ABSTRACT
The technological and environmental risk factors of underground coal gasification (UCG) can be mainly summarized as cavity collapse or roof subsidence, gas leakage, and groundwater contamination. The trends as well as advances in computational modeling for optimizing and for addressing concerns about adverse impacts on surroundings will help realize the true potential of UCG. This chapter summarizes the status of computational modeling and how it can be used for pushing the frontiers of UCG technology. Besides the environmental impact during the life of a UCG operation, an appropriate closure and end-of-life management of the cavity generated by UCG to prevent subsequent groundwater contamination is essential. UCG offers unique opportunities for harnessing coals of low rank/low calorific value and coals with high ash content. The chapter also presents some closing thoughts on the key concepts discussed in the preceding chapters of this book.
