Advancing Energy Recovery from Sugarcane Leaf via Two-Stage Anaerobic Digestion for Hydrogen and Methane Production: Impacts on Greenhouse Gas Mitigation and Sustainable Energy Production
Prawat Sukphun, Chaweewan Ponuansri, Worapong Wongarmat, Sureewan Sittijunda, Kanathip Promnuan, Alissara Reungsang
Abstract
This study aims to enhance energy recovery from sugarcane leaf (SCL) through two-stage anaerobic digestion (TSAD) for hydrogen and methane production. The influence of hydraulic retention time (HRT) on this process was investigated. Optimal conditions established through batch experiments (5% total solids (TS) (w/v) and rice straw compost inoculum) were applied in semi-continuous stirred tank reactors (CSTR-H2 and CSTR-CH4). Remarkably, the highest production rates were achieved with HRTs of 5 days for CSTR-H2 (60.1 mL-H2/L·d) and 25 days for CSTR-CH4 (238.6 mL-CH4/L·d). Microbiological analysis by 16s rRNA sequencing identified Bacillus as predominant in CSTR-H2 followed by Lactobacillus and Clostridium. Utilizing SCL for TSAD could reduce greenhouse gas (GHG) emissions by 2.88 Mt-CO2 eq/year, compared to open-field burning, and mitigate emissions from fossil-fuel-based power plants by 228 kt-CO2 eq/year. This research underscores the potential of TSAD for efficient energy recovery and significant GHG emission reductions.