Treatment method for alkali liquor oxidation regeneration tail gas containing mercaptide

Abstract

The invention relates to a treatment method for an alkali liquor oxidation regeneration tail gas containing mercaptide. The treatment method comprises the following steps: feeding a to-be-treated alkali liquor oxidation regeneration tail gas containing mercaptide from the bottom of a washing tank, penetrating though a gas distribution plate in the tank, discharging from an exhaust gas pipe at the top of the washing tank, and feeding to an air inlet in the bottom of a dewatering tank; drying through a drying agent in the dewatering tank, feeding into a supergravity separator, contacting diesel oil fed from a liquid-phase inlet of the supergravity separator, and feeding into a gasoline and diesel oil separation recovery tank from a gas-phase outlet of the supergravity separator, wherein a crane of the supergravity separator is a rotary packing bed which is operated in a gas-liquid countercurrent, cocurrent flow or baffle flow form; and the operation ranges of the supergravity separator are as follows: the gas-liquid ratio is (5-2,000) to 1, the operation gage pressure is 0-0.3MPa and the operation temperature is 10-60 DEG C. According to the method, ultra-low sulphur emission of a liquefied gas alkali liquor oxidation regeneration tail gas is reached; desulfurization treatment can be carried out on absorbent diesel oil in a hydrogenation device; and the total sulfur emission in three wastes of factories is effectively reduced.

Description

technical field [0001] The invention belongs to the field of oil refining and chemical industry, and relates to a treatment method for oxidation regeneration tail gas of alkaline solution containing mercaptan. Background technique [0002] Since crude oil contains sulfides to varying degrees, during the refining process of crude oil, sulfur in different forms of light and heavy will enter the corresponding products according to the difference in boiling point. According to the characteristics of the distillation range of liquefied gas products, the sulfur form entering into it is mainly hydrogen sulfide , Methanethiol and Ethanthiol. At present, the demercaptan process of liquefied petroleum gas mainly adopts alkali washing. Under certain temperature, pressure and sufficient contact conditions, mercaptan contained in liquefied petroleum gas reacts with sodium hydroxide solution to form sodium mercaptide, which becomes inorganic sulfur and enters the alkali solution. , so as...

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Problems solved by technology

This type of organic sulfur belongs to the oil phase, which has high relative volatility and is relatively easy to enter the oxidation tail gas phase. If it is discharged directly or after incineration, the discharge will not meet the standard and cause serious environmental pollution.

[0003] Patent CN101940872B provides a water washing-membrane separation-oxidation lye oxidation regeneration tail gas desulfurization method. This method has a long process, and both membrane separation components and adsorbent consumption will lead to increased desulfurization costs.

Patent CN201210174207.1 invented a desulfurization device and method for waste gas containing disulfide, which can reduce disulfide to 200mg / Nm 3 , it is difficult to meet the requirements of future emission standards

Patent CN201110433220.X proposes a treatment and utilization method of oxidative desulfurization tail gas. The tail gas to be treated is absorbed by the absorbent of the desulfurization tower, and then goes to the adsorption tank to remove organic hydrocarbons after desulfurization. Since the adsorbent is replaced regularly, the absorption effect is unstable and replaced at the same time The final absorbent also presents new disposal problems

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