This paper examines the effect of particle sizes in substrates on methane production yields of wheat and rice straw biomass without any other applied pretreatment. Anaerobic digestion of three different mean particle size (MPS) substrate of 1.5 mm, 0.75 mm, and 0.30 mm of wheat and rice straw biomass was carried out at 37 oC mesophilic temperature. The observed result revealed that mean particle size of 0.30 mm, and 0.75 mm had increased methane production yield by 4.7%, and 38.7%, respectively, compared to 1.50 mm particle size of wheat straw. However, in case of rice straw substrates the methane production yield was found 7.9%, and 13.0% higher, respectively, for mean particle size of 0.30 mm, and 0.75 mm, compared to 1.50 mm particle size. Mean particle... |