Hydrogen production from coal by separating carbon dioxide during gasification

Hydrogen generation during the reaction of a coal/CaO mixture with high pressure steam was investigated using a flow-type reactor. Coal, CaO and CO reactions with steam, and CO2 absorption by Ca(OH)2 or CaO occurred simultaneously in the experiment. It was found that H2 was the primary resultant gas, comprising about 85% of the reaction products. CO2 was fixed into CaCO3 and CO was completely converted to H2. Pyrolysis of the coal/CaO mixture carried out in N2 was also examined. The pyrolysis gases were compared with gases produced by general coal pyrolysis. While general coal pyrolysis produced about 14.7% H2, 50.5% CH4, 12.0% CO and 12.0% CO2, the gases produced from coal/CaO mixture pyrolysis were 84.8% H2, 9.6% CH4, 1.6% CO2 and 1.1% CO.