PROCESS OF DEASPHALTING TAR Russian patent published in 1996 - IPC

FIELD: petroleum products. SUBSTANCE: two-step process of deasphalting tar is performed by way of selective extraction of tar with propane. First-step extraction is conducted at 78-82 C to obtain 1st-step deasphalted product solution and 1st-step asphalt solution. The latter is diluted with further propane taken in amount of 25-60% based on total propane fed into 2nd step of extraction. Resulting solution is heated to 78-82 C and vigorously agitated at Reynolds number 12000-50000 for 3-7 sec followed by 2nd-step extraction at the same temperature as in the 1st step. First and second-step deasphalted product solutions and asphalt solutions are finally evaporated to expel the solvent. As a result, up to 55% of deasphalted product suitable to produce motor oils is obtained. EFFECT: increased resources for motor oils. 3 tbl