Ultra-deep combined desulphurization method for full-fraction FCC gasoline

Abstract

The invention relates to an ultra-deep combined desulphurization method for full-fraction FCC gasoline. The method comprises the following steps: (1) with full-fraction FCC gasoline and hydrogen as raw materials, successively contacting the raw materials with a protective agent 1, a protective agent 2 and a selective dialkene removing catalyst in a dialkene removing reactor under proper operation conditions to remove the most of dialkene in the full-fraction FCC gasoline raw material; (2) contacting the full-fraction FCC gasoline having undergone dialkene removal in step (1) with a catalyst in a selective hydrodesulfurization reactor under proper operation conditions so as to remove 40 to 60% of sulfur in the full-fraction FCC gasoline; and (3) subjecting the full-fraction FCC gasoline having undergone selective hydrodesulfurization in step (2) to separation in a gas-liquid separator and gas stripping to remove hydrogen sulfide dissolved in the full-fraction FCC gasoline, then mixing the full-fraction FCC gasoline with fresh hydrogen and contacting the full-fraction FCC gasoline with a catalyst in an adsorption ultra-deep desulphurization reactor under proper operation conditions so as to remove the most of sulfur in the gasoline, thereby obtaining a gasoline product with ultra low content of sulfur. The method has the advantages of low loss of an octane value, high liquid yield, high adsorptive selectivity of an adsorbent, great sulfur capacity and the like while carrying out ultra-deep desulphurization.

Description

technical field [0001] The invention relates to a combined method for ultra-deep desulfurization of full-fraction FCC gasoline, in particular to a combined method for de-diene, selective hydrodesulfurization and adsorption ultra-deep desulfurization of full-fraction FCC gasoline with a sulfur content of 100-200 ppmw. The combined method can desulfurize sulfur The sulfur in the full-cut FCC gasoline with a content of 100-200ppmw is removed to less than 10ppm, while the octane number loss is less than 1.5 units, and the liquid yield is greater than 99.8%. Background technique [0002] SO produced by the combustion of organic sulfur compounds in gasoline 2 There are many harms to the environment, mainly including: acid rain, irreversible poisoning of the precious metal "three-way catalyst" in the engine exhaust gas purification system, the main contributor to particulate matter in the atmosphere, and corrosion of metal equipment. For this reason, the United States promulgated ...

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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