Numerical modelling of underground coal gasification and itsapplication to Australian coal seam conditions

摘要

In the last 5 years there has been an increasing interest in the Australian energy and miningindustry for the development of new operating underground coal gasification (UCG) systems togenerate synthetic gas from coal seams underground. A pilot burn in a shallow coal seam insouthern Queensland has been operating since early 2000. In Australia the UCG gas will beinitially used as a competitive fuel for power generation followed by use as a feedstock for thepetro-chemical industry. In line with these renewed UCG activities, CSIRO Energy Technologyand the University of NSW have undertaken to develop a numerical model of the UCG processaimed at simulating the physico-chemical processes together with cavity growth and, ultimately,strata collapse.In this paper a CFD based model capable of representing the UCG as a channel gasifier ispresented. The model includes coupling of the heat and mass transfer and chemical reactionsoccuring at the boundary of the cavity. The performance characteristics of underground coalgasification in the channel mode is examined with reference to a previous field trial.In light of the simulation results and experiences from previous field trials, the potentialperformance of UCG in Australian coal seam conditions is discussed.