A review：Geological feasibility and technological applicability of underground coal gasification

Underground coal gasification (UCG) is a potential new method of coal utilization, which is of great significance for alleviating China’s energy crisis, ensuring national energy security, and achieving carbon peaking and carbon neutrality goals. It has always been valued by countries all over the world. On the suitability of UCG resource conditions, the feasibility of process and technology, and the controllability of environmental impact, this paper summarizes the development status of UCG technology, and clarifies the coal resource reserves suitable for UCG technology, different standards of geological area selection and location selection technology, the development history and applicable conditions of the gasification process, engineering and environmental factors affecting the implementation of gasification. According to the analysis, UCG’s geological area selection technology is mainly the qualitative analysis of favorable areas under specific geological conditions, lacking quantitative index systems and methods, which is mainly for shallow and middle coal seams. And the evaluation system needs to be improved, especially for the development of areas with multiple coal seams and deep coal seams. The influence of environmental factors on the development of UCG industrialization is increasing, which will be one of the main directions of future research.