A number of vacuum residua (VR)in China and abroad were separated by using supercritical fluid extraction and fractionation technology (SFEF).It is showed that the properties of the obtained narrow cuts depend on the solvent solubility

by which the asphaltene and metals are enriched in the unextractable endcuts and thus the properties of extract cuts greatly improved.A new process of heavy oil deep stage separation is put forward based on the discovery.Research on deep stage separation of Dagang VR and Liaohe VR was carried out on 1 kg·h-1 and 10 kg·h-1 capacity unit with n-pentane as solvent.Effects of solvent to feed ratio S/O

temperature and pressure on the yield and the properties of the deasphated oil (DAO)were investigated and the optimized process parameters were determined as following: extraction temperature within 160—170 ℃

pressure 4.0—5.0 MPa and S/O (mass ratio)4.0—4.5.The appropriate supercritical solvent recovery conditions were determined in range of temperature of 200—220℃ and pressure 4.0—4.5 MPa.The novel aspect is that deoiled asphalt (DOA)are discharged as fine particles by coupling the supercritical extraction and spraying granulation.The fluidization properties of the DOA powders were measured also for transportation purpose.The results provide the basis for industrial scale-up of the heavy oil deep stage separation.