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 liquidphase 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.