Using sugarcane vinasse as raw material for producing hydrogen in a two-chamber microbial electrolysis cell
摘要
Currently, technologies for hydrogen production are widely studied by characterizing a zero-carbon energy source at the point of end use. Among these, microbial electrolysis cell (MEC) stand out due to their use of microbial biocatalysts and low-cost organic substrates. This study assessed hydrogen production in two-chamber MEC systems using sugarcane vinasse from ethanol biorefineries. The electrogenic microbial community was enriched using a sodium acetate medium, reaching maximum current densities of 5 A m–3 and 18 A m–3 at applied voltages of 0.6 V and 0.8 V, respectively. Under continuous mode with acetate, hydrogen production averaged 738 and 1474 µmol H2 L− 1 d− 1, with hydrogen purities of 93% and 97%, respectively. After acclimation to vinasse (5–40% v/v), coupling two MEC modules in series resulted in a 3.6-fold increase in hydrogen production compared with single module operation, achieving a maximum of 5256 µmol H2 L− 1 d− 1. These results demonstrated the feasibility of directly converting vinasse into hydrogen through a bioelectrochemical process and highlight the potential for integrating MEC systems into sugarcane biorefineries for clean energy recovery.