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

Platanus orientalis Linn is 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°C). The solid–liquid ratio, residence time, and temperature determined by energy balance calculation were 6%, 2.0 h, and 180°C, respectively, and the energy balance was 1.823 kJ/g biomass. Under these conditions, the methane yield of the process water was 56.85 mL/g·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·d) and 1.332 d, respectively. The research results suggest that HTP has an important role in promoting the large-scale AD application of FLPOL. [ABSTRACT FROM AUTHOR]