Solvent deep deasphalting of Liaohe heavy oil vacuum residuum

Liaohe heavy oil vacuum residuum was separated into the light de-asphalted oil (LDAO), heavy de-asphalted oil (HDAO) and de-oiled asphalt (DOA) in a continuous de-asphalting device by deasphalting under supercritical conditions with pentane as solvent. The effects of pressure (4.0MPa～7.0MPa) and temperature (155℃～170℃) on the yield and properties of the de-asphalted oil were investigated. The Conradson carbon residue (CCR) and removal rates of N and Ni elements were correlated with that of supercritical fluid extraction fractions (SFEF). With the increase of pressure and the decrease of temperature, the total yield of deasphalted oil (DAO) is increased; meanwhile, the contents of CCR and elements like S, N, Ni and V in LDAO and HDAO are also increased. When the total yield of DAO is 74.23% (the yields of LDAO and HDAO are 57.68% and 16.55%, respectively), the removal rates of Ca, Ni, CCR, N and S are 92.75%, 74.50%, 62.13%, 40.17% and 24.10%, respectively; the removal rates for DAO correlate well with that for the SFEF fractions. The properties of DAO can be correlated with the extent of deasphalting and the properties of Liaohe heavy oil vacuum residuum feed.