DEAROMATIC PURIFICATION METHOD OF HYDROCARBON OIL

PROBLEM TO BE SOLVED: To provide a dearomatic purification method of a hydrocarbon oil, especially a heavy hydrocarbon oil such as LCO (Light Cycle Oil) including separating and collecting a polycyclic aromatic hydrocarbon, and a dearomatic purification method including separating an aromatic hydrocarbon into a monocyclic aromatic hydrocarbon and a polycyclic aromatic hydrocarbon and collecting the resultant. SOLUTION: The dearomatic purification method of a hydrocarbon oil includes a step (c') wherein a hydrocarbon oil is brought into contact with an ionic liquid B to separate into two phases, and a step (d') wherein a phase containing a concentrated fraction of a monocyclic aromatic hydrocarbon is removed from the phase without containing the ionic liquid B of the two phases obtained in the step (c'), wherein the ionic liquid B is that including a particular imidazolium cation and one or two or more anions selected from bis(trifluoromethylsulfonyl)imide and the like. COPYRIGHT: (C)2011,JPO&INPIT