Super deep desulfurization combined method for FCC (fluid catalytic cracking) gasoline

Abstract

The invention relates to a super deep desulfurization combined method for FCC (fluid catalytic cracking) gasoline. The method comprises the steps of (1) with full fraction FCC gasoline and hydrogen as raw materials, enabling the raw materials to contact with protective agents 1 and 2 and a catalyst selectively removing alkadiene in a reactor removing alkadiene under proper conditions so as to remove most alkadiene in full fraction FCC gasoline raw material; (2) after the full fraction FCC gasoline with alkadiene removed in step (1) passes through a gas-liquid separator, dividing the liquid entering a fractionating tower into a light gasoline fraction and a heavy gasoline fraction; (3) enabling the heavy gasoline fraction obtained in step (2) to contact with the catalyst in a selective hydrogen desulfurization reactor under proper operation condition; (4) mixing the light gasoline fraction obtained in step (2) with the heavy gasoline fraction subjected to selective hydrogen desulfurization in step (3), then mixing with new hydrogen, and enabling the mixture to contact with an adsorbent in an adsorbing super deep desulfurization reactor under proper condition so as to remove most sulphur in the gasoline to obtain the ultra low sulphur gasoline product with content of sulphur less than 10ppmw.

Description

technical field [0001] The invention relates to a combined method for ultra-deep desulfurization of FCC gasoline, in particular to a combined method for ultra-deep desulfurization of FCC gasoline with a sulfur content of 200-1000 ppmw. The combined process can desulfurize FCC gasoline with a sulfur content of 200-1000 ppmw to below 10 ppm , while the octane loss is less than 1.5 units, and the liquid yield is greater than 99.8%. Background technique [0002] The SOx produced by the combustion of organic sulfur compounds in gasoline has many hazards to the environment, mainly including: acid rain, irreversible poisoning of the noble metal "three-way catalyst" in the engine exhaust gas purification system, and the main contributor to particulate matter in the atmosphere , corrosion of metal equipment, etc. For this reason, the United States promulgated a new Clean Air Act Amendment (CAAA) in the early 1990s, formulated more stringent environmental regulations, and imposed str...

AI Technical Summary

Problems solved by technology

This shows that the adsorption sulfur capacity of the adsorbent still cannot meet the requirements of industrial applications; greatly limit its industrial application

[0009] To sum up, in the existing literature or patents, there are still some shortcomings in the ultra-deep desulfurization (sulfur content below 10ppmw) technology of gasoline: 1. The choice of hydrodesulfurization process is long, energy consumption is high, octane 2. In the process of selective hydrodesulfurization, the process of alkali washing to remove mercaptans also produces a large amount of alkali residue and other environmental problems; 3. The adsorption selectivity and adsorption of sulfide by the adsorbent used in selective adsorption desulfurization The capacity is low, and it is difficult to achieve industrialization; 4. In the fluidized bed hydrogenation reaction-adsorption desulfurization, the operating conditions are harsh, the energy consumption is high, the loss of the adsorbent is serious, and the operating cost is high

Especially when the olefin content is high, the resulting octane loss exceeds 2 units; 5. In the fluidized bed hydrogenation reaction-adsorption desulfurization, the sulfur capacity of the adsorbent is low, the regeneration of the adsorbent is frequent, the energy consumption is high, and the operating cost is high. high

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