Enhanced hydrogen production from methanol by liquid-phase array electrode plasma discharge

Methanol emerges as a promising candidate for on-board hydrogen production, owing to its sustainability and safety attributes. This study focuses on optimizing hydrogen production from methanol decomposition utilizing a liquid-phase array electrode plasma discharge reactor featuring gliding arc discharge. Various factors affecting hydrogen production, such as discharge parameters, electrode structure, and the conductivity of methanol–water solutions, are systematically examined. Comparative analysis revealed that, under identical discharge power, the array high-voltage electrode outperforms a single electrode in terms of hydrogen yield, with the maximum hydrogen flow rate significantly increased by 118.3 % to 1188.54 mL/min. Furthermore, the array-needle ring electrode configuration is proven to be more favorable for liquid-phase gliding arc discharge, demonstrating superior hydrogen production and energy efficiency compared to the array-needle hole-plate configuration, with a best H2 selectivity of 65 % and a prime energy conversion efficiency of 71.12 %. Additionally, a higher conductivity of methanol–water solution leads to a lower hydrogen flow rate, failing to trigger reforming reactions to enhance hydrogen concentration in the syngas. Generally, optimization efforts result in an impressive 33.8 % reduction in energy consumption for hydrogen production, achieving an optimal energy consumption of 1.28 kWh/Nm3H2 in the array electrode setup. This study provides valuable insights into the intricacies of liquid-phase gliding arc discharge for methanol-based hydrogen production, offering a foundation for optimizing reactor configurations and operational parameters to maximize efficiency and minimize energy consumption.