Fundamental studies on hydrogasification of Taiheiyo coal

Rapid hydrogasification of a Japanese Taiheiyo coal was performed in a specially developed laboratory scale batch type reactor under conditions similar to an industrial gasifier to obtain fundamental data and a comprehensive understanding of the process. The experiments were carried out at 1073 K, 7.1 MPa atmosphere, with varying reaction times from 1 to 80 s and H2/coal ratio in the range of 0.05–0.30 g/g. It was found that coal conversion was promoted at a higher H2/coal ratio. The amount of methane was seen to increase with reaction time, whereas most of the other products showed dynamic characteristics with maximum formation during the observed reaction time. A comparison with results of pyrolysis in helium indicated that hydrogasification is mainly composed of two steps, initial primary pyrolysis followed by secondary gas phase reactions, including hydrocracking of intermediate hydrocarbons and methanation of carbon oxides.