A review of different pretreatment techniques for enhancing biogas production

This paper presented a comprehensive view of various pretreatment methods used to enhance biogas production by anaerobic digestion. Biogas yield intensification by using pretreatment techniques has been given much attention as biogas might be considered to be a substitute for conventional energy sources. Various pretreatment methods have been investigated including thermal, chemical, thermochemical, mechanical, ultrasonic, electron beam pretreatment and biological pretreatment, and mostly showed significant improvement in biogas production in comparison with non-pretreatment processes. The general purpose of applying pretreatment is to increase biodegradability and bioavailability of digested materials thus enhancing biogas production in further anaerobic digestion. For pretreatment of certain type of biomass, the choice of pretreatment technique has to be considered firstly and the optimal treatment conditions have to be determined aiming to achieve a more efficient process in both economic and environmental aspects.