Reuse of CO-Oxidation Spent Catalysts for Dry Reforming of Methane: Techno-Economic Analysis

Abstract

We report an upcycling route for Pt-based spent CO-oxidation catalysts in stationary plants. By simple Ni impregnation, the spent modules are converted into active dry reforming of methane (DRM) catalysts (oxiCO/Ni). Under DRM at 750 °C, oxiCO/Ni achieves CH4 and CO2 conversions >73 and >94%, respectively, with high structural and thermal stability maintained over 7 h of continuous operation. The superior activity and resistance to deactivation are attributed to the formation of the NiAl2O4 spinel phase, strong metal-support interactions, and synergistic effects from residual Pt and La in the spent catalyst. A techno-economic analysis was conducted for a recycling plant capable of processing 205 tons/y of raw spent oxiCO catalyst modules, yielding 16.2 tons/y of oxiCO/Ni catalyst for DRM. The profitability analysis showed that the investment in such a project is profitable with a maximum tipping credit of 6500 US$/ton, giving a net present value of US$ 6.9 million, an internal rate of return of 43%, and a discounted payback time of 4 years and 1 month. This approach couples waste minimization with catalyst circularity, delivering both environmental and economic benefits.