METHOD OF DESULFURIZING GASOLINE Russian patent published in 2017 - IPC C10G25/05 C10G45/02 C10G61/06 

FIELD: chemistry.

SUBSTANCE: method includes the following steps: a) conducting the demercaptization step by adding, at least, a portion of mercaptans to olefins by contacting the gasoline with, at least, the first catalyst at a temperature of 50 to 250°C, a pressure of 0.4 to 5 MPa and a liquid space velocity (LHSV) of 0.5 to 10 h^-1, wherein the first catalyst is sulphide and contains the first carrier, at least, one metal selected from group VIII, and, at least, one metal selected from group VIb of the Periodic Table of the Elements, wherein the first catalyst has the following characteristics: a carrier consisting of gamma-modification of aluminium oxide with a specific surface area of 180 to 270 m²/g, the metal content of group VIb expressed as oxide is from 4 to 20 wt % with respect to the total weight of the catalyst, the metal content of group VIII expressed as oxide is from 3 to 15 wt % with respect to the total weight of the catalyst, the molar metal ratio of Group VIII to the metal of group VIb is 0.6 to 3 mol/mol; b) fractioning the gasoline leaving step a) is carried out in the distillation column to, at least, the first intermediate light gasoline fraction with a total sulfur content that is lower than that of the original gasoline and the second intermediate heavy gasoline fraction containing most of the starting sulfur-containing compounds; c) introducing a hydrogen stream and, at least, the second intermediate heavy gasoline fraction leaving step b) to the catalytic distillation column (14) comprising, at least, one reaction zone (15), containing, at least, one second catalyst in sulfide containing the second medium, at least one metal of group VIII, and one metal of group VIb, with the metal content of group VIII expressed in the form of oxide, constituting from 0.5 to 25 wt % with respect to the weight of the catalyst, and the metal content of group VIb expressed in the form of oxide comprising from 1.5 to 60 wt % with respect to the weight of the catalyst, wherein the conditions in the catalytic distillation column are selected so that in the presence of hydrogen the intermediate heavy gasoline to be brought in contact, leaving step b), with the second catalyst for the breakdown of sulfur-containing compounds to H₂S, wherein the bringing into contact with the second catalyst is carried out under a pressure of 0.1 to 4 MPa and at a temperature of 210 up to 350°C; d) at least, one end light gasoline fraction containing H₂S and the desulfurized heavy gasoline fraction are removed from the catalytic distillation column, wherein the light end gasoline fraction is withdrawn at a point located above the reaction area, and the desulfurized heavy gasoline fraction is withdrawn at a point located below the reaction zone.

EFFECT: increasing the degree of purification.

14 cl, 4 dwg, 4 tbl, 1 ex