Method for modifying low-grade gasoline

Abstract

The invention discloses a method for modifying low-quality gasoline. The low-quality gasoline is cut into light and heavy fractions, wherein the light fraction accounts for 10-50% by weight, and the rest is heavy fractions. The distillate is mixed with hydrogen first, and then contacted with a pre-hydrogenation catalyst. The pre-hydrogenated oil is contacted with a hydrogenation catalyst for hydrotreating. The hydrotreated oil is then washed with alkali to remove the light fraction of mercaptans. Mixed to get the product gasoline. When the method is used to treat the catalytic cracking gasoline, the sulfur content of the gasoline can be reduced below 150 μg / g, the olefin content can be reduced by 15-30 percentage points, and the gasoline anti-knock index can be increased by 0.1-2.0 units.

Description

technical field [0001] The invention belongs to the field of hydrocarbon oil refining, more specifically, the invention relates to a upgrading method for desulfurizing inferior gasoline and reducing olefins to increase octane number. Background technique [0002] As we all know, people are paying more and more attention to the air pollution caused by toxic and harmful substances in automobile exhaust. Countries around the world have successively legislated to formulate strict new standards for clean gasoline, and strictly limit the content of sulfur, olefins, aromatics and benzene in gasoline to reduce automobile exhaust. pollution of the atmospheric environment. There is still a large gap between the quality of gasoline for vehicles in my country and the standard of clean gasoline in advanced countries. 90% of the sulfur and olefin content in my country's motor gasoline comes from catalytic cracking gasoline. Therefore, reducing the content of sulfur and olefins in FCC ga...

AI Technical Summary

Problems solved by technology

USP5,041,208 uses a noble metal catalyst containing a high silicon-aluminum ratio faujasite to treat catalytic gasoline, which can reduce the sulfur content and increase the octane number, but the reaction temperature is relatively high, which is 450-540 ° C in the examples. In addition, the catalyst requires The final boiling point of raw oil does not exceed 177°C, and the process is cumbersome

CN1458235 has introduced a kind of octane recovery agent and its application, after catalytic cracking gasoline selective desulfurization, carry out octane recovery with a kind of Ni / ZSM-5+beta zeolite catalyst, but still have octane loss

CN1465666A introduces a method for gasoline desulfurization and olefin reduction. Catalyzed gasoline is cut into light and heavy fractions, the light fractions are demercaptanized, and after the heavy fractions are hydrodesulfurized, the octane number is recovered with RIDOS catalyst, but there is still octane number loss , and the gasoline yield is generally less than 90%

CN1488723A introduces a two-stage combination process of hydrorefining and aromatization. After catalytic gasoline hydrodesulfurization, it is treated with a metal-modified small-grain ZSM-5+beta zeolite catalyst, which can increase gasoline yield and reduce sulfur and Olefin content reduces the loss of octane number, but the antiknock index still has a loss of 1.0-1.5

CN1356378A has introduced a kind of by VIB, VIII group metal, modified ZSM-5, TiO 2 The catalyst composed of catalyst and binder can effectively reduce the sulfur and olefin content after treating the catalytic gasoline, and make the octane number not decrease or increase, but the catalytic gasoline contains a certain amount of dienes and colloids, which are prone to rubber Substances, easy to coke on the catalyst, affecting the long-term operation of the catalyst