Abstract: With the increasing concerns of global climate change caused by the consumption of fossil fuels, much efforts have been spent on the exploration of renewable energy sources in the last couple of decades. Biogas produced from the treatment of organic waste materials is one of the renewables that have attracted a lot of attentions. This paper provides a summary of the studies on thermophilic anaerobic digestion or co-digestion of various organic waste materials for biogas production. Discussions in this paper include main advantages of thermophilic anaerobic digestion technology over mesophilic one, factors that critically impact the efficiency of the anaerobic digestion such as temperature, pH, total solids, carbon/nitrogen ratio, and hydraulic retention time, the effect of the pretreatment of lignocellulosic materials on the biogas production from anaerobic co-digestion of animal manure and agricultural residues, and mathematical models describing the anaerobic digestion processes.

Key words: anaerobic digestion, biogas, organic wastes, renewable energy, thermophilic