Cleaner production in China's pulp and paper industry

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  • Journal of Cleaner Production 6 (1998) 349355

    Cleaner production in Chinas pulp and paper industryXin 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 Chinas 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 Chinas 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 Chinas 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- 65 26 (98)00 02 3- 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) 349355

    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 Chinas 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 WastewaterName Raw material capacity capacity Bleaching alkaliemployees process recycling handling treatment(TPA) (TPA) recovery

    Batch 2Zhongmu 2400 Wheat straw 25,000 34,000 NaOHAQ CEH Operating Operating None Biochem.

    plannedLuohe 950 Wheat straw 18,000 35,000 NaOHAQ CEH Operating Operating None Biochem.

    installedSuiping 980 Wheat straw 17,000 20,000 NaOHAQ CEH Operating None Basic None

    lignin sep.Xixian 720 Wheat straw 20,000 3000 NaOHAQ 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 NaOHAQ H Partly operating Operating None Biochem.

    beinginstalled

    Weihui 1500 Wheat straw 8700 11,000 NaOHAQ 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 NaOHAQ 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 Chinas pulp and paper mills is gener-ally rather poor, in particular with respect to basic busi-ness management and costbenefit awareness. Weakpoints widely existent in small- and medium-sized pulpand paper mills were:1. Measuring and monitoring, especially on-line, were

    insufficient 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) 349355

    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 1020%. 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 optionsoptions implemented

    Waste water COD reduction t/a SS reduction t/areduction 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 Chinas 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 Chinas agro-based pulp and paper mills,with the managerial aspect being another prevalentweak point.

  • 352 X. Ren / Journal of Cleaner Production 6 (1998) 349355

    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. ProductName 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

  • 353X. Ren / Journal of Cleaner Production 6 (1998) 349355

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

    Aspect Option category Frequency Subtotal

    Technology (process) change and 1. Switch to alkalisodium sulfite pulping 1 35optimization

    2. 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 drum 7 22date 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 and 1. Reuse of white water in pulp washing 3 1recovery

    2. 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 8090% 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...

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