Experience of Biogas Technology in China

Biogas has a long history in China. China is one of those countries, which pioneered in the research, development and utilization of biogas. Mr. Lo Guo-rui initiated his own research work on biogas in early 1920s with the aim to reduce import of kerosene and meet fuel crisis. He built the first biogas plant in his own house in Swatow city in Kuanglong province. The plant worked well and could meet the cooking need of his 6 family members. Subsequently he constructed about a dozen of digesters. Their performance was good. In 1929 Mr. Lo established a company named ‘Guo-Rui Gas Light Col’ for the marketing of his products. In 1930 his model received patent right from the Ministry of Industries. Soon after, he shifted to Shanghai and renamed his company as ‘China Guo Rui Gas General Cooperation’.

With the construction of digesters, he started developing appliances like burner, lamp, valve etc. Gradually, he expanded his activities in 13 provinces. At his initiative more than one hundred plants have been built. In some cities biogas is used for lighting in stores. Some rich people used biogas for lighting and cooking. Even after 50 years, some of his digesters were found functioning. These are mainly rectangular. Only a few are cylindrical. The sizes vary from 6m3-108m3. These are made of cement and bricks/rocks. From technical point of view, the plants were successful. But, high construction cost hindered popularization of the technology. Cost of one 8m3 plant was US$ 600. In 1936 Lo constructed 7 rectangular shaped and series connected digesters with a total capacity of 96m3. Cattle dung and fresh grass were used as fermentation materials. The gas produced was supplied to 70 stores and households for lighting.

In Shanghai, attempts were made to generate electricity using biogas. Mr. Lo started to organize technical training courses to solve the problem of shortage of skilled manpower. He developed training materials for conducting training. In 1935 he edited and published a book ‘The China Practice Lecture of Guo Rui Natural Gas Digester’. The process was stopped when the Second World War started.

During 1950s

Biogas was first officially promoted in 1958, when Chairman Mao during his visit to Wuhan and Anhui mentioned that biogas could be used for cooking, lighting and fertilizing and should be developed throughout China. Scientists took interest in biogas. A good number of scientific papers were published. Many plants were constructed. But, the results were not encouraging as the cost could not be brought down to affordable limit. Yet, about 6000 plants were in use in 1968.

During 1970s

In 1970s, there was a serious fuel crisis all over the world and China was not an exception. Again, there is revival of biogas construction movement in rural areas. Some peasants in Zhongjiang County, Sichuan could develop an improved model of biogas digester, successfully constructed some biogas plants and could show that waste materials produce gas without reducing their nutritive value. Their initiative could attract the government, which contributed guidance and promotion at various levels. Government started giving support to the wide extension of the technology. Since 1972 three national conferences were held in Sichuan, attended by representatives from different concerned ministries, to exchange information on biogas development and replicate in other parts of the country. This resulted to rapid extension in the following years. By 1979 about 7.2 million biogas plants could be built throughout the country as shown below:
Year Number of digester built
1971 50
1972 500
1973 2,800
1974 440,000
1975 1,500,000
1976 3,400,000
1977 4,300,000
1978 5,000,000
1979 7,200,000
Source: 1979 seminar report

Due to over zealot of seeking quantity, people vie for the high number of digesters built, the quality of digesters were seriously neglected. So, troubles developed only after a short time of operation with most of the digesters and they were putout of use altogether.
By 1979 a total of 7.2 million biogas plants were built in China, of which 70% were in Sichuan alone. This may be due to high population density, favorable climate and concentration of cattle/pig population in Sichuan. The population of Sichuan was then 97 million, of whom 3.8% were enjoying biogas facility. The commune members are to purchase building materials, the production team provides free labor and the government provides technical training. There was also provision of bank loan. To provide service to the farmers, there were biogas offices in 178 counties out of out of 209 counties. By 1979 200,000 technicians are trained.

During 28 July-25 August 1979 at the initiative of United Nations Environment Program (UNEP) and China Environment Protection Office of the State Council (EPOSC) of the Government of the People’s Republic of China with the cooperation of the Ministry of Agriculture organized a training seminar on biogas technology. 18 participants from the developing countries including Bangladesh attended. First four days of the seminar held in Beijing and the rest in Chengdu, Sichuan. The strengths and weaknesses of the China Biogas Program were discussed in the seminar. Based on the findings and recommendations of the seminar, the government revised dissemination strategy.

Before 1979 the strategy was ‘biogas for every rural household’ and ‘do it in a big way’. With this policy they could achieve progress at 1.6 million plant per year. After seminar, the strategy changed to ‘every plant is a success’, ‘to emulate through consolidation, to develop positively, pay attention to both construction and after sale service, hence the practical benefit’. As a result of this shift, the progress came down to 500 thousand per year, but quality improved a lot. Under the wise guidance laid down in 1979 for the readjustment, reform, rectification and improvement of the national economy, the quality and management of the biogas digester were emphasized, the pace of popularizing is eased, and hence the biogas construction was led on the way of sound development.

During the period from 1979-84 3.3 million plants were built, of which 10-20 thousand are made of red mud and of flouting dome model. In 1985 the total number of plants came down to 4.48 million. The sizes were between 6-10m3. Earlier, the technology was mainly in the rural areas. During 1980s due to availability of raw materials in the urban, the technology expanded to urban areas also. There are many winery, food, agriculture and husbandry farms in the urban areas. Organic city wastes are also good for biogas production. In 1985 there were about 10,000 large and medium size plants in China. These plants would supply gas to small gas supplying stations, small power stations, and small electricity generation stations. There were about 422 biogas power stations, 822 biogas electric stations, which would supply gas and power to about 17,000 households. In order to control use of gas, they used flow meter. There were some seasonal biogas plants based on seasonal crops like potato. Through experiments they found that, one ton of city waste can produce 200-300m3 of gas, which is equivalent to 100-150 kg oil and 500-600 kg fertilizer. Louzhi county distillery, Sichuan has built a 2x1000m3 plant with a daily gas production capacity of 3000 m3 plants. They are supplying gas to 2-120 kw power generation station, drive a 4 ton truck and to the residential quarters. By 1985, there were 25 offices in 25 province and municipalities. There were 2000 Rural Energy Resource Offices for providing service to the rural people. There were 50 institutions in the country conducting research on biogas

Recent Development:

Chinese biogas development has crossed four periods:
1973-1983: Swift development and fall
1984-1991: Adjustment and stressing science and technology
1992-1998: Rebound and benefit appearing
1999-onward: Full speeding up and quick development

By 2005 18 million biogas plants could be completed, mostly 6-10 m3 size producing 6.9 billion m3 gases annually. The technology now spread over 31 provinces out of 34.

China took a massive program for the coming years as shown below:
2006: 18 million
2010: 39 million
2015: 61 million
2020: 84 million

In 2006 government declared biogas as part of rural development.

In order to promote biogas government provided subsidy in the national budget to the tune of:
2005: 1.0 billion Yuan
2006: 2.5 billion Yuan
2007: 5.0 billion Yuan

Behind the success:

Commitment of the government: The state leaders are committed and have paid great attention to rural biogas development. As early as in 1958, Chairman Mao issued directives for the development of the technology. In July 1980, Mr. Deng Xiaoping pointed out during his visits in Sichuan that biogas development could help to solve rural energy problem. In March 1991, President Jiang Zemin pointed out during his visit in Hunan that biogas development could contribute to both farmers’ living and environment protection. In 2003, President Hu Jintao visited biogas demo-sites in three provinces of Hunan, Jiangxi and Hebei and showed interest. On September 19, 2002, Premier Wen Jiabao signed a document, saying that biogas development not only provides living energy but also contributes to ecological environment protection. It is a significant and meaningful public welfare cause.

In the recent years, investment has increased dramatically. During the Ninth Five-Year plan period, Chinese government has invested 6 billion Yuan for biogas development. Since 2003, the annual investment has been over 1 billion Yuan and in 2006 over 2.5 billion Yuan. The financial support has accelerated biogas development to a great extent.
Legislative support: A favorable policies and legal environment is crucial for the promotion of any technology. The Agricultural Law (1993), Energy Saving Law (1997) and Renewable Energy Law (2005) have all emphasized the importance of rural energy security. Rural energy development has also been included into the 21st Century Agenda of China and Midterm and Long-term National Social and Economic Development Plan. All these legislations have provided a long and stable policy supportive mechanism and policy guidance for the rural energy development. Based on the above-mentioned laws and policies, MOA issued 2005~2010 Rural Energy Development Plan.
Institutional support: A complete and efficient network is the basis for the success of biogas development. MOA is the governmental agency at the state level that is in charge of policymaking, legislation and formulating midterm and long-term plan. At the same time, Rural Energy Offices are setup in more than 30 provinces, 1900 counties and 8000 towns as the executive bodies. Moreover, more and more colleges, universities, research institutes, social groups and enterprises have joined in the technology research and development, technology dissemination, products production and after sale services.
Capacity building: Training, education and publicizing are important. In order to demonstrate and disseminate biogas technologies, many training and publicizing activities have been carried out and many training manuals, leaflets, flyers, TV program and radio program have been formulated. More than 1500,000 technicians have got national qualification certificates. 50 enterprises and trainees have been trained and many farmers have learnt new knowledge from the training and publicizing materials.

Conclusion

Biogas is one of the low cost solutions in ensuring energy security for the rural people of Bangladesh and thus stops rural-urban migration. During last one decade, there is a growing interest among the common people and the technology is gradually getting momentum. In steering the process in the right direction, the experience of China is of great importance.

Biogas Consultant, Grameen Shakti

Source:
1. Proceedings of International Biogas Training Seminar held in Chengdu, China in 1979.
2. Fourth International Symposium on Anaerobic Digestion held in Guangzhou, China in 1985.
3. Paper written by Li Jingming, Secretary General China Biogas Association.
4. Paper presented by Prof. Zhang Mi in the International Biogas Gathering held in March 2007.

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