Lubo Zhou - Fox River Grove IL
208208R, 208209, 208211, 208212, 208213, 208218, 208226, 208227, 208228, 208230
A process for desulfurizing a gasoline stream while continuing to maintain the octane rating of the blend stock. A gasoline stream containing sulfur compounds and olefins is introduced into a fractionation zone to produce a low boiling fraction containing mercaptan sulfur compounds and olefins, a mid boiling fraction containing thiophene and olefins, and a high boiling fraction containing sulfur compounds. The low boiling fraction containing mercaptan sulfur compounds is contacted with an aqueous alkaline solution to selectively remove mercaptan sulfur compounds. The mid boiling fraction containing thiophene is extracted to produce a raffinate stream containing olefins and having a reduced sulfur content relative to the mid boiling fraction and a hydrocarbonaceous stream rich in thiophene. The resulting hydrocarbonaceous stream rich in thiophene and the higher boiling fraction containing sulfur compounds is reacted in a hydrodesulfurization reaction zone to produce a hydrocarbonaceous stream having a reduced sulfur concentration.