UNDERGROUND LIGNITE GASIFICATION AT TEXAS A&M UNIVERSITY.

The title research program consisted of laboratory work, mathematical modeling and field testing. A series of combustion tube runs were made to determine the effect of the water/air injection ratio on the produced gas composition. Runs made on lignite samples from the field test and at a pressure compatible with the field test indicated that the optimum water/air molar injection ratio is about 0. 18 and that the produced gas should have a heating value of approximately 150 BTU/scf. A simple mathematical model predicted the produced gas composition and the flame front velocity. The model was also used to predict the heating value of the dry gas as a function of the water/air injection ratio. The objectives of the field experiment were to test the procedures of ignition, back burn, gasification and to gather environmental data.