Asia: Chinese Biogas: Still Expanding

By Wu Libin, China Biogas Society (CBS) China

As a pioneer country in the use of biogas, China is still expanding the practice, using traditional household biogas plants and in a number of other applications.

Family biogas plant, and its uses.

More and Larger Biogas for Agriculture

The biogas uses in farm households are still growing and currently about 8 million households have biogas plants. Biogas use greatly augments the farmer’s income as well as development of the rural economy and improvement of the environment.

Not only do the plants provide farm households with clean gas fuel and excellent organic fertilizer, they increasingly serve a number of other purposes.

The digested slurry is used to feed fishes and pigs, and seeds are soaked in it, while the biogas is used to store grain and fruits.

In addition to the household farms, larger farms are increasingly using biogas. A particular interesting development is the "North Biogas Ecological Agriculture Model" (generally called the Four-in-one model). It is an efficient production model that integrates biogas technology, solar energy, greenhouses, livestock, and cropping as a whole with biogas technology as ligament.

It is effective due to its multilevel energy utilization and benign cycle of substances.

It has been promoted to 230 thousand farm households in the northern area of China and is seen as the "well-off" project, by which local farmers can get rich.

Biogas in Wastewater Treatment

Biogas technology is increasingly used in wastewater treatment in China, ranging from treatment of "easy-to-degrade" wastewater from large farms, to treatment of more difficult or hazardous wastewater from hospitals, paper industries, pharmaceutical industries, dyeing, and other industries. In several cases, research has resulted in development of processes for anaerobic digestion of "hard-to-degrade" industrial wastewater. In some cases, this can be done by combining anaerobic digestion with other processes.

The anaerobic digestion can also be helped by addition of trace elements or by special digester designs, e.g. with bio-membranes. Further, special anaerobic bacteria are cultivated and used for special purposes.

Now household biogas digesters are often produced in pre-fabricated modules.

Wastewater treatment plant on a pig farm in Shenzhen City

Large support Structure

China has established a complex network responsible for administrative management of biogas construction, research, technology promotion, education, and training. The China Biogas Society and its over 2000 members cooperate closely with this network.