Experimental Investigation on the Sequential Pretreatment of Agricultural Biomass Wastes for Increased Biogas Production

摘要

Objectives: In the present work, different pretreatment methods (milling, ultrasonication, liquid hot water, and alkali hydrolysis) were evaluated on rice straw and coconut shell that can be used as a substrate for biogas production for vehicle fuel, provide heat and generate electricity. Methods: This was achieved by the sequential combination of ultrasonication, hot water, and alkali hydrolysis treatment at a various concentration (4% and 5% w/v) was evaluated. Additionally, Fourier Transform Infrared (FT-IR) was used as one of the methods in identifying structural differences and identification of compounds in the treated biomass. Findings: The results showed that the combination of ultrasonication-alkali hydrolysis, hot liquid water using 3% of NaOH improved methane yield of 150% for rice straw and 290% for coconut shell compared with the original treatment. Additionally, FT-IR identified modifications in the biomass structure after different types of pretreatments and conditions. Application: The results of this research are the initial steps for the development of new processes using the Ultrasonication-NaOH LHW pretreatment, for the production of biogas from agricultural biomass waste.