Method for removing organic sulfur in liquid hydrocarbon

Abstract

The invention provides a method for removing organic sulfur in liquid hydrocarbon, the method is characterized by comprising the following steps: sending sulfur-containing liquid hydrocarbon and an anhydrous desulfurizing agent into a mixer, fully mixing and extracting, sending into a settling tank, taking out the liquid hydrocarbon without organic sulfide from the top, and obtaining a mercaptan-containing desulfurizing agent from the bottom; wherein the desulfurizing agent is obtained by dissolving and dispersing sodium mercaptide into an organic solvent, and the mass content of the sodium mercaptide is 5-40%; wherein the mass content of the desulfurizing agent is 1-10 times that of sulfur in the hydrocarbon liquid. According to the method, the problem that alkali residues are inevitablygenerated in the existing liquid hydrocarbon organic sulfur removal process is thoroughly solved, and desulfurized sulfur-containing substances can also be used as raw material wastes for pesticide production. The method provided by the invention has the advantages of simple device, low investment, extremely low desulfurizer dosage, simple and easily available raw materials, low price, low desulfurization cost, simple operation, environmental protection and extremely easy popularization.

Description

technical field [0001] The invention relates to a method for removing organic sulfides from petroleum and coal-made naphtha, light hydrocarbons, carbon four fractions, and liquid hydrocarbons such as condensate and natural gas. Background technique [0002] With the exploitation of new oil and gas fields and the rapid development of coal chemical industry, there are more and more light oil and gas by-products, such as condensate, naphtha, light hydrocarbons, and various liquid hydrocarbons containing C4C5. Natural gas, etc., these light oil and gas can be used as raw materials for crude benzene, ethylbenzene, mixed xylene, civil gas and other devices, but because the organic sulfur content is as high as 3000ppm to 20000ppm, the odor is very strong, which is seriously affected during loading and unloading. environment, and hydrogenation is expensive. [0003] In the process of petroleum refining, the refining process of light oil products containing mercaptans is called deod...

AI Technical Summary

Problems solved by technology

In the deodorization process, a certain amount of waste lye is discharged, and a large amount of inorganic alkali is consumed.

[0006] The obvious disadvantages of the Merox method are: 1. Mercaptans are weakly acidic, and because they cannot form hydrogen bonds, their solubility in water is relatively small, so they may not be completely removed when they are in contact with lye for a short time, resulting in excessive sulfur content in liquefied gas; 2. The rate at which sodium mercaptide is oxidized to disulfide is slow, and unoxidized sodium mercaptide accumulates repeatedly in the circulation system, which will greatly reduce the efficiency of lye, which is equivalent to increasing the content of mercaptan in the feed, such a vicious cycle As a result, the sweetening effect is not good, resulting in frequent replacement of lye and large discharge of alkali slag, which not only increases the cost but also pollutes the environment

This process requires large investment, high energy consumption, serious loss of oil and gas entrainment in tail gas, worsens the processing conditions of heavy oil, incomplete sweetening of light oil, poor economic benefits, and large discharge of alkali waste residue, which cannot be eliminated

The above-mentioned desulfurization process also cannot remove carbonyl sulfide, so carbonyl sulfide needs to be removed separately. The existing carbonyl sulfide removal process generally can only process materials with carbonyl sulfide lower than 100ppm, and the content of carbonyl sulfide produced by the coking unit can reach 800ppm of liquid hydrocarbons can do nothing

[0008] CN01115579.5 discloses a preparation for light oil or liquefied petroleum gas to remove mercaptan sulfur compounds and its removal process. It uses a mixed preparation of inorganic strong alkali sodium hydroxide, organic amine or alcohol amine, catalyst, and water for liquefied petroleum gas, For gasoline sweetening, the concentration of sodium hydroxide is preferably higher than 35%, the mercaptide formed by the reaction is easy to crystallize, and the system pressure drop is large; the sweetening catalyst has poor alkali solubility in high-concentration lye, is easy to deactivate, and needs to be replenished regularly , the cost of the catalyst is high; alkali embrittlement is prone to occur during oxidation and regeneration of high-concentration lye, resulting in equipment corrosion

[0009] CN201010562902.6 discloses a sweetening agent composition, which uses a quaternary ammonium base, an organic amine, and a water mixture to carry out demercaptanization of liquefied gas, does not use inorganic alkali sodium hydroxide, and has no alkali slag discharge, but the quaternary ammonium base, organic amine, etc. The cost of organic reagents is much higher than that of the current solvent-alkali sweetening process; organic reagents also have the properties of surfactants, and are easily carried into liquefied petroleum gas and gasoline during the sweetening process, affecting the quality of oil products

[0010] CN105797564A discloses a method for desulfurization of liquefied gas. The coking liquefied gas that has passed the alkali cleaning is fully mixed with the solvent through a static mixer. The regenerated poor solvent, and then enter the secondary reaction static mixer for full contact, and carry out the secondary extraction and sweetening reaction. The process is very complicated

Although this solution completely solves the problem of lye discharge, the cost of ionic liquid is relatively high

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