Cascade and hybrid processes for co-generating solar-based fuels and electricity via combining spectral splitting technology and membrane reactor

Abstract

Efficient solar-driven production of fuels and electricity is significant for achieving a decarbonized society. However, the existing systems still suffer from drawbacks including limited photovoltaic (PV) efficiency under high temperatures and large irreversibility in solar-to-thermal conversion. In this research, a novel system involving the integration of PV modules and membrane reactor via spectral splitting technology is proposed to cogenerate fuels and electricity with improved efficiency. The sunlight with suitable wavelengths for the PV power generation is directed on the PV module, and the residual part is concentrated on a membrane reactor for solar fuels production via dry reforming of methane (DRM). Instead of generating waste heat in PV system, the thermal energy from sunlight can be utilized by thermochemical reactions and stored in solar fuels, leading to a decline of the PV temperature and enhanced PV efficiency. Based on membrane reactors, the equilibrium of DRM shifts forward for achieving a high methane conversion at a relatively low temperature. This system can deliver 75% of energy efficiency, 34% of solar-to-electric efficiency, and 71% of exergy efficiency. Additionally, the carbon dioxide reduction rate (CDRR) could reach 514.5 kg m−2 year−1. Our findings provide insights into high-efficient solar energy utilization involving membrane reactors.