A review of crop straw pretreatment methods for biogas production by anaerobic digestion in China

Producing biogas from straw is an effective way to manage straw from crops. However, there are difficult technical problems in the biogas fermentation process because it is difficult for anaerobic bacteria to degrade crop straw to produce biogas. Currently, pretreatment of straw is considered as a good way to enhance anaerobic digestion rate and improve biogas production. This paper summarizes the effects of different pretreatment methods of crop straw to enhance biogas production including physical, chemical, biological and combined methods in China. Each single pretreatment method has its limitations, while combined pretreatment method has synergistic pretreatment effect which has better performance than single method. Also, current and future developments are evaluated to promote straw pretreatment technology for biogas production. The development of crop straw biogas project with an economically feasible comprehensive straw pretreatment scheme is promising.