Optimization of the Physicochemical Parameters of Selected Crop Residues for Enhanced Biosynthetic Gas Yields

In this study, the influence of physico-chemical parameters; average particle size, moisture, and cellulose content on the yield of biosynthetic gas from biomass pyrolysis was investigated. Response Surface Methodology and Box-Behnken design methods were used to analyze the experimental data. The results showed that at a given average particle size, the biosynthetic gas yield increased gradually with increase in cellulose content until at cellulose content of 35% when the yield starts to decrease with further increase in cellulose content. This implies that within experimental conditions, a cellulose content of 35% was ideal for obtaining maximum biosynthetic gas yield. The variations in average particle size affected biosynthetic gas yield in such a way that at low cellulose content below 30% and for a given average particle size, the biosynthetic gas yield was nearly constant. The same trend was observed at high cellulose content beyond 40%. However, between 30% and 40% cellulose content, the biosynthetic gas yield decreased with increase in average particle size until about 1.81 mm when the biosynthetic gas yield starts to increase with increase in average particle size. This implied that the minimum biosynthetic gas yield was obtained at 1.81 mm average particle size. It was concluded that for better biosynthetic gas yields, cellulose content of 35% would be preferred at average particle sizes other than 1.81 mm which yielded lowest biosynthetic gas.