The Analytical Modeling of Underground Coal Gasification through the Application of a Channel Method

Underground coal gasification is a process of recovery of the energy of coal through partial combustion and gasification of coal by means of injected oxidant; and, the produced syngas is collected for processing for a variety of end uses. In this work, an analytical model of underground coal gasification is developed by applying a channel method on one-dimensional coal seams and assuming four reactions with constant reaction rates. The process is assumed to be steady-state, so that a closed-form solution can be obtained. The model can be used to perform sensitivity analyses of operating parameters, such as the steam/oxygen ratio, the rate of oxidant injection, and the length of channel on the composition of the species in the syngas, so that the findings can be applied to numerical simulations.