In situ fluidized mining and conversion solution to alleviate geological damage and greenhouse gas emissions due to coal exploitation: A numerical analysis and evaluation

Abstract

Coal remains a primary energy source for the foreseeable future. However, existing approaches for coal exploitation and utilization are highly detrimental to the geological formations from which they are extracted and the atmospheric environment. Moreover, underground mining can induce earthquakes that lead to fatalities and financial losses. The demand to abandon coal mining is increasing worldwide, and the need for efficient, safe, and environmentally acceptable coal exploitation and utilization has garnered widespread attention. We propose a novel unmanned automatic machine-based mining and in situ conversion method for the safe and clean exploitation and utilization of subsurface coal resources. Solid coal is transformed in situ into fluidized energy resources using this method. To evaluate its effectiveness, a geological model of a coal mine was generated, and a numerical simulation based on the continuum-based discrete element method was conducted to compare the mining-induced stress distribution, roof subsidence, coal wall failure, and microseismicity for fluidized and traditional mining methods. Our results indicate that the proposed mining method can significantly reduce damage to the geological formation and greenhouse gas emissions associated with the exploitation and utilization of coal resources. We also discuss the limitations of the current study and future research possibilities.