Biogas: Potential, challenges, and perspectives in a changing China

Abstract

Biogas is an important renewable biomass energy source. Currently, China's biogas production is one of the highest globally, with 12.366 G m3 of gas being produced, which can improve the energy structure of rural areas in China. China's biogas plants have undergone rapid development in the last 10 years. From 2008 to 2017, the number of biogas plants has increased 2.76 times. In addition, the biogas production contribution of biogas plants to whole national biogas production has increased from 5.88% in 2008 to 21.09% in 2017. The development of large-scale agricultural residues biogas plants has been fast, with good benefits. China's biogas production has huge potential. According to the estimates, the total biomass of crop straws in China in 2017 was 1.158 G t, and the total amount of livestock and poultry manure was 1.788 G t. In addition, invasive plants with large biomass can undergo co-fermentation, converting waste into a valuable resource. However, electricity generation utilizing biogas is still in the initial stages. In 2017, the installed capacity of biogas grid-connected electricity generators in China was 500 M W, and the electricity generation potential is large. The oriented field of China's biogas development includes the development of large-scale biogas plants (biomethane plants), biogas electricity generation grid plants, household biogas digesters, and small-scale biogas digesters in poor mountainous areas; the integrated use of biogas digestate; construction of diverse capital investment mechanisms; and incentives to improve the biogas industry.