Study on Biological Pathway of Carbon Dioxide Methanation Based on Microbial Electrolysis Cell

Abstract

Realization of CO2 resource utilization is the main development direction of CO2 reduction. The CO2 methanation technology based on microbial electrolysis cell (MEC) has the characteristics of ambient temperature and pressure, green and low-carbon, which meets the need of low-carbon energy transition. However, the lack of the system such as the change of applied voltage and the reactor amplification will affect the methane production efficiency. In this research, the efficiency of methane production with different applied voltages and different types of reactors was carried out. The results were concluded that the maximum methane production rate of the H-type two-chamber microbial electrolysis cells (MECs) at an applied voltage of 0.8 V was obtained to be 1.15 times higher than that of 0.5 V; under the same conditions of inoculated sludge, the reactor was amplified 2.5 times and the cumulative amount of methane production was 1.04 times higher than the original. This research can provide a theoretical basis and technical reference for the early industrial application of CO2 methanation technology based on MEC.