influence of pretreatment with fenton’s reagent on biogas production and methane yield from lignocellulosic biomass

biomass from miscanthus giganteus, sida hermaphrodita and sorghum moensch was treated with fenton’s reagent for 2 hours under optimal conditions (ph = 3, mass ratio of [fe²⁺]:[h₂o₂] equals 1:25 for miscanthus and sorghum and 1:15 for sida). the degrees of delignification were 30.3%, 62.3% and 48.1% for the three plant species, respectively. the volatile fatty acids concentration after chemical pretreatment was high enough for production of biogas with a high methane content. combined chemical oxidation and enzymatic hydrolysis with cellulase and cellobiase led to glucose contents of above 4 g/l. among the tested plants, the highest biogas production (25.2 ndm³/kg ts fed) with a 75% methane content was obtained with sorghum moensch. the results of the three-step process of biomass degradation show the necessity of applying a chemical pretreatment such as oxidation with fenton’s reagent. moreover, the coagulation of residual fe³⁺ ions is not required for high biogas production.