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 H-2 was the primary resultant gas, comprising about 85% of the reaction products. CO2 was fixed into CaC03 and CO was completely converted to H2. Pyrolysis of the coal/CaO mixture carried out in N-2 was also examined. The pyrolysis gases were compared with gases produced by general coal pyrolysis. While general coal pyrolysis produced about 14.7% H-2, 50.5% CH4, 12.0% CO and 12.0% CO2, the gases produced from coal/CaO mixture pyrolysis were 84.8% H-2, 9.6% CH4, 1.6% CO2 and 1.1% CO. (C) 2002 Elsevier Science Ltd. All rights reserved.