Papers Delivered at International Conference on Cleaner Production
Beijing, China -- September 2001 -- Paper 8 of 30

Current Situation of Cleaner Production in Chinese Pulp and Paper Industry and Experience on Cleaner Production Audit 

Wang Ping*, Liao Yonghong
Chemical Engineering College of Beijing Technology and Business University

Abstract: Current situation on Chinese paper industry was introduced. Effluents from paper industry has become the largest pollution source in China. Cleaner production audit on paper industry had been carried out in China to solve the pollution. The audit information and experiences were summarized.

Keywords: Cleaner production audit, paper industry.

1. Introduction 

1.1 Survey of Chinese Paper Industry 
Chinese paper industry has been progressing very much since China’s opening, the annual yield of paper and paper board has increased by an average of 10% from 1978 to 1998 and amounts to 35 million tons in 2000.It’s expected that the annual output will reach into 45 million tons in 2005 and 60 million tons in 2010.No doubt, Chinese paper market is very prospective. However, along with conversion from planned economy to market economy and because of variations and high competition of foreign and domestic paper markets, seller’s market has become buyer’s market in China, contradictions and shortages in Chinese paper industry have revealed, the following problems must be solved in order to keep sustainable development of Chinese paper industry and meet the requirements of the future market.

1. Irrational make-up of paper products: The current paper and paperboard varieties were too few and their manufacture technology is too low. The paper and paper board products are mainly medium and low grade, low grade products make up 50% of total output, medium grade products make up 20% and high grade products make up 30%. There are only about 600 varieties of paper products in China, 50 of them are low grade, whereas there are more than 1000 varieties medium and high-grade products in developed countries.
    
2. Irrational make-up of feedstock. Non-wood fiber feed stocks are major raw materials of Chinese paper industry, wood pulp only makes up a few share, there are less than 200 paper mills using wood, reed, bamboo and bagasse as raw materials, and most of paper mills use rice straw, wheat straw and waste paper instead. Less than 10% of the yield is wood pulp, 48% is non wood pulp (straw pulp 40%), 38% is waste paper pulp, and 4% is other pulp. This low wood pulp structure is the main restriction of the development of Chinese paper industry.
    
3. Small scale and irrational structure: Paper mill scale in China is too small, the paper mill number in villages and towns ever amounts to 10 thousand from 1970s to 1980s,their average annual yield is less than 6000 tons. Under recent several years environment treatments of Huai River basin and Tai Lake basin, about 5000 small paper mills under 5000 TPY were shut down, yet there are around 5000 paper mills in China. According to statistics in 1997,there are about 1180 paper mills with their yields more than 10 thousand TPY, and their total annual output is 18.58 million tons which make up 68% of total annual output in China; There are about 130 paper mills over 30 thousand TPY, their total annual output is 6 million tons which make up 22% of total annual output in China. There are 30 paper mills whose TPY are more than 100 thousand and only 3 paper mills whose TPY are more than 200 thousand. The average annual output of Chinese paper mills is 5915 tons, much less than 40 thousand of the world’s.

Such being the case, structure regulations and technology improvements must be executed in Chinese paper industry, i.e.: regulating make-up of feed stocks, varieties of products and scales of enterprise, strengthening technology reforms and environment treatments.

1.2 Pollution of Chinese Paper Industry 
It’s the irrational make-up of the feed stocks, small scale and irrational structure, low technology that was blamed for the heavy effluents discharges of Chinese paper industry. On the basis of statistics in 1997,the total effluents discharge of counties, villages and towns paper mills is 2.7 billion tons, made up 13% of the total industrial effluents discharge in China whereas COD discharge is 4.07 million tons, made up 47.5% of the total industrial COD discharge in China, and SS discharge is 2.029 million tons, made up 23.6% of total industrial SS discharge in China. Therefore, pollution treatment of paper industry is the most important part of Chinese environment protection. Pollution treatment measures must be taken to maintain sustainable development of Chinese paper industry, paper industry authority must make a series policies to regulate structure of paper industry, encourage enterprises to make use of new technology and improve their equipments and ensure pollution treatment of Chinese paper industry to reach a higher level, these relate to the Chinese environment goals of 21st century.

1.2.1 Pollution Amount from Straw pulping 
The pollution from straw pulping comes from following 3 parts: 1.Digesting waste liquor; 2.Effluents from medium stage; 3.White water from paper machine.

1.2.1.1 Digesting Black Liquor from Pulping 
The pollution of chemical pulping comes from digesting black liquor with its COD_CrBOD making up 90% pollution of the total process. Take alkaline wheat straw pulping as an example, 2.2 tons wheat straw and 300kg caustic sodium (NaOH) was needed to turn out 1 ton chemical pulp, 1.5 tons mass went into digesting waste black liquor, 1 ton of them was organics (40% was lignin) and 0.5 ton of them was inorganics (mainly caustic sodium), 1300kg COD/t pulp was produced.

If black liquor was discharged without treated or comprehensively utilized, it would be a huge waste of resources and create serious pollution to environment.

1.2.1.2 Effluents in Medium Pulping Stage 
Black liquor was extracted from digesting liquor (suppose extracted black liquor was sent into alkaline recovery stage to be burned and pollutants elimination rate was 100%.), suppose extraction rate was 80%, therefore 20% black liquor was taken into washing stage, the 20% pollutants went into waste washing water. A certain amount pollutants were produced in bleaching water in the bleaching process (bleaching process is also a delignin process), about 50kg CODCr/t pulp. So washing liquor, bleaching water and paper machine white water were totally called medium stage effluents. The amount of medium stage effluents was very large because of low-level administration of paper mill in China, The current average water consumption amounts to over 300 M3/t pulp. In order to conform effluents discharge criterions of papering, the deep color medium stage water (CODCr 1300~2000mg/L, its loading has close relations with extraction rate and black liquor treatment process) should also be treated.

1.2.1.3 White Water from Paper Machine 
The white water mainly comes from paper making process, waste water filtered from paper machine is called white water, including short fibers and other pollutants. Most of the paper machines in China are equipped with white water recovery apparatus. White water recovery technology has been widely popularized in China. Large scale paper machines are generally equipped with multi-disc filter, while medium and small paper machines are equipped with gas floating pool and multi-disc filter for white water recovery, some paper mills have fulfill white water cycling. White water recovery is feasible in technology. The treatment of digesting wastewater and medium stage wastewater is the key point in Chinese paper industry pollution treatment.

1.3 Current Policies and Goals 
To be aimed at the characteristics and unsolved problems, Chinese State Council, National Commission of Economy and Trade, Commission of Environment Protection, National Bureau of Environment Protection and administration department of light industry had issued many environment protection policies on paper industry. The development of Chinese paper industry must be coordinated with development of overall Chinese national economy and improving paper product quality will be emphasized from 1995 to 2010.Measures must be taken to change feedstock structure, enlarge scale of paper mill, enhance paper product qualities, increase product varieties, strengthen equipments, save energy and decrease loss, promote economical efficiency. Over 34 thousand TPY straw pulp paper mills will be encouraged to develop whereas less than 17 thousand TPY chemical pulp paper mills in alkaline process will be shut down.

2.Cleaner Production Situation of Chinese Pulp and Paper Mills and Experience on Cleaner Production Audit 
Three batches of cleaner production audits on pulp and paper mills had been carried out from 1995 to 1999,the auditing demonstration programmes were co-organized by Pollution Control Department of Chinese National Bureau of Environment Protection, General Society of Light Industry and Ministry of Economy and Trade. These were also one of the activities of NIEM in third stage; the cost comes from NIEM and UNIDO. The audit group members included famous foreign experts, domestic experts from universities or colleges, research institutes and administrative departments. They are very experienced in paper industry and environment protection. Six paper mills with good management and advanced equipments were selected as the first batch for auditing, they distributed in Shandong province, Henan province, Jiangsu province, Zhejiang province and Hunan province, the audits began from August, 1995,and ended in April, 1996;The nine paper mills in Huai basin were taken as second batch for auditing, they distributed in Anhui province and Henan province, most of them belonged to time limit pollution treatment enterprise, the audits began from April,1996,and ended in April,1997.Yinghe Paper Mill, Gaotang Paper Mill, Hupingyongfa Paper Mill and Chengming Paper Group etc. fifteen enterprises in Shandong Province were determined as the third batch for auditing. The audits began from August 1998,and ended in May 1999.

2.1 Experience Summarized from Audit

1. Enterprise leaders must pay attention to cleaner production, the one who is commissioned to be responsible for cleaner production must know technique and technology, he must be in charge of production and have power to coordinate with every department. Cleaner production isn’t necessarily associated with hard wares of enterprise, if enterprises pay enough attention to it, they will have unexpected achievements. For example, Anhui Paper Mill took a series of cleaner production steps during cleaner production auditing from April to December in 1996,2.45 million cubic tons water, 17 thousand tons coal, 2.93 kwh electricity and others was saved, the total saved cost summed up 7.4 million yuans in contrast to same period last year, and 7000 t COD, 1100 t SS. more than 2 million tons effluents was lowered.
2. Local environment protection authorities and paper industry authorities must give much more support and directions to paper mills in policies and techniques. Local experts must play more active roles in cleaner production.
3. According to incomplete statistics, by three years cleaner production audit, eighteen of the audited enterprises put forward 765 cleaner production suggestions, 345 of them were put into execution, most were low and no cost projects. The other demonstration enterprises presented medium or high cost projects, but had difficulties in financing and execution.
   By practicing cleaner production project, the 15 enterprises in first and second batches auditing totally cut down 11.3796 million tons effluents, 25.94 tons COD a year, their total invests were 5.5 million yuans, the average cost for treating 1 ton COD spent 212 yuans. Refer to simple statistics, the benefit from no and low cost cleaner production project were 52.105 million yuans a year, thus a great deal of resources and energies were saved (Table 1-4), Table 5 reflects information of Table 5.
4. Either medium and high cost project or low and no cost project is of no negligence, cleaner production and end treatment are both important.
5. Popular awareness and enterprises’ understandings of environment protection boost a large; environment protection can enhance competiveness of enterprises and improve their corporate identity (CI).
6. It’s wished that National Environment Bureau and National Commission of Economy and Trade would popularize cleaner production to all industries, the cleaner production audit are carried out according to areas instead of industries and was mainly done by local experts who may be assisted by national experts. Government may partially subsidize enterprises to carry out cleaner operation and help them to audit gradually by self-financing. What’s more, profit hunting must be prevented in cleaner production.
7. Government and bank should give favorable loan or other financial policies to cleaner production audited enterprises, policies should be issued for local environment protection department and industry administration department to support and encourage enterprises to carry out cleaner production, so as to facilitate cleaner production expanding and auditing.
8. It’s suggested that several experts may be commissioned to be responsible for continuous long-term cleaner production affairs on major enterprises including consultation, connection or spot guidance, the expense could be assumed by government and enterprises.

2.2 Experience of Cleaner Production Audit in Third Batch (Shandong) 

1. The audits were supported by Environment Protection Bureau and No. 1 Light Industry Bureau of Shandong Province and environment protection department of local city or county, the audits were also greatly supported by local experts, and the results were better than the former two batches. These will be good examples for the expanding of clean production audit.
2. By two years of cleaner production audits in paper industry, cleaner production has been commonly understood by populaces, government departments and enterprises. Enterprises actively and consciously applied to join cleaner production audit. Gaotang Paper Mill and Shouguang Paper Mill also applied for ISO14000 audit. The differences from the past are as follows: (1) Cleaner production was known to be the need of development of enterprises. (2) Suggestions, operations and encouraging measures moved by some enterprises are good references and push to other enterprises. (3) Higher criteria for audit were put forward.
3. Equipments were obviously improved, the three audited enterprises in Shandong all had black liquor recovery systems, two of them were alkaline recovery systems, the other was to build a alkaline one; Medium stage water treatment systems had been normally operated in two enterprises ,the other was building new one. Improved equipments also reflected in improved pulping, one enterprise adopted dry or wet feed stuffs preparation, continuous digesting. Two enterprises adopted continuous bleaching technology, one was CEHP, the other was oxygen bleaching technology which substituted for chlorine bleaching, the oxygen bleaching was first used in wheat straw pulp in the world, organic chlorine and COD pollution was clearly lowered. Computers were broadly used in technology control. These were all favorable for cleaner production.
4. In general, management level of all these enterprises were high, low and no cost project would be used in ordinary factories had already been adopted in these factories. Their cleaner production technologies were by no means inferior to that of the world.
5. Cleaner production is closely associated with the products location. Industrial structure regulations were proceeded in these enterprises, according to location on paper industry in Shandong province, LinQing Paper Mill manufactured medium-grade culture paper, Gaotang Paper Mill manufactured packing paper, Shouguang Paper Mill manufactured high-grade culture paper. Cleaner Production was indispensable for the high products location.
6. Effective and strict environment administration systems are needed for cleaner production, many excellent experiences were summed up as follows: (1) All pollution discharge of paper mill was limited and the quota was distributed at every workshop (End control was substituted by process control), the discharge control was connected to achievement evaluation of each workshop. (2) Cleaner production fund was established. (3) Cleaner production experience exchanging conferences were held and the experiences were expanded. (4) Exchanges were made during medium term evaluations. (5) Senior experts were invited to give a spot guiding.
7. Medium term evaluation time was too short to evaluate middle and high cost cleaner production projects, the evaluation time should be elongated in the future auditing.
8. Benefit calculations were the old difficulties in cleaner production audit, some were because administration was difficult to be quantified, some was because cost of water recovering was difficult to calculate in short time, only by long time statistics could the cost be accurately calculated. It is said a monograph study have been listed for this.

Table 3 Comparison before and after Cleaner Production Audit of Five Paper Mills  in Second Batches in Anhui Huai Basin

Enterprise name	Liuan Mill		Anhui Mill		Yingshang Mill		Yingshang -liushipu Mill		Wuoyang Mill
Index name	Before CP	After CP	Before CP	After CP	Before CP	After CP	Before CP	After CP	Before CP	After CP
Water consumption (t/t paper)	200	170	287	263	180	176	86	35	250	200
Water consumption (t/t pulp)	430	390	394	342.9	200	176	No record	No record	250	200
Effluents (t/t paper)	211	170	190	/	105	20	30	25	250	30
Effluents (t/t pulp)	450	370	382	328.7	251	240	No record	No record	250	200
Wheat straw Consumption (kg/t crude pulp)	2700	2680	2882 (fine pulp)	2796 (fine pulp)	2200	2200	1700	1650	2600	2200 - 2680
Alkaine consumption (kg/t crude pulp)	380	360	372.8 (fine pulp)	362.8 (fine pulp)	310	302	190 (ammo- nium sulfite)	190 (ammo- nium sulfite)	400 (ammo- nium sulfite)	3800 (ammo- nium sulfite)
Steam consumption (kg/t white pulp)	3800	3700	6977.7	6271.7	3250	3130	2120	/	2200	2100
Ca(ClO)2 (kg/t bleaching pulp)	210		/	/	240	230	/	/	240	200
Chlorine (kg/t bleaching pulp)	105		115	105	120	115	__	__	240	200
Electricity consumption (kwh/t pulp)			381	354.7	710		360	360	700	680
Coal consumption (t/t paper)			4.08*	2.55*	0.6		0.52	0.52	0.7	0.5

*Total coal consumption

Table 4 Comparison before and after Cleaner Production Audit of Four Paper Mills in Second Batches in Henan Huai Basin

Enterprise name	Luohe Mill		Zhongmo Mill		Xixian Mill		Shuiping Mill
Index name	Before CP	After  CP	Before CP	After CP	Before  CP	After  CP	Before CP	After CP
Water consumption (t/t paper)	120	70	175	151	380-400	240-260	350	211
Water consumption (t/t pulp)	110	65	204	179	400-420	270-290	138	135
Effluents (t/t paper)	/	/	280	226	368	240	329	247
Effluents (t/t pulp)	/	/	200	200	/	/	118	48
Wheat straw consumption (t/t crude pulp)	2.424	2.234			2.32	1.82
Wheat straw Consumption (t/t fine pulp)			2.7	2.5	3.2-3.3	2.7-2.8	2.82	2.33
Bleaching pulp production rate(%)	/	/	37	40	30	35-37	36	43
Alkaine consumption (kg/t crude pulp)	320	290			288	230	/	/
Alkaine consumption (kg/t bleaching pulp)	340	319	362	345
Steam consumption (kg/t crude pulp)	2.5	2.5	9.6	9.4	6.3	4.7	/	/
Steam consumption (kg/t bleaching pulp)	120	119	90	86	100-110	80-90	76	70
Electricity consumption (kwh/t pulp)	/	/	417	350	930	750	645	505
Electricity consumption (kwh/t paper)			1386	1019			563	503

3. Viable Cleaner Production Way for Paper Mills 

1. Development of low pollution new products
   Lowering paper weight, developing paper products substituting for plastic products, developing high-grade non-wooden products, developing high pulping rate technology.
2. Feedstock substitution
   Fiber regenerating, energy reusing, high-grade non-wood feedstock base building.
3. Technology improvement
   Dry and wet feedstock preparation, continuous cooking and time delay cooking, continuous multi-stage bleaching, novol auxiliary.
4. 4.Improvement of operation and equipments
   High effective and low energy consumption equipments must be furnished and must be automatically controlled as possible, equipments should be regularly examined and repaired in order to ensure their normal operation,
5. Technology optimization
   No or low pollution bleaching technology, alkaline recovery technology, straw feed stocks simultaneous digesting and desilicating technology and effluents comprehensive utilization technology should be used.
6. Administration strengthening
   Environment administration systems must be built and the environment goals must be made. Cleaner production audit must be done at suitable intervals, relevant rewards or punishments must be made in time.
7. Resource recycling
   All discharged water, gas, residues should be separated according to their loading and well utilized. Cooling water and clean condensed water must be cyclically utilized, turbid condensed water must first be steam extracted then used for pulp washing. Alkaline and white lime should be recovered. Different pulp residues are used for producing different grade papers. Gas is recovered by anaerobic fermentation.
8. Enhancing qualities of faculty and staff and their environment protection awareness
   Environment laws and rules, science and technology must actively propagandized to workers. Training and examining must be taken regularly.

4. Problems Existed in New-built Non Cleaner Production Paper Mills 

Authors have finished cleaner production and its audits of more than ten pulp and paper enterprises since 1994,there are following problems about new-built non cleaner production paper mills: (1) New-built projects still had foibles in cleaner production. (2) Enterprises didn’t build their projects according to designs of design academy, the cleaner production projects were often omitted or jerry built. (3) Some new-built or amelioration projects were not designed by certificated organizations. (4) There are no existent dependable cleaner production technologies for some feed stocks or products. All above problems should be solved by coordination of government, industrial administration departments and environment protection departments.

* Environment professor ,11 Fucheng Road, Haidian District,Beijing:100037.