Selective hydrodesulfurization method for high-sulfur high-olefin catalytic gasoline

Abstract

The invention relates to a clean production method for high-sulfur high-olefin catalytic gasoline, which comprises the following steps of: performing selective hydrogenation on full fraction catalytically cracked gasoline in the presence of a gasoline hydrogenation pretreatment catalyst to remove active sulfide such as micro-molecular mercaptan, thioether, disulfide and the like, wherein the process conditions of the selective hydrogenation are that: hydrogen partial pressure is 1.5 to 3.0MPa, the reaction temperature is between 200 and 260 DEG C, liquid hourly space velocity is 6.0 to 12.5h<-1>, and the volume ratio of hydrogen to the gasoline is 150:1-500:1; performing fractionation segmentation on the gasoline subjected to the selective hydrogenation to form a light gasoline fraction and a heavy gasoline fraction, mixing the heavy gasoline fraction and the hydrogen, adding into a deep hydrodesulfurization unit and performing hydrofining in the presence of a gasoline hydrofining catalyst to obtain heavy fraction hydrogenated gasoline with low sulfur content, wherein the process conditions of the hydrofining are that: the hydrogen partial pressure is 1.5 to 2.5MPa, the reaction temperature is between 220 and 350 DEG C, the liquid hourly space velocity is 3.0 to 6.0h<-1>, and the volume ratio of the hydrogen to the gasoline is 200:1-500:1; and blending light fraction gasoline with the heavy fraction hydrogenated gasoline to obtain China IV clean gasoline.

Description

technical field [0001] The invention relates to a method for deep desulfurization of catalytic cracking gasoline to produce clean 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 fuels in order to reduce environmental pollution caused by the emission of harmful substances. On July 1, 2007, the National III standard was officially implemented nationwide. However, until December 31, 2009, clean gasoline that meets the National III standard will be available nationwide. Although the National IV (sulfur content less than 50μg / g) standard is used in some cities, the existing gasoline production costs are too high, which is difficult for petrochemical companies and the market to accept. The backwardness of clean gasoline production technology has become a major obstacle to the upgrading of gasoline standards and market demand. Therefore, it ...

AI Technical Summary

Problems solved by technology

However, due to the limited desulfurization effect of the deodorization unit, it has poor adaptability to local refineries with high sulfur content

[0010] In the prior art, the production of low-sulfur clean gasoline from FCC gasoline with high sulfur and high olefin content is difficult to solve in the following aspects: the contradiction between deep desulfurization and excessive loss of octane number, the generation of mercaptan during desulfurization contradiction

It makes it impossible for the existing technology to obtain clean gasoline with low sulfur content, low octane loss and qualified mercaptan under relatively mild conditions

In addition, the existing technology has problems such as single operation of the fractionation unit and poor adaptability of raw materials.

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