Plasma-Assisted CO2 Conversion to Methanol in Energy Systems: Parameter Optimization and Synergistic Effects

The integrated process of CO2 hydrogenation and catalytic methanol synthesis under plasma conditions holds great potential for CO2 conversion from waste gases. This process connects a dielectric barrier discharge (DBD) plasma reactor and a methanol synthesis fixed-bed reactor through a pressurization device, achieving the stepwise conversion of CO2 to CO and then to methanol, thereby establishing a low-carbon and high-efficiency energy conversion system. This study experimentally investigated the key parameters influencing the CO2 hydrogenation process in the DBD plasma reactor and the methanol synthesis process in the fixed-bed reactor. The results show that in the plasma reaction, discharge power, discharge gap, gas flow rate, and gas composition significantly affect CO2 conversion efficiency. In the methanol synthesis process, the CO/CO2 mixed feed exhibits superior catalytic performance compared to pure CO2. The optimal operating conditions for the integrated process are a plasma voltage of 40 V and a downstream reaction temperature of 240 °C, under which the system achieves the best overall performance.