Electricity-Price-Driven Equivalence Ratio Optimization for Low-Carbon Hydrogen Production from RDF via Plasma...

Converting refuse-derived fuel (RDF) into low-carbon hydrogen by plasma reforming is a promising waste-to-hydrogen pathway, yet its economic viability is constrained by the high electricity demand of plasma generation. Oxygen addition offers a potential strategy to improve process feasibility. Based on process simulation, techno-economic analysis, and life cycle assessment, this study identifies the equivalence ratio (ER) as a key parameter governing the energy penalty, carbon footprint, and techno-economic performance of RDF plasma reforming. Oxygen input reduces plasma power demand by supplying heat through partial oxidation; however, it also lowers hydrogen yield and introduces additional costs associated with air separation and CO2 management. The optimal ER is therefore determined by the trade-off among oxygen-assisted electricity savings, hydrogen production loss, these additional costs, and the regional electricity price. Under the Sichuan electricity price of 0.5174 CNY kWh-1 (0.072 USD kWh-1), ER = 0.20 was selected as the optimal operating point near the maximum net present value. Compared with steam-only plasma reforming, this route substantially reduced the carbon footprint from 2.16 to 0.43 kg CO2 eq kg-1 H2, while maintaining the LCOH at 20.52 CNY kg-1 H2 (2.85 USD kg-1 H2). Overall, the appropriate ER depends on electricity price and the selected economic criterion, highlighting the need for region-specific ER selection rather than a universal optimum.