A kinetic study of non-catalysed and catalysed coal was conducted using a DuPont 951 thermogravimetric analyzer. A kinetic model in which the apparent activation energy is assumed to be a rectilinear function of the extent of reaction was used to describe the pyrolysis of Hanna coal. For the hydrogasification of char the apparent activation energy was found to vary as a second degree polynomial with respect to conversion. The order of reaction was found to be about 0.3 for the pyrolysis step and 0.67 for the hydrogasification step. The effect of hydrogen partial pressure could not be investigated since the thermogravimetric analyzer was not designed to operate under pressure.
Most of the proved coal reserves in the western states of the United States have high moisture and ash and low heating values. Several of these vast coal deposits are present at depths too great to be economically attractive for conventional mining. In-situ gasification offers an attractive and feasible alternative. An understanding of the chemical reactions and kinetics of pyrolysis and gasification is of utmost importance in optimizing the utility of coal in an insitu gasification process. Extensive experiments are being carried out by the Laramie Energy Research Center of the U.S. Department of Energy, at Hanna, Wyoming1Y2 in a 9.15 m (30 ft) thick seam of subbituminous coal at a depth of 122 m (400 ft)3. A core sample of Hanna No. 1 coal from well D-4 was used in this program to develop kinetic parameters described in this article.