METHOD FOR PRODUCING FEEDSTOCKS OF HIGH QUALITY LUBE BASE OIL WITH HIGH VISCOSITY INDEX AND LOW VOLATILITY

摘要

Lube oil feedstock is produced from atmospheric residue by: (1) vacuum distillation to give vacuum gas oil (VGO); (2) hydrotreating VGO to purify it; (3) hydrocracking purified VGO to produce light hydrocarbons; (4) fractionation to separate light hydrocarbons from unconverted oil (UCO); (5) vacuum distillation of UCO to produce feedstock; and (6) recycling UCO to hydrocracker. Also claimed is a related process in which only part of UCO is vacuum distilled and remainder is recycled to the hydrocracker.