以水为溶剂褐煤超临界萃取研究

在半连续实验装置上，以水为溶剂对大雁褐煤进行了超临界萃取实验。考察了压力、终温对萃取过程产率及产品组成的影响。结果表明，用水萃取褐煤在合适条件下，可得到高的转化率及萃取物产率；萃取压力增加，转化率和萃取物产率增加；萃取终温增加，转化率增加，但增加量主要为气体和轻油组分。在超临界条件下，萃取物主要馏分为予沥青烯。萃取过程中气体产率约为２０％，其主要组分为ＣＯ２；经萃取后的褐煤（约占原煤５０％），具有比原煤高的碳含量，低挥发分及氧含量，几乎不含水，可作为气化或燃烧的原料。

Investigation of supercritical extraction of lignite with water

In a semi-continuous apparatus, Dayan lignite is extracted with water under sub-and supercritical states. The experiments are carried out to investigate effects of the pressure and the final temperature on the extraction yields, and product components. The results indicate that high conversion and extract yield can be obtained by supercritical water extraction of lignite on appropriate conditions. With the increase of the pressure the conversion and the extract yield increase; With the increase of the final temperature the conversion also increases, but the increment is mainly gas and light oil. The main fraction in extract is preasphaltene, and the main gas component is CO2. The extraction residue is a good feedstock for gasification or combustion.