Biomimetic low carbonization efficient solar-driven thermochemical energy storage reactor design inspired by the diatoms’ superior photosynthesis capacity

Abstract

Photon is the energy source that drives solar thermochemistry. Photon-based radiative transfer in the reactor space is an essential mode of energy transfer. However, there often exists mismatch between the radiative and chemical fields in direct solar thermochemical processes, which can lead to ultra-high temperature gradients and high carbonization rates. While, the vicious cycle that exists between high temperature gradients and higher carbonization rates could severely limit the thermochemical efficiency. To improve the efficiency and reduce the temperature gradient and carbonization, inspired by the superior performance of diatom photosynthesis, a biomimetic radiation-regulated reactor is proposed. The paper establishes multi-field model of steam methane reforming, and analyzes the energy conversion processes at pore-scale. In numerical analyses, compared to the conventional reactor, the biomimetic reactor enhances the light forward scattering in fore-end and the backward scattering in rear-end, which increases the light absorption efficiency by 6.8% and reduces the temperature gradient by 41.3%. In experimental investigation, the methane conversion and the solar-fuel efficiency of the biomimetic reactor is 48.6% and 44.0%, which is increased by 11.5% and 10.7% respectively. It also demonstrates high efficiency and stability under long operating conditions. The biomimetic reactor provides a new strategy for industrial solar-driven methane conversion.