Hydrothermal pretreatment of Platanus orientalis Linn fallen leaves: effects of process conditions on anaerobic digestion

Platanus orientalis Linnis widely distributed as a famous street tree, and its fallen leaves are a rich biomass resource. The fallen leaves of Platanus orientalis Linn(FLPOL) can be resourcefully treated by generating biogas through anaerobic digestion. This study aimed to assess the anaerobic digestion (AD) performance of FLPOL under different hydrothermal pretreatment (HTP) conditions(solid-liquid ratio 2-10%, residence times 0.5-2.5 h, and temperatures 120-200 degrees C). The solid-liquid ratio, residence time, and temperature determined by energy balance calculation were 6%, 2.0 h, and 180 degrees C, respectively, and the energy balance was1.823 kJ/g (biomass). Under these conditions, the methane yield of the process water was 56.85 mL/g<middle dot>VS. The methanogenic potential, hydrolysis rate, maximum methanogenic rate, and the lag period obtained by the Fitzhugh first-order kinetic model and the modified Gompertz model were 101.803 mL/g.VS, 0.130 d-1,14.207 mL/(g.VS<middle dot>d) and 1.332 d, respectively. The research resultssuggest that HTP has an important role in promoting the large-scale AD application of FLPOL.