CO2 separation during hydrocarbon gasification

Hydrocarbon can be gasified with steam into fuel gas, including CO, CO2, H2, CH4, etc. For H2 production, it is necessary to separate the other gases from hydrogen. In this study, hydrogen production by removal of carbon oxides during hydrocarbon gasification with CaO and other metal oxides was examined theoretically and experimentally.It was experimentally confirmed that when the hydrocarbon, water, and Ca(OH)2 were set in a micro-autoclave at a temperature of 973 K and a pressure of 25 MPa, the only gas products were hydrogen along with a small amount of methane. CO was converted to CO2, and CO2 was absorbed by Ca(OH)2 to form CaCO3 completely. CaOSiO2 can absorb CO2 to form CaCO3 under the same experimental conditions. Others such as MgO, SnO, and Fe2O3 were found to be unsuitable sorbents for CO2 absorption in the gasifier at high temperature.By calcination, CaCO3 can reform to CaO. Because the chemical energy contained in CaO can be released during hydrocarbon gasification, H2 production efficiency as high as 70–80% can be expected.