Deep desulfurization method for gasoline

Abstract

The present invention relates to a deep desulfurization method for a gasoline. According to the method, a gasoline raw material and hydrogen are mixed, and then enter a pre-hydrogenation reactor to carry out hydrogenation on diene in catalytic gasoline to obtain mono olefin; the pre-hydrogenation product enters a water washing tower to carry out water washing, partial alkaline nitrides in the gasoline is removed, the obtained material enters a catalytic distillation tower, partial thiophene sulfides in the gasoline is subjected to weight gain under an effect of an olefin thiophene alkylation catalyst on the upper portion of the catalytic distillation tower, and concurrently the gasoline is divided into three components such as light gasoline, heavy gasoline and light diesel oil; the heavy gasoline component enters a selective hydrodesulfurization reactor to carry out deep desulfurization, hydrogen sulfide generated during the reaction is removed from the desulfurization product, and the hydrogen sulfide-removed desulfurization product is mixed with the light gasoline to obtain the deep desulfurization gasoline product; and light diesel oil on the bottom of the tower is adopted as a hydrodesulfurization raw material, or is adopted as low freezing point diesel oil blending component to be subjected to blending producing. With the method, sulfur content in gasoline can be substantially reduced, and octane number loss caused by the deep desulfurization process can be reduced.

Description

technical field [0001] The invention relates to a method for deep desulfurization of gasoline, in particular to a method for deep desulfurization of secondary processed gasoline such as catalytic cracking gasoline. Background technique [0002] In recent years, in order to protect the environment, countries around the world have put forward stricter restrictions on the composition of engine fuel in order to reduce the emission of harmful substances. Beijing implemented the Beijing local standard DB11 / 238-2007 for motor gasoline on January 1, 2008. The standard stipulates that the sulfur content of motor gasoline should not exceed 0.005% (m / m), and the olefin content should not exceed 30%. It is expected that Beijing will implement the National V standard in 2012, stipulating that the sulfur content of motor gasoline shall not exceed 0.001% (m / m), and the olefin content shall not exceed 25%. The proportion of FCC gasoline in my country's motor gasoline accounts for more than...

AI Technical Summary

Problems solved by technology

[0005] With the continuous improvement of gasoline standards, the low yield of light gasoline will be further reduced, resulting in an increase in the amount of heavy gasoline entering the hydrogenation unit, an increase in the olefin content in heavy gasoline, and an increase in the octane number brought about by hydrodesulfurization. Increased losses, making it less necessary to reduce octane losses in the hydrodesulfurization process through light and heavy fractionation operations

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