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

Abstract 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.