Mechanical pretreatment of lignocelluloses for enhanced biogas production: Methane yield prediction from biomass structural components

•Mechanical pretreatments were applied to different lignocellulosic biomass.•The structural components of all biomass were deconstructed by the pretreatment.•There was enhancement in methane yield up to 22% over the untreated biomass.•Correlation was established between chemical composition and biodegradability. In this study, mechanical pretreatment was applied to six different lignocelluloses in two different treatment phases and the prediction of their methane yield was done from biomass chemical composition. Physicochemical, proximate and microbial analyses were carried out on both pretreated and untreated biomass using standard methods. Mechanical pretreatments caused the breakdown of structural materials in all the used biomass which was characterized by reduction of the lagging time during anaerobic digestion and the subsequent increase in methane yield up to 22%. The different loading rate of biomass had no effect on the overall methane yield increase. Both single and multiple linear regressions models were used in order to correlate the chemical composition of the biomass with their methane potentials and a fairly high correlation (R2 = 0.63) was obtained. The study also showed that the pretreatments are economically feasible. Therefore, its further application to other biomass is encouraged.