The characteristics of hydrogasification to generate substitute natural gas (SNG) by using various bituminous coals such as Alaska, Cyprus, Curragh, and Datong have been determined in an entrained-flow hydrogasifier (0.025 m I.D. X 1 m high) with high pressure coal feeder and data acquisition system. The effects of reaction pressure (60-80 atm), reaction temperature (600-800 degrees C) and H-2/coal ratio (0.3-0.5) on composition of product gas and carbon conversion have been determined. The concentration of SNG and carbon conversion increased with an increasing of reaction pressure and temperature, but the carbon conversion and concentration of each bituminous coal were quite different because of different coal properties. Also the H-2/coal ratio affected the carbon conversion and the concentration of SNG. (C) 2005 Elsevier Ltd. All rights reserved.