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Journal of Cleaner Production 6 (1998) 349–355

Cleaner production in China’s pulp and paper industry

Xin Ren *

China National Cleaner Production Center (CNCPC), Anwai Lishuiqiao, 8 Da YangFang, Beijing 100012, PR China

Abstract

The article summarizes the achievements of the Cleaner Production (CP) project in China’s pulp and paper industry from theperspective of industry and environmental regulators. Analyses of CP options have revealed that technology updates, equipment-related modifications, reuse and recycling were predominant improvement opportunities. Black liquor (BL) was identified as thetop environmental problem facing China’s non-wood paper industry. Insights about major bottlenecks that have hindered cleanerproduction within the paper industry are presented. The article explores the means of sustaining CP, both at the mill and at thenational levels, with an emphasis upon the internal and external mechanisms fostering the continuous implementation of CP. Basedon the analyses of CP activities in the paper industry, suggestions for further action are presented. 1998 Elsevier Science Ltd.All rights reserved.

Keywords:Cleaner production; Pulp and paper

1. Introduction

Cleaner Production (CP) in China’s pulp and paperindustry was initiated in 1995 within the framework ofthe third-phase activity of the network of industrialenvironmental management (NIEM), a network of theUNEP Regional Office for Asia and Pacific, with thesupport of the National CP Center Program ofUNIDO/UNEP IE. The China National Cleaner Pro-duction Center (CNCPC), the Environmental ProtectionInstitute (EPI) of the Light Industry Council, and theNational Environmental Protection Agency (NEPA) arecore members of this project. From August 1995 untilApril 1997, a total of 15 mills throughout China partici-pated in the project.

1.1. Context

According to the third national survey on industrialpollution sources and latest official statistics, there are5085 pulp and paper mills in China, over 70% of whichare non-wood mills, with nearly 40% wheat straw-based.

* Current address: International Institute for Industrial Environmen-tal Economics, P.O. Box 196, Tegnersplatsen 4, S-221 00 Lund,Sweden. Tel:1 46-46-2220210; Fax:1 46-46-2220200.

0959-6526/98/$19.00 1998 Elsevier Science Ltd. All rights reserved.PII: S0959-6526 (98)00023-7

There are only 43 mills with an annual productionexceeding 30,000 t/a, and 1187 between 10,000 and30,000 t/a. The remaining 3898 mills are smaller than10,000 t/a, of which 3200 produce less than 5000 t/a.These plants account for 63% of the total number ofmills in China, and most of them are rural enterprises.These SMEs contribute to over 60% of the total annualproduction (28,123,000 tons of paper and paperboard in1995) of China.

With obsolete technology, equipment, and manage-ment, the Chinese paper industry is recognized as beingone of the most highly polluting sectors. Its plants dis-charged 3,214,000 t/a of COD in 1995, accounting for41.8% of the overall industry pollution load of China.Non-wood pulp and paper companies are of particularconcern, as most of them are SMEs. Efficiency ofresource usage at these SMEs is extremely low com-pared with the international average.

In contrast to the first batch of mills, which is spreadnationwide, the second batch is located in the Huaiheriver basin, one of the most severely polluted areas ofChina. In this region, the paper industry alone contrib-utes to 82% of the overall industrial pollution load(COD). Thus, the central government mandated that allpulp and paper mills in this region should be compliantwith the effluent standards by the end of 1997.

350 X. Ren/Journal of Cleaner Production 6 (1998) 349–355

1.2. Procedure

The CP initiative in the pulp and paper mills wasundertaken by means of a CP audit. The procedure,applied in all participating mills, was based on themethod developed by the World Bank (WB) technologyassistance program to China, ‘Promoting CP in China’,and was adapted to the real situation in China’s pulpand paper industry. It included seven steps, i.e. plan andorganization, pre-assessment, assessment, option gener-ation and screening, feasibility analysis, implementation,and continuation of CP. Background information on the15 participating mills is presented in Table 1.

Table 1Background of 15 CP participating pulp and paper mills in China

Pulp Paper Status ofNo. of Pulping Whitewater Other BL Wastewater

Name Raw material capacity capacity Bleaching alkaliemployees process recycling handling treatment

(TPA) (TPA) recovery

Batch 2Zhongmu 2400 Wheat straw 25,000 34,000 NaOH–AQ CEH Operating Operating None Biochem.

plannedLuohe 950 Wheat straw 18,000 35,000 NaOH–AQ CEH Operating Operating None Biochem.

installedSuiping 980 Wheat straw 17,000 20,000 NaOH–AQ CEH Operating None Basic None

lignin sep.Xixian 720 Wheat straw 20,000 3000 NaOH–AQ CEH,H None Being Acid lignin Biochem.

installed sep. plannedAnhui 4500 Straw, reed, jute 40,000 40,000 NaOH CEH,H Planned Operating None Biochem.

beingexpanded

Liuan 2200 Wheat straw 24,000 24,000 NaOH CEH,H Operating Installed None Biochem.planned

Guoyang 800 Wheat straw 20,000 20,000 Sulfite H Installed — Fodder, Noneplanned

Yingshang 800 Wheat straw 15,000 25,000 NaOH H Operating None Partly Nonereuse incooking

Yingshang 500 Wheat straw 10,000 13,500 Sulfite- unbleached Trialoperation — Partly Biochemical,60th Pu semichem. reuse, operating

partlyfertilizer

Batch 1Anqiu 1800 Wheat straw 18,000 30,000 NaOH–AQ H Partly operating Operating None Biochem.

beinginstalled

Weihui 1500 Wheat straw 8700 11,000 NaOH–AQ H None None Basic Physichem.lignin sep. planned

Minfeng 5000 W. straw, reed 18,500 51,000 NaOH H,HH Operating Operating None Biochem.operating

Taizhou 2000 Wheat straw 18,000 30,000 NaOH CEH,H Partly operating Installed None Biochem.planned

Binzhou 1500 Wheat straw 24,000 50,000 NaOH–AQ H None Being None Noneinstalled

Wdongting 1400 Bagasse, reed 18,000 20,000 Sulfate H None Installed None None

Note: All 15 mills apply batch cooking, either exclusively or predominantly. Types of paper machine applied are fourdrinier and cylinder.

2. Outputs

2.1. Improve management

Management at China’s pulp and paper mills is gener-ally rather poor, in particular with respect to basic busi-ness management and cost–benefit awareness. Weakpoints widely existent in small- and medium-sized pulpand paper mills were:

1. Measuring and monitoring, especially on-line, wereinsufficient and unreliable, resulting in blindness inplanning, wasting of resources, and heavy pollution;

2. Periodic maintenance system was often ignored;3. Operators lacked a feeling of responsibility, environ-

351X. Ren/Journal of Cleaner Production 6 (1998) 349–355

mental awareness, and operational training. Super-vision of operational practice was weak.

The latter two problems have been the source of seri-ous spills and leakage at all the mills. Improvements inmanagement have cut down the pollution load by 10–20%. Good management and a change in attitude,especially that of the manager with respect to resourcesand the environment, were found to be essential for thesuccess of CP.

2.2. Environmental and economic gains

2.2.1. Environmental improvementSatisfactory environmental improvement has been

achieved through the implementation of 308 of a totalof 492 CP options generated within the 15 mills, i.e. theimplementing rate was 60%. The overall investment of5,590,000 RMB (700,000 USD) reduced up to 26,300tons of COD/a, i.e. 0.22 RMB/kg COD (0.03 USD/kg)with a reduction rate ranging from 7% to 49%. Mostresults were achieved through non/low cost options (seeTable 2).

2.2.2. Economic gainsThe implementation of waste reduction options,

mainly non/low cost, helped the companies to realizesignificant economic benefits. Total savings at the 15mills were 52,105,300 RMB/a (6,500,000 USD/a)

Table 2Environmental improvement due to implementation of CP options

Non/low cost No. of options Environ. improvementCompany name Total options

options implemented

Waste waterCOD reduction t/a SS reduction t/a

reduction 10,000 t/a(%) (%)

(%)

Batch 21 Luohe 44 24 24 27.7 (8.5) 511 (12) 49 (10.6)2 Zhongmu 74 69 65 137.7 660 —3 Xixian 36 32 32 175 (35) 2004 (15) —4 Suiping 56 43 42 181.2 (34) 6398 (39) —5 Liuan 22 7 7 27.2 720 4506 Anhui 32 9 9 260 9100 —7 Yingshang 25 13 13 48.96 1503 —8 Yingshang 60pu 58 52 41 103.6 1517 (40) 5059 Guoyang 47 20 21 50 1500 (17) —

Subtotal 394 269 254 1011.36 22,410 1004Batch 11 Anqiu 13 5 5 210 (25)2 Minfeng 38 26 26 442.8 (49)3 Taizhou 8 5 5 1351 (18)4 Westdongting 8 3 3 NA5 Binzhou 13 6 6 680 (7)6 Weihui 18 9 9 1251 (13)

Subtotal 98 54 54 3935.6Total 492 323 308 26,345

through the conservation of water, coal, electricity, andcaustic soda by 15,720,000 t/a, 32,500 t/a, 10,260,000kwh/a and 3535 t/a, respectively (see Table 3). It is obvi-ous that CP is more cost-effective than merely relyingon EOP pollution abatement; moreover, the average pay-back period is less than 2 months.

2.3. Generate substantial CP options

Nearly 500 CP options were generated and arepresented according to the categories in Table 4. It canbe deduced from Table 4 that technology and processmodification are the top priorities for China’s paperindustry. Equipment-related change and maintenance,on-site reuse, and recycling are of secondary importance,followed by management, training and motivation ofemployees, and the use of cleaner raw materials. Adetailed analysis of options corresponding to Batch 1 ispresented in Table 5. It reveals that black liquor (BL)-related options have the highest frequency (13 options),followed by bleaching and raw material quality (sevenoptions, each). This indicates that a consensus had beenreached that BL extraction was the top environmentalconcern for China’s agro-based pulp and paper mills,with the managerial aspect being another prevalentweak point.


Table 3Economic benefit of CP at 15 mills (mainly non/low cost options)

Investment Savings (10,000Name of mills Resource conservation

(10,000 RMB) RMB/a)

Water (10000 Electric. (10,000Coal (t/a) Alkali (t/a)

t/a) kwh/a)

Batch 21 Luohe 42.12 142 123.7 146 — 371.572 Zhongmu 18 137.7 NA 520 — 2823 Xixian 42.78 175 4200 1560 168.7 1013.34 Suiping 132.7 170.36 1800 456 240 6035 Liuan 19.4 68 1350 200 — 81.66 Anhui 114 316 21,500 NA 381 706.77 Yingshang 19.5 81.6 51 25.5 — 132.038 Yingshang 60pu 47 142.45 2275 Surfite 54.6 168.49 Guoyang 44 210 1250 Surfite 90 450

Subtotal 498.9 1445.9 32,549.7 2907.5 934 3808.63Batch 11 Anqiu 3.86 6% 8% 5% 278.42 Minfeng 3.0 2.1 NA NA 2043 Taizhou NA 68.4 249.6 92.7 5894 West dongting 3.5 0.9% NA NA 145 Binzhou 24.7 26.4 NA NA 174.56 Weihui 24 34.6 378 NA 142

Subtotal 59.1 126.6 627.6 92.7 1401.9Total 559 1572.5 32,549.7 3535.1 1026.7 5210.53

Table 4Option category for pulp and paper mills in Huaihe river basin

EquipmentCleaner raw Tech. Product

Name change and Reuse recycling Housekeeping Training etc.material modification specification

maintain.

Batch 1 4 35 22 21 9 7 0Batch 2 39 142 62 79 48 19 5Total 43 177 84 100 57 26 5Percent 8.7% 36% 17% 20.3% 11.6% 5.4% 1%

2.4. Set up a new mode for regional pollution control

The CP approach set up a new mode for regional pol-lution control. Take the example of the Huaihe riverbasin, a total of 259 pulp and paper mills, which has aneffluent of over 100 tons/d, and a discharge of COD upto 605,000 tons/a in total. If this amount of COD hadbeen removed by the EOP approach, the operation costalone would have been estimated at 0.9 billion RMB, onthe basis of 1.5 RMB/kg COD, which is close to theoverall profit of these 259 mills (1.11 billion RMB ofthat year). Under such circumstances, CP provided analternative solution. It was proved that through CPimplementation, some of the participating mills couldmeet the deadline compliance requirement with afford-able EOP measures, while others could manage to sur-vive by switching to mere paper-making. NEPA plansto apply this promising approach in other regions, such

as the Liao river basin and the Chao Lake, etc., by inte-grating a CP audit into the procedure for the issuing ofdischarge permits in the hopes that environmental targetswill not jeopardize local economic development.

3. Discussion

3.1. Technical bottlenecks

3.1.1. Quality of raw materialsThe low quality of raw materials, assistant materials

(like talc), and energy (coal) still poses a common prob-lem, which hurts production and results in poor environ-mental compliance, as well. The measures are usuallynon/low cost and work well. For example, integral wetand dry preparation, which costs more than just improv-ing the existent dry method, is recommended if alkali


Table 5Summary of sector-specific CP options of Phase 1

Aspect Option category Frequency Subtotal

Technology (process) change and1. Switch to alkali–sodium sulfite pulping 1 35

optimization2. Change and improve bleaching (from single stage hypochlorate to CEH, etc.) 73. Optimize cooking technical parameters 44. Auto-control of cooking by microcomputer 35. De-silica when cooking (test) 16. Counter-current washing pulp 37. Mixed cooking of straw with reed, bamboo 28. Improve materials purchasing and preparation 79. Improve BL extraction by higher vacuum and temp. 610. Develop new papermaking additives

Equipment: modification, up-to- 1. BL washer modification or updating (e.g. from belt washer to vacuum drum7 22

date washer)2. Apply anti-corrosion bleaching equipment 13. Modify continuous digester and de-pith machine 24. Modify de-duster to reduce fibre loss 15. Strengthen maintenance, instruction, supervision 66. Convert steam boiler to cogeneration mode 17. Supplement measuring and monitoring means 28. Repair electric de-duster and causticizer 2

On-site reuse, recycling and1. Reuse of white water in pulp washing 3 1

recovery2. Recover condensate for washing and boiler 53. Reuse cooking heat in washing, alkali dissolving 24. Recycle screening and bleaching wastewater 35. Utilize BL to produce lignin, lignin sulfonate, etc. 26. Utilize straw ash as fuel 17. Install and operate the alkali recovery system 38. Restore or modify the alkali recovery system 2

Raw material substitution 1. Use long fibre grass instead of straw 1 42. Use reed 13. Mix reed with straw 14. Mix reed-bamboo with straw 1

Operation, housekeeping 1. Revise and supplement operation practice 6 92. Strengthen housekeeping 3

Training and incentive 1. Reinforce on-job training 6 72. CP knowledge examination, in relation to salary 1

recovery is to be operational. Whatever kinds of tech-nology are adopted, CP begins with cleaner rawmaterials.

3.1.2. Black liquor extractionBL generates 80–90% of the overall pollution load of

the paper industry in China. BL must be extracted asmuch as possible from brown stock before any kind offurther handling, such as alkali recovery, drying, andburning. The remaining BL usually goes into the EOPtreatment facility, along with the wastewater frombleaching and screening. For wood pulp, the extractioncan reach as high as 98–99%, while non-wood seldomexceeds 90% in China, mainly because of the high silicacontent and high viscosity of the non-wood rawmaterials. As a result, a huge amount of pollutants flowinto the pulping effluent, which makes recycling diffi-cult, and in turn leads to higher water consumption, aswell as a higher load discharged to EOP. The low BL

extraction plays a key role in this vicious cycle at non-wood pulp and paper mills.

3.1.3. Alkali recoveryThe CP initiative verified that the alkali recovery is

the best available and the most economically viable tech-nology for BL from caustic pulping, the predominantprocess in China (over 70%). It can remove most of theCOD load, and at the same time recover chemicals andheat to such a great amount that it makes itself economi-cally feasible. The BL from non-wood mills, however,is diluted, cold, and often insufficient in volume due tolow BL extraction. As a result, it is more difficult tooperate an alkali recovery system economically than inwood-based or mixed mills. Nevertheless, several alkalirecovery units, e.g. Anqiu and Minfeng in batch 1, eithersolely wheat straw-based or mixed with 20–30% reedand typically medium-sized (with annual productionaround 18,000 t/a), managed to survive for years. The


major cause of failure was found to be equipment parti-cular to the extraction process. Other problems were (1)the operation of the entire system was not in good matchwith the pulping capacity, and (2) each part of the alkalisystem, i.e. extraction, evaporation, burning, etc., did notmatch well. Thus, in order to properly operate an alkalirecovery unit, comprehensive management is required,which is exactly what CP pursues.

3.1.4. Water reuseSpecific water consumption and specific wastewater

discharges are generally much higher than rec-ommended. Low BL extraction makes it difficult toreuse/recycle the primary wastewater. Improper layoutand operation, and poor management due to the low pric-ing of water, are also considerable factors. Similar diffi-culties exist in the paper plants, in particular with respectto thin, white water recycling. Most of the mills onlyapply screening/settlement separation, as saveall is notcommonly available so far. Hence, fines and filler sub-stances cannot be recovered, which is necessary in orderto increase the water reuse rate. General speaking, apartfrom the difference in the unit consumption of differenttechnologies and products, there is still a big gap to theinternational average in resource use efficiency, evenamong Chinese mills themselves.

3.2. Sustainability of CP at mills

A prevalent phenomenon is that quite a few mills goback to their old ways once outside donors leave. Thiscan be interpreted that there is not enough incentive orpressure for CP. CP is more complicated and takes alonger time than EOP to abate pollution. However, thisis the common feature of any solution dealing with thesource of the problem.

3.2.1. How to sustain CP on a long-term basis at themill

1. Commitment of the top management is a decisive fac-tor, while the education, training, and motivation ofemployees are essential.

2. Both the mechanism and its related organization arecrucial for CP. For export-oriented mills, CP can beadopted in combination with EMS (ISO14000), whileSMEs may combine CP with Total Quality Control(TQC).

3. Achievements from CP should be well-documentedand incorporated into operational practices, rules, andindexes, and supervised on a long-term basis.

4. Improving on-line measuring and monitoring willensure the quality of production management and theaccuracy of the CP audit as well.

3.2.2. How to sustain CP at the national levelThough CP is regarded as a self-driven, industry-mot-

ivated approach, it requires incentives. However, inChina, policies in favour of CP are still rare. The prevail-ing environmental regulations and standards stick largelyto the concept of EOP. The main function of local regu-lators is primarily the supervision of environmental com-pliance instead of pollution prevention. Furthermore,most of the current regulating instruments are direct,such as deadline compliance, and discharge permits.However, driven by the fast growing economy, market-oriented, indirect instruments are needed more than ever.Both types of instruments should work hand-in-hand andbe more in harmony with resources, energy, and industrypolicies within the framework of sustainable develop-ment. Other typical problems are the unreasonable pricesof water and energy. Co-operation among different regu-lators (light industry, forest industry, etc.) and betweenregulators and business is far from sufficient.

3.3. Technical support and information service

3.3.1. Indicator system, database, and networkThe effective enforcement of either direct or indirect

environmental instruments in favour of CP requires cri-teria to judge whether the process is clean or not, or notsufficiently clean. Thus, a study on the CP indicators ofthe paper industry is fundamental. It is suggested, first,to investigate unit consumption and discharge of differ-ent types of raw materials, processes, technology, equip-ment, etc. Second, collect and screen data to identifyindicators for the performance of utilities. All the infor-mation is to be processed in the form of computerizeddatabase material and a network. This information canalso be used by mills for benchmarking purposes.

3.3.2. Guideline for non-wood alkali recoveryThe previous analyses on technical bottlenecks indi-

cated that alkali recovery was the best available cleanertechnology for the non-wood pulp and paper industry ofChina. Expertise and experience of BL-related pro-cesses, equipment, operation, and management etc., areurgently needed. Therefore, a guideline for theproper/cleaner operation of an alkali recovery system onthe basis of a summary of expertise, experience, and les-sons learned from over 100 existent units is highly rec-ommended.

4. Conclusion

The CP initiative shows that there is a great potentialfor promoting CP in China’s pulp and paper industry.Pollution loads have been considerably reduced at amuch lower price compared to the traditional EOP treat-


ment. The key issue facing the paper industry withrespect to pollution control is black liquor, which isexpected to be solved by the continuous pursuit of cle-aner production, combined with much reduced EOPtreatment. The best available and most economicallyviable solution lies in alkali recovery for the caustic

pulping process, which represents over 70% of the paperproduction of China. The major means of launching CPhave proven to be non/low cost options, which not onlycut down pollution quickly and significantly, but alsocreate a sound foundation for high cost changes and acompetitive advantage on the market.