Liquid hydrocarbon mercaptan removal technique capable of deeply removing total sulfur

Abstract

The invention relates to a liquid hydrocarbon mercaptan removal technique capable of deeply removing total sulfur, in particular to a sweetening technique for liquefied gas in an oil refinery. The oil refining liquid hydrocarbon refers to components of liquefied gas and light gasoline, wherein the liquefied gas is a raw material for producing MTBE, and the light gasoline is a component for producing high-cleanness gasoline. In order to solve the problem of high total sulfur in the oil refining MTBE and the light gasoline, according to the shape and the distribution rule of sulfocompounds in the liquid hydrocarbon, processes such as functional reinforcement of a recycle solvent, three-phase mixed reinforced regeneration, regenerated catalyst and extractant separation and recycle solvent deoxidization and the like are adopted in the conventional process of liquid hydrocarbon extraction, oxidization and mercaptan removal, so the technical effects of reinforcing the mercaptan removal depth, improving carbonyl sulfide removal rate, and avoiding forming disulphide in the extracting, saving energy and reducing emission and the like are achieved. Thus, the liquid hydrocarbon can be deeply desulfurated, the problem of high total sulfur in the oil refining MTBE and the light gasoline is solved and the slag discharging quantity in the conventional process is greatly reduced.

Description

technical field [0001] The invention relates to a liquid hydrocarbon sweetening technology, in particular to a refinery liquefied gas sweetening technology. Background technique [0002] Refinery liquefied gas mainly comes from catalytic cracking and delayed coking units. Catalytic cracking liquefied gas is the main raw material for the production of refining propylene and MTBE. In recent years, with the deepening requirements of comprehensive utilization of resources, coking liquefied gas has also been used as a raw material for the production of propylene and MTBE in oil refining. In the production process of MTBE, like methanol, mercaptans and isobutene can also undergo etherification reactions, and at the same time, self-etherification reactions may also occur; in addition, MTBE has higher solubility for sulfides than C4 hydrocarbons and other factors , when MTBE and ether are separated by C4 distillation, the sulfides in C4 raw materials are almost all enriched by MTB...

AI Technical Summary

Problems solved by technology

These two aspects are the factors that lead to high total sulfur after liquefied gas refining

[0009] In addition, the regenerated catalyst in the traditional process is dissolved in lye for recycling, and when the catalyst and dissolved oxygen in the lye undergo extraction reactions, part of the sodium mercaptide is generated The side reaction of conversion to disulfide is eliminated, and the side reaction is especially significant when the alkali sulfur load is high.

Some enterprises have adopted strict secondary back-extraction measures after regeneration, but the disulfide content is still high after refining, which is the reason

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