Deep desulfurization-octane value recovery hydrogenation modification method for low grade gasoline

Abstract

The invention relates to a hydro-upgrading method of ultra-deep desulfurization and octane number preservation of poor gasoline. In the method, the poor gasoline is treated by using coupling of two-stage reaction so that the poor gasoline is contacted and reacted with two different catalysts in two-stage reaction zones. The temperature of the first-stage reaction zone is low, and unstable diene and difficultly deprived sulfur compound are deprived from the gasoline by using Al-Ti-Mg complex carrier catalyst having double functions of diene deprivation and high-selective hydrodesulfurization; the temperature of the second-stage reaction zone is high, and modified HZSM-5 zeolite by comprehensive treatment of hot water, organic acid-organic acid and the catalyst of Ti-Al compound carrier realize further desulfuration, diene reducing and product octane number preservation. The method can obtain better hydro-upgrading effect particularly for medium-sulfur and high-olefin poor FCC gasoline,can reduce octane number loss and keep higher product liquid yield while greatly reducing the contents of olefin and sulfur.

Description

technical field [0001] The present invention relates to a method for hydrogenation and upgrading of low-quality gasoline, in particular to a deep desulfurization-recovery octane used in the field of petroleum refining such as catalytic cracking (FCC) gasoline, especially low-quality FCC gasoline with medium, high sulfur and high olefins value hydrogenation upgrading method. Background technique [0002] At present, the high olefin content and sulfur content in FCC gasoline have become the key problems that plague the world's clean gasoline production. In the case of less high-octane reformed gasoline and alkylated gasoline, in order to meet the increasingly stringent clean gasoline standards, FCC gasoline hydro-upgrading has become one of the key technologies for the production of clean fuel for vehicles . [0003] USP 5770047, USP 5417697, etc. introduced the desulfurization and olefin reduction process mainly based on hydrofining-cracking / single-branched hydroisomerizati...

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Problems solved by technology

The olefin content of the product obtained according to this patented method is low, but the sulfur content of the product is difficult to meet the national IV standard of no more than 50μg.g -1 requirements; on the other hand, this method is aimed at high-sulfur oil, in order to improve the RON of the final blended product, one of the key points of this patented method is to aromatize heavy distillate gasoline after hydrodesulfurization, but aromatics are coke Precursor, higher aromatics generation (product aromatics higher than raw material 10v%) is extremely unfavorable to the stability of the catalyst; moreover, the catalyst carrier in the patented process requires TiO 2 Mainly, this also greatly reduces the strength of the catalyst, which is not conducive to its long-term stable operation and regeneration

[0014] It can be seen that there have been a lot of researches on my country's FCC gasoline with high sulfur content and high olefins. Most of them are to desulfurize FCC gasoline (whole fraction or heavy fraction) on a hydrogenation catalyst first, and the olefins in the reaction product It is usually saturated by a large amount, and then cracking and aromatization are carried out by a catalyst with high cracking activity to achieve the effect of recovering the octane number. Although these disclosed methods have their own advantages, a more reasonable upgrading process is to be explored. Catalysts with appropriate functions and activities, while maintaining octane number, can achieve deep desulfurization and greatly reduce olefins, and solve the problems of unsatisfactory catalyst stability and high processing costs, which are always the goals pursued by the field of petroleum refining

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