Study Of Microwave-assisted CS₂-NMP Extraction Of Yilan Oil Shale

Oil shale was an important potential energy sources with enormous reserves and its reserves in fossil fuel was in the second place just inferior to coal when converted into the quantity of heat. The reserves of oil shale in the world was up to 475 billion ton when converted into shale oil and 5.4 times equivalent to the natural oil which proven to be recoverable reserves. And thus the development of a clean and efficient processing technology of oil shale has become an important topic. Years of researches show that the solvent extraction was an important way to gain the organic matter from the oil shale.In this paper the methods of solvent extraction with microwave assistant were conducted with the oil shale in area of Yilan in Heilongjiang province. First of all, in some condition of microwave the best extraction solvent CS2-NMP was determined through the single-factor extraction experiment. Factors are selected to mineral granularity, solvent volume, extraction time and microwave power under extraction solvent CS2-NMP through the orthogonal experiment with four factors and four levels, the optimum conditions of microwave solvent extraction of oil shale are: mineral granularity is 0.094～0.119mm, solvent volume is 55ml, extraction time is 15min, microwave power is 600W, and significant factors are mineral granularity, solvent volume and microwave power, the extraction rate could be up to 10.9%, it was higher nearly 2 percentage point than mild conditions. The analysis of Fourier transform infrared spectroscopy showed that the small molecular substances was mainly effected by the solvent under the conditions of microwave-assisted extraction, the aliphatic hydrocarbons and the material containing oxygen functional groups in extraction residue were increased while that in extracts were increased simultaneously, these have a similar variation tendency of mild conditions, but the peak increase in absorption intensity. The analysis of GC/MS showed that the mixed solvent CS2-NMP had better extraction capacity, and its extracts were mainly the aliphatic hydrocarbons and the heteroatom compounds with oxygen, sulfur, silicon, halogens and a small amount of aromatic compounds, and meanwhile the content of aliphatic hydrocarbons were dominated, detection material of the extract much more than mild conditions in quantitative terms.