Cold isotherm pressing pretreatment for effective improvement of methane production from Hybrid Pennisetum.

[Display omitted] • A static ultra-high pressure pretreatment method for AD has been developed. • Electron transfer capacity of system was analyzed by electrochemical test. • A better digestion performance obtained at CIP samples of Hybrid Pennisetum. • Higher accessibility between material and inoculum through CIP was proved by mapping. Ultra-high pressing pretreatment has been employed to effectively improve methane production from Hybrid Pennisetum. In this study, Hybrid Pennisetum was pretreated by cold isostatic pressing (CIP) to improve methane production. The pretreatment enhanced the accessibility between the substrate and inoculum. The decomposition of the compact biomass structure was analyzed through Fourier Transform Infrared Spectrometer (FT-IR) and X-ray Diffractometer (XRD). Moreover, the electron transfer capability in the system was evaluated by electrochemical analysis. The systematic experiment yielded the highest methane production at a pressure of 400Mpa, reaching 227.67 mL/g VS. The pretreatment changed the reducing sugar content (RS), pH, and volatile fatty acids (VFAs) in the AD system, which in turn increased the cumulative methane production. This study provides a promising platform for the development of an efficient methanogenic pretreatment. [ABSTRACT FROM AUTHOR]