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CN-116924951-B - Preparation method of sodium mercaptide organic solution

CN116924951BCN 116924951 BCN116924951 BCN 116924951BCN-116924951-B

Abstract

The invention relates to a preparation method of a sodium mercaptide organic solution, which can be used for obtaining a liquid sodium mercaptide solution containing high-concentration mercaptan, is convenient for use, storage and transportation of low-molecular-weight mercaptan and sodium mercaptide, can be used for producing solid sodium methyl mercaptide with the content of more than 85 percent, and can be used for enriching and recovering mercaptan in oil gas. The method comprises the preferred implementation steps of slowly adding dehydrated mercaptan into an organic solution containing sodium alkoxide, and keeping the system temperature unchanged in the process until the mercaptan concentration of the system reaches a set value. Or adding the organic solution containing sodium alkoxide into the oil gas product containing the thiol, fully mixing and settling, continuously returning the sediment to be mixed with the raw oil gas, and continuously adsorbing the thiol therein until the sodium thiol solution with the set concentration is generated, wherein the concentration of the thiol can reach 30-60 percent at most.

Inventors

  • LIU XIAOLING

Assignees

  • 兰州信元新型材料有限责任公司

Dates

Publication Date
20260512
Application Date
20220407

Claims (10)

  1. 1. A preparation method of a sodium mercaptide organic solution is characterized by comprising the following steps of mixing dehydrated mercaptan with a water content of less than or equal to 0.5% with an organic solution containing sodium alkoxide until the concentration of the mercaptan in the system reaches a set value, wherein the mercaptan refers to mercaptan, ethanethiol, propanethiol or oil gas products of naphtha, gasoline, light hydrocarbon, liquefied gas and natural gas generated in the exploitation and processing of coal and petroleum with mixed mercaptan dissolved therein, sodium alkoxide refers to one or more of sodium methoxide, sodium ethoxide and sodium glycol, the mass percentage of sodium alkoxide in the organic solution containing sodium alkoxide is 5% -45%, the alcohol content is 55% -95%, the alcohol ether content is 0% -10%, the amide content is 0% -0.8%, the alcohol is monohydric alcohol, dihydric alcohol or a mixture of the monohydric alcohol and the dihydric alcohol, and the reaction temperature is 20 ℃ -45 ℃.
  2. 2. The method for preparing the sodium mercaptide organic solution according to claim 1, wherein the organic solution containing sodium mercaptide is fully mixed with the oil gas product containing mercaptan and then subjected to sedimentation separation, and the sediment containing sodium mercaptide is continuously returned to be mixed with the oil gas product containing mercaptan, so that the mercaptan in the sediment is continuously adsorbed until the sodium mercaptide solution with the set concentration is generated.
  3. 3. The method for preparing the sodium mercaptide organic solution according to claim 1, wherein the monohydric alcohol is methanol, ethanol, butanol or octanol, and the dihydric alcohol is ethylene glycol, methyl ethylene glycol or propylene glycol.
  4. 4. The method for preparing the sodium mercaptide organic solution according to claim 1, wherein the sodium alkoxide content in the sodium alkoxide-containing organic solution is 10% -40% by mass, the alcohol content is 60% -90%, the alcohol ether content is 0.5% -6% and the amide content is 0.1% -0.6%.
  5. 5. The preparation method of the sodium mercaptide organic solution according to claim 1, wherein the mass percentage of sodium alkoxide in the sodium alkoxide-containing organic solution is 15% -35%, the alcohol content is 65% -85%, the alcohol ether content is 1% -5%, and the amide content is 0.2% -0.5%.
  6. 6. The method for preparing an organic sodium mercaptide solution according to claim 4 or 5, wherein the alcohol ether is ethylene glycol butyl ether, propylene glycol butyl ether, and the amide is dimethylformamide.
  7. 7. The method for preparing the organic solution of sodium mercaptide according to claim 1, wherein the content of water in the mercaptan and the system is less than or equal to 0.5% when the mercaptan is mixed with the organic solution containing sodium mercaptide.
  8. 8. The method for preparing the sodium mercaptide organic solution according to claim 1, wherein the temperature difference of the system is kept below 15 ℃ during the preparation process.
  9. 9. The method for preparing the sodium mercaptide organic solution according to claim 8, wherein the temperature difference of the system is kept below 10 ℃ in the preparation process, and the temperature of the preparation system is controlled.
  10. 10. A method for preparing solid sodium mercaptide by using the method for preparing the sodium mercaptide organic solution as claimed in claim 1, which is characterized in that the obtained sodium mercaptide organic solution is concentrated and dried to obtain a solid sodium mercaptide product.

Description

Preparation method of sodium mercaptide organic solution Technical Field The technology relates to a preparation method of sodium mercaptide organic solution, in particular to an environment-friendly preparation method of high-concentration sodium mercaptide organic solution. The method can obtain the sodium mercaptide organic solution containing high-concentration mercaptide, is favorable for the use, storage and transportation of low-molecular-weight mercaptide and sodium mercaptide, and can produce high-purity sodium methyl mercaptide with the content of more than 85 percent. Background Thiols and sodium thiols are important organosulfur raw materials, in particular methyl thiols and sodium methyl thiols, as raw materials for pesticides, medicines, dye intermediates, antidotes for hydrogen sulfide poisoning. Methyl mercaptan is gaseous at normal temperature due to its low boiling point, and is usually stored and used in the form of aqueous sodium methyl mercaptan solution. The existing sodium methyl mercaptan production technology adopts an intermittent method to produce sodium methyl mercaptan, and has the structure that a single reaction kettle is used for reacting sodium hydrosulfide with dimethyl sulfate to produce methyl mercaptan gas, then 3-4 washing barrels connected in series are matched for armored sodium mercaptan solution or dilute alkali liquor to carry out bubbling washing on the methyl mercaptan gas, impurity gases such as hydrogen sulfide and the like in the methyl mercaptan gas are washed out, and then the methyl mercaptan gas enters a fixed primary and secondary absorption kettle to absorb methyl mercaptan by the alkali liquor to produce the sodium methyl mercaptan solution. The intermittent production technology has low efficiency, large production investment, large equipment occupation space, low bubbling washing cleanliness, low purity of the washed methyl mercaptan gas, and a certain amount of hydrogen sulfide gas in the generated methyl mercaptan gas, if the gas is insufficient, the sodium sulfide content of a sodium methyl mercaptan product is easily high, the product is reddish, the washing liquid is replaced one by one, the washing liquid is replaced without complete invalidation, the waste exists, the cost is increased, and the pollutant emission is increased. The waste water produced by the process contains various organic matters such as sodium methyl sulfate, sodium methyl mercaptan, methanol, dimethyl sulfide, dimethyl disulfide and the like, the COD is as high as 10 ten thousand ppm, and the surrounding air is malodorous. The solid sodium methyl mercaptan contains more crystal water, is not easy to crush, can be used after being heated and melted during use, is not easy to package, has large smell and is easy to cause environmental pollution, so that enterprises using sodium methyl mercaptan as a raw material generally purchase sodium methyl mercaptan solution directly. Because the saturated concentration of the sodium methyl mercaptan aqueous solution is about 20wt% at normal temperature, crystals are easy to be precipitated in the transportation and storage processes due to the fact that the concentration is continuously increased, and the content of the sodium methyl mercaptan solution is inaccurate, the concentration of the commercially available sodium methyl mercaptan solution is generally about 20wt%, namely, the water content in the sodium methyl mercaptan commodity is about 80wt%, the water consumption of sodium methyl mercaptan manufacturers is high, the transportation efficiency is low, the transportation cost is high, for example, 20wt% sodium methyl mercaptan solution is produced and sold by sodium methyl mercaptan companies in inner Mongolian regions, the sodium methyl mercaptan solution is sold to Zhejiang zone, the hundred of customers is up to 4000 yuan/ton, and the transportation cost is very high. The high-purity solid sodium methyl mercaptan has unique properties, wherein the free alkali content is required to be low, and the catalytic performance is excellent. The prior art obtains sodium methyl mercaptan solid by concentrating aqueous sodium methyl mercaptan solution. Because sodium mercaptide molecules are associated with water molecules, the concentration of the sodium methyl mercaptide with the concentration of 20 weight percent can only remove crystal water by increasing the temperature when concentrating and dehydrating, and the crystal water is difficult to completely remove. Along with the rise of temperature, the decomposition of sodium methyl mercaptan in aqueous solution can be accelerated to continuously generate gaseous methyl mercaptan, the generated methyl mercaptan can continuously escape from a concentration system, so that the target concentration cannot be reached, a large amount of sodium hydroxide and other impurities are generated in the concentrated sodium methyl mercaptan, the content of free alkali and crystallization water in