Development of an apparatus for the supercritical CO2 extraction of organic matter from coal based on CO2 sequestration in coal seams

In order to establish a technical foundation for the investigation of the effect of the soluble compounds of small molecular organic-matters in coal with Sc-CO2 on the CO2 sequestration,and the development of a method of Sc- CO2 extraction biomarker in coal at a mild condition,an experiment apparatus of coal extraction with Sc-CO2 was built based on the interaction between supercritical CO2(Sc-CO2 ) and the organic matter in coal in the fields of greenhouse gas CO2 sequestration into deep and unmineable coal seams. The apparatus could be employed in coal extraction with Sc-CO2 in both static and dynamic extraction modes under the controlled conditions based on the low content of extrac- ted matter in coal and easier penetration of coal dust into gas line. The paper describes in detail on the technique of CO2 pressure enhancement and coal dust control,the regulating method for extraction conditions,and the process of ex- tract collection and enrichment. The apparatus consists of CO2 pressure enhancement,coal extraction,collection and enrichment of extracts. The apparatus can be used to carry out the Sc-CO2 extraction of trace amounts of soluble organ- ic matters in coal at high pressure and under a controlled condition.