大雁褐煤超临界水萃取研究

STUDY ON THE SUPERCRITICAL EXTRACTION OF DAY AN LIGNITE

在间歇式高压釜中进行了大雁褐煤的超临界水萃取研究。考察了萃取温度、时间、溶剂量及供氢溶剂等参数对过程产率及产品组成的影响。结果表明,褐煤超临界水萃取过程的转化率及产率受多种因素的影响,得到的萃取物组成也随条件变化而改变,过程中产生的气体主要成分为CO_2。经水萃取后的褐煤具有比原煤低的水分、低氧含量、高碳含量及一定的挥发分,即质量得到了提高。

I■ a ■ch ■oc■ave apparatus, Dayan lignite was extracted by su■ercritic■l w■ter, The effects of extraction temperature, time,so■v■t m■, and H-dono■ solvent on conversion of lignite, extr■ct yield and p■uct compo■sitioa were investigt■d. The results indicated that with inerease of temp■at■e, the co■ersio■ increases, while the extract yield exists a maximum;longer extraction time,higher w■ter/lignite ratio,or higher tetralin content in water results in higher conversion, but long extraction time leads to low extract yield. The major component in extract is oil. Its content changes with change of the extraction conditions.Higher ■ure o■ longer e■ction time is benefit to forming oil.With adding tet■lin in water, the oil content decreases greatly. The main com■o■ent of the g■ formed during the extraction is CO_2. The extraction ■esidue, has less moisture, lower oxygen, higher carbo■,and hence higher quality, than those of raw lignite.