Ionic liquid desulfurization process incorporated in a low pressure separator

摘要

Initial high sulfur levels of a hydrocarbon feedstock are reduced to desired low levels without the need for integration of substantial new equipment or hardware with existing hydroprocessing reactors. Ionic liquids are utilized as organic sulfur extraction agents and are added to and mixed with the hydrocarbon feedstock containing organosulfur compounds in, or upstream of, an existing cold separator vessel. The ionic liquid and hydrocarbon mixture is maintained in contact under conditions which promote the formation of ionic sulfur-containing derivatives that are soluble in the ionic liquid to be formed, thereby enabling extractive removal and separation of the organosulfur compounds from the feedstock.

主权项

1. A process to reduce the sulfur and nitrogen content of a hydrocarbon oil feedstock containing organosulfur compounds and organonitrogen compounds, the process comprising:
a. introducing the hydrocarbon oil feedstock and hydrogen gas to a catalytic reactor; b. conveying a catalytic reactor effluent stream to a high pressure separator to separate a hydrogen stream and a mixed high pressure separator effluent, the mixed high pressure separator effluent including hydrogen sulfide, ammonia, and a hydroprocessed hydrocarbon mixture having a reduced organosulfur compound content and a reduced organonitrogen compound content; c. contacting the mixed high pressure separator effluent with water; d. contacting the mixed high pressure separator effluent with ionic liquid; e. conveying the mixed high pressure separator effluent containing water and ionic liquid to a low pressure separator, wherein the ionic liquid and the hydroprocessed hydrocarbon mixture are retained in contact for a time sufficient for extractive removal of organosulfur compounds to produce hydrocarbons and ionic sulfur-containing derivatives soluble in the ionic liquid, and for extractive removal of organonitrogen compounds to produce hydrocarbons and ionic nitrogen-containing derivatives soluble in the ionic liquid; f. removing water from the low pressure separator; g. purging hydrogen sulfide and ammonia from the low pressure separator; h. conveying a low pressure separator effluent to a fractionator, the low pressure separator effluent including ionic liquid, ionic sulfur-containing derivatives, ionic nitrogen-containing derivatives, and an ionic liquid treated hydrocarbon mixture having a further reduced organosulfur compound content due to extractive removal and a further reduced organonitrogen compound content due to extractive removal; i. removing ionic liquid, ionic sulfur-containing derivatives and ionic nitrogen-containing derivatives from the fractionator; and j. recovering the ionic liquid treated hydrocarbon mixture from the fractionator.