Deep desulfurization method for catalytically cracked gasoline

Abstract

The invention provides a gasoline fraction solvent extraction desulfurization method comprising the steps of enabling a gasoline fraction to enter from the lower middle part of an extraction tower, enabling a solvent to enter from the top of the extraction tower, filling saturated C5 into a reflux device at the bottom of the extraction tower, controlling the temperature of the top of the extraction tower at 55-100 DEG C, the temperature of the bottom of the extraction tower at 40-80 DEG C, the pressure of the top of the extraction tower at 0.2-0.7MPa, the solvent to gasoline fraction ratio at 1.0-5.0 and the saturated C5 to gasoline fraction feeding ratio at 0.1-0.5, ejecting the extracted and desulfurized gasoline fraction out of the extraction tower, and washing to obtain a desulfurized gasoline fraction; discharging the solvent from the bottom of the extraction tower, separating a C5-contained light component, a sulfur-rich component, water and the solvent, returning the light component to the reflux device of the extraction tower, returning the water to the washing step, and returning the solvent to the top of the extraction tower, wherein sulfides, aromatic hydrocarbons and the C5 are extracted by the solvent. The invention also provides a deep desulfurization method for catalytically cracked gasoline. The solvent extraction desulfurization method is flexibly combined with the traditional desulfurization technology used by an enterprise, so that the deep desulfurization is realized, and meanwhile, the octane value loss of the gasoline fraction is remarkably reduced.

Description

technical field [0001] The invention relates to a gasoline desulfurization method, in particular to a method for catalytic cracking gasoline deep desulfurization. Background technique [0002] Facing the situation of increasing smog, the government has accelerated the pace of upgrading the quality of gasoline and diesel. In 2014, the National IV emission standard for oil products will be implemented nationwide, requiring the sulfur content of gasoline to be reduced to below 50ppm; at the same time, the National V quality The standard requires reducing the sulfur content to below 10ppm, and it was first implemented in Beijing, Shanghai, and Guangzhou in 2013. FCC gasoline accounts for about 70-80% of gasoline product components in my country. The main task of gasoline sulfur reduction is actually FCC gasoline sulfur reduction. [0003] Existing catalytic cracking gasoline sulfur reduction technologies are mainly represented by Sinopec S-zorb, Academy of Petroleum Sciences RS...

AI Technical Summary

Problems solved by technology

Prime-G+ was developed by Axens company in France. It adopts the technological process of pre-hydrogenation of whole fractions, segmentation of light and heavy gasoline, and selective hydrodesulfurization of heavy fractions. It acts to form high-boiling sulfides, olefins are not saturated, and then cut light and heavy gasoline to obtain light fractions with a sulfur content of less than 10ppm and high-sulfur heavy fractions, and the heavy fractions go to hydrodesulfurization; this technology is the same as RSDS, although some low-sulfur light Components can not be hydrotreated, but because the output of light components less than 10ppm is very small, most of them need to be hydrotreated, resulting in the loss of octane number of whole distillate gasoline between 3.0 and 4.0

[0004] To sum up, the existing technologies for reducing the sulfur content of FCC gasoline generally have the problems of large proportion of hydrotreating and large loss of octane number when meeting the requirements of deep desulfurization

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