Combined multi-stage process of partial solvent de-asphalting and delayed coking of a charge by thermal cracking in the absence of hydrogen with fractionation of oil and vapour from the coking unit

摘要

Process for the production of de-asphalted oils(DAO) and obtaining of a high quality coke in a delayed coking process. The process is effected in the following stages :- 1) A pre-heated charge and extraction solvent are mixed in an extractor and a solution of de-oiled asphalt withdrawn form the lower part of the unit ; the de-asphalted oil from the upper part represents 70 - 95% of the charge after recovery of the solvent ; 2) Part or all of the DAO and recycled oil, optionally with an additional coking charge, then passes through the convection and radiation sections of the furnace of a delayed coking unit and finally through a barrel section to undergo the coking reaction.Oil and vapour from this section is then fractionated and separated into gas, petrol, diesel and gasoil, with coke remaining in the barrel.