FORMATION OF C-1-C-3 HYDROCARBONS DURING PRESSURE PYROLYSIS AND HYDROGASIFICATION IN RELATION TO STRUCTURAL-CHANGES IN COAL

A comparative study on pyrolysis and hydrogasification of a bituminous coal was conducted under non-isothermal heating at 3 K min(-1) to 1200 K. The kinetics of C-1-C-3 hydrocarbon formation were measured and total yields of the products were evaluated. The chemical and optical structures of the coal chars obtained at different temperatures were also investigated. At temperatures > 750 K, the influence of gas atmosphere (Ar or H-2) on the kinetics of hydrocarbon formation was found significant. The use of hydrogen atmosphere even at the relatively low experimental pressure of 2.5 MPa resulted in a high conversion (40%) of carbon to C-1-C-3 hydrocarbons as well as in inhibition of the formation of optical anisotropic structures in the char.