Comparison of solid-state to liquid anaerobic digestion of lignocellulosic feedstocks for biogas production

► Solid state anaerobic digestion (SS-AD) of eight types of lignocellulosic biomass. ► Liquid anaerobic digestion (L-AD) of eight biomass feedstocks was compared with SS-AD. ► No significant difference in methane yield between SS-AD and L-AD. ► Volumetric biogas productivity of SS-AD was 2- to 7-fold greater than that with L-AD. ► Methane yields from crop residues were higher than those from woody biomass.