Biogas development

As a big energy consuming country, the development and utilization of new energy is of great significance to the sustainable development of national economy in China. With the rapid development of rural social economy, rural energy consumption is also increasing. In this context, as a new energy with great application prospect, the development and utilization of biogas resources is an effective measure to solve the problem of rural energy supply under the situation of energy shortage, and its development has been paid more and more attention by the state. Since 2000, the central government has continuously increased its investment in rural biogas construction. Since the 11th Five-Year Plan, the central government has invested a total of 2,654.38+0.2 billion yuan in rural biogas construction.

With the guidance of the central policy and the support of capital investment, the scale of biogas industry in China has increased year by year, especially the number of household biogas digesters, which has become the main force of biogas industry. Rural household biogas digesters in China have increased year by year in recent years. By the end of 2000, there were 8.48 million household biogas digesters in rural areas, 22 million by the end of 2006, 26.5 million by the end of 2007, 28 million by the end of 2008, 35 million by the end of 2009 and more than 40 million by the end of 20 10. It can be seen that the number of household biogas digesters has been increasing.

201212 On February 25th and 26th, the National Rural Biogas Work Conference was held in Chengdu, Sichuan. Zhang Taolin, Vice Minister of Agriculture, said that over the years, with the promotion of central investment and the joint efforts of all localities, the development of rural biogas in China has entered a new stage of great development and rapid development. By the end of 20 1 1, the household biogas reached 39.96 million households, accounting for 23% of the total rural households, benefiting more than/kloc-0.5 billion people. The central government supported the construction of 24,000 small biogas projects and more than 3,690 large and medium-sized biogas projects, and a new pattern of diversified development was initially formed; There are 90,000 rural service outlets and more than 800 county-level service stations nationwide, serving about 30 million biogas users, with a coverage rate of 75%.

According to the plan of the Ministry of Agriculture, during the Twelfth Five-Year Plan period, the central government will give priority to supporting large and medium-sized biogas projects that provide centralized gas supply to farmers. Under the condition of ensuring the supply of "household biogas", it is necessary to expand "biogas users", adjust the development layout of biogas, and promote the development of commercial biogas through pilot demonstration; In 20 15 years, the number of biogas users in rural areas reached 50-55 million.

Biogas was discovered in the swamp by Italian physicist A. Volta in 1776. 19 16, the first methanogenic bacteria (but not pure) was isolated from β п Omelyanski in Russia. Methanosporidia was successfully isolated for the first time in China on 1980. Nearly 20 kinds of methane have been isolated in the world.

The world's first biogas generator (also known as automatic purifier) was improved from a simple sedimentation tank by French L. Mullah in 1860. In 1925, Germany and in 1926, the United States built biogas digesters with heating facilities and gas collection devices, which are modern biogas digesters.

Prototype of large and medium-sized biogas generating device. After World War II, some western European countries developed biogas fermentation technology, but it was affected by the influx of cheap oil into the market. Later, with the emergence of the global energy crisis, biogas once again attracted people's attention. 1955 a new biogas fermentation process-high-speed anaerobic digestion process came into being. It breaks through the traditional technological process, and increases the gas production rate per unit pool volume from 0.7 ~ 1.5 cubic meters of biogas per day to 4 ~ 8 cubic meters of biogas at moderate temperature, and shortens the residence time from 15 days or longer to several days or even hours.

In the early 1920s, China built the first biogas digester in Chaomei, Guangdong Province from Low Kwok Sui, and then established China Rivas Corporation to promote biogas technology. Rural household biogas digesters in China have reached130,000 households. However, the productive experimental device of high-efficiency anaerobic digestion process has been running normally in sugar factories and wineries.