Bi-Functional Catalyst/Sorbent for a H2-Rich Gas from Biomass Gasification

Abstract

The aim of this work is to identify the effect of the CaO phase as a CO2 sorbent and mayenite (Ca12Al14O33) as a stabilizing phase in a bi-functional material for CO2 capture in biomass syngas conditioning and cleaning at high temperature. The effect of different CaO weight contents is studied (0, 56, 85, 100 wt%) in sorbents synthesized by the wet mixing method. These high temperature solid sorbents are upgraded to bi-functional compounds by the addition of 3 or 6 wt% of nickel chosen as the metal active phase. N2 adsorption, X-ray diffraction, scanning electronic microscopy, temperature-programmed reduction analyses and CO2 sorption study were performed to characterize structural, textural, reducibility and sorption properties of bi-functional materials. Finally, sorption-enhanced reforming of toluene (chosen as tar model), of methane then of methane and toluene with bi-functional compounds were performed to study the best material to improve H2 content in a syngas, provided by steam biomass gasification. If the catalytic activity on the sorption enhanced reforming of methane exhibits a fast fall-down after 10–15 min of experimental test, the reforming of toluene reaches a constant conversion of 99.9% by using bi-functional materials.