CN108484364B - Method for separating m-ethylphenol and p-ethylphenol - Google Patents
Method for separating m-ethylphenol and p-ethylphenol Download PDFInfo
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- CN108484364B CN108484364B CN201810343498.XA CN201810343498A CN108484364B CN 108484364 B CN108484364 B CN 108484364B CN 201810343498 A CN201810343498 A CN 201810343498A CN 108484364 B CN108484364 B CN 108484364B
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/50—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by reactions decreasing the number of carbon atoms
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
- B01J31/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
- B01J31/0277—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides comprising ionic liquids, as components in catalyst systems or catalysts per se, the ionic liquid compounds being used in the molten state at the respective reaction temperature
- B01J31/0278—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides comprising ionic liquids, as components in catalyst systems or catalysts per se, the ionic liquid compounds being used in the molten state at the respective reaction temperature containing nitrogen as cationic centre
- B01J31/0281—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides comprising ionic liquids, as components in catalyst systems or catalysts per se, the ionic liquid compounds being used in the molten state at the respective reaction temperature containing nitrogen as cationic centre the nitrogen being a ring member
- B01J31/0284—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides comprising ionic liquids, as components in catalyst systems or catalysts per se, the ionic liquid compounds being used in the molten state at the respective reaction temperature containing nitrogen as cationic centre the nitrogen being a ring member of an aromatic ring, e.g. pyridinium
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/11—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by reactions increasing the number of carbon atoms
- C07C37/14—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by reactions increasing the number of carbon atoms by addition reactions, i.e. reactions involving at least one carbon-to-carbon unsaturated bond
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
- C07C37/86—Purification; separation; Use of additives, e.g. for stabilisation by treatment giving rise to a chemical modification
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
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Abstract
The invention provides a method for separating m-ethylphenol and p-ethylphenol, and particularly relates to a method for separating m-ethylphenol and p-ethylphenol by using a composite ionic liquid as a catalyst and a solvent, under a certain condition, performing tert-butyl reaction on the m-ethylphenol and the p-ethylphenol and then rectifying to separate two isomers, and removing tert-butyl to obtain an m-ethylphenol product and a p-ethylphenol product.
Description
Technical Field
The invention relates to a method for separating m-ethylphenol and p-ethylphenol, in particular to a method for separating m-ethylphenol and p-ethylphenol by performing tert-butyl reaction and rectification on the m-ethylphenol and the p-ethylphenol to separate two isomers and obtaining a m-ethylphenol product and a p-ethylphenol product through tert-butyl removal.
Background
The p-ethylphenol is an important pesticide intermediate, can be used for producing a series of high-grade, low-toxicity and low-residue pesticides, and is also a raw material for producing synthetic resins, medicines, plasticizers and the like. At present, two products of m-ethylphenol and p-ethylphenol generally exist simultaneously in the method for producing p-ethylphenol, and because the boiling point difference of the two isomers is very small, the two isomers are difficult to be completely separated by common rectification, so other separation methods are needed. The method involving separation of alkylphenol isomers includes, in addition to rectification (or azeotropic rectification), crystallization separation, adsorption separation, complexation separation, alkylation separation, and the like. Chinese patent CN 1129208 and british patent GB 2291056 disclose methods for separating m-ethylphenol and p-ethylphenol by adsorption-desorption methods, respectively; chinese patent CN101863742A and Chinese patent CN 101353293A respectively disclose that mixed solution of m-cresol and p-cresol is used as raw material, phenol tertiary butyl group is catalyzed, rectification is carried out to separate isomers, dealkylation reaction is carried out in the presence of catalyst, and rectification is carried out to obtain high-purity m-cresol and p-cresol products.
Although the separation methods of m-alkylphenol are more and some methods are already industrialized, certain disadvantages still exist. Such as: the crystallization separation method has strict requirements on the composition proportion of raw materials, and the yield is not high; the adsorption separation method needs a large amount of solvent and has higher requirement on separation operation; the complex separation method also needs a large amount of solvent, and the separation and application processes of the complexing agent are complex and have higher cost; the alkylation separation method is a common method for separating m-cresol and p-cresol in China at present, but when liquid acid, acidic ionic liquid and aluminum phenolate are used as catalysts, the separation of the catalysts is difficult to a certain extent, and when solid acid is used as the catalyst, isobutylene is easy to polymerize on the catalysts, so that the deactivation of the catalysts is accelerated, and the service life is influenced.
Disclosure of Invention
The invention aims to provide a novel catalyst for alkylation separation of m-ethylphenol and p-ethylphenol aiming at the defects of the separation of m-ethylphenol and p-ethylphenol by the traditional alkylation method, the catalyst has small corrosion to equipment, no side reaction, easy separation of alkylation products, easy recycling of the catalyst and energy conservation. The method comprises the steps of taking a mixed solution of m-ethylphenol and p-ethylphenol as a raw material, isobutene as an alkylating agent, and composite ionic liquid consisting of azomethyl pyrrolidone hydrogen sulfate and sulfamic acid as a solvent and a catalyst, carrying out alkylation reaction to obtain a mixed solution of 2-tert-butyl p-ethylphenol and 6-tert-butyl m-ethylphenol, and rectifying the mixed solution to obtain high-purity products of 2-tert-butyl p-ethylphenol and 6-tert-butyl m-ethylphenol; respectively carrying out dealkylation reaction and rectification on the obtained high-purity 2-tert-butyl-p-ethylphenol and 6-tert-butyl-m-ethylphenol in the presence of a solid catalyst to respectively obtain high-purity m-ethylphenol and p-ethylphenol products; the isobutene generated by dealkylation is recycled and reused. The method has the advantages that the tert-butyl ethylphenol generated by the reaction of m-para-ethylphenol and isobutene has low solubility in the ionic liquid, so that the tert-butyl ethylphenol product can be separated from the ionic liquid and floats on the surface of the ionic liquid after being generated, the separation from the catalyst is realized, and the reaction product is basically mono-tert-butyl ethylphenol. In addition, the reaction conditions are mild, and isobutene is hardly generated with polymers in the reaction process.
The technical scheme adopted by the invention is as follows:
the m-ethylphenol and the p-ethylphenol are separated by an alkylation method, and the separation steps are as follows:
(1) Dissolving a certain amount of mixture of m-ethylphenol and p-ethylphenol in composite ionic liquid consisting of N-methyl pyrrolidone hydrogen sulfate and sulfamic acid, and adding the mixed solution into a bubbling bed reactor with a constant-temperature circulating water bath jacket.
(2) Starting a circulating water bath, controlling a certain temperature and pressure, starting to blow isobutene, and separating out the generated m-ethylphenol tert-butyl esterification product due to the fact that the m-ethylphenol tert-butyl esterification product is difficult to dissolve in the ionic liquid along with the reaction and floating on the surface of the ionic liquid.
(3) And removing and rectifying the tert-butyl phenol product on the upper layer to obtain a 6-tert-butyl m-ethylphenol product and a 2-tert-butyl p-ethylphenol product.
(4) Adding the rectified 6-tert-butyl-m-ethylphenol product or 2-tert-butyl-p-ethylphenol product into a cracking kettle, adding a certain amount of solid acid catalyst, and heating under normal pressure stirring to crack the product.
(5) After no more isobutene is generated in the cracking kettle, filtering materials in the kettle, recycling the catalyst, rectifying the filtrate to obtain high-purity m-ethylphenol or p-ethylphenol, and recycling the isobutene obtained by cracking.
In the method for separating m-ethylphenol and p-ethylphenol, when a phenol ionic liquid solution is prepared, the mass fraction of phenol in ionic liquid is controlled to be 1-50%.
In the method of the technical scheme, when isobutene is blown in for tertiary butyl reaction, the reaction temperature is controlled to be 30-100 ℃.
In the method of the technical scheme, when isobutene is blown in for carrying out tertiary butyl alkylation, the reaction pressure is controlled to be between normal pressure and 0.5MPa.
In the method of the technical scheme, the tert-butyl phenol product is separated by adopting a rectification mode, and the rectification can be normal pressure rectification or vacuum rectification.
In the method of the technical scheme, the solid catalyst used for cracking the tert-butyl phenol can be strong acid resin and an acid molecular sieve, and the dosage of the solid catalyst is 1-30% of the mass fraction of phenol.
In the method of the technical proposal, the temperature of the tert-butyl phenol cracking reaction is controlled to be 120-250 ℃.
In the method of the technical scheme, the cracking product is refined by adopting a rectification mode, and the rectification can be normal pressure rectification or vacuum rectification.
Detailed Description
Example 1
200 kg of a mixture of m-ethylphenol and p-ethylphenol (the mass content of m-ethylphenol is 61 percent and the mass content of p-ethylphenol is 39 percent) is dissolved in 800 kg of composite ionic liquid consisting of N-methyl pyrrolidone hydrogen sulfate and sulfamic acid, and then the mixed solution is added into a bubbling bed reactor with a constant-temperature circulating water bath jacket. Starting a circulating water bath, controlling the temperature of the water bath to be 50 ℃, then blowing isobutene under normal pressure, controlling the reaction temperature to be not more than 60 ℃, and separating out the generated m-ethylphenol tert-butyl esterification product due to the fact that the m-ethylphenol tert-butyl esterification product is difficult to dissolve in the ionic liquid along with the reaction and floating on the surface of the ionic liquid. The tert-butyl phenol product on the upper layer is removed and rectified under reduced pressure to obtain 172 kg of 6-tert-butyl-m-ethylphenol product and 112 kg of 2-tert-butyl-p-ethylphenol product.
Adding 172 kg of 6-tert-butyl m-ethylphenol product obtained by rectification into a cracking kettle, adding 20 kg of acidic SBA-15 molecular sieve catalyst, heating to 200 ℃ under normal pressure stirring to crack the product, filtering materials in the kettle after no more isobutene is generated in the cracking kettle, recycling the catalyst, carrying out reduced pressure rectification on the filtrate to obtain 117 kg of m-ethylphenol with the purity of 99.63%, and recycling the isobutene obtained by cracking. In the same manner, 76 kg of p-ethylphenol having a purity of 99.72% was obtained.
Example 2
100 kg of a mixture of m-ethylphenol and p-ethylphenol (the mass content of m-ethylphenol is 36 percent and the mass content of p-ethylphenol is 64 percent) is dissolved in 900 kg of composite ionic liquid consisting of N-methyl pyrrolidone hydrogen sulfate and sulfamic acid, and then the mixed solution is added into a bubbling bed reactor with a constant-temperature circulating water bath jacket. Starting a circulating water bath, controlling the temperature of the water bath to be 40 ℃, then blowing isobutene under the pressure of 0.2MPa, controlling the reaction temperature to be not more than 50 ℃, and separating out the generated m-p-ethylphenol tert-butyl esterification product due to the fact that the m-ethylphenol tert-butyl esterification product is difficult to dissolve in the ionic liquid along with the reaction and floating on the surface of the ionic liquid. The tert-butyl phenol product on the upper layer is removed and rectified under reduced pressure to obtain 52 kg of 6-tert-butyl-m-ethylphenol product and 93 kg of 2-tert-butyl-p-ethylphenol product.
Adding 52 kg of the 6-tert-butyl m-ethylphenol product obtained by rectification into a cracking kettle, adding 2 kg of strong-acid cation exchange resin, stirring under normal pressure, heating to 150 ℃ to crack the product, filtering materials in the kettle after no more isobutene is generated in the cracking kettle, recycling the catalyst, and carrying out reduced pressure rectification on the filtrate to obtain 35 kg of m-ethylphenol with the purity of 99.67%, wherein the m-ethylphenol is used for indiscriminately for isobutene obtained by cracking. In the same manner, 63 kg of p-ethylphenol having a purity of 99.76% was obtained.
Example 3
300 kg of a mixture of m-ethylphenol and p-ethylphenol (the mass content of m-ethylphenol is 47% and the mass content of p-ethylphenol is 53%) was dissolved in 700 kg of a composite ionic liquid consisting of N-methylpyrrolidone hydrogen sulfate and sulfamic acid, and the mixed solution was fed into a bubbling bed reactor with a constant-temperature circulating water bath jacket. Starting a circulating water bath, controlling the temperature of the water bath to be 60 ℃, then blowing isobutene under the pressure of 0.5MPa, controlling the reaction temperature to be not more than 70 ℃, and separating out the generated m-p-ethylphenol tert-butyl esterification product due to the fact that the m-ethylphenol tert-butyl esterification product is difficult to dissolve in the ionic liquid along with the reaction and floating on the surface of the ionic liquid. The tert-butyl phenol product on the upper layer is removed and rectified under reduced pressure to obtain 201 kg of 6-tert-butyl-m-ethylphenol product and 229 kg of 2-tert-butyl-p-ethylphenol product.
Adding 201 kg of the 6-tert-butyl m-ethylphenol product obtained by rectification into a cracking kettle, adding 40 kg of HMCM-41 molecular sieve, stirring under normal pressure, heating to 180 ℃ to crack the product, filtering the materials in the kettle after no more isobutene is generated in the cracking kettle, recycling the catalyst, carrying out reduced pressure rectification on the filtrate to obtain 137 kg of m-ethylphenol with the purity of 99.58%, and recycling the isobutene obtained by cracking. In the same manner, 156 kg of p-ethylphenol having a purity of 99.60% was obtained.
Example 4
400 kg of a mixture of m-ethylphenol and p-ethylphenol (the mass content of m-ethylphenol is 28% and the mass content of p-ethylphenol is 72%) was dissolved in 600 kg of a composite ionic liquid consisting of N-methylpyrrolidone hydrogen sulfate and sulfamic acid, and the mixed solution was fed into a bubbling bed reactor with a constant-temperature circulating water bath jacket. Starting a circulating water bath, controlling the temperature of the water bath to be 70 ℃, then blowing isobutene under the pressure of 0.1MPa, controlling the reaction temperature to be not more than 80 ℃, and separating out the generated m-p-ethylphenol tert-butyl esterification product due to the fact that the m-ethylphenol tert-butyl esterification product is difficult to dissolve in the ionic liquid along with the reaction and floating on the surface of the ionic liquid. The upper tert-butyl phenol product was removed and rectified under reduced pressure to yield 159 kg of 6-tert-butyl-m-ethylphenol and 415 kg of 2-tert-butyl-p-ethylphenol.
159 kg of 6-tert-butyl m-ethyl phenol product obtained by rectification is added into a cracking kettle, 15 kg of strong-acid cation exchange resin is added, the temperature is raised to 160 ℃ under normal pressure stirring to crack the product, after no more isobutene is generated in the cracking kettle, the materials in the kettle are filtered, the catalyst is recycled, the filtrate is subjected to reduced pressure rectification to obtain 108 kg of m-ethyl phenol with the purity of 99.61%, and the isobutene obtained by cracking is used indiscriminately. In the same manner, 283 kg of p-ethylphenol having a purity of 99.67% was obtained.
The above embodiments are all specific embodiments of the present invention, and the present invention is not limited by the above embodiments. It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention, and it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
Claims (8)
1. A method for separating m-ethylphenol and p-ethylphenol comprises the following separation steps:
(1) Dissolving a certain amount of mixture of m-ethylphenol and p-ethylphenol in composite ionic liquid consisting of N-methylpyrrolidone bisulfate and sulfamic acid, and then adding the mixed solution into a bubbling bed reactor with a constant-temperature circulating water bath jacket;
(2) Starting a circulating water bath, controlling a certain temperature and pressure, starting to blow isobutene, and separating out a generated m-ethylphenol tert-butyl esterification product due to the fact that the product is insoluble in ionic liquid along with the reaction and floating on the surface of the ionic liquid;
(3) Removing and rectifying the tert-butyl phenol product on the upper layer to obtain a 6-tert-butyl m-ethylphenol product and a 2-tert-butyl p-ethylphenol product;
(4) Adding the rectified 6-tert-butyl-m-ethylphenol product or 2-tert-butyl-p-ethylphenol product into a cracking kettle, adding a certain amount of solid acid catalyst, and heating under normal pressure stirring to crack the product;
(5) After no more isobutene is generated in the cracking kettle, filtering materials in the kettle, recycling the catalyst, rectifying the filtrate to obtain high-purity m-ethylphenol or p-ethylphenol, and indiscriminately using isobutene obtained by cracking.
2. The method for separating m-ethylphenol and p-ethylphenol according to claim 1, wherein the mass fraction of phenol in the ionic liquid is controlled to be 1-50% when the ionic liquid solution of phenol is prepared.
3. The process of claim 1, wherein the reaction temperature is controlled to 30 ℃ to 100 ℃ when isobutylene is fed for the tertiary butylation.
4. The process of claim 1, wherein the reaction pressure is controlled to be from atmospheric pressure to 0.5MPa when isobutylene is bubbled into the mixture to effect the tertiary butylation.
5. The method of claim 1, wherein the tertiary butyl phenol product is separated by rectification, which can be atmospheric rectification or vacuum rectification.
6. The method of claim 1, wherein the solid catalyst used for cracking tert-butyl phenol is selected from the group consisting of strongly acidic resin and acidic molecular sieve, and the amount of the solid catalyst is 1-30% of the mass fraction of phenol.
7. The process of claim 1, wherein the temperature of the tert-butylphenol cleavage reaction is controlled to 120 ℃ to 250 ℃.
8. The method of claim 1, wherein the cracked product is refined by distillation, and the distillation can be atmospheric distillation or vacuum distillation.
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| CN113698278B (en) * | 2021-04-08 | 2022-08-23 | 盐城工学院 | Method for extracting 3, 5-xylenol from 3, 5-xylenol/m-p-ethylphenol |
| CN113582819A (en) * | 2021-08-07 | 2021-11-02 | 成武奥瑞特化学有限公司 | Synthesis method of 2-tert-butyl-4-ethylphenol |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101863742A (en) * | 2010-06-07 | 2010-10-20 | 吴鸿宾 | Separation method of m-cresol and p-cresol mixture |
| CN103212438A (en) * | 2013-05-02 | 2013-07-24 | 天津北洋国精科技股份有限公司 | Catalyst for alkylation separation of m-cresol and p-cresol and separation method |
| CN104496759A (en) * | 2014-05-22 | 2015-04-08 | 安徽时联特种溶剂股份有限公司 | Method for fixed bed alkylation separation of m-cresol and p-cresol |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101863742A (en) * | 2010-06-07 | 2010-10-20 | 吴鸿宾 | Separation method of m-cresol and p-cresol mixture |
| CN103212438A (en) * | 2013-05-02 | 2013-07-24 | 天津北洋国精科技股份有限公司 | Catalyst for alkylation separation of m-cresol and p-cresol and separation method |
| CN104496759A (en) * | 2014-05-22 | 2015-04-08 | 安徽时联特种溶剂股份有限公司 | Method for fixed bed alkylation separation of m-cresol and p-cresol |
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