Fractional utilization of coal by prior separation and precise usage: A new concept

The current utilization of coal,an important energy source,is still limited to combustion,gasification,coking, and liquefaction,which are technologies used hundreds or even thousands of years ago. Considering the technology used in petroleum industry,i. e. ,oil fractional separation followed by fraction upgrading,the authors proposed a new approach for coal utilization:prior separation followed by precise usage of the separated fractions. By using a home- made extraction and back-extraction method,the coal was separated into four fractions:heavy component (HC),dense medium component (DMC),loose medium component (LMC),and light component (LC). The as-acquired four frac- tions were characterized in detail to identify the most suitable strategies for their usage and thereby to achieve the effective utilization of the coal resource. As guided by this new concept,based on the theory of coal embedded structure model and the new coking mechanism of coking-coal,the paper summarized the recent results of our research group on coal fractional utilization. The potential use of the above-mentioned fractions was discussed,including but not limited to foam carbon and porous electrode prepared by LMC,mesophase semi-coke prepared by DMC,separation membrane prepared by DMC,and new method of coal blending for coking. A truly ordered separation of coal organic matter was a- chieved for the first time. The separated group components showed significantly different properties and were identified to be the source materials responsible for coal nature,e. g. ,the DMC was the source material of mesophase and re- sponsible for the fluidity nature of coal,the LMC was responsible for the coal swelling nature. The individual conver- sion of these source materials realized the high-efficient utilization of the coal energy. The obtained products exhibited outstanding performance and the conversion method is simple and robust. The proposal of “prior separation followed by precise usage” is feasible and promising.