Hydrogen-Rich Gas Production from Steam Gasification of Biomass using CaO and a Fe-Cr Water-Gas Shift Catalyst

The technical feasibility of using calcium oxide (CaO) as a sorbent for CO2 and Fe-Cr as a catalyst for the water-gas shift (WGS) reaction using syngas for the steam gasification of biomass was investigated. The effects of temperature, steam to biomass mass ratio, CaO to biomass molar ratio, and Fe-Cr WGS catalyst on gas composition were studied. Within a temperature range of 250 degrees C to 550 degrees C, the H-2 concentration increased from 1.2% to 17.1%, with a total increase of 16%. As the steam rate increased within the range of 0 kg/h to 0.12 kg/h, the maximum value of H-2 concentration increased from 12.1% to 17.13%, with a total increase of 5%. As the CaO to biomass molar ratio was increased from 0 to 2, the CO2 concentration demonstrated a minimum value of 1.3%, and the H-2 concentration exhibited a maximum value of 53.1%. A catalyst to biomass mass ratio of 1 resulted in the minimum value of CO2 concentration, which decreased from 7.9%, in the absence of CaO, to 1.6%. A CaO to biomass molar ratio of 1.5 resulted in the maximum value of H-2 concentration, which increased from 27.6%, in the absence of CaO, to 63%.