First Experiment on Underground Coal Gasification with a Directed Flow Supply in the Plane of the Coal SEAM

摘要

During the experiment 2350 tons of coal were gasified. The average heating value of the gas over the entire operating period was 915 kcal/nm exp 3 . In the course of the experiments with a directed flow supply for gasification, the temperature of the exhaust gases was 100 to 150 exp 0 C lower than the gas temperature in the gas-outlet boreholes of gas generators of the Moscow Podzemgaz Station with ordinary flow supply. The exhaust gas temperature during directed flow supply decreases mainly for two reasons: first, as a result of more complete occurrence of the reduction reactions; and second, on a comparatively short section en route to the gas outlet, the gas formed yields part of its physical heat to heating of the country rock around the coal seam, and to drying the coal in the crosslinking channel. This in turn creates favorable conditions for reduction reactions in the gasification channel, given chance disruptions of the gasification process on the concave contour. In contrast to the previous experiment, where significant subsidence of the coal seam roof occurred during coal gasification according to survey data, there was no shifting of the earth's surface either during this experiment or for a long time afterwards. By comparing the results of the experiments on elongated channels, it is not difficult to satisfy oneself that practically equivalent process indices were obtained with different behavior of the coal seam roof. Consequently, experimental work with a directed flow supply in the coal seam plane has confirmed the feasibility of controlling the gasification process by aerodynamic means and, to a significant degree, independently of the behavior of the coal seam roof. (ERA citation 05:026797)