Review of Underground Coal Gasification Technologies

In the wake of increasing challenges of high prices of oil and gas and uncertainties about political stability in many oil and gas producing countries, coal becomes more and more important in the coming years for its vast reserves and wide distribution all over the world. The technology of Underground Coal Gasification (UCG), converting in-situ, unmined coal into combustible gases, has continued to attract worldwide interest because of its ability to exploit coal which is otherwise unminable by conventional mining techniques due to deep deposit depths, thin seam thickness or low quality, in an economical, safe and environmentally friendly manner. We have recently reviewed the current status of UCG throughout the world and analyzed the criteria for selecting UCG in the Red River Delta (RRD)-Viet Nam. This article presents the main results of this work.