Process for removing sulfur compounds from vacuum gas oil

A process for removing nitrogen compounds and sulfur compounds from a vacuum gas oil comprising:

• (a) contacting the vacuum gas oil comprising the nitrogen and sulfur compounds, with a vacuum gas liquid-immiscible phosphonium ionic liquid to produce a mixture comprising the vacuum gas oil and the vacuum gas liquid-immiscible phosphonium ionic liquid to remove said nitrogen compounds;
• (b) then contacting said vacuum gas oil with a vacuum gas oil-immiscible phosphonium ionic liquid to produce a mixture comprising the vacuum gas oil and the vacuum gas liquid-immiscible phosphonium ionic liquid to remove said sulfur compounds;
• and
• (c) separating the mixture to produce a vacuum gas oil effluent and a vacuum gas oil-immiscible phosphonium ionic liquid effluent, the vacuum gas liquid-immiscible phosphonium ionic liquid effluent comprising the nitrogen and sulfur compounds wherein said vacuum gas oil first undergoes hydrotreating, then said vacuum gas oil is contacted with said vacuum gas oil-immiscible phosphonium ionic liquid and then said vacuum gas oil undergoes a second step of hydrotreating.

A process for removing a nitrogen compound and a sulfur compound from a vacuum gas oil comprising:

• (a) contacting the vacuum gas oil comprising the nitrogen compound with a VGO-immiscible phosphonium ionic liquid to produce a mixture comprising the vacuum gas oil, and the VGO-immiscible phosphonium ionic liquid to remove said nitrogen compound;
• (b) contacting the vacuum gas oil comprising the sulfur compound with a VGO-immiscible phosphonium ionic liquid to produce a mixture comprising the vacuum gas oil, and the VGO-immiscible phosphonium ionic liquid to remove the sulfur compound;
• (c) separating the mixture to produce a vacuum gas oil effluent and a VGO-immiscible phosphonium ionic liquid effluent, the VGO-immiscible phosphonium ionic liquid effluent comprising the nitrogen compound, the sulfur compound or mixtures thereof;
• (d) washing at least a portion of the vacuum gas oil effluent with water to produce a washed vacuum gas oil stream and a spent water stream;
• (e) contacting the VGO-immiscible phosphonium ionic liquid effluent with a regeneration solvent and separating the VGO-immiscible phosphonium ionic liquid effluent from the regeneration solvent to produce an extract stream comprising the nitrogen compound and a regenerated VGO-immiscible phosphonium ionic liquid stream;
• and
• (f) drying at least a portion of at least one of the VGO-immiscible phosphonium ionic liquid effluent the spent water stream, and the regenerated VGO-immiscible phosphonium ionic liquid stream to produce a dried VGO-immiscible phosphonium ionic liquid stream wherein said vacuum gas oil is contacted with said vacuum gas oil-immiscible phosphonium ionic liquid before said vacuum gas oil undergoes hydrotreating.