| 摘要 |
<p>1495722 Extraction of oils from shale and tar sand COAL INDUSTRY (PATENTS) Ltd 8 July 1975 [25 July 1974] 32892/74 Heading C5E Oil shale or tar sand is heated in the presence of an extractant component above its critical temperature and within the range 80‹ to 550‹ C., the extracted constituents and the extractant are separated from the residue and the extract is recovered from the extractant; during the extraction the extractant has a pressure not less than the critical pressure of the component and the extractant is above its critical temperature by not more than 200‹ C. The extraction can be carried out at an extractant to shale or sand weight ratio between 1 and 30 and a pressure of 500-10,000 p.s.i., e.g. in a fluidized bed or a series of fluidized beds. Many suitable extractants are listed, the extractants used in examples are toluene, pentane, methyl cyclohexane, pyridine and tetrahydrofuran; the extractant can comprise a mixture of compounds.</p> |
