This work presents the influence of alkali pretreatment on the enzymatic hydrolysis and efficiency of
anaerobic digestion of lignocellulosic biomass pretreated both in a one- (chemical or enzymatic) and
two-step (chemical and enzymatic) process. In this study two species of energy crops were used Miscanthus
giganteus and Sida hermaphrodita. The aim of this work was to compare biogas production and
methane yield during fermentation of pretreated and untreated energy crops. The results show that
alkali pretreatment is necessary for the effective biogas generation from plant material due to high
delignification level and significant hemicellulose degradation. The two-step hydrolysis process consisting
on the alkali and enzymatic step leads to the release of high concentrations of glucose (about
20 g L1
). The best results were achieved for M. giganteus with biogas production yield of
421.5 Ndm3 kg TS1 and with methane production yield of 257 Ndm3 kg TS