Coal reactivity measurements

Measurements have been made of reaction rates of coals and coal chars with reacting gases present in the underground coal gasification processes. Thermogravimetric analysis (TGA) was employed for this purpose. Results show that char-CO/sub 2/ reaction becomes significant at about 650/sup 0/C, and that the activation energy for this reaction is approximately 40 kcal/mole for Wyodak coal. 6 refs., 6 figs.