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close this bookSustainable Energy News - No. 23 - Newsletter for International Network for Sustainable Energy - Desertification Theme (INFORSE, 1998, 16 pages)
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View the documentWarm welcome for biogas plants in china

Warm welcome for biogas plants in china

Edited from articles provided by Wu Libin, China Biogas Society (CBS).

Co-authors are Zhang Anrong (CBS); Wen Shiding, Biogas Research Institute of Ministry of Agriculture; Pei Li, China Association for Science and Technology.

The China Biogas Society is looking for new cooperations. Biogas technology plays an increasingly important role in China.

This is a result of more than 50 years of effort, the last 10 of which have seen concentrated research and 200 demonstration projects.

Since 1990, the number of household digesters in China has grown by 200,000 annually.

5.7 million household digesters supply 25 million people in the country's rural areas. 35,700 urban biogas septic systems treat the domestic waste water.

A Chinese Biogas Septic System with 120 m3 under construction in Chongzhou City, Chengdu, Sichuan, China, September 1998. Photo by: Wu Libin, CBS.

Research Leading to Progress

In the last 10 years, more than 10 universities and institutes in China have taken part in the research and exploitation of anaerobic digestion technology to treat organic waste, to control environmental pollution, and to produce energy. The application of the results has led to additional development in the field.

The government in cooperation with the China Biogas Society, financially supports and organises the research, design, marketing, and technical training as well as stipulation of the standards and norms to popularize biogas digesters.


Biogas for 5.7 Million Households, 25 Million People

Various small, highly efficient digesters, each with a capacity of about 6m3, were warmly welcomed by farmers. Since 1990. more than 200,000 new household digesters have been built in China each year. By the end of 1995, there were 5.7 million household digesters in the country, of which 2.2 million are in Sichuan province, where the digesters are the most popular. 25 million people in rural areas have been able to use biogas as high-quality fuel, which greatly improves their lives. The construction of digesters in rural areas gained great impetus from the 100 model-county projects built curing 1991-1995 in counties with varying levels of economic development, weather and natural conditions. Between 1995-2000, another 100 model projects were chosen for further development.

84,000 Households Enjoy Biogas from 600 Large and Middle-sized Biogas Plants

Projects for the production of biogas from organic waste have been adopted widely by poultry- and cattle farms, breweries, sugar refineries, and pharmaceutical factories. More than 600 biogas projects have been built all over the country with a total capacity of 220,000 m3 and a supply of biogas for 84,000 households, the largest of which is the biogas project of Nanyang Distillery in Henan province. It has two anaerobic digesters of 5,000 m3 and a gas storage tank of 10,000 m3 built in 1987. It produces 40,000 m3 Of biogas per day and supplies gas fuel for 20,000 city households.

357,000 Urban Biogas Septic Systems Treat 2 Million People's Sewage

Since the mid 1980's, the research on the use of anaerobic digestion technology in sewage treatment in medium-size and small towns has accelerated. Related state departments have stipulated standards for various types of biogas septic systems that have been effective in at least 10 provinces of southern China. By the end of 1995, 35,700 biogas septic systems had been built, the total capacity of which amounted to 1.38 million m3, with the ability to treat sewage water for more than 2 million people and an annual output of 17.6 million m3 of biogas to provide 22,000 households with high quality fuel.

5 % Harvest Gain

The utilization of the digested residue is one of the most important parts in the strategy of sustainable agricultural development. In China, besides being used in cooking, biogas also powers electricity generation, incubation, retardation of fruit spoilage and grain storage. The digested slurry is used in pig-and fish farming. Soaking crop seeds in the digested slurry has been popular as well. In 1995, some 730,000 hectares of crops were grown using this technique, which resulted in an increase of 5% in the harvest. When digested sludge is used in the culture and cultivation of mushrooms, vegetables, and fruits, the output is increased. As a high-quality, highly efficient fertilizer, the slurry has other organic effects besides the improvement of soils. It also decreases plant diseases and pests, thus improving the quality and yield of the crops. 60% of the digester users in the south adopted this comprehensive utilization. More than 100,000 households in the north adopted the "north rural energy-ecology", which combines a digester, a pig's sty, a lavatory, and a plastic-film-covered greenhouse. The result is that the farmers' income increased 400 RMB Yuan annually.

Bright Prospects

In the next decade, it is expected that the construction of the biogas plants will increase both in the rural areas and in the towns. The increases in town population will be advantageous to the large and medium-sized biogas plants. Around the towns, the amount of municipal sewage to treat will increase as well as the number of intensive pig- or poultry farms and, accordingly, the construction of biogas projects. The living standard in the rural areas is increasingly benefiting from the utilisation of the energy and residues from the biogas plants. The biogas technology brings about remarkable benefits in energy, environment, ecology, and economy, so it attracts the attention of the government and gains support from the whole society. Therefore, we believe that this technology has a bright future in China.

CBS experts - designed biogas project on 10,000- pig farm in Shenzen

Governmental Plans, Biogas Society Calls for Cooperation

In 1996, China formulated its "9th Five-Year Plan" and a long-range program for the year 2010. It was decided that the research institutions will remain engaged and that the government will continue its financial support. In 1996, The Ministry of Agriculture, of the People's Republic of China issued a notice to promote the development of energy-environment projects. The Department of Environment Protection and Energy of the Ministry of Agriculture and the China Biogas Society (CBS) are now engaged in the organization and promotion of the work.

About 20 breweries, food processing factories, and/or animal farms are being chosen as model projects, adopting new anaerobic fermentation processes pretreating the materials for fermentation, and pretreating the anaerobically digested residue in order to achieve overall benefits.

Related research areas include high-efficiency anaerobic digestion processes: Upflow Anaerobic Sludge Blanket Reactor, Anaerobic Fluidized Bed Reactor, Upflow Anaerobic Sludge Bed Filter Reactor, Upflow Solid Reactor, and the Anaerobic Attached Film Expanded Bed.

The CBS welcomes cooperation from all over the world.

Contact: Wu Libin, CBS, China Biogas Society, 4-13, People's South Street, Chengdu, Sichuan 610041, China.
Ph: +86-285-551571,
fax: +86-28583039,
e-mail: bobo@cd

Rural household biogas digesters and fish ponds fed with digested slurry.

The China Biogas Society (CBS) is an academic association engaged in research, development. It has 1600 individual members and 53 group members. The CBS publishes a magazine, "China Biogas", as well as other publications including video films and slides. The CBS provides consultation; it also organizes international conferences and training courses.

· Population of China: 1.2 billion.

· Number of counties: 2,200.

· Most of the 200,000 new biogas digesters built each year are rural hydraulic biogas digesters with concrete structures cast in-situ.

· Financial supporting system for the 100 demonstration counties:

30% central government.
30% province-based government.
40% local government from the prefectures and counties.

· Digester-building nowadays is mainly financed and carried out by farmers themselves.

One Chinese household hydraulic biogas digester costs about 800 - l,000 RMB Yuan (about 100-125 USD) according to different prices of materials and labour in different economic development areas. This cost is not so high that a farmer could not afford it. Only very poor farmers in remote mountain areas can apply for loans or poverty-relief fund support from the government.