Method for reducing sulfur content in gasoline

Abstract

The invention discloses a method for reducing the sulfur content in gasoline which includes of cutting fraction oil containing sulfur gasoline into a light fraction and a heavy fraction; a hydrogenation refining method is adopted to desulfurize the heavy fraction gasoline; the method including the following steps is adopted to desulfurize the light fraction gasoline: a) in an extraction unit which takes an ion liquid as an extraction agent and under the extraction condition of the ion liquid, the light fraction gasoline is contacted with the ion liquid, then the light fraction gasoline with reduced sulfur content and the ion liquid rich in sulphocompounds are obtained through separation; b) in an extraction unit which takes water as an extraction agent, the ion liquid of the sulphocompounds obtained in step a is contacted with the water, then the sulphocompounds and the mixture of water and ion liquid are obtained through separation; c) the mixture of the water and the ion liquid are obtained through the separation step b of a distilling method and then a regenerated ion liquid is obtained; d) the heavy fraction gasoline desulfurized through the hydrogenation refining method is mixed with the light fraction gasoline the sulfur content of which is reduced, thus obtaining product oil.

Description

technical field [0001] The invention relates to a method for upgrading gasoline, in particular to a method for upgrading gasoline by reducing the sulfur content in gasoline. Background technique [0002] Due to its high octane number, FCC gasoline is an important component source of finished gasoline. However, because the olefin content and sulfur content in this gasoline are relatively high, generally 15-45% and 500-5000ppm respectively, it is difficult to meet the requirements of gasoline product standards. For example, in the referenced Euro II Motor Gasoline Technical Requirements 1, it is stipulated that the sulfur content is not more than 500ppm, the olefin content is not more than 30%, and the aromatic hydrocarbon content is not more than 40% (the benzene content in the aromatic hydrocarbon is not more than 2.5%); Euro III Motor gasoline technical requirement 2 stipulates: when the sulfur content is not more than 150ppm, the aromatics content is not more than 35%, th...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the alkylation product can only be separated from the gasoline fraction after distillation, and when the distillation method is used for separation, a large amount of gasoline products are distillates, and a small amount is composed of sulfur-containing compounds such as mercaptans and sulfides. And thiophene and olefins generated by the alkylation reaction are divided into bottoms, high energy consumption

The disadvantages are: (1) the raffinate needs to be eluted with alkali to remove sulfides and mercaptans to obtain ultra-low sulfur gasoline; (2) aromatics and thiophenes are extracted together, resulting in high-octane aromatics in the raffinate component loss

For the method of regenerating ionic liquids such as sulfur-containing compounds in ionic liquids with organic solvents, because in the recovery process of organic solvents, a large amount of organic solvents are usually separated from a small amount of extracts in the form of distillates, which can Problems such as high consumption and volatilization of organic solvents limit the industrial application of such methods

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