CN-117567336-B - Method for recycling byproduct cyclohexene still residues

CN117567336BCN 117567336 BCN117567336 BCN 117567336BCN-117567336-B

Abstract

The invention discloses a recycling method of byproduct cyclohexene still residues, which belongs to the technical field of byproduct cyclohexene still residues recycling, wherein liquid chromatography-mass spectrometry is carried out on the still residues, according to the content of chlorocyclohexane in the still residues, the chlorocyclohexane and disodium disulfide react under the condition of a catalyst, after standing and phase separation, dicyclohexyldisulfide and cyclohexene are obtained from an oil phase through rectification, and a water phase can be recycled. The catalyst is formed by compounding sulfonated castor oil and a phase transfer catalyst, can improve the conversion rate of chlorocyclohexane and the selectivity of dicyclohexyldisulfide, and simultaneously greatly shortens the reaction time. The invention can realize recycling and utilizing the residue in the kettle, avoid wasting resources and polluting the environment, save the chemical production cost and accord with the environmental protection concept of green chemical industry.

Inventors

SONG KUIJING
YAO HONGMEI
CHENG YONG
ZHANG WENXI
ZHAO NA

Assignees

汤阴永新化学有限责任公司

Dates

Publication Date: 20260505
Application Date: 20231115

Claims (6)

1. The method for recycling the byproduct cyclohexene still residue is characterized by comprising the following steps of: S1, sampling residue of a byproduct cyclohexene after distillation, and performing qualitative and quantitative analysis by liquid chromatography-mass spectrometry to obtain the contents of chlorocyclohexane, cyclohexene and dicyclohexyldisulfide serving as main components; S2, according to the content of chlorocyclohexane in the kettle residue, mixing chlorocyclohexane with sodium sulfide, sulfur=1 (0.4-0.8) and sulfur=0.3-0.8, adding and stirring sodium sulfide, sulfur and water or mother liquor, heating to 60-80 ℃, and preserving heat for 0.5-1.5 h until the materials are completely dissolved to obtain a disodium disulfide solution; S3, adding quantitative cyclohexene distillation residues into the disodium disulfide solution obtained in the step S2, adding a catalyst at the same time, performing airtight stirring reaction for 4-6 hours under the conditions of the temperature of 80-110 ℃ and the pressure of 0.8-2.5 MPa, then cooling, standing and phase separation, and obtaining an oil phase containing crude dicyclohexyl disulfide and cyclohexene, a water phase containing the catalyst and sodium chloride respectively after separation; S4, separating dicyclohexyldisulfide and cyclohexene from the oil phase obtained in the step S3 through a rectifying tower after rectification, and separating and recycling sodium chloride, wherein the obtained water phase containing the catalyst can be recycled; The catalyst is prepared by compounding sulfonated castor oil and a phase transfer catalyst; the phase transfer catalyst is one of polyethylene glycol-400, tetrabutylammonium bisulfate, tetrabutylammonium bromide, tetrabutylammonium chloride and benzyl triethylammonium bromide.
2. The method for recycling byproduct cyclohexene still residues, which is characterized by 1, wherein the mass fraction of the disodium disulfide solution is 10-30%.
3. The method for recycling cyclohexene still residues as recited in claim 1, wherein the sulfonated castor oil is 0.1-0.5% by volume of the aqueous phase.
4. The method for recycling byproduct cyclohexene still residues according to claim 1, wherein the phase transfer catalyst is 0.5-1% by mass of chlorocyclohexane.
5. The method for recycling residue of byproduct cyclohexene still in accordance with claim 1, wherein the original cyclohexene and dicyclohexyl disulfide in the residue are introduced into the oil phase together.
6. The method for recycling a byproduct cyclohexene still residue in accordance with claim 1, wherein the aqueous phase containing the catalyst is used as a mother liquor for preparing disodium disulfide solution for recycling.

Description

Method for recycling byproduct cyclohexene still residues Technical Field The invention relates to the technical field of recycling of byproduct cyclohexene still residues, in particular to a recycling method of byproduct cyclohexene still residues. Background Dicyclohexyl disulfide is an important intermediate in fine chemical industry, is a key intermediate for preparing rubber auxiliary agent scorch retarder N-cyclohexylthio-phthalimide (CTP for short), is also a novel edible spice approved by the Ministry of health of China, and is a thioether spice. The synthesis method of dicyclohexyl disulfide mainly comprises two methods, namely a cyclohexyl mercaptan oxidation method and a halogenated cyclohexane vulcanization method. The method for preparing dicyclohexyl disulfide by using halogenated cyclohexane vulcanization has the advantages of high economy, mild reaction conditions and long reaction time. In the process of preparing dicyclohexyl disulfide by reacting chlorocyclohexane with disodium disulfide, besides the main product dicyclohexyl disulfide is generated, a small amount of crude cyclohexene product is generated, dicyclohexyl disulfide and cyclohexene are respectively obtained after rectification, and cyclohexene can be used for producing adipic acid, glyoxal and cyclohexanal, is an important intermediate of organic reaction, can also be used as an extractant or a stabilizer of high-octane gasoline, and is manufactured and sold in commercial products. After the cyclohexene distillation process is finished, partial high-boiling-point rectifying still residue materials are generated, most of the still residue materials are combinations of unreacted chlorocyclohexane, unseparated cyclohexene, carried dicyclohexyldisulfide, cyclohexene polymers and the like, and the components are complex and difficult to separate and reuse, so that the residue materials are usually used as hazardous waste to treat, the environment is influenced, the cost is increased, and the economic benefit is low. Meanwhile, when chlorocyclohexane in the residue reacts with disodium disulfide again, the conversion rate is extremely low, the reaction process is slow, and the product yield is reduced. Disclosure of Invention In order to overcome the defects of the prior art, the invention aims to provide a recycling method of byproduct cyclohexene distillation still residues, which is used for recycling main components in the still residues, namely chlorocyclohexane, cyclohexene and dicyclohexyldisulfide, and has the advantages of mild reaction conditions, safe and simple operation, shortened reaction time, improved utilization rate of the distillation still residues, and reduced environmental pollution and resource waste. In order to achieve the above purpose, the invention adopts the following technical scheme: a method for recycling byproduct cyclohexene still residues, which comprises the following steps: S1, sampling residue of a byproduct cyclohexene after distillation, and performing qualitative and quantitative analysis by liquid chromatography-mass spectrometry to obtain the contents of chlorocyclohexane, cyclohexene and dicyclohexyldisulfide serving as main components; S2, according to the content of chlorocyclohexane in the kettle residue, mixing chlorocyclohexane with sodium sulfide, sulfur=1 (0.4-0.8) and sulfur=0.3-0.8, adding and stirring sodium sulfide, sulfur and water or mother liquor, heating to 60-80 ℃, and preserving heat for 0.5-1.5 h until the materials are completely dissolved to obtain a disodium disulfide solution; S3, adding quantitative cyclohexene distillation residues into the disodium disulfide solution obtained in the step S2, adding a catalyst at the same time, performing airtight stirring reaction for 4-6 hours under the conditions of the temperature of 80-110 ℃ and the pressure of 0.8-2.5 MPa, then cooling, standing and phase separation, and obtaining an oil phase containing crude dicyclohexyl disulfide and cyclohexene, a water phase containing the catalyst and sodium chloride respectively after separation; S4, separating dicyclohexyldisulfide and cyclohexene from the oil phase obtained in the step S3 through a rectifying tower after rectification, and separating and recycling sodium chloride, wherein the obtained water phase containing the catalyst can be recycled; The catalyst is prepared by compounding sulfonated castor oil and a phase transfer catalyst. Preferably, the molar ratio follows that chlorocyclohexane, sodium sulfide and sulfur=1, (0.5-0.6) and (0.5-0.6). Further, the mass fraction of the disodium disulfide solution is 10-30%. Further, the sulfonated castor oil is 0.1-0.5 per mill of the volume of the water phase. Further, the phase transfer catalyst is one of polyethylene glycol-400, tetrabutylammonium bisulfate, tetrabutylammonium bromide, tetrabutylammonium chloride and benzyl triethylammonium bromide. Further, the phase transfer catalyst is 0.5-1%o of the mass of chlorocyclohexa