Research progress and prospect on producing biogas from crop straws

Producing biogas from crop straws is an effective and potential route to obtain bio-energy. But it once suffered the setback because fermentation technology has some defects. In recent years, much beneficial achievement has been obtained in some exploration, including: pretreating crop straws for improving the fermentation characteristics through nutrition regulation and texture improvement, adding gridiron in the reactor to prevent float and scum shell of crop straws, alternately feeding between the two reactors for equation of biogas production, altering the inoculation and its concentration for accelerating reaction startup，ameliorating fermentation process for enhancing efficiency, etc, which also points out the direction for further research. The technology in the inoculation of reactor is dependable at present. Finding the appropriate pretreatment method, improving the structure of the reactor, exploiting vigorous trade inoculation, keeping the temperature of biogas digester invariableness and totally separating the hydrolysis and the methanogenesis are the key directions for the future production of biogas from crop straws.