Method and device for lye extraction desulfurization

Abstract

The invention provides a method and device for desulfurization from hydrocarbon flow thorough alkaline liquid suction. It is to add a gas- removal system between oxidation system and phase separation system, and introduce inert gas into gas- removal system to exchange oxidative gas and then effectivelyt promote the separation of sulfur dioxide or sulfur dioxide- containing solvent from regenerative alkaline liquid in phase separation system, and the thiol in hydrocarbon flow can be inhibited from oxidation by oxidative gas in suction system, which enables thorough desulfurization by alkaline liquid suction.

Description

technical field [0001] The invention belongs to the refining field of hydrocarbon materials. Specifically, the present invention relates to a method and equipment for desulfurizing hydrocarbon material fluids, ie hydrocarbon streams, through alkaline extraction. Background technique [0002] Alkaline extraction is a traditional method for refining hydrocarbon materials, widely used in the sweetening and refining of hydrocarbon materials such as liquefied petroleum gas, gasoline, diesel oil, naphtha, alkanes, and olefins. The method is to contact the fluid of the hydrocarbon material, that is, the hydrocarbon stream with the lye, and the mercaptan in the hydrocarbon stream is removed from the oil by reacting with the lye to form mercaptide. [0003] If the lye containing mercaptide is discharged directly, it is neither economical nor environmentally friendly. Oxidation is usually used to oxidize mercaptides into disulfides so that the lye containing mercaptides is regenerat...

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Problems solved by technology

However, it must be noted that in the prior art, especially in practical applications, the content of mercaptans absorbed into the lye changes accordingly due to changes in the content of mercaptans in the hydrocarbon stream. Alkali regeneration is complete, and it is usually necessary to inject an oxidizing gas much higher than the theoretical meter into the oxidation system, and the excess oxidizing gas usually flows into the phase separation system together with the alkali solution, and it is difficult to completely release it in the phase separation system

[0007] This leads to two defects: one is that the oxidizing gas flowing into the phase separation system is easy to form bubbles in the lye, which affects the settlement and separation of the regenerated lye and the disulfide phase or the solvent phase containing disulfide, making the regenerated lye Disulfides or disulfide-containing solvents are still entrained. When the regenerated alkali liquor is returned to the extraction system for recycling, the disulfides will be back-extracted into the hydrocarbon stream, resulting in insignificant desulfurization effect; The oxidizing gas in the liquid returns to the extraction system along with the regenerated lye, and at least a part of the mercaptans in the hydrocarbon stream generate disulfides under the action of the oxidizing gas and the oxidation catalyst circulating with the lye, and the disulfide Does not react with lye, but remains in the hydrocarbon stream, so the purpose of treating the hydrocarbon stream with lye for desulfurization cannot be achieved, at least the desulfurization effect is not obvious

[0008] The existing technology ignores the adverse effects of the oxidizing gas entrained in the lye on the phase separation and extraction, resulting in an insignificant desulfurization effect

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