Method for preparing phenolic products from m-p-isopropyl phenol / m-p-propyl phenol

Abstract

The invention belongs to the technical field of organic synthesis and separation, and particularly relates to a method for preparing phenolic products from m-p-isopropyl phenol / m-p-propyl phenol. The invention provides a method for preparing a phenolic product from m-p-isopropyl phenol / m-p-propyl phenol. The method comprises the following steps: (1) adding silicon-aluminum oxide and zirconium phosphate into a mixture of m-p-isopropyl phenol / m-p-propyl phenol to carry out dealkylation reaction; (2) after the dealkylation reaction is finished, carrying out first cooling treatment, then adding a sulfuric acid solution and a mixture of phenol and m-cresol for reaction, after the reaction is finished, carrying out second cooling treatment, discharging gas, replacing reaction liquid with nitrogen, and then carrying out filtering treatment to obtain reaction product mixed liquid, the reaction product mixed solution is prepared from methanol, phenol, m-cresol, o-isopropyl phenol, p-isopropyl phenol, m-isopropyl phenol, 2-isopropyl-5-cresol and 4-isopropyl-3-cresol; and (3) carrying out normal pressure rectification on the reaction product mixed solution to recover methanol, adding a sodium hydroxide solution for neutralization, and carrying out reduced pressure rectification to obtain petrochemical grade phenol, pharmaceutical grade m-cresol, o-isopropyl phenol, p-isopropyl phenol crude products, 2-isopropyl-5-cresol and 4-isopropyl-3-cresol.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis and separation, and particularly relates to a method for preparing phenol products by using m-p-isopropylphenol / m-p-propylphenol. Background Art

[0002] Crude phenol is distilled to obtain phenol, o-cresol, tri-cresol, m-p-cresol containing 55% of the meta position, 99% of m-p-cresol, and industrial xylenol. These are sold directly as products without fine separation. In fact, the industrial xylenol distillation residue also contains a m-p-isopropylphenol / m-p-propylphenol fraction with a boiling point of 227-231°C, which is mainly composed of m-isopropylphenol, p-isopropylphenol, m-propylphenol, and p-propylphenol, and also contains some impurities such as 2-ethyl-3-methylphenol, 2-methyl-3-ethylphenol, 3-ethyl-5-methylphenol, and 2,4,5-trimethylphenol. Since m-isopropylphenol, p-isopropylphenol, m-propylphenol, and p-propylphenol are difficult to separate by distillation, tert-butylation, and the current market use of the m-p-isopropylphenol / m-p-propylphenol mixture is limited, it is necessary to carry out appropriate treatment to achieve the purpose of utilizing the m-p-isopropylphenol / m-p-propylphenol mixture.

[0003] CN113544112 A discloses a method for producing cresols from a feed containing phenol. The method comprises: introducing a feed stream containing phenol into a first separation zone, wherein the feed stream containing phenol is separated in the first separation zone into at least a phenol stream containing phenol, an alkylphenol stream containing heavy methylphenols and heavy alkylphenols, and a cresol stream containing cresols. The heavy alkylphenols in the alkylphenol stream are dealkylated in a dealkylation reaction zone under dealkylation conditions to produce a dealkylated effluent stream containing phenol, cresols, heavy methylphenols, and olefins. In the dealkylation separation zone, the dealkylated effluent stream is separated into at least an olefin stream containing olefins and a second stream containing phenol, cresols, and heavy methylphenols. The second stream is transalkylated in a transalkylation reaction zone under transalkylation conditions to produce a transalkylation effluent stream containing cresols, unreacted phenol, unreacted heavy alkylphenols, and unreacted heavy methylphenols. One or more of the following: at least a portion of the phenol stream, the olefin stream, or the cresol stream is recovered. This patent is about the high-temperature catalytic dealkylation of higher phenols such as ethylphenol, propyl / isopropylphenol, butylphenol, and methylethylphenol to convert them into phenol, cresol, and various olefins. This will result in a huge waste of resources such as m-ethylphenol, p-ethylphenol, m-propylphenol, p-propylphenol, m-isopropylphenol, p-isopropylphenol, butylphenol, and 5-ethyl-3-cresol. This patent also allows heavy cresols to undergo an isomerization reaction with phenol, and the removed methyl group reacts with phenol to produce cresol and other substances. Since many dimethylphenols and heavy cresols (such as 2,3,5-trimethylphenol, 3,5-dimethylphenol, 3,4-dimethylphenol, 2,5-dimethylphenol, 2,4-dimethylphenol, etc.) have a certain market, the product price is many times higher than that of phenol. The demethylation and methyl transposition reactions are much more difficult than those of ethyl, propyl, and butyl. The reaction conversion rate and selectivity are not ideal, and the production cost is high. It currently does not seem to be economically feasible. Summary of the Invention

[0004] The present invention aims to at least partially address one of the technical problems in the related art. To this end, embodiments of the present invention provide a method for preparing a phenolic product from m-isopropylphenol / m-isopropylphenol, which can produce high-quality phenol, o-isopropylphenol, and p-isopropylphenol with simple operation, minimal waste, and low production cost.

[0005] The method for preparing a phenolic product using m-isopropylphenol / m-p-propylphenol according to an embodiment of the present invention comprises the following steps:

[0006] (1) adding silica-aluminum oxide and zirconium phosphate to a m-p-isopropylphenol / m-p-propylphenol mixture to carry out a dealkylation reaction; the m-p-isopropylphenol / m-p-propylphenol mixture comprises: at least two of m-isopropylphenol, p-isopropylphenol, m-propylphenol and p-propylphenol, with a content of 85-100 wt%, 2,4,5-trimethylphenol 0-1 wt%, 2-ethyl-3-methylphenol / 2-methyl-3-ethylphenol 0-1 wt%, 3-ethyl-5-methylphenol 0-10 wt%, and other 0-3 wt%;

[0007] (2) after the dealkylation reaction is completed, a first cooling treatment is performed, and then a sulfuric acid solution and a mixture of phenol and meta-cresol are added to react. After the reaction is completed, a second cooling treatment is performed and the gas is exhausted. The reaction liquid is replaced with nitrogen and then filtered to obtain a reaction product mixture, wherein the reaction product mixture includes methanol, phenol, meta-cresol, o-isopropylphenol, p-isopropylphenol, meta-isopropylphenol, 2-isopropyl-5-methylphenol and 4-isopropyl-3-methylphenol;

[0008] (3) The reaction product mixture obtained in step (2) is first subjected to atmospheric distillation to recover methanol, and then sodium hydroxide solution is added for neutralization and subjected to vacuum distillation to obtain petrochemical-grade phenol, pharmaceutical-grade m-cresol, o-isopropylphenol, crude p-isopropylphenol, 2-isopropyl-5-methylphenol and 4-isopropyl-3-methylphenol.

[0009] The advantages and technical effects brought by the method for preparing phenol products from m-isopropylphenol / m-isopropylphenol of the embodiment of the present invention are as follows: 1. The method of the embodiment of the present invention removes the isopropyl / propyl group in the m-isopropylphenol / m-isopropylphenol mixture of the crude phenol distillation extract at high temperature to obtain phenol and propylene, and then reacts the removed propylene with excess low-grade phenol and meta-cresol to obtain petrochemical-grade phenol by distillation, and converts m-isopropylphenol / m-isopropylphenol into o-isopropylphenol and p-isopropylphenol products, thereby increasing the added value; 2. The o-isopropylphenol obtained by the method of the embodiment of the present invention has a large boiling point difference from phenol, p-isopropylphenol, etc., and is easily distilled to obtain a 99% o-isopropylphenol product; 3. The method of the embodiment of the present invention is simple and easy to operate, produces less three wastes, and has low production costs.

[0010] In some embodiments, in step (1), the amount of zirconium phosphate used is 1 to 10% of the mass of the silicon-aluminum oxide;

[0011] And / or, in step (1), the amount of the silicon-aluminum oxide is 10 to 30% of the mass of the m-isopropylphenol / m-p-propylphenol mixture;

[0012] And / or, in step (1), the silicon-aluminum oxide comprises silicon dioxide and acidic aluminum oxide, and the mass ratio of silicon dioxide to acidic aluminum oxide is 1:0.01-50.

[0013] In some embodiments, in step (1), the temperature of the dealkylation reaction is 250-350° C., the time of the dealkylation reaction is 5-8 h, and the pressure rises to 1.5-4 MPa during the dealkylation reaction. When the pressure remains stable, sampling is performed through an automatic sampling system kept at 50° C. The collected samples enter an online automatic detection system for detection, and the reaction ends when the m-isopropylphenol content is ≤0.5%.

[0014] In some embodiments, in step (2), the first cooling includes lowering the temperature to below 180° C. within 0.5 to 1 hour;

[0015] And / or, in step (2), the dealkylation reaction is carried out in a stainless steel high-pressure reactor with an external stainless steel condenser and an inner coil; the first cooling treatment uses the heat transfer oil in the inner coil for programmed cooling, and the cooling rate of the heat transfer oil is 100 to 200°C / h.

[0016] In some embodiments, in step (2), the concentration of the sulfuric acid solution is 95-98%, and the amount of the sulfuric acid solution is 0.5-5% of the mass of the m-isopropylphenol / m-p-propylphenol mixture;

[0017] And / or, in step (2), the amount of the phenol and m-cresol mixture is 0.5 to 2 times the mass of the m-isopropylphenol / m-p-propylphenol mixture;

[0018] And / or, in step (2), the nitrogen compound and the sulfide compound in the mixture of phenol and m-cresol are both greater than 30 ppm;

[0019] And / or, in step (2), the reaction temperature is 150-200° C., the reaction time is 2-6 hours, and the reaction is terminated when the pressure remains stable for 0.5-1 hour;

[0020] And / or, in step (2), the second cooling treatment is to reduce the temperature to below 100° C. within 1 to 2 hours, and the nitrogen replacement time is 0.5 to 1 hour;

[0021] And / or, in the step (2), the filtering treatment includes washing the filter cake with methanol after the filtering treatment and filtering again, and the amount of methanol used is 5-20% of the mass of the silicon aluminum oxide.

[0022] In some embodiments, in step (2), the phenol and m-cresol mixture is replaced with phenol, and the reaction product mixture includes methanol, phenol, o-isopropylphenol, p-isopropylphenol and a small amount of m-isopropylphenol, and then the petrochemical-grade phenol, o-isopropylphenol and p-isopropylphenol crude products are obtained by distillation in step (3);

[0023] Alternatively, in step (2), the mixture of phenol and meta-cresol is replaced with meta-cresol, and the reaction product mixture includes methanol, phenol, meta-cresol, o-isopropylphenol, p-isopropylphenol, m-isopropylphenol, 2-isopropyl-5-cresol, and 4-isopropyl-3-cresol, and then the distillation in step (3) obtains petrochemical-grade phenol, pharmaceutical-grade meta-cresol, o-isopropylphenol, crude p-isopropylphenol, 2-isopropyl-5-cresol, and 4-isopropyl-3-cresol;

[0024] Preferably, the nitrogen compound and the sulfide compound in the phenol or m-cresol are both greater than 30 ppm;

[0025] The amount of phenol or meta-cresol used is 0.5 to 2 times the mass of the meta-para-isopropylphenol / meta-para-propylphenol mixture.

[0026] In some embodiments, in step (3), the concentration of the sodium hydroxide solution is 30-35%, and the molar mass of the sodium hydroxide is 2-2.4 times the molar mass of the sulfuric acid solution;

[0027] And / or, in step (3), the vacuum degree of the reduced pressure distillation is -0.085 to -0.095 MPa, and the reflux ratio is 10 to 25:1.

[0028] In some embodiments, the method further comprises step (4): stirring and mixing the crude para-isopropylphenol and methanol, heating the mixture to 60-70° C. to completely dissolve the mixture, then cooling the mixture to 30-40° C. with circulating water for 2-3 hours, then cooling the mixture to -10-10° C. with chilled brine for 2-4 hours, keeping the mixture warm for 1-3 hours, filtering, draining, and drying the mixture to obtain ≥99% para-isopropylphenol;

[0029] The mass of the methanol is 0.5 to 2 times the mass of the crude 4-isopropylphenol.

[0030] In some embodiments, when the m-isopropylphenol / m-propylphenol mixture also includes 3-ethyl-5-methylphenol, the reaction product mixture also includes 3-ethyl-5-methylphenol, and after the vacuum distillation in step (3), crude 3-ethyl-5-methylphenol is obtained.

[0031] In some embodiments, the crude 3-ethyl-5-methylphenol and methanol are stirred and mixed, and then heated to 60-70° C. to completely dissolve the materials. The mixture is then cooled to 30-40° C. using circulating water for 2-3 hours, and then cooled to -10-10° C. using chilled brine for 2-4 hours. The mixture is kept warm for 1-3 hours, filtered, drained, and dried to obtain ≥99% 3-ethyl-5-methylphenol.

[0032] The amount of the methanol used is 0.5 to 2 times the amount of the crude 3-ethyl-5-methylphenol. DETAILED DESCRIPTION

[0033] The following describes in detail embodiments of the present invention. The embodiments are exemplary and intended to explain the present invention, but are not to be construed as limiting the present invention.

[0034] The method for preparing a phenolic product using m-isopropylphenol / m-p-propylphenol according to an embodiment of the present invention comprises the following steps:

[0035] (1) adding silica-aluminum oxide and zirconium phosphate to a m-p-isopropylphenol / m-p-propylphenol mixture to carry out a dealkylation reaction; the m-p-isopropylphenol / m-p-propylphenol mixture comprises: at least two of m-isopropylphenol, p-isopropylphenol, m-propylphenol and p-propylphenol, with a content of 85-100 wt%, 2,4,5-trimethylphenol 0-1 wt%, 2-ethyl-3-methylphenol / 2-methyl-3-ethylphenol 0-1 wt%, 3-ethyl-5-methylphenol 0-10 wt%, and other 0-3 wt%;

[0036] (2) after the dealkylation reaction is completed, a first cooling treatment is performed, and then a sulfuric acid solution and a mixture of phenol and meta-cresol are added to react. After the reaction is completed, a second cooling treatment is performed and the gas is exhausted. The reaction liquid is replaced with nitrogen and then filtered to obtain a reaction product mixture, wherein the reaction product mixture includes methanol, phenol, meta-cresol, o-isopropylphenol, p-isopropylphenol, meta-isopropylphenol, 2-isopropyl-5-methylphenol and 4-isopropyl-3-methylphenol;

[0037] (3) The reaction product mixture obtained in step (2) is first subjected to atmospheric distillation to recover methanol, and then sodium hydroxide solution is added for neutralization and subjected to vacuum distillation to obtain petrochemical-grade phenol, pharmaceutical-grade m-cresol, o-isopropylphenol, crude p-isopropylphenol, 2-isopropyl-5-methylphenol and 4-isopropyl-3-methylphenol.

[0038] The method for preparing phenol products from m-isopropylphenol / m-isopropylphenol according to the embodiment of the present invention comprises the following steps: removing the isopropyl / propyl group from a mixture of m-isopropylphenol / m-isopropylphenol obtained by distillation of a crude phenol extract at high temperature to obtain phenol and propylene; reacting the removed propylene with excess low-grade phenol and meta-cresol to obtain petrochemical-grade phenol by distillation; and converting the m-isopropylphenol / m-isopropylphenol into o-isopropylphenol and p-isopropylphenol products, thereby increasing added value; according to the method of the embodiment of the present invention, the o-isopropylphenol obtained has a large boiling point difference from phenol, p-isopropylphenol, etc., and can be easily distilled to obtain a 99% o-isopropylphenol product; and the method of the embodiment of the present invention is simple and easy to operate, produces little three wastes, and has low production costs.

[0039] In some embodiments, preferably, the meta-isopropylphenol / meta-propylphenol mixture comprises meta-isopropylphenol, para-isopropylphenol, meta-propylphenol and para-propylphenol.

[0040] In some embodiments, preferably, in step (1), the amount of zirconium phosphate used is 1 to 10% of the mass of the silicon-aluminum oxide;

[0041] And / or, in the step (1), the amount of the silicon-aluminum oxide is 10 to 30% of the mass of the m-isopropylphenol / m-p-propylphenol mixture.

[0042] In some embodiments, preferably, in step (1), the silicon-aluminum oxide comprises silicon dioxide and acidic alumina, and the mass ratio of silicon dioxide to acidic alumina is 1:0.01 to 50. Further preferably, the mass ratio of silicon dioxide to acidic alumina is 1:0.05 to 20.

[0043] In some embodiments, preferably, in step (1), the temperature of the dealkylation reaction is 250-350° C., the time of the dealkylation reaction is 5-8 hours, and the pressure during the dealkylation reaction rises to 1.5-4 MPa. When the pressure remains stable, a sample is taken through an automatic sampling system kept at 50° C. The collected sample enters an online automatic detection system for detection, and the reaction is terminated when the m-isopropylphenol content is ≤0.5%. During the sampling and analysis process, if the m-isopropylphenol content is ≥2%, a catalyst needs to be added to continue the reaction; if the m-isopropylphenol content is ≤2%, the temperature can be increased by 10-20° C. and the reaction can be continued until the content is qualified.

[0044] In some embodiments, preferably, in step (2), the first cooling comprises lowering the temperature to below 180° C. within 0.5 to 1 hour;

[0045] And / or, in step (2), the dealkylation reaction is carried out in a stainless steel high-pressure reactor with an external stainless steel condenser and an inner coil; the first cooling treatment uses the heat transfer oil in the inner coil for programmed cooling, and the cooling rate of the heat transfer oil is 100 to 200°C / h.

[0046] In some embodiments, preferably, in step (2), the concentration of the sulfuric acid solution is 95-98%, and the amount of the sulfuric acid solution is 0.5-5% of the mass of the m-isopropylphenol / m-p-propylphenol mixture;

[0047] And / or, in step (2), the amount of the phenol and m-cresol mixture is 0.5 to 2 times the mass of the m-isopropylphenol / m-p-propylphenol mixture;

[0048] And / or, in step (2), the nitrogen compound and the sulfide compound in the mixture of phenol and m-cresol are both greater than 30 ppm;

[0049] And / or, in step (2), the reaction temperature is 150-200° C., the reaction time is 2-6 hours, and the reaction is terminated when the pressure remains stable for 0.5-1 hour;

[0050] And / or, in step (2), the second cooling treatment is to reduce the temperature to below 100° C. within 1 to 2 hours, and the nitrogen replacement time is 0.5 to 1 hour;

[0051] And / or, in the step (2), the filtration treatment includes washing the filter cake with methanol after filtration treatment and filtering again, and the amount of methanol used is 5-20% of the mass of the silicon aluminum oxide.

[0052] In some embodiments, preferably, in step (2), the mixture of phenol and m-cresol is replaced by phenol, and the reaction product mixture includes methanol, phenol, o-isopropylphenol, p-isopropylphenol and a small amount of m-isopropylphenol, and then the crude products of petrochemical-grade phenol, o-isopropylphenol and p-isopropylphenol are obtained by distillation in step (3);

[0053] Alternatively, in step (2), the mixture of phenol and meta-cresol is replaced with meta-cresol, and the reaction product mixture includes methanol, phenol, meta-cresol, o-isopropylphenol, p-isopropylphenol, m-isopropylphenol, 2-isopropyl-5-cresol, and 4-isopropyl-3-cresol, and then the distillation in step (3) obtains petrochemical-grade phenol, pharmaceutical-grade meta-cresol, o-isopropylphenol, crude p-isopropylphenol, 2-isopropyl-5-cresol, and 4-isopropyl-3-cresol;

[0054] Preferably, the nitrogen compound and the sulfide compound in the phenol or m-cresol are both greater than 30 ppm;

[0055] The amount of phenol or meta-cresol used is 0.5 to 2 times the mass of the meta-para-isopropylphenol / meta-para-propylphenol mixture.

[0056] In some embodiments, preferably, in step (3), the concentration of the sodium hydroxide solution is 30-35%, and the molar mass of the sodium hydroxide is 2-2.4 times the molar mass of the sulfuric acid solution;

[0057] And / or, in step (3), the vacuum degree of the reduced pressure distillation is -0.085 to -0.095 MPa, and the reflux ratio is 10 to 25:1.

[0058] In some embodiments, preferably, the process further comprises step (4): stirring and mixing the crude para-isopropylphenol and methanol, heating the mixture to 60-70° C. to completely dissolve the mixture, then cooling the mixture to 30-40° C. with circulating water for 2-3 hours, then cooling the mixture to -10-10° C. with chilled brine for 2-4 hours, keeping the mixture warm for 1-3 hours, filtering, draining, and drying the mixture to obtain ≥99% para-isopropylphenol;

[0059] The amount of the methanol used is 0.5 to 2 times the amount of the crude 4-isopropylphenol.

[0060] In some embodiments, preferably, when the m-isopropylphenol / m-propylphenol mixture also includes 3-ethyl-5-methylphenol, the reaction product mixture also includes 3-ethyl-5-methylphenol, and after the vacuum distillation in step (3), crude 3-ethyl-5-methylphenol is obtained.

[0061] In some embodiments, preferably, the crude 3-ethyl-5-methylphenol and methanol are stirred and mixed, and then heated to 60-70° C. to completely dissolve the materials, and then cooled to 30-40° C. with circulating water for 2-3 hours, and then cooled to -10-10° C. with chilled brine for 2-4 hours, kept warm for 1-3 hours, filtered, drained, and dried to obtain ≥99% 3-ethyl-5-methylphenol;

[0062] The amount of the methanol used is 0.5 to 2 times the amount of the crude 3-ethyl-5-methylphenol.

[0063] The technical solution of the present invention is described in detail below in conjunction with specific embodiments.

[0064] Example 1

[0065] Step 1: Cleavage and translocation reaction

[0066] In a stainless steel high-pressure reactor with an external stainless steel condenser and an inner coil, 1500 parts of an acidic silica-alumina solid catalyst (all parts are measured by weight in the examples) (the mass ratio of silica to acidic alumina is 1:1) and 15 parts of zirconium phosphate are added, and 7500 parts of a m-isopropylphenol mixture (containing 4821 parts of m-isopropylphenol and 2679 parts of p-isopropylphenol) are added. The reactor is sealed and heated to 340°C for 5 hours. The pressure is gradually increased to a stable level of 3.1-3.3 MPa. Sampling is performed through an automatic sampling system kept at 50°C. The collected samples are detected by an online automatic detection system. The reaction is terminated when the m-isopropylphenol content reaches 0.23%.

[0067] The inner coil was cooled with programmed thermal oil at a cooling rate of 170-180°C / h, and the temperature was lowered to 170°C in 1 hour. 100 parts of 98% sulfuric acid solution, 3000 parts of 99.1% phenol (nitride 46ppm, sulfide 39ppm), and 4000 parts of 99.3% m-cresol (nitride 77ppm, sulfide 65ppm) were added through a constant pressure device, and the mixture was kept at 180-190°C for 4 hours. The pressure of the reactor dropped to 0.04MPa and remained stable. After cooling to 78°C in 1.5 hours, the gas was exhausted and the reaction liquid was treated with nitrogen. The mixture was replaced for 0.5 hours and filtered. The filter cake was washed with 100 parts of methanol (the amount of methanol used was 6.8% of the mass of the silica-alumina catalyst). The reaction product mixture was filtered to obtain 14280.3 parts (100 parts of sulfuric acid, 98.6 parts of methanol, 4543.5 parts of phenol, 1934.9 parts of m-cresol, 2288.1 parts of o-isopropylphenol, 2509.7 parts of p-isopropylphenol, 57.9 parts of m-isopropylphenol, 1594.2 parts of 2-isopropyl-5-methylphenol, 1107.8 parts of 4-isopropyl-3-methylphenol and 45.6 parts of others). The solid catalyst was applied as is.

[0068] Step 2: Distillation separation of reaction liquid

[0069] 14280.3 parts of the reaction product mixture obtained by filtering the step 1 was added to the bottom of a distillation tower (100 parts of dimethyl diphenyl ether high boiling point solvent had been added to the bottom of the tower, and the tower had 300 theoretical plates), and 97.1 parts of methanol were recovered under normal pressure; the temperature was lowered to 80°C, 271 parts of a 31% sodium hydroxide aqueous solution (the molar mass of sodium hydroxide was 2.1 times that of the sulfuric acid solution) was added dropwise, and vacuum distillation was performed (vacuum degree -0.09 MPa, reflux ratio 20-25:1) to obtain 9 4461.6 parts of 9.9% phenol (0.9 ppm nitrogen compound, 0.6 ppm sulfide compound), 1853.5 parts of 99.8% m-cresol (0.7 ppm nitrogen compound, 0.5 ppm sulfide compound), 2101.9 parts of 99.5% o-isopropylphenol, 2249.2 parts of 97.7% crude p-isopropylphenol, 1446.5 parts of 99.3% 2-isopropyl-5-methylphenol, and 1041.1 parts of 99.6% 4-isopropyl-3-methylphenol.

[0070] 2249.2 parts of crude 97.7% p-isopropylphenol and 2000 parts of methanol were added to a reactor, stirred, and heated to 65°C to completely dissolve the materials. The mixture was then cooled to 33°C in a cold water bath for 2.5 hours, then cooled to 5°C in an ice-water bath for 2.5 hours, kept warm for 2 hours, filtered, drained, and dried to obtain 2047.6 parts of 99.7% p-isopropylphenol with a refining yield of 92.9%. The mother liquor was added to a rectifying kettle for distillation to remove methanol, and 1956 parts of methanol was recovered and used again. The mixture was then rectified to obtain 191.2 parts of 99.4% m-isopropylphenol (50.1 parts of m-isopropylphenol, 140 parts of p-isopropylphenol, and 1.1 parts of other substances).

[0071] Example 2

[0072] Step 1: Cleavage and translocation reaction

[0073] A stainless steel high-pressure reactor with an external stainless steel condenser and an inner coil is charged with 750 parts of an acidic silica-alumina solid catalyst (the mass ratio of silicon dioxide to acidic alumina is 1:1) and 10 parts of zirconium phosphate. 5000 parts of a meta-para-propylphenol / meta-para-propylphenol mixture (containing 1754 parts of meta-isopropylphenol, 1449 parts of para-isopropylphenol, 654 parts of meta-propylphenol, 579 parts of para-propylphenol, 33 parts of 2,4,5-trimethylphenol, 28 parts of 2-ethyl-3-methylphenol, 19 parts of 2-methyl-3-ethylphenol, 426 parts of 3-ethyl-5-methylphenol, and 58 parts of others) is added. The reactor is sealed and heated to 280° C. for 6 hours. The pressure is gradually increased to a stable level of 2.4-2.5 MPa. Sampling is performed through an automatic sampling system kept at 50° C. The collected samples are sent to an online automatic detection system for detection. The reaction is terminated when the meta-isopropylphenol content reaches 0.29%.

[0074] The inner coil was cooled with programmed thermal oil at a cooling rate of 110-120°C / h, and the temperature was lowered to 170°C in 1 hour. 50 parts of 98% sulfuric acid solution and 3000 parts of 99.1% phenol (nitride 46 ppm, sulfide 39 ppm) (0.6 times the mass of the raw material m-isopropylphenol / m-p-propylphenol mixture) were added through a constant pressure device. The reaction was kept at 170-180°C for 4 hours. The pressure of the reactor dropped to 0.06 MPa and remained stable. After cooling to 70°C in 1.5 hours, the gas was exhausted and the reaction liquid was replaced with nitrogen for 0.5 hours. , filtered, 50 parts of methanol were used to wash the filter cake (the amount of methanol was 6.7% of the mass of the silica-alumina catalyst), and 7970.9 parts of a reaction product mixture was obtained by filtration (50 parts of sulfuric acid, 49.6 parts of methanol, 2984.7 parts of phenol, 2049.5 parts of o-isopropylphenol, 2204.1 parts of p-isopropylphenol, 50.5 parts of m-isopropylphenol, 443.5 parts of 3-ethyl-5-methylphenol, 24.7 parts of 2-ethyl-3-methylphenol / 2-methyl-3-ethylphenol, 19.1 parts of 2,4,5-trimethylphenol, and 95.2 parts of others), and the solid catalyst was applied.

[0075] Step 2: Distillation separation of reaction liquid

[0076] 7970.9 parts of the reaction product mixture obtained by filtering the step 1 was added to the bottom of a distillation tower (100 parts of dimethyl diphenyl ether high boiling point solvent had been added to the bottom of the tower, and the tower had 300 theoretical plates), and 48.8 parts of methanol were recovered under normal pressure; the temperature was lowered to 80°C, 145 parts of a 31% sodium hydroxide aqueous solution (the molar mass of sodium hydroxide was 2.24 times the molar mass of the sulfuric acid solution) were added dropwise, and vacuum distillation was performed (vacuum degree -0.09 MPa, reflux ratio 20-25:1) to obtain 2746.2 parts of 99.9% phenol (0.8 ppm nitrogen, 0.4 ppm sulfide), 1701.4 parts of 99.5% o-isopropyl phenol, 2032.2 parts of a crude product of 96.5% p-isopropyl phenol, and 528.1 parts of a crude product of 82.3% 3-ethyl-5-methylphenol.

[0077] 2032.2 parts of crude 96.5% para-isopropyl phenol and 2000 parts of methanol were added to a reactor, stirred, and heated to 65°C to completely dissolve the materials. The mixture was then cooled to 35°C in a cold water bath for 2 hours, then to 5°C in an ice water bath for 3 hours, kept warm for 1 hour, filtered, drained, and dried to obtain 1833.3 parts of 99.8% para-isopropyl phenol with a refined yield of 93.3%. The mother liquor was added to a distillation kettle to distill and remove methanol. 1938 parts of methanol were recovered and used again. The mixture was then distilled to obtain 178.6 parts of 98.2% meta-para-isopropyl phenol (45.6 parts of meta-isopropyl phenol, 129.8 parts of para-isopropyl phenol, and 3.2 parts of other substances).

[0078] 528.1 parts of crude 82.3% 3-ethyl-5-methylphenol and 1000 parts of methanol were added to a reactor, stirred, and heated to 65°C to completely dissolve the materials. The mixture was then cooled to 32°C in a cold water bath for 3 hours, then cooled to -10°C in an ice water bath for 3 hours, kept warm for 2 hours, filtered, drained, and dried to obtain 322.5 parts of 99.6% 3-ethyl-5-methylphenol with a refined yield of 73.9%.

[0079] Example 3

[0080] Step 1: Cleavage and translocation reaction

[0081] A stainless steel high-pressure reactor with an external stainless steel condenser and an inner coil is charged with 750 parts of an acidic silica-alumina solid catalyst (the mass ratio of silica to acidic alumina is 1:1) and 10 parts of zirconium phosphate, and 5000 parts of a m-para-isopropylphenol mixture (containing 3214 parts of m-isopropylphenol and 1786 parts of p-isopropylphenol) are added. The reactor is sealed and heated to 320°C for 6 hours. The pressure is gradually increased to a stable level of 2.9-3.0 MPa. Sampling is performed through an automatic sampling system kept at 50°C. The collected samples are tested by an online automatic detection system. The reaction is terminated when the m-isopropylphenol content reaches 0.21%.

[0082] The inner coil is cooled with programmed thermal oil at a cooling rate of 150-160°C / h, and the temperature is reduced to 170°C in 1 hour; 75 parts of 98% sulfuric acid solution and 4000 parts of 99.3% m-cresol (nitride 77ppm, sulfide 65ppm) are added through a constant pressure device, and the reaction is kept at 180-190°C for 4 hours. The pressure of the reactor is reduced to 0.05MPa and remains stable. After cooling to 80°C in 1.5 hours, the gas is exhausted, and the reaction liquid is replaced with nitrogen for 0.5 hours, filtered, and 50 parts are added. The filter cake was washed with methanol (the amount of methanol was 6.7% of the mass of the silica-alumina catalyst), and 9089.4 parts of a reaction product mixture was obtained by filtration (75 parts of sulfuric acid, 49.8 parts of methanol, 1628.9 parts of phenol, 2088.6 parts of m-cresol, 1227.7 parts of o-isopropylphenol, 1346.8 parts of p-isopropylphenol, 31 parts of m-isopropylphenol, 1541.4 parts of 2-isopropyl-5-methylphenol, 1070.4 parts of 4-isopropyl-3-methylphenol, and 29.8 parts of others), and the solid catalyst was applied as is.

[0083] Step 2: Distillation separation of reaction liquid

[0084] 9089.4 parts of the reaction product mixture obtained by filtering the step 1 was added to the bottom of the distillation tower (100 parts of dimethyl diphenyl ether high boiling point solvent had been added to the bottom of the tower, and the tower had 300 theoretical plates), and 48.8 parts of methanol were recovered under normal pressure; the temperature was lowered to 80°C, 200 parts of 31% sodium hydroxide aqueous solution (the molar mass of sodium hydroxide was 2.06 times that of sulfuric acid solution) were added dropwise, and vacuum distillation was performed (vacuum degree -0.09 MPa, reflux ratio 20-25:1) to obtain 9 1602.7 parts of 9.7% phenol (0.8 ppm nitrogen compound, 0.6 ppm sulfide compound), 2013.1 parts of 99.5% m-cresol (0.6 ppm nitrogen compound, 0.5 ppm sulfide compound), 1178.2 parts of 99.3% o-isopropylphenol, 1327.3 parts of 97.1% crude p-isopropylphenol, 1505.7 parts of 99.5% 2-isopropyl-5-methylphenol, and 1042.4 parts of 99.4% 4-isopropyl-3-methylphenol.

[0085] 1327.3 parts of crude 97.1% para-isopropylphenol and 1600 parts of methanol were added to a reactor, stirred, and heated to 65°C to completely dissolve the materials. The mixture was then cooled to 34°C in a cold water bath for 2 hours, then to 0°C in an ice water bath for 3 hours, kept warm for 2 hours, filtered, drained, and dried to obtain 1215 parts of 99.6% para-isopropylphenol with a refined yield of 93.9%. The mother liquor was added to a rectifying kettle for distillation to remove methanol, and 1569.6 parts of methanol were recovered for use.

[0086] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0087] Although the above embodiments have been shown and described, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those skilled in the art are all within the scope of protection of the present invention.

Claims

1. A method for preparing phenolic products from m-isopropylphenol / m-propylphenol, characterized in that: The following steps are involved: (1) adding silica-aluminum oxide and zirconium phosphate to a m-p-isopropylphenol / m-p-propylphenol mixture to carry out a dealkylation reaction; the m-p-isopropylphenol / m-p-propylphenol mixture comprises: at least two of m-isopropylphenol, p-isopropylphenol, m-propylphenol and p-propylphenol, with a content of 85-100 wt%, 2,4,5-trimethylphenol 0-1 wt%, 2-ethyl-3-methylphenol / 2-methyl-3-ethylphenol 0-1 wt%, 3-ethyl-5-methylphenol 0-10 wt%, and other 0-3 wt%; (2) after the dealkylation reaction is completed, a first cooling treatment is performed, and then a sulfuric acid solution and a mixture of phenol and meta-cresol are added to react. After the reaction is completed, a second cooling treatment is performed and the gas is exhausted. The reaction liquid is replaced with nitrogen and then filtered to obtain a reaction product mixture, wherein the reaction product mixture includes methanol, phenol, meta-cresol, o-isopropylphenol, p-isopropylphenol, meta-isopropylphenol, 2-isopropyl-5-methylphenol and 4-isopropyl-3-methylphenol; (3) The reaction product mixture obtained in step (2) is first subjected to atmospheric distillation to recover methanol, and then sodium hydroxide solution is added for neutralization and subjected to vacuum distillation to obtain petrochemical-grade phenol, pharmaceutical-grade m-cresol, o-isopropylphenol, crude p-isopropylphenol, 2-isopropyl-5-methylphenol and 4-isopropyl-3-methylphenol.

2. The method for preparing phenolic products from meta-isopropylphenol / meta-propylphenol according to claim 1, wherein: In the step (1), the amount of the zirconium phosphate is 1 to 10% of the mass of the silicon-aluminum oxide; And / or, in step (1), the amount of the silicon-aluminum oxide is 10 to 30% of the mass of the m-isopropylphenol / m-p-propylphenol mixture; And / or, in step (1), the silicon-aluminum oxide comprises silicon dioxide and acidic aluminum oxide, and the mass ratio of silicon dioxide to acidic aluminum oxide is 1:0.01-50.

3. The method for preparing phenolic products using meta-p-isopropylphenol / meta-p-propylphenol according to claim 1 or 2, characterized in that: In the step (1), the temperature of the dealkylation reaction is 250-350° C., the time of the dealkylation reaction is 5-8 h, and the pressure rises to 1.5-4 MPa during the dealkylation reaction. When the pressure remains stable, sampling is performed through an automatic sampling system kept at 50° C. The collected samples are tested by an online automatic detection system. The reaction ends when the m-isopropylphenol content is ≤0.5%.

4. The method for preparing phenolic products from meta-isopropylphenol / meta-propylphenol according to claim 1, wherein: In the step (2), the first cooling comprises lowering the temperature to below 180° C. within 0.5 to 1 hour; And / or, in step (2), the dealkylation reaction is carried out in a stainless steel high-pressure reactor with an external stainless steel condenser and an inner coil; the first cooling treatment uses the heat transfer oil in the inner coil for programmed cooling, and the cooling rate of the heat transfer oil is 100 to 200°C / h.

5. The method for preparing phenolic products from meta-isopropylphenol / meta-propylphenol according to claim 1, characterized in that: In the step (2), the concentration of the sulfuric acid solution is 95-98%, and the amount of the sulfuric acid solution is 0.5-5% of the mass of the m-isopropylphenol / m-p-propylphenol mixture; And / or, in step (2), the amount of the phenol and m-cresol mixture is 0.5 to 2 times the mass of the m-isopropylphenol / m-p-propylphenol mixture; And / or, in step (2), the nitrogen compound and the sulfide compound in the mixture of phenol and m-cresol are both greater than 30 ppm; And / or, in step (2), the reaction temperature is 150-200° C., the reaction time is 2-6 hours, and the reaction is terminated when the pressure remains stable for 0.5-1 hour; And / or, in step (2), the second cooling treatment is to reduce the temperature to below 100° C. within 1 to 2 hours, and the nitrogen replacement time is 0.5 to 1 hour; And / or, in the step (2), the filtering treatment includes washing the filter cake with methanol after the filtering treatment and filtering again, and the amount of methanol used is 5-20% of the mass of the silicon aluminum oxide.

6. The method for preparing a phenolic product using meta-p-isopropylphenol / meta-p-propylphenol according to claim 1, 4 or 5, characterized in that: In the step (2), the phenol and m-cresol mixture is replaced by phenol, and the reaction product mixture includes methanol, phenol, o-isopropylphenol, p-isopropylphenol and m-isopropylphenol, and then the crude products of petrochemical-grade phenol, o-isopropylphenol and p-isopropylphenol are obtained by distillation in the step (3); Alternatively, in step (2), the mixture of phenol and meta-cresol is replaced with meta-cresol, and the reaction product mixture includes methanol, phenol, meta-cresol, o-isopropylphenol, p-isopropylphenol, m-isopropylphenol, 2-isopropyl-5-cresol, and 4-isopropyl-3-cresol, and then the distillation in step (3) obtains petrochemical-grade phenol, pharmaceutical-grade meta-cresol, o-isopropylphenol, crude p-isopropylphenol, 2-isopropyl-5-cresol, and 4-isopropyl-3-cresol; Preferably, the nitrogen compound and the sulfide compound in the phenol or m-cresol are both greater than 30 ppm; The amount of phenol or meta-cresol used is 0.5 to 2 times the mass of the meta-para-isopropylphenol / meta-para-propylphenol mixture.

7. The method for preparing phenolic products from meta-isopropylphenol / meta-propylphenol according to claim 1, characterized in that: In step (3), the concentration of the sodium hydroxide solution is 30-35%, and the molar mass of the sodium hydroxide is 2-2.4 times the molar mass of the sulfuric acid solution; And / or, in step (3), the vacuum degree of the reduced pressure distillation is -0.085 to -0.095 MPa, and the reflux ratio is 10 to 25:

1.

8. The method for preparing phenolic products from meta-isopropylphenol / meta-propylphenol according to claim 1, characterized in that: The method further comprises the step (4): mixing the crude para-isopropylphenol and methanol, heating the mixture to 60-70° C. to completely dissolve the mixture, cooling the mixture to 30-40° C. with circulating water for 2-3 hours, cooling the mixture to -10-10° C. with chilled brine for 2-4 hours, keeping the mixture warm for 1-3 hours, filtering, draining, and drying the mixture to obtain para-isopropylphenol with a concentration of ≥99%; The mass of the methanol is 0.5 to 2 times the mass of the crude 4-isopropylphenol.

9. The method for preparing phenolic products from meta-isopropylphenol / meta-propylphenol according to claim 1, characterized in that: When the m-isopropylphenol / m-propylphenol mixture also includes 3-ethyl-5-methylphenol, the reaction product mixture also includes 3-ethyl-5-methylphenol, and crude 3-ethyl-5-methylphenol is obtained after the vacuum distillation in step (3).

10. The method for preparing phenolic products from m-isopropylphenol / m-propylphenol according to claim 9, characterized in that: The crude 3-ethyl-5-methylphenol and methanol are stirred and mixed, and then heated to 60-70° C. to completely dissolve the materials. The mixture is then cooled to 30-40° C. with circulating water for 2-3 hours, and then cooled to -10-10° C. with chilled brine for 2-4 hours. The mixture is kept warm for 1-3 hours, filtered, drained, and dried to obtain ≥99% 3-ethyl-5-methylphenol. The amount of the methanol used is 0.5 to 2 times the amount of the crude 3-ethyl-5-methylphenol.