energy
-58-
use in the industry.16 / A coordinated approach would provide assistance
to such associations to hold seminars on energy-related issues, to collect,
collate and distribute energy consumption information to enable mill
managers to compare their performance with others, to ensure the free
exchange of energy-saving ideas and to help establish realistic targets for
energy-efficiency improvement in the sector. Industry-wide energy audits
could be conducted through the association which wqould be invaluable in
measuring progress towards energy efficiency. If credit facilities are
arranged to help finance energy-conservation measures, a producers'
association could be an appropriate vehicle to distribute information
concerning such facilities, and to help establish sectoral priorities for
their use.
Mill-Specific Activities
6.12 As with most industries, the first step in identifying specific
energy-saving measures which could be introduced in a specific plant would
be to conduct an energy audit. The extent to which outside assistance
would be required for such an audit would vary significantly from plant to
plant, but even in plants with highly-trained technical personnel, external
monitoring of the audit program would be desirable. In any event, and
particularly in countries where a sector-wide approach is being undertaken,
a systematic content and format should be followed to simplify analysis and
comparison.
16/ In Indonesia, for example, the Indonesian Pulp and Paper Associationis playing an active role in ensuring industry-wide participation inthe ongoing restructuring study (para 6.06). It is anticipated thatthe Association will also provide assistance in helping to implementany of the programs which are developed as a result of this study.
- 59 -
6.13 Once the audit is concluded, it should be critically reviewed by
technical specialists from outside the plant in conjunction with the
concerned mill personnel. Following the review, an action plan for
improving energy efficiency should be devised. Typically, such a plan
would focus first on short-term activities, such as operational and
maintenance improvements, and small investments, which are relatively
simple to carry out. Long-term activities, which would require more
detailed engineering and more significant capital investments, would be
included in an inidicative way in the plan, and the necessary studies to
confirm their desirability would be initiated.
6.14 A recent workshop on energy in the paper and cement industries in
India (Ref 18) incorporated useful lists of the types of activities which
might be included in both a short-term program and a long-term program.
Short-term activities would largely focus on improvements to the operation
of existing equipment by such means as operator education, better metering
and control, and improved insulation, Longer-term activities would include
new installations to improve energy efficiency. The full lists developed
as a result of discussions at the workshop are presented in Annex 5.
6.15 The costs and benefits associated with each of the proposed
activities should be carefully estimated, and priorities assigned on the
basis of the anticipated net benefits. As work on implementing the action
plan proceeds, the energy audit should be periodically reviewed in order to
monitor the results.
- 60 -
VII. CONCLUSIONS AND RECOMMENDATIONS
Conclusions
7.01 The principal conclusions reached in this paper are as follows:
(a) Paper production is an energy-intensive activity. Industrialized
countries at the present time use approximately 0.75 toe for each
ton of paper produced, of which about one-half is generated
internally from process wastes (paras 1.01 and 3.02);
(b) Unit energy consumption for paper production in industrialized
countries is declining. Based on statistics from selected
countries, overall unit energy consumption has declined by about
10%, and purchased energy by 20-30%, over the past decade
(paras 3.06-3.09);
(c) On average, unit energy consumption for paper production in
developing countries is generally 2-3 times higher than in
industrialized countries (paras 3.10-3.11);
(d) The main techniques which have been used for reducing energy
consumption in industrialized countries are: (i) in-plant
measures to reduce energy consumption at the point of use and
recover waste heat; (ii) improved utilization of waste residues
as fuels; and (iii) cogeneration (Chapter IV); and
- 61 -
(e) The main reasons why unit energy consumption is so much higher in
developing countries are (i) small plant size; (ii) design
technology; (iii) the operating environment; and (iv) operational
managemnent and personnel (paras 5.06-5.08).
Recommendations
7.02 Programs should be initiated in those developing countries which
have a significant paper industry, and which are Tnterested in reducing
energy consumption by that industry in the context of national energy
conservation initiatives. The program should be conducted in three stages:
(a) A review of national policies to identify and modify those which
encourage inefficient energy use by the industry, and introduce
others which would encourage improved energy efficiency;
(b) Initiatives at the sector level to improve energy-efficient
sectoral planning, and to collect information and publicize the
nature and extent of the benefits to be had through improving
energy efficiency; and
(c) The development of mill-specific action programs beginning
with an energy audit which would identify specific short-term and
longer-term actions leading to improved energy efficiency.
- 62
7.03 Because it is already involved in aiding the development of the
pulp and paper industries in a number of countries, both through direct
lending and through local financial institutions, the World Bank is
well-suited to help with the planning for and implementation of such
programs.
- 63 -
ANNEX 1
SELECTED REFERENCES
(1) Various specific mill and project studies in World Bank andconsultants files.
(2) FAO Yearbook of Forest Products Statistics. Food and AgricultureOrganization of the United Nations. Rome. 1983.
(3) Pulp and Paper International. Annual Review Issue. July 1983.
(4) Energy Balances of OECD Countries, 1983, Annual Publication.
(5) Energy Efficiency and Fuel Substitution in the Cement Industry withEmphasis on Developing Countries. Mogens H. Fog and KishoreL. Nadkarni, Washington D.C.: The World Bank, December 1983.
(6) "Report of-the American Paper Institute to the Department of Energyon Energy Efficiency Improvement in the Paper and Allied ProductsIndustry in 1983." API, New York. June 1983.
(7) "Model Mills." Paper on energy consumption in hypothetical pulp andpaper mills prepared by AB Energikonsult. Stockholm. c. 1978.
(8) "Rationalization Efforts of Energy Consumption in Pulp and PaperIndustry: Japanese Experiences." Prepared by TechnologyEnvironmental Division, Japan Paper Association, Tokyo. Presentedat Symposium on Energy Conservation in Pulp and Paper Industry,Japan. June 1983.
(9) "Swedish Experiences on Energy Conservation in Pulp and PaperIndustry." Prepared by Modecell AB, Oernsoeldsvik, Sweden.Presented at Symposium on Energy Conservation in Pulp and PaperIndustry, Japan. June 1983.
(10) "Experiences of Energy Conservation in Pulp and Paper Industry."Ekono, Helsinki. May 1983.
(11) "Progress in Energy Self-sufficiency," (pp. 48-49) and "Brazil andWood Energy," (pp. 50-53). Pulp and Paper International. November1983.
(12) International Financial Statistics. Washington DC: IMF, 1983.
(13) "Energy Conservation in Pulp and Paper Industry." Prepared byHindustan Paper Corporation Ltd., Calcutta. Presented at Symposiumon Energy Conservation in Pulp and Paper Industry, Japan, June 1983.
- 64 -
(14) "Energy Analyses in Industry: Pulp and Paper Industry in Columbia."Prepared under German Technical Cooperation for the National EnergyStudy. Bogota, Columbia. February 1982.
(15) "Assessment of Energy Consumption and Optimisation of Usage in thePaper Industry." Prepared by the Imperial College of Science andTechnology for the Commission of the European Communities. London,1981.
(16) "Pulp and Paper Industry in Thailand." Presented at Symposium onEnergy Conservation in Pulp and Paper Industry. Japan. June 1983.
(17) "Indonesia:' Pulp and Paper Sub-sector Review." World Bank ReportNo. 4484-IND. Washington, D.C. June 1983.
(18) "Workshop on Energy: Paper and Cement Industries." SummaryProceedings and Papers. The Industrial Credit and InvestmentCorporation of India, Limited. Bombay. 1981.
(19) "Comparative Study of Policy Incentives for Industrial EnergyConservation" prepared by T. Balabanov, UNIDO consultant - DraftUNIDO Report dated February 16, 1984.
- 65 -
ANNEX 4-1
ENERGY CONSUMPTION IN UNIT PROCESSES
Introduction
1. For the mill configurations discussed in Chapter IV of this
report, a bleached kraft pulp mill, a linerboard mill and a newsprint mill,
typical base-case energy consumption data are assumed for the various unit
processes incorporated in each mill, which in some cases are subsequently
modified to show the effects of introducing energy efficiency programs.
Actual mill data on energy consumption varies widely, partly as a result of
different equipment configurations, and partly as a result of programs to
reduce energy consumption.
2. This annex presents ranges of reported energy consumption for
unit processes, from relatively large mills in industrialized countries.l/
The reason for variation in each case, and the basis of the selection of a
single figure for the mill analyses, are briefly discusses.
Wood Preparation
3. Normally, wood preparation will include debarking, chipping and
screening, together with handling of both logs and chips. Sometimes logs
are debarked by hand in the forest. Chipping and screening are not
necessary for stone groundwood mills where pulp is produced directly from
logs. Typical energy consumption figures are as follows:
1/ Most data are derived from Refs 1, 2 and 3.
- 66 -
Wood Preparation - Electrical Consumption per Cubic Metre of Wood
Electrical(kWh)
Debarking 2-4Chipping & Screening 10-15Materials Handling 2-4
Total 14-23
The residual bark and chip screening normally amount to 15-25% of the
volume of wood processed with a typical figure being 20%. Assuming a basic
density for both bark and wood of 0.4-0.5 bdkg per cubic meter, one cubic
meter of pulpwood will deliver 80-100 bdkg of fuel. Depending on the
method of debarking, the bark may be wet or at the same moisture content as
the incoming wood (usually about 50%). If wet, it can be pressed to a
reasonable (40-45%) dryness. Bark at this moisture content, in a boiler of
reasonable efficiency, can deliver about 11-14 GJ per bone dry ton. This
figure can be increased considerable if the berk is dried.
4. The amount of wood consumed per ton of paper, and therefore the
energy consumed and produced by the wood preparation process, is a function
of both wood density and pulping yield. Pulping yield will depend on the
pulping process and the grade of paper to be produced. For bleached kraft
pulp, typical figures will be 4-6 m3; and for newsprint (assuming 85%
thermomechanical pulp and 15% chemical pulp), 2.7-3.5 m3.
5. For the mill configurations examined, base-case values near the
mid-points of all of the above ranges have been selected as being
representL2tive of mills built with technology of the 1960s and early
- 67 -
1970s. Lower energy consumption would be more typical of mills in
Scandinavian countries, even at that time. A small amount of heat has been
included as many mills in industrialized countries require heating during
winter. The selected values are presented in the summary table at the end
of this Annex.
Pulping and Washing
Kraft Pulping
6. Energy consumption for kraft pulping depends primarily on the
equipment which is being used, the extent to which heat recovery systems
have been installed, and on the grade of pulp being produced. Electrical
energy is required to operate mechanical drives, and steam for the pulping
process itself. Typical figures are as follows:
Electrical Energy 100-140 kWh/ton
Heat Energy 2.5-5.0 GJ/ton
7. These ranges are considerable, as a result of the wide range of
process options and energy conservation opportunities. Steam requirements
for the cooking process itself depend on the raw material conditions (type,
temperature and moisture content), the cooking liquor conditions (strength
and temperature), the pulping yield (a higher yield gives lower unit energy
consumption), the cooking conditions (time and temperature), the method of
digester heating (direct or indirect), and the extent to which heat is
- 68 -
recovered from the pulping system. In addition to these variables, since
much of the steam is used for heating the fibrous raw material and the
liquor for the cooking conditions, there may be a considerable variation
from summer to winter in regions with marked seasonal temperature changes.
With batch digesters, heat consumption is usually higher than in continuous
digesters, and heat recovery efficiency is lower.
8. Electrical energy requirements depend primarily on the equipment
configurations. To some extent, lower heat requirements may be accompanied
by higher e'lectrical energy requirements to drive pumps and other equipment
associated with measures to reduce heat energy consumption. For the
bleached kraft pulp mill case, figures of 120 kWh/ton of electrical energy
and 3.5 GJ/ton of steam energy were selected as being appropriate for the
base case mill with some energy conservation measures, but with scope for
improvement. Slightly lower figures were selected for the linerboard mill,
solely because of the higher pulping yield assumed for that case.
Thermo-mechanical Pulping
9. It has been assumed that the newsprint mill would incorporate a
thermo-mechanical pulp mill which would provide 85% of its newsprint fibre
furnish. Thermo-mechanical pulp from most wood species requires about 2000
kWh per ton to produce, which translates to 1700 kWh per ton of newsprint.
Power consumption may be higher for certain species, particularly pine.
Although steam is used to pretreat chips in thermo-mechanical pulping, this
is normally generated in the process itself and no primary heat consumption
has been considered.
- 69
Blaaching
10. Bleaching is incorportced only in the bleached kraft pulp mill
case. Bleaching is accomplished in several stages by mixing chemicals with
the pulp, and passing the mixture through retention towers at elevated
temperatures. The pulp is washed between each stage. Heat in the form of
steam may be used to produce hot water for washing, and to achieve the
desired temperature in each bleaching stage. Electrical energy is used for
mechanical drives for pumps, agitators, washers, etc. Typical energy
consumption figures are as follows:
Electrical Energy 130-200 kWh/ton
Heat Energy 1.0-6.0 GJ/ton
11. The very large range is due primarily to the significant scope
for increasing energy efficiency by reducing the net flow of process water
into the bleach plant by ie-usina effluent streams. Some modern bleach
?la', : also incorporate in-tower washing which substantially reduces the
requirement for both steam and electrical energy. The bleach plant is a
part of the process in a bleached kraft pulp mill which offers great scope
for improving energy efficiency. For the base-case mill analysis, figures
oi5 5.0 GJ and 190 kWh per ton have been used, which it has been assumed
could be reduced to 2.5 GJ and 150 kWh by internial energy conservation
measures. In a new plant designed to be energy-efficient, significantly
lower figures would be feasible.
- 70 -
Pulp Drying
12. Pulp drying is incorporated only in the bleached kraft pulp mill
case. Pulp may be f lash-dried, but is normally dried in a continuous web
in a machine not unlike a paper machine, and subsequently cut into sheets
and baled for shipping.2/ Electrical energy is used to drive the
machinery, including vacuum pumps and presses which mechanically remove
water. Steam is used to further dry the pulp web either in drying
cylinders over which the pulp is passed, or by heating air which is blown
under and over the sheet to dry it and carry it through the pulp dryer.
There are substantial possibilities for the production of hot water in a
heat recovery system which can be used elsewhere in the process. Typical
energy consumption figures are:
Electrical Energy 130-190 kWh/ton
Heat Energy 2.5-6.0 GJ/ton
13. For the base case, heat consumption of 3.6 GJ and electrical
consuimption of 160 kWh per ton of pulp have been used. After a program of
energy-efficiency improvement, it has been assumed that these could be
reduced to 2.5 GJ and 150 kWh. the main scope for improvement, apart from
improving the eff£iciency of heat recovery, is to increase the efficiency of
mechanical water removal (vacuum and pressing) to improve the dryness of
the sheet entering the dryer and thus directly reduce the quantity of steam
required.
2/ It is noteworthy that all of the energy used for pulp drying, andsubsequently for reslushing the pulp, is saved in a,- btegrated mill.
- 71 -
Chemical RecoverZ
14. Chemical recovery is incorporated in the bleached kraft pulp mill
and the linerboard cases. A lime-reburning kiln is a usual component of
the chemical recovery system and this is normally fired directly with oil
or natural gas. The quantity of fuel required will vary according to the
amount of lime being burned (less is required for higher-yielding pulps
such as are used for linerboard production), and the efficiency of heat
recovery systems. The following figures have been used for the analyses
contained in this report:
Lime Kiln Fuel Requirements(kg/ton produced)
Base Case After Energy-EfficiencyImprovement
Bleached kraft pulp 60 55Linerboard 50 45
15. The main requirement for steam in the chemical recovery system is
for liquor evaporation. The amount of steam required will vary depending
on the initial liquor concentration after pulp washing, and on the
efficiency of the multiple-effect evaporation plant. The main determinant
of evaporator efficiency is the number of evaporator effects. The optimum
number of effects is a function of plant costs and energy cost. Steam is
also used in the recovery process for heating black liquor, and for other
minor uses. Electrical energy is used for mechanical drives such as pumps,
fans and agitators. Typical figures for the consumption of energy in the
recovery system (excluding lime kiln oil) are:
72 -
Electrical Energy 55-85 kWh/ton
Heat Energy 3.0-7.0 GJ/ton
16. For the bleached kraft pulp mill, figures of 5.2 GJ and 75 kWh
per ton have been used for the base case, dropping to 4.1 GJ and 70 kWh per
ton after energy efficiency improvement. Because of higher pulping yield,
slightly lower figures have been used for the linerboard case.
Stock Preparation
17. Stock preparation is required in the two paper-producing cases
(linerboard and newsprint), to refine the pulp to the degree necessary to
produce the desired grade of pulp. Power requirements will differ
substantially depending on the starting pulp characteristics, the type of
refiner, and the desired end-product quality. From the rather wide range
of values reported, the following have arbitrarily been selected as
representative for this analysis:
Power Requirements for Stock Preparation(kWh/ton)
After Energy-EfficiencyBase Case Improvement
Linerboard 240 230Newsprint a/ 100 95
a/ Includes 10 kWh/ton for slushing purchased pulp
- 73
Paper Machines
18. Energy consumption in a paper machine is basically for the same
purposes as for pulp drying as described above (para 12). Consumption per
ton of product is higher, however, primarily because of the higher speeds
at which paper machines operate, and the complexity of the web which mak s
water-removal somewhat more difficult. Typical figures are as follows:
Electrical Energy 170-300 kWh/ton
Heat Energy 3.5-7.0 GJ/ton
19. These figures also vary with the grades of paper being produced:
Compared with linerboard, newsprint uses more electrical energy (because it
X produced at a higher speed), and less heat energy (because the sheet is
lighter). The figures selected for this analysis are shown in the summary
table at the end of this Annex.
Total Eri rgy Consumption
20. In addition to the energy used in specific processes described in
the preceding paragraphs, energy is used elsewhere in the plant for pumping
water, effluent treatment, space heating and a variety of other uses. The
quantities required for these purposes will vary significantly according to
the specific mill location and configuration. Typical levels, before and
after energy-efficiency improvement, are presented along with the process
consumptions in the following summary table.
Typical Process EnergY Requirements Iefore and After Internal Energy-Efficiency Improvement
(heat in GJ and power in kWlh per ton of product)
Before Ener-y-Efficiency Improvement After Energy-Efficiency Im rovement
BK Pulp Linerboard Newsprint l)K Pulp Linerboard NewEprint
lleat Power Hleat Power Ileat Power Heat Power Heat Power legt PowerWood Preparation 0.1 65 0.1 55 0.1 45 0.1 60 0.1 50 0.1* 45Pullping & wasihing 3.5 120 3.0 210 - 1710 2.8 115 2.4 200 - 1625icaltig 5.0 190 - -. -Pulp drying 3.6 160 - - - - 2.5 *150 - -
Chiemilcal recovery 5.2 75 4.2 65 - 4.1 70 3.3 60 - -
Stock preparation - - - 240 100 - - - 230 95Paper machines - - 6.5 190 5.8 250 - - 4.6 180 4.1 240Miscellaneous 1.1 130 1.2 .140 1.0 100 098 125 0.9 135 0.8 95
Tota-ls 18.5 740 15.2 900 6.9 2205 12.5 7700 11.3 .855 5.0 2100
- 75 -
ANEX 4-2
ENERGY BALANCE WITH LOW INTERNAL ENERGY EFFICIENCY
TABLE I - BLEACHED KRAFT PULP HILL
Steia Electric Power Oil(GJlton) (kWhIton) (kqlton)
- .-- -- -- -- -- - -- -----
Energy Consumption
Process Energy- Wood Prepanation 0.10 65- Pulpinq & VashinQ 3.50 120- Bleachinq 5.00 190- Pulp Dryinq 3.60 160- Lime Kiln 0.20 10 60- Other Chemical Recovery 5.00 65- mliscellaneous 1.10 130
---- ---- - --
- Sub-total 18.50 740 60
Energy for Power Generation- Back Pressure Power- Condensinq Power
- Sub-Total
Total Energy Consumption 18.50 740 60
Energy Supply
Internal Generation- Steam
- from waste wood- froa waste liquor 14.0- froml oil 4 .00
---- - -- - ---
- Sub-total 18.50
- Electricity- back pressvre- condensing
- Sub-total
Purchased Enerqy- Oil
- for line kiln 60- for steam generation - 120
- Sub-total 180
- Electricity 740-- - -- ---
Total Enerqy supply 18.50 740 18O
---------------------------------------------------------------------------------------
Notes: (1) Based oa airket pulp sill with 250 000 tons annual caoacity.(2) Assumes full cheaical recovery,(3) Purchased enerqy costs assumed to be USB30 per HWh for eli.ctric power
and US$200 per tont for oil.(4) For other assumptions see test
Net purchased enerqgy cost: US$58 per ton
Industrt DepartmentDecember 1984
- 76
ANNEX 4-2
ENERGY BALANCE WITH LOW INTERNAL ENERGY EFFICIENCY
TABLE 2 - LINERBOARD HILL------------------------ .
Steas Electric Power Oil(CJIton) (kWhltoa) (kglton)
-- ---- - --- -- ------- ------
Enerqv Consumption
Process Eneray- Wood Preparation 1.1Q 55- PulpiNq & Vashing 3.00 210- Stock Preparation - 240- Paper Makinq 6.50 190- Line Kiln 0.20 10 50- Other Chemical Recovery 4.00 55- miscellaneous 1.20 140
- Sub-total 15.00 900 so
Enerqy for Power Generation- Back Pressure Power- Condensing Power
- Sub-Total
Total Enerqy Consumption 15.00 900 50
Enerqy Supply-- - - - ----
Internal Generation- Steia
- from waste wood- from waste liquor 10.50- from oil 4.50
- Sub-total 15.00
- Electricity- back pressure- condensing
- Sub-total
Purchased Energy- Oil
- for line kiln 50- for steam qgueration 135
- Sub-total -1-85
- Electricity -00
Total Enerqy Supply 15.00 900 185
----------------------------------- e---w-----!-----------o------------o---------^--------
Notes: (1) Based on mill with 250 000 tons annual capacity.(2) Assumes full chemical recovery.(3) Purchased energy costs assumid to be US$30 per lWli for electric power
and US$200 per ton for oil.(4) for other assumptions see t§st
Met purchased energy cost: US$M per ton
Industry DepartaentDecember 1984
7 77
ANNEX 4-2
ENERGY BALANCE WITH LOW INTERNAL ENERGY EFFICIENCY
TABLE 3 - NEWSPRINT HILL
Steam Electric Power Oil(GJIton) (kWhlton) (kqlton)-- --- - ---- ------ -- --- - -- -- - ---.
Enetry Consumption- - - -------- ----
Process Enerqy- Wood Preparation 0.10 45- THP plant - 171- Pulp Slushinq 10- Stock Preparation t- Paper Hill 5.80 250- miscellaneous 1.00 lOG
- Sub-total 6.90 2205
Energy for Power Generation- Back Pressure Power- Condensinq Power
- Sub-Total--- - --- - - -
Total Enerqy Consumption .2.90 205
Enerqy Supply--- - - - - -
Internal Generation- Steam
- from waste wood- from oil 6.90
- Sub-total 6.90
- Electricity- baok pressure- condensinq
- Sub-total
Purchased Enerqy- Oil 2- a0- Electricity 220-
Total Enerqy Supply 6.90 2205 205
--- - --- --- -- - - ------ -- -- -- - ---- -w------ - --- ---- -- -- -- -- - ---- -- - ----- - --- - --- e----- -----
Notes: (1) Based on mill with 250 000 tons annual capacity(2) Assumes 90% therao-aechanical pulp and 10% purchased semi-bleached kraft pulp(3) Purchased enerqy costs assumed to be USM30 per MhWb for electric power
and US$200 per "on for oil.(4) For other 4ssuuptions see text
Net purchased enerqy cost: USS107 per ton
Industry DepartmentDecember 1984
- 78 -
ANNEX 4-3
ENERGY BALANCE WITH HIGH INTERNAL ENERGY EFFICIENCY
TABLE 1 - BLEACHED KRAFT PULP HILL
Steai Electric Power Oil(GJWton) (kWhlton) (kglton)----- -- - --- --- - -- ----
Energy Consuapti on
Process Energy- Wood Preparation 0.10 60- Pulping & WashinQ 2.10 115- Bleachinq 2.20 180- Pulp Dryinq 2.50 150- Liae Kiln 0.10 10 55('her Chemical Recovery 4.00 60
iliscellaneous 0.80 125
- Sub-total 12.80 705 55Enerqy for Power GeneratioR- Back Pressure Power- Condensinq Power 1.60
- Sub-Total 1.60
Total Enerqy Consumption 14.50 705 55
Energy Supply-o----- -- -----
Internal Generation- Sttam
- from waste wood- from waste liquor 14.50- from oil -
- Sub-total 14.50
- Electricity- back pressure- condensinq 155
- -- --- ---- Sub-total 155
Purchased Enerqy- Oil
- for line kiln 55- for steas Generation -- Sub-total - 55
- Electricity 550 S
Total Energy Supply 14.50 705 55=3282S 2s1Z:ta:
------------------------ S----------------------------------------------------------------
Notes: (J) Based on sarket pulp mill with 250 000 tons annual capacity.(2) Assumes full cheaical recovery.(3) Assumes efforts made to reduce enerqy consumption at point of use andto recover waste heat.(4) Energy from waste fuels additional to Process reouirements has been
converted to electric power assuminq a condensinq turbine and purchasedpower reguitemants have been reduced zccordinaly.
(5) Puzchased energv costs assused to be US$30 per NWh for electric nowerand US$200 per ton for oil.(I) For other assumptions see text
get purchased enerqy cost: US$27 per ton
Industry DepaxtmentDeoember 1984
- 79 -
NEX 4-3
ENERGY BALANCE WITH HIGH INTERNAL ENERGY EFFICIENCY
TABLE 2 - LINERBOARD H4ILL
Steam Electric Power Oil(GJWton) MkWlhPon) (kglton)
Enerqy Consuaption- - - - - - --- ---
Process Enerqy- Wood Preparation i.lQ 50- Pulpinq & Washinq 2.40 200- Stock Pr- 'ation - 230- Paper Hl!.ino 4.60 1l0- Line Kiln 0.10 10 50- Other Chemical Recovery 3.20 50-1iseellaneous 0.90 135
- --- - --- ---
- Sub-totail 11.50 855 50
Enerqy for Power Generation- Back Pressure Power- Condensing Power
- Sub-Total
Total Enerqv Consumption 11.50 855 50
Enerqy Supply- - - - - - -
Internal Generation- Stea
- from waste wood- from waste liquor 10.50- fron oil 1.00
- Sub-total 11.50
- Electricity- back pressure -- condensinq
- Sub-total
Pu rchased Energy- Oil
- for lime kiln 50- for steas qeneration - 30
- Sub-total -I
- Electricity 855
Total Enerqy Supply 11.50 855 soC::2222 a:s= a=z=:
----------------------------------------------------------------------------------------
Notes: (1) Based on aill with 250 000 tons annual capacity.(2) Assumes full cheaical recovery.(3) Assumes efforts made to reduce energy consumption at point of use and
to recover waste heat.(4) Energy from waste fuels additional to process requireaents has been
converted to electrio power assuminq a condensinq turbine and purchasedpower requirem.nts have been reduced accordingly.
(5) Purchased enerqy costs assumed to be US$30 p*r NWh for electric powerand US$200 per ton for oil.
(6) For other assuaptions see teit
Net purchased enerqgy ost: US$42 per ton
Industry DepartaentDecember 1984
- 80 -
ANNEX 4-3
ENERGY BALANCE WITH HIGH INTERNAL ENERGY EFFICIENCY--------- t-.--- ----------------------- ------
TABLE 3 - NEWSPRINT HILL
Steai Electric Power Oil(GJIton) (kWhlton) (kglton)
- - - --- --- -O- ------- - -- ---
Energy Consumptiom---- - --- - ---- -- -- -
Process Enerqy- Wood Preparation 0.10 45- TMP plant 1625- Pulp Slushinq - 10- Stock Preparation - 15- Paper Hill 4.10 240- Miscellaneous 0.80 95
- Sub-total 5.00 2095
Enerqy for Power Generation- Back Pressure Power- Condensinq Power
- Sub-Total
Total Energy Consuaption 5.00 2095
EnerQy Supply-- --- -- ----- -
Internal Generation- Steam
- fres waste wood- from oil 5.00
- Sub-total 5.00
- Electricity- back pressure- condensinq
- Sub-total
Purchased Energy- Oil 150- Electricity 2095
Total Energy gSpply 5.00 2095 151X== , :--'z 2 a=-
---------------------------- ------- o--------------------------------O--------------------
Notes; (1) Based on mill with 250 000 tons annual capacity(2) Assumes 9?0 thermo-mechanical pulp and 10% purchased seai-bleached kraft pulp(3) Assumes efforts made to reduce enerqy consuaption at point of use and to
recover waste heat(4) Purchased entrgy costs assumed to be US$30 per NVh for electric power
and US$200 per ton for oil.(5) For other assumptions see test
Net purchased ederqy cost: US$93 per ton
Industry DepartmentDecember 1984
- 81 -
ENERGY BALANCE WITH EFFICIENT WASTE RECOVERY AND HIGH INTERNAL ENERGY EFFICIENCY---- -- ---- --- --- --- ------ -- .----- -- ------ ,-------------------
TABLE I - BLEACHED XRAFT PULP HILL
Steam Electric Power Oil(GJIton) (kWhIton) (kqlton)
Energy Consumption
Process Enerqy- Wood Preparation 0.10 60- Pulpinq & Washinga z.80 115- Bleachinq 2.20 l8B- Pulp Dryinq 2.50 150- Lime Xiln 0.10 10 55- Other Chemical Recovery 4.00 60- miscellaneous 0.80 125
- Sub-total 12.80 705 55
Enerqy for Power Generation- Back Pressure Power - - -- Condensinq Power 5.50
- Sub-Total 5.50
Total Enerqv Consuaption 18.40 705 55
Energy Supply
Internal Generation- Steam
- fron waste wood 2.50- from waste liquor 15.90- from oil
- Sub-total 18.40
- Electricityback pressure -
- condensinq 530
- Sub-total 530
Purchased Enerqy- Oil
- for lime kiln 55- for steam generation
- Sub-total 5- 5
- Electricity 175
Total Enerqy Supply 18.40 7 705 55ZZz:2 =Wtz2x
Notes: (1) Based on market pulp mill with 250 000 tons annual capacity.(2) Assumes full cheaical and waste wood recovery at hiqh efficiency(3) Assumes efforts made to reduce eaergy consumption at point of use and
to cecover w?,ste heat.(4) Enerqy from waste fuels additional to process requirements has been
converted to electric power assuminq a condensinq turbine and purchasedpower requirements have been reduced accordinqly.
(5) Purchased enerqy costs assumed to be US$30 per HWh for electric powerand US$200 per ton for oil.
(6) For other assumptions see teat
Met purchased enerqy cost: US$16 per ton
lIdustry DepartmentDecember 1984
- 82
ANNEX 4-4
ENERGY BALANCE WITH EFFICIENT VASTE RECOVERY AND HIGH INTERNAL ENERGY EFFICIENCY-------- ---------------------------------- ----------------- ------ ----
TABLE 2 - LINERBOARD HILL
Steam Zlectric Power Oil(GJlton) (kWhlton) (kglton)
Enerqy ConsuuPtiou
Process Energy- Wood Preparation 0.10 50- Pulpinq & Washinq 2.40 200- Stock Preparation - 230- PaDer Rakinq 4.60 10- Lime Kiln 0.10 10 50- Other Cheuical Recovery 3.20 50- mtiscellaneous 0.90 135
- Sub-total 11.50 855 50
Enerqy for Power Generatioa- Back Pressure Power- Condensinq Power 1.90
- Sub-Total 1.90
Total Energy Consumption 13.50 855 50
Enerqy Supplv
Internal Generation- Steam
- froa waste wood 2.00- from waste liquor 11.50- from oil -
- Sub-total 13.50
- Electricity- back ;ressure- condensinq 185
- Sub-total 185
Purchased Energy- Oil
- for line kiln - S0- for steam generation
Sub-total 50
- Electricity 670
Total Energy Supply 13.50 855 50
Notes: (1) Based on mill with 250 000 tons annual capacity.(2) Assumes full chemical and waste wood recovery at hiqh efficiency(3) Assumes efforts sade to reduce energy conswuption at point of use and
to recover waste beat.(4) Energy froa waste fuels additional to process requirements has been
convertnd to electric power assuminq a condensinq turbine and purchasedpower retuireaents have been reduced accordingly,
(5) Purchased enerqy costs assued to be US$30 per KWh for electric powerand US$200 per ton for oil.
(6) For other assuptions see test
Net purchased enery cost: US$30 per ton
Industry DepartmentBecember 1934
- 83 -
ANNEX 4-4
ENERGY BALANCE WITH EFFICIENT VASTE RECOVERY AND HIGH INTERNAL ENERGY EFFICIENCY-------------------------- ------ ---------------- -- -- ------------- ----
TABLE 3 - NEWSPRINT HILL
Steam Electric Power Oil(GJIton) (kWhlton) (kqlton)--- -- - -- - -- -- -- ----- -----
Euerqv Consumption
Process Entrqy- Wood Preparation 0.10 45- TNP plant - 1625- Polo Slushinq 10- Stock Preparation - 15- paper Kill 4.10 240- mIiscellaneous 0.60 5
- Sub-total 5.00 2095
mnercy for Power Generation- Bact Pressure Power- Condensinq Polwer
- Sub-Total
Total Enerqy Consumption 5.00 2095sP-=:: ss::: suzs
Enerqy Supply
Internal Generation- Steaa
- from waste wood 2.00- from oil 3.00
- Sub-total 5.00
- Electricity- back pressure- condensinq
- Sub-total
Purchased Enerqy- Oil 90- Electricity 20-5
Total Enerqy Supply 5.00 2095 902=2Yx sxsr cX
Notes: (1) Based on mill with 250 000 tons annual capacity(2) Assumes 90% thermo-machanical pulp and 101 purchased semi-bleached kraft pulp(3) Assumes full recovery of wood-wastes for combustion.(4) Assumes efforts made to reduce eneroy consumption at point of use and to
recover waste heat(5) Purchased enerqy costs assuaed to be US$30 per lNWh for electric power
and US$200 per ton for oil.(6) for other assumptions see text.
Net purchased energy cost: US$ll per ton
Industry DepartmentDecember 1984
- 84 -
ANNEX 4-5
ENERGY BALANCE WITH COGENERATION AND WITH EFFICIENT WASTE RECOVERY AND HIGH INTERNAL ENERGY EFFICIENCY- ----. ,- ---- ---- -- --- ---------- --------- ------------------------------- *,----- 1- ---------
TABLE I - BLEACHED KRAFT PULP HILL
steam Electric Power Oil(GJI ton) (kWh t o i) { kq/tOn)
Energy Consumptioa
Process Enerqy- Wood Preparation 0.10 60- Pulpinq & Vashinq 2.80 115- Bleachinq i.26 180- Pulp Dryinq 2.50 150- time Xiln 0.10 10 55- Othte Chemical Recovery 4.00 o0- Hiscellaneous 0.80 125
- Sub-total 12.80 705 55
Enerqy for Power Generation- Back Pressure Power 2.80- Condensinq Power 2.70
- Sub-Total 5.50
Total Eneroy Consuaption 11.40 705 55
Enerqy Supply
Internal Generation- Steam
- fron waste wood 2.50- from waste liquor 15.90- from oil
- Sub-total 18.40 -
- Electricity- baCk pre0sure - 750- condensinq 20-
- Sub-total l010
Purchased Enerqy- Oil
- for lime kiln 55- for steam qeneration -
- Sub-total 5- 5
- Electricity - 305)
Total Energy Supply 18.40 705 55
---------------------------.-------------------------------------------------- o----------
Notes: (1) Bastd on market pulp aill with 250 000 tons anunal capacity.(2) Assumes full chemical and waste wood recovery at hiqh efficiency(3) Assumes efforts made to reduce enerqy consumption at poiut of use and
to recover waste heat.(4) Electric power production from an extraction turbine has been assumed
to the extent that the process can utilize extraction steam.(5) Energy from waste fuels additional to process and back-pressure powor requirements
has been converted to electric power assuainq a condensinq turbine. Purchasedpower requirements have been reduced accordinqly.
(6) Purchased enerqy costs assumed to be US$30 per KWh for electric powerand USS200 per ton for oil. Excess power has been assumed sold at US$25 per fUh."
(7) For other assumptions see text
Net pPrchased energy cost: US1I per ton
lndustry DepartmentDecember 1984
-85-
iNNEX 4-5
ENERGY BALANCE WITH COGENERATION AND WITH EFFICIENT WASTE RECOVERY AND NIGH INTERNAL ENERGY EFFICIENCY
TABLE 2 - LINERBOARD MILL
Steam Electric Power Oil(GJ/ton) (kWhlton) (kq/ton)
- -- --- - --- - - - - - --- - -EnerQy Consumption
Process Enerqy- Wood Preparation 0.10 50- Pulping I Vashinq 2.40 200- Stock Preparation - 230- Paper Hakinq 4,60 180- Line Xiln 0.10 10 50- Other Chemical Recovery 3.20 50- Miscellaneous 0.90 135
- Sub-tot&I 11.50 855 50
Enerqy for Power Generation- Back Pressure Power 2.50- Condensing Power -
- Sub-Total 2.50
Total Enerqy Consnmption 14.10 855 50
Enerqy Supply-- -- ---- - ----
:
Internal Generation- Steam
- from waste wood 2.00 -- from waste liquor 11.50- fr1m oil 0.50
- Sub-total 14.10 -
- Electricity- back pressure - 675- condensing -
- Sub-total 675
Purchased Energyoil
- for lime kiln 50- for steam qeneration - 15
- Sub-total 65
- Electricity 180 -
Total Enerqv Supply 14.10 855 65
Notes: (1) Based on iil1 with 250 000 tons annual capacity.(2) Assumes full chemical and waste wood recovery at high efficiency(3) Assumes efforts made to reduce enerqv oonsumption at point of use and
to recover waste heat.(4) Electric power production from an estraction turbine bas been assused
to the extent that the process can utilise extraction steam.(5) Enerqy from waste fuels additional to process and back-pressure power requirements
has been converted to electric power assuminq a condensimq turbine. Purchasedpower reouirements have been reduced accordingly.
(1) Purchased enerqv costs assumed to be US$30 per MWh for electric powerand USS200 per ton for oil. Excess power has been assused sold at US$25 per MWh."(7) For other assumptions see text
Met purchased energy cost, US$18 per ton
Industry DepartmentDecemNer 198
- 86 -
ANNEX 4-5
ENERGY RALANCE WITH COGENERATION AND WITH EFFICIENT WASTE RECOVERY AND HIGH INTERNAL ENERGY EFFICIENCY
TABLE 3 - NEWSPRINT IILL
Steam Electric Power Oil(GJ/ton) QWVh/ton) (Ikqiton)
Eneroy Consumption
Process Enerpy- Wood Preparation 0.10 45- TNP plant - 1625 -- Pulp Slushina 10- Stock Preparation - 05- Paper will 4.10 240- Miscellaneous 0.80 95
- Sub-total 5.00 2095
Eneray for Power Generation- Back Pressure Power 1.10- Condensinq Power
- Sub-Total 1.10 -
Total Enervy Consumption 6.20 20l5
Energy Supply---- -- -- - --- -
Internal Generation- Steam
- from waste wood 2.00- from oil 4.20
- Sub-total 6.20 -
- Electricity- back pressure 295- condensinq
- Sub-total 295
Purchased Enerqy- Oil 125- Electricity 1300
Total Energv Supply 6.20 2095 125
----------------------- Z------------------------------a---------------l-----------v-------
Notes. (1) Based on aill with 250 000 tons annual capacity(2) Assumas 90% thermo-mechanical pulp and I0O purchased seai-bleached kraft pulp(3) Assumes full recoverv of wood-wastes for combustion.(4) Assumes efforts made to reduce energy cosumption at point of use and to
recover waste heat(5) Electric power production from an extraction turbine has been assumed to the
ectent that the prouets can utilize extraction steam.(6) Purchased enerqy costs assuaed to be US$30 per HWh for electric power
and US$200 per ton for oil.(7) For other assumotions see test,
Net purchased enerqg cost: US$79 per ton
Industrw DepartmentDecember 1984
87 -
ANNEX 5
SHORT- AND LONG-TERM ENERGY EFFICIENCY IMPROVEMENT ACTIVITIES
1. The following list was formulated for a workshop on energy
consumption in the paper and cement industries organized by the Industrial
Credit and Investment Corporation of India, Limited, in April 1981. it
'presents typical activities for improving energy-efficiency in paper mills.
Short-Term Measures
2. Short-term measures primarily relate to better housekeeping and
minor improvements in various systems which together could result in an
energy saving of 10-15%, investments required for implementing them being
rather modest. Some of these are:
(a) improving power factor by installation of capacitor banks, high
power factor motors and rotary phase advancers (it was noted that
some units have been operating on a power factor in the range of
0.80-0.90. It is felt that it should be possible to increase the
power factor up to 0.95);
(b) improving load factor by suitable monitoring of loads (it was
observed that some units have been operating at a load factor of
0.78-0.80. It is felt that by replacement of higher rating
motors by appropriate rating motors and by proper monitoring of
starting of various loads, it should be feasible to improve the
load factor to around 0.88);
- 88 -
(c) reduction in idle running time of all equipment to the maximum
possible extent;
(d) reduction in consumption of power for lighting and other
non-productive uses and optimizing use of power by installation
of high efficiency lamps;
(e) installation of reliable metering equipment;
(f) ensuring complete combustion of fuels, reductioii of unburned
carbon in ash, control of the excess air;
(g) improvement in thermal insulation of piping system to reduce
energy losses;
(h) full condensate recycling;
(i) ensuring that the energy in waste streams has been utilized to
the fullest possible extent;
(j) effective utilization of heat of intermittent blow down,
evaporator, condensator, etc.;
(k) reduction in consumption of fresh water to the maximum possible
extent;
(1) minimizing run of refiners on partial loads;
- 89 -
(m) concentration of black liquor so that solids content is higher
before firing;
(n) use of optimum stock consistency; and
(o) achieving dryness to the maximum extent in the paper web after
press section.
Long-Term Measures
3. The long-term measures relate to revamping, to an extent, the
existing systems and introduction of modern technologies. These measures
necessarily envisage capital expenditure of varying amount and are thus.
investment decisions. Although the recently set up paper units have
incorporated energy-efficient practices, it is felt that considerable scope
exists in several other units to adopt long-term energy conservation
measures after analyzing their technical and financial viability. Some of
the measures indicated are:
(a) introduction of total energy concept, wherever feasible;
(b) changeover from oil-fired to coal-fired boilers;
(c) introduction of systems for use of cheaper fuels like bark and
wood waste (in the form of pellets);
- 90
(d) installation of boilers suitable to adopt low-quality (high-ash
content) coal;
(e) use of thyrister drives instead of conventional drives;
installation of continuous cooking as against batch cooking;
(f) installation of disc refiners;
(g) installation of modern washers;
(h) installation of blow heat recovery system;
(i) installation of steam turbine sets for paper machine drive and
for refiners, etc., where relatively higher horsepower is
required;
(j) use of micro-processors for controlling moisture content at the
paper-making stage;
(k) installation of vapor hoods for paper machine;
(1) installation of optimum number of stages in multiple effects
evaporators;
(m) installation of low-pressure turbine for I.D. fan; and
-91-
(r) automatic systems for operation of electrical equipment to; avoid
long periods of running with no loads.
World Bank The Construction Industry: Employment and DevelopmentIssues and Strategies in of Small Enterprises
P"ubliGations Developing Countries David L. Gordon, coordinating9f elat Emesto E. Henriod, coordinating author
author Examines the potential role of theInterest Presents a profile of the construction World Bank in encouraging developing
industry. Points out that construction countries to assist small enterpriseswork rep?esents 3 to 8 percent of the and suggests that efficient substitutiongross domestic product of developing of labor for capital is possible in acountries. Fostering a domestic capa- broad spectrum of small-scale manu-bility in construction, therefore, is im- facturing and other activities that are
A Brief Review of the World portant. Discusses problems and con- able to absorb a rapidly growing laborLube Oils Industry straints of the industry and formulates force.A. Ceyhan, H. Kohli, L. strategies for future actions. Draws Seftor Policy Paper. 1978. 93 pages (in-Wijetilleke, and B.R. Choudhury heavily from the experience of the cliding 3 annexes).
World Bank in supporting domestic Stock Nos. BK 9060 (English), BK 9061This report assesses the structure, construction industries over the past (French), BK 9062 (Spanish). $5.background, and outlook for the world ten years. Useful to contractors, enigi-lube oils industry. Presents the histori- neers, and administrators in construc- Estimating Total Factorcal and projected lube oils demand tion industry. ErodutiviW Goth int aand trends in manufacturing technolo- 1984. 120 s.Prodetivity Growth in agies and production capacity and pro- P g Developing Countvides an indicative assessment of the ISBN 0-8213-0268-X.Stock No. BK 0268. Anne 0. Krueger and Baraneconomics of lube oil production with $5 Tuncerdetailed market andl economic data. Tne
Energy Industries Report Series No. 1. Cost-Benefit Evaluation of Staff Working Paper No. 422, 1980. 64Energy Industries {includg 1neries, N. LDC Industrial Sectors Which pages (including references, appendix).erences). Have Foreign Ownership Stock No. WP 0422. $3.
ISBN 0-8213-0054-7. Stock No. BK 0054. Garry G. Pursell Financing Small-Scale Industry$3. Staff Working Paper No. 465. 1981. 45 and Agriculture in Developing
pages. Countries: The Merits andCapital Utilization in Stock No. WP 0465. $3. Limitations of 'Commercial'Manufacturing: Colombia, Pol -c -Israel, Malaysia, and the Development Finance Policies
Philppies CmpaiesDennis Anderson and FaridaPhilipp ines Companies KhambataRomeo M. Bautista, Helen Examines the role of development fi- Staff Working Paper No. 519. 1982. 41Hughes, David Lim, David nance companies as major mechanisms pages (including references).Morawetz, and Francisco E. for assisting medium-scale productiveThoumi industries, assesses their potential for ISBN-0-8213-0007-5. Stock No. WP 0519.
The authors surveyed 1,200 manufac- aiding small enterprises in meeting so-turng firms in four developing coun- cioeconomic objectives of developing Fostering the Capital-Goodstries to establish actual levels of capital countres, and discusses the evolution Sector in LDCs: A Survey ofutilization. The information collected of World Bank assistance to them. Evidence and Requirementswas the first and remains the only Sector Policy Paper. 1976. 68 pages (in- Howard Packdata base available for the study of cluding 7 annexes). Staff Working Paper No, 376. 1980. 64capital utilization. It was found that Stock Nos. BK 9040 (Englishl), BK 9058 pages (including references).capital utilization is not as low as had (French), BK 9041 (Spanish). $5. stoc N WP 0376. $been supposed. The study is con- Stock No. WP 0376. $3.cerned with factors that cause differ- Empirical Justification for Incorporating Uncertainty intoences in levels of capital utilization Infant Industry Protection Planning of Industrializationand the policies that might be used to Larry E. Westphal Strategies for Developingincrease it.Oxford University Press, 1982. 288 pages Staff Working Paper No. 445. 1981. 38 Countries(including bibliography, index). pages (including references). Alexander H. Sarris and Irma
LC 81-9526. ISBN 0-19-520268-6, Stock Stock No, WP 0445. $3. AdelmanNo. OX 520268. $22 hardcover. Staff Working Paper No. 503. 1982. 58
pages (including appendix, references).
Stock No. WP-0503. $3.
EPUbliCations Order Mrm
SEND TO: YOUR LOCAL DISTRIBUTOR OR TO WORLD BANK PUBLICATIONS(See the other side of thisLform.) P.O. BOX 37525
WASHINGTON, D.C. 20013 U.S.A.Date ._ . _ . _
Name Ship to: (Enter if different from purchaser)
Title . Name
Firm Title
Address-, Firm
City State Postal Code Address
Country 'IlTephone c ) City State__ Postal Code_
Purchaser Reference No. Country Tlhephone
Check your method of payment.Enclosed is my O Check El] International Money Order a Unesco Coupons O International Postal Coupon.Make payable to World Bank Publications for U. S. dollars unless you are ordering from your local distributor.Charge my O VISA El MasterCard El American Express El Choice. (Credit cards accepted only for orders addressed
to World Bank Publications.)
Credit Card Account Number Expiration Date SignatureO Invoice me and please reference my Purchase Order No.
Please ship me the items listed below.
Customer Internal .Stork Numlxr Author/ Title Routing Code Quantity Unit Price Total Amount S
.. . - -_____________
All prices subject to change. Prices may vary by country. Allow 6-8 weeks for deliivery.
Subtotal Cost S___
'Thtal copies .. Air mail surcharge if desired ($2.00 each) $_____
Postage and handling for more than two complimentary items ($2.00 each) $____
Tbtal $___
ISRD-OM3Thank you for your order.
Distibutrs of World Attn: Mr, Giancarlo Bigazzi Attn: Mr. J.M. HenandezVia Lamarnora 45 Castello 37Bank Publications 50121 Madrid -Florence
ARGENTINA SRI LANKA AND THE MALDIVESCarlos Hirsch, SRL, JAPAN * . - Lake House BookshopAttn: Ms. Monica Bustos Eastem Book Service Attn: Mr. Victor WalataraFlo.fda 163 4° i Attn: Mr. Terumasa Hirano 41 Wad Rarnanavake MawathaGaleria Guemes 37-3, Hongo 3-Chome, Bunkyo-ku 113 Colombo 2Buenos Aires 1307 Tokyo SWEDENAUSTRALIA, PAPUA NEW GUINEA, KENYA ABCE Fritzes Kungl. Hovbokhand.4FIJI, SOLOMON ISLANDS, Africa Book Services (E.A.) Ltd. Attn: Mr. Eide Segerback
WETR AO,ADAttn: Mr. M.B. Oar ReB 0enri'5tan 12, Box 16356WESTERN SAMOtA, AND n .a -0 tchlVANUATU P.O. Box 45245 s.- tchlThe Australian Financial Review Nairobi SWITZERLANDInformation Service (AFRIS) KOREA, REPUBLIC OF Librairie PavotAttn: Mr. David Jamieson Pan Korea Book Corporation Attr.: Mr. Henri de Perrot235-243 Jones Street Attn: Mr. Yoon-Sun Kim 6, rue GrenusBroadway P.O. Box 101, Kwanghwamun 1211 GenevaSydney, NSW 20001 Seoul TANZANIABELGIUM MALAYSIA Oxford University PressPublications des Nations Unies University of Malaya Cooperative Attn: Mr. Anthony TheoboldAttn: Mr. Jean de Lannoy Bookshop Ltd, Maktaba Road, P.O. Box 5299av. du Roi 202 Attn, Mr. Mohammed Fahim Htj Dar es Salaam1060 Brussels Yacob THAILANDCANADA P.O. Box 1127, Jalan Pantai Baru Central Department Store, Head OfficeLe Diffuseur Kuala Lumpur Attn: Mrs. RatanaAttn: Mrs. Suzanne Vermette MEXICO 306 Silom RoadC.P. 85, Boucherville J4B 3E6 INFOTEC BangkokQuebec Attn: Mr. Jorge Ce eda Thailand Management AssociationCOSTA RICA San Lorenzo 153-11, Cal. del Valle, Attn: Mrs. SunanLibreria TreOs Deleg. Benito Juarez 308 Silom RoadAttn: Mr. n ugo Chamberlain 03100 lMexico, D.F. BangkokCalle 11-13, Av. Fernandez Guell MIDDLE EAST TUNISIA.San Jose Middle East Marketing Research Societe Tunisienne de DiffusionDENMARK Bureau Attn: Mr. Slaheddine Ben HamidaSanfundslitteratur Attn: MIr. George Vassilou 5 Avenue de CarthageSafnsitrtrMitsis Bldg. 3 TunisAttn: Mr. Wilfried Roloff ,Mlakarios III Avenue TURKERosenderns Alle 11 icoiaEYDK-1970 Copenhagen V. Cvprus Haset Kitapevi A.S.EGYPT, Arab Republic of (Iranch offices in Bahrain, Greece, Attn: Mr. lzzet IzerelAl Ahram Iorocco. Kuwait, United Arab 469, Istiklal CaddesiAl Galaa Street Emirates, Jordan) Bevoglu-istanbulCairo NETHERLANDS UNITED KINGDCM AND
MBE BV . NORTHERN IRELANDFINLAND Attn: Mr. Gerhard van Bussell Microinfo Ltd.Akateeminen Kirjakauppa Noorderwal 38, Attn: Mr. Roy SelwynAttn: Mr. Kari Litmanen 7241 BL Lochem Newman Lane, P.O. Box 3Keskuskatu 1, SF-00100 NORWAY Alton, Hampshire GU34 2PGHelsinki 10 Johan Grundt Tanum A.S. EnglandFRANCE Attn: Ms. Randi Mikkelborg UNITED STATESWorld Bank Publications P.O. Box 1177 Sentrum The World Bank Book Store66, avenue d'l&na Oslo 1 600 19th Street, N.W.75116 Paris PANAMA Washington. D.C. 20433GERMANY, Federal Republic of Ediciones Libreria Cultural Panamena (Postal address: P.O. Box 37525UNO-Verlag Attn: Mr. Luis Fernandez Fraguela R. Washington, D.C. 20013, U S A.)Attn: Mr. Joachim Krause Av. 7, Espana lb Baker and Tavlor CompanvSimrockstrasse 23 Panama Zone 1 501 South Glidiola AvenueD-5300 Bonn I PHILIPPINES Momence, Illinois, 60954HONG KONG, MACAU National Book Store 380 Edison WayAsia 2000 Ltd, Attn: Mrs. Socorro C. Ramos Reno, Nevada, 89564Attn: Ms. Gretchen Weafing Smith 701 Rizal Avenue 5O K-hv Avenue6 Fl., 146 Prince Edward Road Manda Somerville, New Jersey, 08876Kowloon PORTUGAL Commerce, Georgia 30599INDIA Li. rarim Portugal Cerce, Georia 309UBS Publishers' Distributors Ltd. \ttn: Mr Antonio Alves Martins n GeorgeIPaltes HifhwaiAttn. Mr. O.P. Veer [RLla Do Carmo 70-74 Lanham, Man-land, 20765 Ansari Road, Post Box 7015 ,OoBNew Delhi 110002 I i,bon Blackwell North Arica, Inc(Branch offices in Bombav, Bangalore, SAUDI ARABIA 1001 Fries Mill RoadKanpur, Calcutta, and Ml%lras) larnr Book Store . Blackwood, New Jersey 08012INDONESIA Attn: Mr. Akram AI-Agil Sidnev Kramer BooksPt. Indira Limited P 0 Box 3196 172-' f Street, N.W.Attn: Mr. Bambang Wahvudi Rivadh Wa,hingtun, D.C. 20006JI, Dr. Sam Ratulangi No. 37 SINGAPORE, TAIWAN, BURMA lnited Nations BookshopJakarta Pusat Informdtion Publications Private, Ltd. United Nations PlazaIRELAND Attn Ms. Janet David New York, N.Y. 10017TDC Publishers 02-06 1st Floor, Pei-Fu Industrial VENEZUELAAttn: Mr. James Booth Building YENElUELA12 North Frederick Street 24 New Industrial Road LibreriM del EsteDublin I Singapore Attn. Mr. Juan PericasAvda Francisco de Miranda, no. 52ITALY SPAIN Edificio Galipan, Aptdo. 60 337Lico7sa Commissionaria Sansoni SPA Mundi-Prensa Libros, S.A. Caracas 1060-A
WORLD BANK TECHNICAL PAPERS (continued)
No. 21. Industrial Restructuring: Issues and Experiences in SelectedDeveloped Economies
No. 22. Energy Efficiency in the Steel Industry with Emphasison Developing Countries
No. 23. The Twinning of Institutions: Its Use as a Technical AssistanceDelivery System
No. 24. World Sulphur Survey
No. 25. Industrialization in Sub-Saharan Africa: Strategiesand Performance
No. 26. Small Enterprise Development: Economic Issues fromAfrican Experience
No. 27. Farming Systems in Africa: The Great Lakes Highlandsof Zaire, Rwanda, and Burundi
No. 28. Technical Assistance and Aid Agency Staff: Alternative Techniquesfor Greater Effectiveness
No. 29. Handpumps Testing and Development: Progress Report on Fieldand Laboratory Testing
No. 30. Recycling from Municipal Refuse: A State-of-the-Art Reviewand Annotated Bibliography
No. 31. Remanufacturing: The Experience of the United Statesand Implications for Developing Countries
No. 32. World Refinery Industry: Need for Restructuring
No. 33. Guidelines for Calculating Financial and Economic Rates of Returnfor DFC Projects