Method for deeply desulfurizing sulfur-containing raw material

Abstract

The invention relates to the field of refining of hydrocarbon materials, and discloses a method for deeply desulfurizing a sulfur-containing raw material. The method is characterized in that solvent extraction of the sulfur-containing raw material and an extracting solvent is carried out through distillation to obtain a sulfur-containing solvent and a desulfurized product, wherein the extracting solvent contains a main extracting solvent and an assistant, the assistant is at least one substance of alcohols, ketones, organic acids and organic nitrides being intermiscible with the main extracting solvent and having a boiling point or a dry point being not more than the boiling point or the dry point of the main extracting solvent and / or water, and the organic nitrides are at least one of amines, carbamides and hydramines. The method can deeply remove sulfides from the sulfur-containing raw material, such as gasoline even under a hydrogen source-free or hydrogen source-deficient condition, and achieves basic no loss of the octane number.

Description

technical field [0001] The invention relates to the field of refining hydrocarbon materials, in particular to a method for deep desulfurization of sulfur-containing raw materials. Background technique [0002] As we all know, the emission of toxic and harmful substances in automobile exhaust seriously affects the air quality. For this reason, countries all over the world have set stricter and stricter standards for the quality of oil used as engine fuel. From January 1, 2013, my country has implemented No. IV emission standards nationwide, and has implemented No. V emission standards in Beijing, Shanghai and other major cities. No. Ⅳ and No. Ⅴ emission standards respectively stipulate that the sulfur content in motor gasoline shall not exceed 50 μg / g and 10 μg / g. [0003] The sulfur in gasoline mainly comes from catalytic cracking gasoline. With the development of heavy oil processing raw materials, the sulfur content of catalytic cracking gasoline will further increase. T...

AI Technical Summary

Problems solved by technology

However, during liquid-liquid extraction, it is difficult to effectively separate the organic solvent from the extracted gasoline, and they are often entrained with each other. The extracted gasoline usually needs further follow-up treatment, such as washing with water, while the solvent absorbs sulfides. At the same time, the entrainment of more gasoline hydrocarbons is not conducive to the maintenance of octane number, nor to the subsequent solvent recovery and regeneration, thus reducing the ability of the solvent to continue to extract sulfides

[0012] During the recycling process of organic solvents, more polymers, sediments, stable salts, etc. are formed due to the dissolution of more hydrocarbon materials and the pyrolysis or oxidation of solvents, resulting in a decrease in the purity of the solvent (compared with fresh solvents ), the desulfurization efficiency drops rapidly, so the amount and frequency of solvent regeneration have to be increased

In particular, conventional solvent regeneration methods mostly use simple flash evaporation, and some soluble hydrocarbon materials are easy to accumulate in the regenerated solvent (flash evaporation only removes residues with a boiling point higher than that of the solvent, for solvents with a boiling point lower than or close to the solvent The residual hydrocarbon material cannot be removed), so it is bound to be detrimental to the desulfurization effect when the solvent is recycled

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