Chemical looping gasification of charcoal with iron-based oxygen carriers in an annular dual-tube moving bed reactor

Abstract

Charcoal used as solid fuel for chemical looping gasification (CLG) with Fe2O3/Al2O3 oxygen carriers was investigated in an annular dual-tube moving bed reactor (ADMBR). Pure CO2 and steam/CO2 mixture were used to gasify the charcoal in a fixed bed reactor. More combustible gases, CO and H2, were observed in the outlet gas streams for charcoal gasification conducted with steam/CO2 mixture than those with only CO2. The yields of fuel gases were determined to modify the equation of oxygen carrier-to-fuel ratio (ϕ) for moving bed operation. More CO and H2 were generated for charcoal gasification conducted in the moving bed reactor operated with higher oxygen carrier-to-fuel ratios. The heat demand for experiment conducted in the ADMBR was calculated to be 60% of output processing capacity due to the heat consumptions of fuel gasification. In sum, ADMBR is technically feasible to be a fuel reactor for partial oxidization of charcoal by CLG to achieve syngas production under appropriate operating conditions without auxiliary fuel.