Pilot plant study on continuous propane deresining of atmospheric crude cylinder stock

Abstract

With the market transition from API Group I to Group II and Group III lubricating base stocks and decline in the Group I supply, highly valuable grades of Group I solvent-refined bright stocks are gaining more attention today. Continuous improvement in the bright stock production is crucial for refineries to accelerate the gain from the volatile Group I base oil market. To develop a pathway for improving the production of bright stock in the refinery, the continuous propane deresining pilot plant study was conducted on the atmospheric crude cylinder stock for propane deresined cylinder stock production. The propane deresined oil is referred to as D-stock, which is the feedstock for MEK dewaxing downstream for bright stock production in the refinery. Different propane solvent to oil (vol./vol.) conditions were studied at Intertek PARC’s continuous solvent deasphalting unit with varying column top and bottom temperatures at a fixed column pressure. A significant improvement in the D-Stock yield was observed without compromising the D-Stock viscosity specification. The Intertek PARC deresining tower with staggered half-moon baffle internals enhanced separation of the D-stock from the resin component. The real-time operational data and analytical measurements were presented for propane dosages. The detailed characterization of Intertek PARC D-stock and resin was studied at 10.5/1 and 8/1 solvent to oil ratios.