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

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.