Clean coal technologies for sustainable coal exploitation and mining innovation

Considering intensifying global environmental imperatives, global coal usage is projected to decline due to its detrimental ecological consequences. Consequently, coal-reliant sectors are increasingly adopting Clean Coal Technologies (CCTs) as a transitional strategy. Conventional CCTs primarily address coal processing and combustion predominantly within power generation yet frequently neglect the substantial environmental burdens associated with extraction. In contrast, unconventional coal exploitation methods, including Coal Bed Methane (CBM) and Underground Coal Gasification (UCG), represent a transformative approach by facilitating in-situ resource utilization, thereby obviating the need for disruptive surface mining and processing. These techniques significantly reduce emissions and surface-level environmental degradation by avoiding coal excavation altogether. This study introduces the concept of “Unconventional CCT” to integrate these in-situ innovations with established CCT frameworks. It critically evaluates the current stage of commercialization, experimental research advancements, and identifies persistent knowledge gaps requiring targeted investigation. Notably, the Underground Gasification Combined Cycle (UGCC), when coupled with Carbon capture and storage (CCS), emerges as a technically and economically promising configuration. Furthermore, the injection of CO2-enriched gases enhances methane recovery from CBM reservoirs, while Microbially Enhanced CBM (MECoM) holds substantial potential, contingent upon future technological breakthroughs. Collectively, these unconventional CCT pathways offer compelling prospects for long-term climate stabilization.