Technical Pathways and Integrated Development Trends of Clean and Efficient Utilization of Low−Rank Coal in China

With the progressive implementation of China's "dual carbon" strategy, Low−rank coal, as one of China's most abundant resources, has become a major focus in efforts to achieve clean and efficient utilization under the dual−carbon strategy. Due to its high moisture and volatile content, low calorific value, and structurally disordered nature. low−rank coal presents major challenges to conventional direct combustion often resulting in low energy efficiency and substantial environmental burdens. Consequently, Integrating multiple technological pathways and optimizing system configurations has become a key research focus. This paper provides a comprehensive review of recent advancements in clean and efficient utilization technologies for low−rank coal, both domestically and internationally. Beginning with an analysis of resource distribution and coal quality characteristics, the study explores how factors such as molecular structure, reactivity, and mineral composition influence the selection of conversion routes. Subsequently, the review examines the technical principles, core processes, and engineering applications of key pathways−including pretreatment and pyrolytic upgrading, gasification and liquefaction, clean combustion with thermal energy recovery, and carbon−based material valorization. A comparative assessment is carried out to evaluate the feedstock compatibility, product value, energy efficiency, and environmental performance of each pathway. Furthermore, this review summarizes the synergistic relationships and integration mechanisms across different pathways and proposes a pyrolysis−centered polygeneration strategy to construct an integrated system of heat, heat, power, carbon management, and materials production. Regional adaptation and configuration strategies are also proposed, based on coal quality and resource endowment. The findings indicate a transition from single−path utilization toward a system optimization paradigm characterized by multi−dimensional integration. Future development should focus on expanding high−value product pathways, building synergistic mechanisms among pyrolysis, material production, and carbon sequestration, introducing intelligent control and optimization methods, and advancing the standardization and modularization of system platforms. This study aims to provide a theoretical foundation and technical reference for the full−process, high−efficiency utilization of low−rank coal from resource extraction to value−oriented transformation.