Coupling of CO2 capture and methanation processes using catalysts based on silica recovered from rice husks

Abstract

The CO2 capture was carried out at high temperature using lithium silicate as sorbent and its subsequent conversion to CH4 was performed employing Ni5/MCF as catalyst. Different operating variables such as temperature, time and H2 concentration were studied to maximize the performance of both the sorbent and the catalyst in the coupled processes. Three different configurations were adopted and implemented for the disposition of the sorbent and catalyst. The gases from the capture and regeneration stage were quantified by chromatography with an FID detector and mass spectrometry. The characterization of the used materials by XRD was carried out to verify their stability under operating conditions. The arrangement that consisted of a single reactor with two beds in series proved to be a promising option since it allowed achieving a high production of CH4 (0.76 molCH4 kgcat−1).