Patent ID: 8574427

Claim:
A process for removing a refractory nitrogen compound from a vacuum gas oil comprising: (a) hydroprocessing the vacuum gas oil; (b) contacting the vacuum gas oil comprising the refractory 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; and (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 refractory nitrogen compound; wherein said refractory nitrogen compound comprises at least one compound selected from the group consisting of indoles and naphthenic indoles, quinolines and naphthenic quinolines, carbazoles and naphthenic carbazoles, acridines and naphthenic acridines, benzocarbazole and naphthenic benzocarbazoles, benzacridines and naphthenic benzacridines, and dibenzocarbazoles and naphthenic dibenzocarbazoles; wherein the VGO-immiscible phosphonium ionic liquid comprises at least one ionic liquid selected from the group consisting of tetraalkylphosphonium dialkylphosphates, tetraalkylphosphonium dialkyl phosphinates, tetraalkylphosphonium phosphates, tetraalkylphosphonium tosylates, tetraalkylphosphonium sulfates, tetraalkylphosphonium sulfonates, tetraalkylphosphonium carbonates, tetraalkylphosphonium metalates, oxometalates, tetraalkylphosphonium mixed metalates, tetraalkylphosphonium polyoxometalates, tetraalkylphosphonium halides, trihexyl(tetradecyl)phosphonium chloride, trihexyl(tetradecyl)phosphonium bromide, tributyl(methyl)phosphonium bromide, tributyl(methyl)phosphonium chloride, tributyl(hexyl)phosphonium bromide, tributyl(hexyl)phosphonium chloride, tributyl(octyl)phosphonium bromide, tributyl(octyl)phosphonium chloride, tributyl(decyl)phosphonium bromide, tributyl(decyl)phosphonium chloride, tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, triisobutyl(methyl)phosphonium tosylate, tributyl(methyl)phosphonium methylsulfate, tributyl(ethyl)phosphonium diethylphosphate, and tetrabutylphosphonium methanesulfonate; wherein the refractory nitrogen compound content of the vacuum gas oil is reduced by at least 10 wt %.