Catalytic activity of coal minerals in hydrogasification of coal

Hydrogasification of six bituminous coals was studied in a fixed-ped flow reactor at pressures up to 2 MPa and temperatures from 790 to 960 °C. Ranges of distinct methane formation are found with all coals between 500 and 600 °C, 750 to 800 °C and >850 °C. The reactions in the first two ranges are determined by the molecular structure of coal and are not affected by catalytic activities of constituents of coal minerals. In the third range, >850 °C, iron as a constituent of mineral matter of coal can accelerate methane formation significantly if the pressure is sufficiently high. Thermodynamic calculations indicate, and were verified by thermogravimetric studies, that iron disulphides in original coals can be desulphurized during gasification. Alkali and alkali earth oxides and carbonates can act as sulphur scavengers via an exchange reaction and thus accelerate the desulphurization of iron sulphides.