VACUUM GAS OIL PURIFICATION PROCESS ASSOCIATED WITH PRODUCTION OF CARBON BLACK MANUFACTURE FEEDSTOCK Russian patent published in 2004 - IPC

FIELD: petroleum processing. SUBSTANCE: invention aims at purifying vacuum gas oil to remove aromatic hydrocarbons, heteroatomic compounds, and heavy metal compounds thereby obtaining high- quality feedstock for hydrocracking and catalytic cracking. Simultaneously, aromatic concentrate with correlation index above 120, which is high-quality feedstock for carbon black manufacture, is obtained. Process is distinguished by performing purification as bimodal liquid extraction process utilizing polar and nonpolar solvents and subsequent azeotropic rectification of extract phase with solvent forming azeotrope mixtures with saturated hydrocarbons of extract phase. As polar solvent, N- methylpyrrolidone with 8-10% water and weight ratio to extraction feedstock (2-3): 1 is used and, as nonpolar solvent, n-heptane or dearomatized gasoline fraction at weight ratio to extraction feedstock (0.4-0.5): 1. Azeotrope- forming agent is ethylene glycol used at weight ratio to extraction feedstock (0.05-0.2):1. EFFECT: increased purification selectivity and enlarged resource of raw materials for manufacture of carbon black. 3 tbl, 2 ex