Method for separating benzenediol isomer and 5-indanol in phenol-containing crude product

Abstract

The embodiment of the invention provides a method for separating a benzenediol isomer and 5-indanol in a phenol-containing crude product, which comprises the following steps: rectifying the phenol-containing crude product to obtain mixed benzenediol with a distillation range of 240-300 DEG C; the method comprises the following steps: carrying out etherification reaction on mixed benzenediol with the distillation range of 240-300 DEG C obtained by rectifying crude phenol rectification residues by adopting etherification reaction: carrying out etherification reaction on the mixed benzenediol and an etherification reagent under the action of a catalyst, recovering excessive etherification reagent in a reactant after the reaction, and rectifying to obtain etherate; wherein hydroquinone dialkyl ether with the purity not lower than 98% is crystallized and purified by adopting a melt crystallization method or a solvent crystallization method; and / or reducing a part of etherate by using mixed trimethylbenzene and hydrobromic acid to obtain various benzenediol isomers and 5-indanol.

Description

Technical Field

[0001] The present application relates to the technical field of coal chemical industry, and in particular to a method for separating diphenol isomers and 5-indanol in a crude phenol-containing product. Background Art

[0002] Crude phenol is distilled to obtain phenol, o-cresol, tri-mixed cresols, m-cresol containing 55% meta-position, 99% m-cresol, and industrial xylenol. For fine separation, m-cresol, 2,4 / 2,5-xylenol, 3,5-xylenol / m-p-ethylphenol, m-p-ethylphenol, and industrial xylenol can be further treated, distilled, refined, crystallized, alkylated, and separated to obtain PU-grade 3,5-xylenol, mixed m-p-ethylphenol, 99% 2,4-xylenol, more than 99% 2,5-xylenol, 99% 3,5-xylenol, 98% 3,4-xylenol, m-ethylphenol, 99% p-ethylphenol, and the like, and corresponding extended products. The remaining materials after extracting the above products are tri-mixed cresols, m-p-cresol, and industrial xylenol, etc.

[0003] After analyzing the components of the residue after the crude phenol was distilled into tricresol, it was found that the content of various diphenols in the 240-290°C fraction of the crude tower distillation residue of gasified crude phenol was very high, ranging from 50 to 60%; and the 240-290°C fraction accounted for an average of about 50% of the total amount of the crude phenol distillation residue, so the content of various diphenols accounted for 6 to 10% of the weight of the crude phenol. The main components of diphenol were catechol, resorcinol, hydroquinone, 4-methylcatechol, 2-methylhydroquinone, 4-methylresorcinol, etc., and the main impurities were 5-indanol, 1-naphthol, 2-naphthol, 5,6,7,8-tetrahydro-1-naphthol, 5,6,7,8-tetrahydro-2-naphthol, etc. Therefore, the gasified crude phenol contained a certain amount of various diphenols and had a high economic value. However, since hydroquinone, resorcinol, catechol and other diphenols have high melting points, high boiling points and their phenolic hydroxyl groups are easily oxidized and deteriorated, how to separate the hydroquinone mixture is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0005] On the one hand, the present application proposes a method for separating catechol isomers and 5-indanol in a crude phenol-containing product, wherein catechol, hydroquinone, resorcinol and other mixed catechols and 5-indanol in the crude phenol-containing product are extracted from the crude phenol distillation residue by etherification, distillation and other methods to obtain catechol monoalkyl ether, hydroquinone monoalkyl ether, resorcinol monoalkyl ether, catechol dialkyl ether, hydroquinone dialkyl ether, resorcinol dialkyl ether, 5-methoxyindane and other products.

[0006] According to an embodiment of the present application, a method for separating diphenol isomers and 5-indanol in a crude phenol-containing product is proposed, comprising the following steps:

[0007] The crude phenol-containing product is distilled to obtain a mixed diphenol with a distillation range of 240 to 300°C;

[0008] The mixed diphenol with a distillation range of 240 to 300° C. obtained by distilling the crude phenol distillation residue by an etherification reaction is treated as follows: the mixed diphenol is subjected to an etherification reaction with an etherification agent under the action of a catalyst, and after the reaction, the excess etherification agent in the reactant is recovered and distilled to obtain an etherified product and a first kettle residue;

[0009] The hydroquinone dialkyl ether with a purity of not less than 98% in the etherified product is crystallized and purified by melt crystallization or solvent crystallization; and / or part of the etherified product is reduced by mixed trimethylbenzene and hydrobromic acid to obtain a plurality of hydroquinone isomers and 5-indanol.

[0010] In some embodiments, the mixed hydroquinone with a distillation range of 240 to 300° C. comprises a whole distillation section of mixed hydroquinone with a distillation range of 240 to 290° C., or

[0011] The distillation range of catechol is 240-260℃ and the distillation range of isoquinone / hydroquinone is 260-290℃.

[0012] In some embodiments, the catechol fraction with a distillation range of 240-260° C. includes an independent catechol fraction with a distillation range of 240-250° C. and an independent 5-indanol fraction with a distillation range of 250-260° C.; it contains 30-90% catechol, 0-30% 4-methylcatechol, 0-60% 5-indanol and 0-10% 3,4,5-trimethylphenol;

[0013] The isoquinone / hydroquinone section with a distillation range of 260-290°C includes an independent section with a distillation range of 260-275°C and an independent section with a distillation range of 275-290°C, which contains 10-80% hydroquinone, 10-80% resorcinol, 0-5% 5,6,7,8-tetrahydro-1-naphthol, 0-5% 5,6,7,8-tetrahydro-2-naphthol, 0-10% o-phenylphenol, 0-5% 1-naphthol, and 0-5% 2-naphthol.

[0014] In some embodiments, the catechol fraction with a distillation range of 240-260° C. contains 70-90% catechol, 0-30% 4-methylcatechol, 0-20% 5-indanol, and 0-2% 3,4,5-trimethylphenol.

[0015] In some embodiments, the resorcinol / hydroquinone fraction with a distillation range of 260-290° C. contains 10-80% hydroquinone, 10-80% resorcinol, 0-5% 5,6,7,8-tetrahydro-1-naphthol, 0-5% 5,6,7,8-tetrahydro-2-naphthol, 0-10% o-phenylphenol, 0-5% 1-naphthol, and 0-5% 2-naphthol.

[0016] In some embodiments, the catalyst is present in an amount of 0 to 100% of the weight of the mixed hydroquinone; the catalyst includes sodium fatty alcohol, inorganic base, pyridine, aminopyridine and 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0017] In some embodiments, the etherification agent is an alkyl etherification agent, including fatty alcohol, alkyl halide, difatty sulfate or difatty carbonate; the conditions of the etherification reaction include: a certain temperature of 0 to 250° C. and a certain pressure of 0 to 10 MPa, and the heat preservation reaction is carried out for 2 to 20 hours.

[0018] In some embodiments, the conditions for obtaining a plurality of etherified products and the first still residue by distillation include: a distillation temperature of 50 to 200° C., and a distillation pressure of -0.01 to -0.1 MPa.

[0019] In some embodiments, the plurality of etherified products obtained by distillation include plurality of catechol dialkyl ethers, hydroquinone dialkyl ethers, resorcinol dialkyl ethers, 5-alkoxyindanes, catechol monoalkyl ethers, hydroquinone monoalkyl ethers and resorcinol monoalkyl ethers.

[0020] In some embodiments, the etherified product partially reduced includes at least one of catechol monoalkyl ether or catechol dialkyl ether, hydroquinone monoalkyl ether or hydroquinone dialkyl ether, resorcinol monoalkyl ether or resorcinol dialkyl ether, 5-indenyl alkyl ether, 1-naphthalene alkyl ether, 2-naphthalene alkyl ether and 5,6,7,8-tetrahydro-1-naphthalene alkyl ether, 5,6,7,8-tetrahydro-2-naphthalene alkyl ether.

[0021] Compared with the related art, this application has the following beneficial effects:

[0022] The present application can extract catechol, hydroquinone, resorcinol and other mixed diphenols and 5-indanol from the crude phenol distillation residue by etherification, distillation and other methods to obtain catechol monoalkyl ether, hydroquinone monoalkyl ether, resorcinol monoalkyl ether, catechol dialkyl ether, hydroquinone dialkyl ether, resorcinol dialkyl ether, 5-alkoxyindane and other products, thereby achieving the purpose of comprehensive utilization of hazardous wastes.

[0023] The present invention adopts a method of first etherification reaction and then distillation to separate catechol, which reduces the difficulty and energy consumption of distillation operation, and can relatively smoothly complete the separation of catechol dialkyl ether, hydroquinone dialkyl ether, resorcinol dialkyl ether, etc. Therefore, the method of the present invention is simple and easy to implement, the process has good operability, strong practicality, and significant economic benefits.

[0024] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0026] Figure 1 This is a flow chart of a method for separating diphenol isomers and 5-indanol from a crude phenol-containing product according to an embodiment of the present application; DETAILED DESCRIPTION

[0027] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the present application includes all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0028] Among them, in the related technology, crude phenol is distilled to obtain phenol, o-cresol, tri-mixed cresol, m-cresol containing 55% meta-position, 99% m-cresol, and industrial xylenol, which are directly sold as products without good fine separation. In fact, m-cresol, 2,4 / 2,5-xylenol, 3,5-xylenol / m-p-ethylphenol, m-p-ethylphenol, and industrial xylenol can be further processed, distilled, refined, crystallized, alkylated and separated to obtain PU-grade 3,5-xylenol, mixed m-p-ethylphenol, 99% 2,4-xylenol, more than 99% 2,5-xylenol, 99% 3,5-xylenol, 98% 3,4-xylenol, m-ethylphenol, 99% p-ethylphenol, etc. and corresponding extended products. The remaining materials after extracting the above products are tri-mixed cresol, m-p-cresol, and industrial xylenol, which are directly sold as products and can also be used to synthesize phenolic resins, insulating paints, etc. At the same time, the crude phenol residue after distillation of xylenol can also collect the industrial trimethylol fraction at 226-240°C; the fraction collected at 241-300°C is mixed diphenol, in which the content of various diphenols is more than 50%, and other useful components such as catechol, resorcinol, and hydroquinone can be further extracted from the mixed diphenol.

[0029] In addition, from the analysis of the residue components after the crude phenol distillation of tricresol, it can be known that the content of various diphenols in the 240-290°C fraction of the crude tower distillation residue of gasified crude phenol is very high, ranging from 50 to 60%; and the 240-290°C fraction accounts for an average of about 50% of the total amount of crude phenol distillation residue, so the content of various diphenols accounts for 6 to 10% of the weight of crude phenol. The main components of diphenol are catechol, resorcinol, hydroquinone, 4-methylcatechol, 2-methylhydroquinone, 4-methylresorcinol, etc., and the main impurity is 5-indene Alcohol, 1-naphthol, 2-naphthol, 5,6,7,8-tetrahydro-1-naphthol, 5,6,7,8-tetrahydro-2-naphthol, etc., have high catechol content and high product prices (catechol, hydroquinone, resorcinol, 4-methylcatechol, 5-methylresorcinol, 4-methylresorcinol, 2-methylhydroquinone prices are about 30,000 yuan / ton, 50,000 yuan / ton, 70,000 yuan / ton, 70,000 yuan / ton, 300,000 yuan / ton, 200,000 yuan / ton, 130,000 yuan / ton), have high recovery value, so it is necessary to extract.

[0030] The hydroquinone fraction contained in the gasified crude phenol accounts for about 6-10% of the crude phenol. There are 6,000-10,000 tons of various hydroquinones in 100,000 tons of gasified crude phenol, so there is a certain amount. In addition, various pure hydroquinones and their derivatives are expensive, so they have a certain extraction value. If they are sold as phenol residues, it will be a waste of resources. Therefore, it is necessary to develop a hydroquinone extraction process. However, since hydroquinone, resorcinol, catechol and other hydroquinones have high melting points, high boiling points, and phenolic hydroxyl groups are easily oxidized and deteriorated, how to separate the hydroquinone mixture is a technical problem that needs to be solved in this application.

[0031] Based on this, the technical solution of the embodiment of the present application provides a method. With respect to the method, the present application provides a method for separating hydroquinone isomers and 5-indanol in a crude phenol-containing product, by converting hydroquinone into various dimethyl ethers (dimethoxybenzene) with low boiling and melting points, and then distilling and separating to obtain products such as o-phenylenedimethyl ether, p-phenylenedimethyl ether, and m-phenylenedimethyl ether, thereby achieving the separation of a hydroquinone mixture. The description of the specific technical solution is as follows.

[0032] In addition, in this application, o-dimethoxybenzene, o-catechol dimethyl ether, also known as veratrol, has a molecular formula of C8H 10 O2, molecular weight: 138.16, chemical substance registration number (CAS NO.): 91-16-7, mp15℃, bp206℃, it is an intermediate of fungicides oxadimethoxine and flumorph, and is also used as an organic synthesis intermediate. In the pharmaceutical industry, it is used to synthesize tetrahydropalmatine, isoprenaline, etc. In addition, o-phenylenedimethyl ether is also a common reagent for testing lactic acid and glycerol in blood.

[0033] Dimethyl ether is also known as 1,4-dimethoxybenzene; hydroquinone dimethyl ether; hydroquinone dimethyl ether; dimethoxybenzene, molecular formula: C8H 10 O2, molecular weight: 138.16, CAS NO.: 150-78-8, mp56℃, bp212℃, it is used as a food flavoring, mainly for the preparation of nut flavors; and it is an organic synthesis intermediate, used in the production of drug methoxyamine hydrochloride, dye black salt ANS, etc. In addition, p-phenylenedimethyl ether is also used as a fixative, used in daily chemicals, the preparation of food and tobacco flavors, and can also be used as an anti-weathering agent for plastics and coatings.

[0034] Isophenyl dimethyl ether is also known as 1,3-dimethoxybenzene, resorcinol dimethyl ether, meta-dimethoxybenzene, molecular formula: C8H 10 O2, molecular weight: 138.16, CAS NO.: 151-10-0, mp-52℃, bp217.5℃. Isophenyl dimethyl ether is used as an intermediate for naphthalene dyes, coatings and plastics, as a fragrance for soaps, detergents and ointments, and as an intermediate for the synthesis of benzamide antipsychotics eticlopride and chlorinated aromatic ether insecticides 2,4-dimethoxyethylbenzene.

[0035] 5-Methoxyindane Molecular formula: C 10 H 12 O, molecular weight: 148.2, CAS NO.5111-69-3, bp231.9℃, it is used as a pharmaceutical intermediate, etc.

[0036] At the same time, "scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be combined arbitrarily, that is, any lower limit can form a scope with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 listed, and if the maximum range values ​​3,4 and 5 are listed, the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0037] To achieve the above object, a method for separating diphenol isomers and 5-indanol from a crude phenol-containing product is proposed according to an embodiment of the present application. Figure 1 As shown, it includes: using etherification reaction to obtain mixed diphenol with a distillation range of 240 to 300° C. by distillation of crude phenol residue, and performing the following treatment:

[0038] S1: distilling the crude phenolic product to obtain a mixed diphenol with a distillation range of 240-300°C;

[0039] S2: treating the mixed diphenol with a distillation range of 240-300° C. obtained by distilling the crude phenol distillation residue by an etherification reaction as follows: conducting an etherification reaction of the mixed diphenol with an etherification agent under the action of a catalyst, recovering excess etherification agent in the reactants after the reaction, and then distilling to obtain an etherified product and the first kettle residue;

[0040] The hydroquinone dialkyl ether with a purity of not less than 98% in the etherified product is crystallized and purified by melt crystallization or solvent crystallization; and / or part of the etherified product is reduced by mixed trimethylbenzene and hydrobromic acid to obtain a plurality of hydroquinone isomers and 5-indanol.

[0041] Among them, in S1, the crude phenol distillation residue is added to the distillation tower and distilled to obtain mixed trimethylols and mixed diphenols. In this application, the mixed diphenol with a distillation range of 240 to 300° C. is treated to separate various diphenol isomers therein, such as hydroquinone, resorcinol, catechol and high-value products such as the main impurity 5-indanol.

[0042] The mixed catechol with a distillation range of 240-300°C includes a mixed catechol whole distillation section with a distillation range of 240-290°C, or a catechol distillation section with a distillation range of 240-260°C and a resorcinol / hydroquinone distillation section with a distillation range of 260-290°C. The catechol fraction with a distillation range of 240 to 260° C. includes an independent catechol fraction with a distillation range of 240 to 250° C. and an independent 5-indanol fraction with a distillation range of 250 to 260° C.; the catechol fraction with a distillation range of 240 to 260° C. includes 30 to 90% catechol, 0 to 30% 4-methylcatechol, 0 to 60% 5-indanol and 0 to 10% 3,4,5-trimethylphenol; further, the catechol fraction with a distillation range of 240 to 260° C. includes 70 to 90% catechol, 0 to 30% 4-methylcatechol, 0 to 20% 5-indanol and 0 to 2% 3,4,5-trimethylphenol.

[0043] The isoquinone / hydroquinone section with a distillation range of 260-290°C includes an independent section with a distillation range of 260-275°C and an independent section with a distillation range of 275-290°C. The isoquinone / hydroquinone section with a distillation range of 260-290°C includes 10-80% of hydroquinone, 10-80% of resorcinol, 0-5% of 5,6,7,8-tetrahydro-1-naphthol, 0-5% of 5,6,7,8-tetrahydro-2-naphthol, 0-10% of o-phenylphenol, 0-5% of 1-naphthol and 0-5% of 2-naphthol. Furthermore, the distillation range is 260-290° C., and the hydroquinone / recombination distillation section contains 30-70% hydroquinone, 20-70% resorcinol, 0-2% 5,6,7,8-tetrahydro-1-naphthol, 0-1% 5,6,7,8-tetrahydro-2-naphthol, 0-5% o-phenylphenol, 0-2% 1-naphthol, and 0-2% 2-naphthol.

[0044] In step S2, the mixed catechol is subjected to an etherification reaction with an etherification agent in the presence of a catalyst, wherein, as can be seen from the above, the mixed catechol fraction having a distillation range of 240 to 290° C., or the catechol fraction having a distillation range of 240 to 260° C. and the iso / hydroquinone fraction having a distillation range of 260 to 290° C., in this process, the mixed catechol and the catalyst are added to the reactor, wherein the catalyst in an amount of 0 to 100% of the weight of the mixed catechol; the catalyst comprises Including sodium fatty alcohol, inorganic base, pyridine, methylaminopyridine and 1,8-diazabicyclo[5.4.0]undec-7-ene. It can be understood that sodium fatty alcohol includes sodium methoxide and sodium ethoxide, etc., inorganic base includes sodium hydroxide and potassium hydroxide, etc., pyridine, methylaminopyridine, 1,8-diazabicyclo[5.4.0]undec-7-ene, and illustratively, the catalyst is sodium hydroxide aqueous solution and 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0045] After the mixed diphenol and the catalyst are put into the reactor, an etherification agent is added or dripped for etherification, wherein the etherification agent is an alkyl etherification agent, including fatty alcohol, halogenated alkane, difatty sulfate or difatty carbonate; fatty alcohol can be exemplified by methanol, halogenated alkane can be exemplified by methyl iodide and methyl chloride, difatty sulfate can be exemplified by dimethyl sulfate and diethyl sulfate, and difatty carbonate can be exemplified by dimethyl carbonate and diethyl carbonate. Further, the etherification agent is dimethyl carbonate and dimethyl sulfate; taking dimethyl carbonate as an example, the molar ratio of the mixed diphenol to dimethyl carbonate is 1:1 to 8, and further, the molar ratio of the mixed diphenol to dimethyl carbonate is 1:1.1 to 6.

[0046] The etherification reaction is carried out at a certain temperature and pressure for 2 to 20 hours, wherein the temperature is 0 to 250°C and the pressure is 0 to 10 MPa; further, wherein the temperature is 40 to 150°C and the pressure is 0 to 1 MPa. The reaction product obtained after analysis is qualified. After the obtained reaction product is depressurized, the excess gaseous etherification reagent is recovered or the excess etherification reagent is recovered by atmospheric distillation, and then the vacuum distillation is continued to obtain various etherification products and the first kettle residue, wherein the vacuum distillation temperature is 50 to 200°C and the distillation pressure is -0.01 to -0.1 MPa.

[0047] In this process, vacuum distillation is used to obtain various etherified products including catechol dialkyl ether, hydroquinone dialkyl ether, resorcinol dialkyl ether, 5-alkoxy indane, catechol monoalkyl ether, hydroquinone monoalkyl ether and resorcinol monoalkyl ether, etc.; further various etherified products include catechol dialkyl ether, hydroquinone dialkyl ether, resorcinol dialkyl, 5-alkoxy indane; further various etherified products include catechol dimethyl ether, hydroquinone dimethyl ether, resorcinol dimethyl ether, 5-methoxy indane. The first kettle residue can be used to further extract products such as decalinyl ether and tetrahydrodecalinyl ether.

[0048] The hydroquinone dialkyl ether obtained in the above embodiment with a purity of not less than 98% is crystallized and purified by melt crystallization or solvent crystallization, wherein the hydroquinone dialkyl ether product containing a small amount of impurities such as catechol dialkyl ether and resorcinol dialkyl ether is melt crystallized or solvent crystallized to obtain a hydroquinone dialkyl ether with a higher purity, for example, the purity of the hydroquinone dialkyl ether can reach 99.8%. In addition, the first part of the hydroquinone dialkyl ether melt crystallization is used for distillation and separation of catechol dialkyl ether, hydroquinone dialkyl ether, and resorcinol dialkyl ether; the middle part of 99% is a hydroquinone dialkyl ether product, which is used to purify a 99.8% high-grade product; and the last part is returned to the mixed hydroquinone etherification reaction product.

[0049] In addition, in some embodiments, at least one of the catechol monoalkyl ether, catechol dialkyl ether, hydroquinone monoalkyl ether, hydroquinone dialkyl ether, resorcinol monoalkyl ether, resorcinol dialkyl ether, 5-indenyl alkyl ether, 1-naphthalene alkyl ether, 2-naphthalene alkyl ether and 5,6,7,8-tetrahydro-1-naphthalene alkyl ether, 5,6,7,8-tetrahydro-2-naphthalene alkyl ether among the multiple etherified products obtained above is subjected to etherified product reduction.

[0050] The method comprises adding 1 to 3 times the mass of the etherified product to a reaction kettle, heating the kettle to 110 to 170° C., and then dripping 1 to 3 times the molar mass of the etherified product with 47% hydrobromic acid for reaction. The bromoalkane gas generated by the reaction is cooled to -10° C. to room temperature through a condenser and a cold trap and enters a bromoalkane storage tank (-15° C. to room temperature). After the reaction is completed, the collection of bromoalkane is stopped, and then the reaction liquid is slightly cooled to separate the hydrobromic acid aqueous solution for recycling, and the solvent layer is washed with a small amount of water. The process is to recover trimethylbenzene from the distillation kettle of the material layer and then distill to obtain one or more of high-purity catechol, hydroquinone, resorcinol, 5-indanol, catechol monoalkyl ether, resorcinol monoalkyl ether, hydroquinone monoalkyl ether, 1-naphthol, 2-naphthol, 5,6,7,8-tetrahydro-1-naphthol, 5,6,7,8-tetrahydro-2-naphthol, etc. with a purity of more than 99.5%. The by-product bromoalkanes can be used as phenol etherification reagents. In this process, various pure products such as benzene and benzene monoalkyl ether are obtained by removing the alkyl group in the benzene alkyl ether with an aqueous solution of hydrobromic acid in a trimethylbenzene solution; and bromoalkanes are produced as by-products, which can be used as etherification reagents for various benzenes.

[0051] Compared with the related art, 2,3,5-trimethylphenol and 3-methyl-5-ethylphenol, catechol, resorcinol, hydroquinone, 5-indanol, etc. in the crude phenol distillation residue from coking are not extracted, and the crude phenol distillation residue from coking is basically used as fuel oil, resulting in a large waste of trimethylphenol and catechol resources. The present application can extract catechol, hydroquinone, resorcinol and other mixed catechols and 5-indanol from the crude phenol distillation residue through etherification, distillation and other methods, and obtain catechol monoalkyl ether, hydroquinone monoalkyl ether, resorcinol monoalkyl ether, catechol dialkyl ether, hydroquinone dialkyl ether, resorcinol dialkyl ether, 5-alkoxy indane and other products, thereby achieving the purpose of comprehensive utilization of hazardous wastes.

[0052] At the same time, the present application can also achieve good separation of naphthol impurities with similar boiling points from resorcinol / hydroquinone through mixed catechol etherification, which is relatively easy to improve the purity of resorcinol dialkyl ether and hydroquinone dialkyl ether, and further obtain mixed naphthol products. In addition, etherification can also convert catechol and 5-indanol impurities with a boiling point difference of 10°C into etherified products with a boiling point difference of 25°C, thereby greatly reducing their separation difficulty. At the same time, etherification can also produce catechol monoalkyl ether, hydroquinone monoalkyl ether, and resorcinol monoalkyl ether products, and achieve separation from catechol dialkyl ether and 5-alkoxy indan, etc.

[0053] Finally, the method of first etherification reaction and then distillation is used to separate diphenyl ether, which reduces the difficulty and energy consumption of distillation operation. In the subsequent distillation and separation of various diphenyl ethers, there is basically no problem of material solidification blocking the tower and pipeline, and the separation of catechol dialkyl ether, hydroquinone dialkyl ether, resorcinol dialkyl ether, etc. can be completed relatively smoothly. This method is simple and easy to operate, with good process operability, strong practicality, and significant economic benefits.

[0054] To facilitate further understanding of the present application, the scheme of the present application is further described below in conjunction with the embodiments. Those skilled in the art will understand that the description in the present application is only part of the examples, and any other suitable specific examples are within the scope of the present application.

[0055] Example 1

[0056] Step 1: Distillation

[0057] 50,000 parts of crude phenol distillation residue are added into the bottom of a distillation tower and distilled under reduced pressure, wherein the parameters of the reduced pressure distillation are vacuum degree -0.088 MPa, reflux ratio 10-15:1, and 13,763 parts of mixed trimethylols are obtained by distillation, wherein the mixed trimethylols include 0.82% of 3,4-dimethylphenol, 5.72% of p-isopropylphenol, 6.96% of m-isopropylphenol, 27.92% of 2,3,5-trimethylphenol, 0.21% of 3-ethyl-2-methylphenol, 38.28% of 3-methyl-5-ethylphenol, 15.85% of 4-ethyl-3-methylphenol, 3.98% of butylphenol, and 0.24% of others.

[0058] The remaining kettle residue sample was analyzed, and the 290°C front fraction accounted for 72.6% of the residue in the kettle. The residue in the kettle contained 10.32% of catechol, 21.62% of resorcinol, 30.55% of hydroquinone, 15.51% of methylbenzene, 10.84% ​​of 5-indanol, 0.53% of naphthol, 1.58% of tetrahydronaphthol, and 9.05% of others by chromatographic analysis. The vacuum degree was further increased to -0.095 MPa for continuous distillation to obtain 2935 parts of catechol fraction with a distillation range of 240-250°C, which contained 82.3% of catechol, 7062 parts of intermediate fractions, 15856 parts of resorcinol / hydroquinone fraction with a distillation range of 275-290°C, which contained 38.63% of resorcinol and 52.38% of hydroquinone, and finally 9780.1 parts of kettle residue were obtained.

[0059] The second step: etherification, including step (1) etherifying the catechol fraction obtained in the second step and step (2) etherifying the iso / hydroquinone fraction obtained in the second step, as follows.

[0060] (1) Add 670 parts of the catechol fraction (82.3% of catechol) from the previous step, 1500 parts of dimethyl carbonate (the molar ratio of dimethyl carbonate to phenol is 2.84:1), and 535 parts of DBU into a reactor, replace the atmosphere with nitrogen twice, heat to 180° C., start stirring, keep the reaction warm for 10 hours, take a sample for analysis, and the content of catechol monomethyl ether is 0.43%. Cool to room temperature. The above reaction liquid was added to the distillation kettle, and 735 parts of dimethyl carbonate were recovered by atmospheric distillation for application, and then changed to vacuum distillation (-0.098MPa), reflux ratio 10:1, temperature 128-132℃, chromatographic analysis of 98.5% of phthalate content, and began to collect phthalate dimethyl ether, and a total of 672 parts of 99.5% phthalate dimethyl ether were collected, and the distillation yield was 96.6%. The distillation was continued until the kettle temperature reached 150℃ and stopped, and 115.3 parts of mixture fraction 1 (containing 73.9 parts of 5-methoxyindane, 29.1 parts of methylbenzene dimethyl ether, and 12.3 parts of others) were obtained, and 554.2 parts of kettle residue catalyst were applied (containing a small amount of phthalate monomethyl ether, etc.). The first kettle residue mainly contained catalyst, did not contain naphthyl methyl ether and tetrahydronaphthyl methyl ether, and contained less phenol ether materials.

[0061] (2) Add 606 parts of the resorcinol / hydroquinone fraction (38.63% resorcinol, 52.38% hydroquinone) from the previous step, 1300 parts of dimethyl carbonate (the molar ratio of dimethyl carbonate to phenol is 2.64:1), and 535 parts of DBU into the reactor, replace the atmosphere with nitrogen twice, heat to 180° C., start stirring, keep the reaction warm for 10 hours, take a sample for analysis, and the content of p-methoxyphenol is 0.42%. Cool to room temperature. The above reaction liquid was charged into a distillation kettle, and 502 parts of dimethyl carbonate were recovered by atmospheric distillation for application, and then changed to vacuum distillation (-0.098MPa), with a reflux ratio of 20-30:1 and a temperature of 135-145°C, and 329.1 parts of hydroquinone dimethyl ether were collected by chromatography, with a content of 99.2%; 115.9 parts of intermediate fractions (64.6 parts of hydroquinone dimethyl ether and 50.7 parts of resorcinol dimethyl ether) were collected; 239.5 parts of 99.3% resorcinol dimethyl ether were collected, and the distillation was continued until the kettle temperature reached 165°C and stopped, to obtain 55.6 parts of mixture fraction 2 (15.1 parts of naphthyl methyl ether, 7.2 parts of tetralinapthyl methyl ether, and 33.3 parts of others), and 537.2 parts of kettle residual catalyst were used (containing a small amount of resorcinol / hydroquinone monomethyl ether, etc.). The mixed fraction containing naphthyl methyl ether, 5,6,7,8-tetrahydronaphthyl methyl ether, etc. is concentrated and used to extract naphthyl ether and tetrahydronaphthyl ether products. The first still residue mainly contains catalysts, naphthyl methyl ether, and tetrahydronaphthyl methyl ether, and contains less phenol ether materials to ensure the application of the catalyst, so the ether materials are basically left in the mixed fraction; in other words, after etherification and distillation of the diphenol materials using high boiling point organic base as catalyst, the still residue is basically the catalyst, which is different from the reaction when sodium hydroxide is used as the catalyst.

[0062] (3) Step 3: Demethylation to produce high-purity 3-methoxyphenol and resorcinol

[0063] Add 239.5 parts of 99.3% resorcinol dimethyl ether and 250 parts of mixed trimethylbenzene into the reactor, heat to 130°C, add 47% hydrobromic acid dropwise for reaction, add dropwise for 2 hours, the methyl bromide gas generated by the reaction is cooled to -10°C by a condenser and two cold traps and enters a bromoalkane storage tank (-15°C), keep warm for 2 hours, stop collecting bromoalkane, add 718.5 parts of 47% hydrobromic acid dropwise, collect 244.6 parts of methyl bromide, and the recovery rate is 97.1%; then the reaction solution is slightly cooled to -10°C and then cooled to -15°C. After cooling, the hydrobromic acid aqueous solution was separated, the solvent layer was washed once with 12 parts of water, the layers were separated, and the water layers were combined to obtain 506.5 parts of 23.6% hydrobromic acid solution (sent to the relevant section for heating and recovery of 47% hydrobromic acid), 246.6 parts of trimethylbenzene were recovered in the material layer distillation kettle, and then vacuum distillation (-0.095 MPa, reflux ratio 10:1) was performed to obtain 98.2 parts of 99.85% resorcinol monomethyl ether and 91.4 parts of 99.63% resorcinol, with a yield of 96.9%.

[0064] Example 2

[0065] The first step: distillation. This process is referred to Example 1 and will not be described in detail.

[0066] The second step: etherification, including step (1) etherifying the catechol fraction obtained in the second step and step (2) etherifying the iso / hydroquinone fraction obtained in the second step, as follows.

[0067] (1) Add 820 parts of the catechol fraction (82.3% of catechol) and 2250 parts of a 30% aqueous sodium hydroxide solution (the molar ratio of alkali to phenol is 2.35:1) to a reactor, start stirring, and begin to dropwise add 800 parts of dimethyl carbonate (the molar ratio of dimethyl carbonate to phenol is 1.23:1). The dropping temperature is controlled not to exceed 80° C. The dropping time is about 4 hours. After the dropping is completed, keep the reaction under a slightly boiling condition for 8 hours and take samples for analysis. The content is 0.38% of catechol monomethyl ether. Cool to 80° C. and let stand to separate. Remove the lower aqueous layer, extract the aqueous layer once with 100 parts of toluene, send the separated aqueous layer to a wastewater station, mix the toluene layer with the material layer, and perform the following treatment.

[0068] The above material layer was added to a distillation kettle, and 98.8 parts of toluene were recovered by atmospheric distillation for application, and then changed to vacuum distillation (-0.098MPa), with a reflux ratio of 15:1 and a temperature of 128-132°C, and 24.8 parts of the first part were recovered; chromatographic analysis showed that the content of catechol dimethyl ether was 98.5%, and 808.2 parts of catechol dimethyl ether with a total content of 99.3% were collected, with a yield of 94.8%, and 165.2 parts of the first kettle residue (13.7 parts of catechol dimethyl ether, 90.4 parts of 5-methoxyindane, 35.6 parts of methyl catechol dimethyl ether, and 25.5 parts of others).

[0069] (2) Add 750 parts of the resorcinol / hydroquinone fraction (38.63% resorcinol, 52.38% hydroquinone) and 2250 parts of 30% sodium hydroxide aqueous solution (the molar ratio of alkali to phenol is 2.35:1) into the reactor, start stirring, and begin to dropwise add 760 parts of dimethyl carbonate (the molar ratio of alkali to phenol is 1.25:1). The dropping temperature is controlled not to exceed 80°C, and the dropping time is about 4 hours. After the dropping is completed, keep the reaction at a slight boiling condition for 8 hours, take samples for analysis, and the content of p-methoxyphenol is 0.43%. Cool to 80°C and let stand to separate. Remove the lower aqueous layer, extract the aqueous layer once with 100 parts of toluene, send the separated aqueous layer to the wastewater station, mix the toluene layer with the material layer, and carry out the following treatment.

[0070] The above material layer is added to the distillation kettle, and 98.1 parts of toluene are recovered by atmospheric distillation, and then changed to vacuum distillation (-0.098MPa), reflux ratio 20-30:1, temperature 135-145℃, chromatographic collection to obtain 412.1 parts of hydroquinone dimethyl ether, content 99.3%, yield 82.3%; collect 146.8 parts of intermediate fractions (76.7 parts of hydroquinone dimethyl ether, 69.5 parts of resorcinol dimethyl ether); collect 287.9 ​​parts of 99.2% resorcinol dimethyl ether, yield 78.6%. The first kettle residue in the process is 72.8 parts (1.5 parts of resorcinol dimethyl ether, 18.5 parts of naphthyl methyl ether, 8.8 parts of tetrahydronaphthyl methyl ether, and 44 parts of others), which are concentrated and used to extract naphthyl ether and tetrahydronaphthyl ether products.

[0071] Step 3: Demethylation to produce hydroquinone

[0072] Add 412.5 parts of 99.3% hydroquinone dimethyl ether and 450 parts of mixed trimethylbenzene into the reactor, heat to 130°C, add 47% hydrobromic acid dropwise for 3 hours, cool the generated methyl bromide gas to -10°C through a condenser and two cold traps and enter the bromoalkane storage tank (-15°C), keep the temperature for 3 hours, sample and analyze 0.11% of hydroquinone monomethyl ether, stop collecting bromoalkane, add 1800 parts of 47% hydrobromic acid dropwise, and collect 556. 9 parts, with a recovery rate of 98%; then the reaction solution was cooled slightly to separate the hydrobromic acid aqueous solution, the solvent layer was washed once with 20.5 parts of water, the layers were separated, and the water layers were combined to obtain 1323.2 parts of 26.7% hydrobromic acid solution (sent to the relevant section for heating and recovery of 47% hydrobromic acid), 445.1 parts of trimethylbenzene were recovered in the material layer distillation kettle, and then vacuum distillation (-0.095MPa, reflux ratio 5:1) was performed to obtain 319.1 parts of 99.75% hydroquinone, with a yield of 96.8%.

[0073] Example 3

[0074] The first step: distillation. This process is referred to Example 1 and will not be described in detail.

[0075] The second step comprises step (1) etherifying the catechol fraction obtained in the second step and step (2) etherifying the iso / hydroquinone fraction obtained in the second step, as follows.

[0076] (1) Add 820 parts of the catechol fraction (82.3% of catechol) and 2250 parts of a 30% aqueous sodium hydroxide solution (the molar ratio of alkali to phenol is 2.35:1) to a reactor, start stirring, and begin to dropwise add 1010 parts of dimethyl sulfate (the molar ratio of dimethyl sulfate to phenol is 1.12:1). The dropping temperature is controlled not to exceed 80° C. The dropping time is about 4 hours. After the dropping is completed, the reaction is kept warm for 8 hours under a slightly boiling condition, and a sample is taken for analysis. The content of catechol monomethyl ether is 0.56%. The temperature is lowered to 80° C. and allowed to stand for stratification. The lower aqueous layer is separated, and the aqueous layer is extracted once with 100 parts of toluene. The separated aqueous layer is sent to a wastewater station, and the toluene layer is mixed with the material layer for the following treatment.

[0077] The material layer is added to the distillation kettle, and 98.3 parts of toluene are recovered by atmospheric distillation for application, and then the vacuum distillation (-0.098MPa) is changed to vacuum distillation (-0.098MPa), the reflux ratio is 15:1, the temperature is 128-132°C, and 24.5 parts of the first part are collected. The chromatographic analysis shows that the content of catechol dimethyl ether is 98.5%, and the catechol dimethyl ether is collected. A total of 807.3 parts of 99.1% catechol dimethyl ether are collected, and the yield is 94.5%; 164.8 parts of the first kettle residue (13.9 parts of catechol dimethyl ether naphthyl methyl ether, 89.9 parts of 5-methoxyindane, 35.3 parts of methyl catechol dimethyl ether, and 25.7 parts of others), among which the mixed fraction containing 5-alkoxyindane and the first kettle residue are concentrated for extracting 5-alkoxyindane.

[0078] (2) Add 750 parts of the resorcinol / hydroquinone fraction (38.63% resorcinol, 52.38% hydroquinone) and 2250 parts of 30% sodium hydroxide aqueous solution (the molar ratio of alkali to phenol is 2.49:1) into the reactor, start stirring, and begin to dropwise add 1020 parts of dimethyl sulfate (the molar ratio of dimethyl sulfate to phenol is 1.20:1). The dropping temperature is controlled not to exceed 80°C, and the dropping time is about 4 hours. After the dropping is completed, keep the reaction at 90-95°C for 8 hours, take samples for analysis, and cool to 80°C to stand for stratification. Remove the lower aqueous layer, extract the aqueous layer once with 100 parts of toluene, send the separated aqueous layer to the wastewater station, mix the toluene layer with the material layer, and carry out the following treatment.

[0079] The above material layer was added to the distillation kettle, and 98.5 parts of toluene were recovered by atmospheric distillation, and then changed to vacuum distillation (-0.098MPa), reflux ratio 20-30:1, temperature 135-145℃, chromatographic collection to obtain 415.6 parts of hydroquinone dimethyl ether, content 99.4%, yield 83.1%; 141.3 parts of intermediate fractions (71.1 parts of hydroquinone dimethyl ether, 69.6 parts of resorcinol dimethyl ether) were collected; 289.7 parts of 99.2% resorcinol dimethyl ether were collected, with a yield of 79.1%. 71.9 parts of the first kettle residue (1.1 parts of resorcinol dimethyl ether, 18.2 parts of naphthyl methyl ether, 8.9 parts of tetrahydronaphthyl methyl ether, and 43.7 parts of others) were concentrated and used to extract naphthyl ether and tetrahydronaphthyl ether products.

[0080] Step 3: Demethylation to produce high-purity catechol monomethyl ether and catechol

[0081] Add 500 parts of 99.1% o-phthalic acid and 500 parts of mixed trimethylbenzene into the reactor, heat to 130°C, add 47% hydrobromic acid dropwise for reaction, add dropwise for 1 hour, cool the generated methyl bromide gas to -10°C through a condenser and two cold traps and enter the bromoalkane storage tank (-15°C), keep the temperature for reaction for 1 hour, sample and analyze 51.3% of o-phthalic acid monomethyl ether, stop collecting bromoalkane, add 1500 parts of 47% hydrobromic acid dropwise, collect 505.2 parts of methyl bromide, and the recovery rate is 97.3%; then After the reaction liquid was cooled slightly, the hydrobromic acid aqueous solution was separated, the solvent layer was washed once with 50 parts of water, the layers were separated, and the water layers were combined to obtain 1090.5 parts of 23.4% hydrobromic acid solution (sent to the relevant section for heating and recovery of 47% hydrobromic acid for application), 492.8 parts of trimethylbenzene were recovered in the material layer distillation kettle for application, and then vacuum distillation (-0.095 MPa, reflux ratio 10:1) was obtained to obtain 205 parts of 99.79% catechol monomethyl ether and 191.3 parts of 99.85% catechol, with a yield of 94.47%.

[0082] Example 4

[0083] The first step: distillation. This process is referred to Example 1 and will not be described in detail.

[0084] The second step: etherification, including step (1) etherifying the catechol fraction obtained in the second step and step (2) etherifying the iso / hydroquinone fraction obtained in the second step, as follows.

[0085] (1) Add 535 parts of catechol fraction (82.3% catechol) from the previous step and 3078 parts of 13% aqueous sodium hydroxide solution (the molar ratio of alkali to phenol is 2.13:1) to a high-pressure reactor, seal it, replace it with nitrogen three times, add 504 parts of methyl chloride (the molar ratio of methyl chloride to phenol is 2.12:1) in portions, start stirring, raise the temperature to 60°C, keep the temperature for 8 hours to terminate the reaction, release the pressure, let it stand and separate the layers, separate the lower oil phase, extract the water layer with 100 parts of toluene once, send the separated water layer to a wastewater station, mix the toluene layer with the oil phase, and carry out the following treatment.

[0086] The above material layer is added into a distillation kettle, and 98.1 parts of toluene are recovered by atmospheric distillation for application, and then changed to vacuum distillation (-0.098MPa), with a reflux ratio of 15:1 and a temperature of 128-132°C, 13.5 parts of the front fraction are collected, and a total of 525.7 parts of 99.3% catechol dimethyl ether are collected, with a yield of 93.4%; 104.6 parts of the first kettle residue (12.4 parts of naphthyl methyl ether of catechol dimethyl ether, 59.1 parts of 5-methoxyindane, 22.5 parts of methyl catechol dimethyl ether, and 20.6 parts of others), and the first kettle residue is concentrated for extracting 5-methoxyindane, etc.

[0087] (2) Add 484 parts of the resorcinol / hydroquinone fraction (38.63% resorcinol, 52.38% hydroquinone) from the previous step and 3080 parts of 13% sodium hydroxide aqueous solution (the molar ratio of alkali to phenol is 2.29:1) into the reactor, seal it, replace it with nitrogen three times, add 520 parts of methyl chloride (the molar ratio of methyl chloride to phenol is 2.36:1) in portions, start stirring, raise the temperature to 70°C, keep the temperature for 7 hours to terminate the reaction, release the pressure, let it stand and separate the layers, separate the lower oil phase, extract the water layer with 100 parts of toluene once, send the separated water layer to the wastewater station, mix the toluene layer with the oil phase, and carry out the following treatment.

[0088] The above material layer was added to the distillation kettle, and 97.9 parts of toluene were recovered by atmospheric distillation, and then changed to vacuum distillation (-0.098MPa), reflux ratio 20-30:1, temperature 135-145℃, chromatographic collection to obtain 258.3 parts of hydroquinone dimethyl ether, content 99.1%, yield 80.5%; 103.8 parts of intermediate fractions (58.9 parts of hydroquinone dimethyl ether, 44.9 parts of resorcinol dimethyl ether) were collected; 184.6 parts of 99.2% resorcinol dimethyl ether were collected, with a yield of 78.2%. 47.2 parts of the first kettle residue (1.6 parts of resorcinol dimethyl ether, 11.7 parts of naphthyl methyl ether, 5.7 parts of tetrahydronaphthyl methyl ether, and 28.2 parts of others) were concentrated and used to extract naphthyl ether and tetrahydronaphthyl ether products.

[0089] 258.3 parts of 99.1% p-phenylenedimethyl ether were added with 50 parts of methanol, the temperature was raised to 50°C and stirred to completely dissolve the material, the temperature was slowly lowered to room temperature over 3 hours, and then the temperature was lowered to 0°C with ice brine over 3 hours, filtered, and dried, and the filter cake was heated from room temperature to 30°C under negative pressure and dried to obtain 238.8 parts of 99.8% hydroquinone dimethyl ether, with a crystallization yield of 93.1%.

[0090] Step 3: Demethylation to produce resorcinol

[0091] Add 184.6 parts of 99.2% resorcinol dimethyl ether and 200 parts of mixed trimethylbenzene into the reactor, heat to 135°C, add 47% hydrobromic acid dropwise for 1.5 hours, cool the generated methyl bromide gas to -10°C through a condenser and two cold traps and enter the bromoalkane storage tank (-15°C), keep the temperature for 3 hours, take samples for analysis of 0.08% of resorcinol monomethyl ether, stop collecting bromoalkane, add 800 parts of 47% hydrobromic acid dropwise, collect 247 bromomethyl gas, and then add 100 parts of bromomethyl ether to the reactor. .2 parts, with a recovery rate of 97.3%; then the reaction solution was cooled slightly to separate the hydrobromic acid aqueous solution, the solvent layer was washed once with 20 parts of water, the layers were separated, and the water layers were combined to obtain 593.6 parts of 26.4% hydrobromic acid solution (sent to the relevant section for heating and recovery of 47% hydrobromic acid), 197.9 parts of trimethylbenzene were recovered in the material layer distillation kettle, and then vacuum distillation (-0.095MPa, reflux ratio 5:1) was performed to obtain 143.2 parts of 99.82% resorcinol, with a yield of 97.2%.

[0092] Example 5

[0093] Step 1: Distillation

[0094] 10,000 parts of the crude phenol distillation residue were added into the bottom of the distillation tower and distilled under reduced pressure (vacuum degree -0.088 MPa, reflux ratio 10-15:1) to obtain 2731.6 parts of mixed trimethylols (composition: 0.86% 3,4-dimethylphenol, 5.81% p-isopropylphenol, 7.11% m-isopropylphenol, 27.46% 2,3,5-trimethylphenol, 0.28% 3-ethyl-2-methylphenol, 37.68% 3-methyl-5-ethylphenol, 15.36% 4-ethyl-3-methylphenol, 3.78% butylphenol, and 1.66% others).

[0095] The remaining kettle residue was analyzed by taking a sample, and the fraction before 295°C accounted for 75.1% of the residue in the kettle (chromatographic analysis showed that the fraction contained 10.52% of catechol, 21.86% of resorcinol, 30.18% of hydroquinone, 16.38% of methylbenzene, 9.69% of 5-indanol, 0.47% of naphthol, 1.38% of tetrahydronaphthol, and 9.52% of others). The vacuum degree was increased to -0.095 MPa and distillation was continued to obtain 5290.6 parts of catechol fraction with a distillation range of 240 to 290°C (11.35% of catechol, 22.43% of resorcinol, 28.11% of hydroquinone, 14.69% of methylbenzene, and 10.29% of 5-indanol), and 948.1 parts of kettle residue.

[0096] Step 2: Etherification

[0097] Add 2330 parts of the 241-290°C catechol fraction (11.35% catechol, 22.43% resorcinol, 28.11% hydroquinone, 14.69% methylbenzene, 10.29% 5-indanol) and 6750 parts of 30% sodium hydroxide aqueous solution (the molar ratio of alkali to phenol is 2.57:1) into the reactor, start stirring, and begin to drop 2150 parts of dimethyl carbonate (the molar ratio of dimethyl carbonate to phenol is 1.21:1). Control the dropping temperature not to exceed 80°C, and the dropping time is about 4 hours. After the dropping is completed, keep the reaction under a slight boiling condition for 10 hours, take samples for analysis, and hydroquinone monomethyl ether is 0.42%. Cool to 80°C and let stand for stratification, separate the lower water layer, extract the water layer with 300 parts of toluene once, send the separated water layer to the wastewater station, mix the toluene layer with the material layer, and carry out the following treatment.

[0098] The above material layer is added to the distillation kettle, and 297.2 parts of toluene are recovered by atmospheric distillation, and then vacuum distillation (-0.098MPa) is changed to vacuum distillation (-0.098MPa), reflux ratio 20-30:1, temperature 128-132℃, 135-138℃, 140-144℃, 145-150℃, 153-160℃, respectively collecting 255.8 parts of 99.2% catechol dimethyl ether, 591.7 parts of 99.0% hydroquinone dimethyl ether, 454 parts of 99.2% resorcinol dimethyl ether, 309.7 parts of methyl catechol dimethyl ether, 230 parts of 99.3% 5-methoxyindane, and the distillation yields are 76.5%, 71.3%, 68.7%, 73.1%, 86.3%, respectively. The residue of the first kettle is concentrated and then used to extract naphthyl ether and tetrahydronaphthyl ether products.

[0099] 300 parts of 99.0% hydroquinone dimethyl ether were heated to 58°C to melt all the materials, then cooled to 52°C at 0.3°C / hr, and 8.7 parts of the uncrystallized first portion were released; then the temperature was raised to 54°C at 0.4°C / hr, and 2.1 parts of the middle portion were released; then the temperature was raised to 57°C at 0.2°C / hr, and 285.6 parts of 99.9% hydroquinone dimethyl ether were released, with a crystallization yield of 95.2%; finally, the temperature was quickly raised to melt the remaining material to obtain 3.3 parts of the last portion.

[0100] Step 3: Demethylation to produce high-purity 5-indanol

[0101] Add 230 parts of 99.3% 5-methoxyindane and 250 parts of mixed trimethylbenzene into the reactor, heat to 130-140°C, add 47% hydrobromic acid dropwise for 2 hours, cool the generated methyl bromide gas to -10°C through a condenser and a second cold trap and enter the bromoalkane storage tank (-15°C), react for 2 hours, take a sample and analyze 0.19% of 5-methoxyindane, stop collecting bromoalkane, add 460 parts of 47% hydrobromic acid dropwise, collect 14 4.2 parts, 97.8% recovered; then the reaction solution was cooled slightly to separate the hydrobromic acid aqueous solution, the solvent layer was washed once with 18 parts of water, the layers were separated, and the water layers were combined to obtain 347.9 parts of 25.3% hydrobromic acid solution (sent to the temperature-raising recovery of 47% hydrobromic acid for application), 245.6 parts of trimethylbenzene were recovered in the material layer distillation kettle for application, and then vacuum distillation (-0.095MPa, reflux ratio 5:1) was performed to obtain 205.2 parts of 99.52% 5-indanol, with a yield of 98.1%.

[0102] Example 6

[0103] Step 1: Distillation

[0104] The remaining 2960.6 parts of mixed catechols (11.35% of catechol, 22.43% of resorcinol, 28.11% of hydroquinone, 14.69% of methylcatechol, and 10.29% of 5-indanol) in Example 5 were added to the bottom of a distillation tower and subjected to vacuum distillation (vacuum degree -0.095 MPa, reflux ratio 10-15:1) to obtain 917.6 parts of a 240-260°C catechol fraction (38.6% of catechol, 20.9% of 4-methylcatechol, and 31.2% of 5-indanol). The bottom residue was enriched and the mixed resorcinol / hydroquinone was further extracted.

[0105] Step 2: Etherification

[0106] Add 917.6 parts of the catechol fraction from the previous step (38.6% of catechol, 20.9% of 4-methylcatechol, 31.2% of 5-indanol), 1500 parts of dimethyl carbonate (the molar ratio of dimethyl carbonate to phenol is 2.2:1), and 730 parts of DBU into the reactor, replace with nitrogen twice, heat to 160°C, start stirring, keep warm for 15 hours, take samples for analysis, and the result is 0.24% of catechol monomethyl ether. Cool to room temperature.

[0107] The above reaction liquid was charged into a distillation kettle, and 460 parts of dimethyl carbonate were recovered by atmospheric distillation, and then changed to vacuum distillation (-0.098MPa), with a reflux ratio of 20-30:1, temperatures of 128-132°C, 133-136°C, and 153-160°C, to collect 297.5 parts of 99.0% of catechol dimethyl ether, 178.8 parts of 99.3% of 4-methylcatechol dimethyl ether, and 280.1 parts of 99.6% of 5-methoxyindane, with distillation yields of 66.3%, 73.8%, and 88.3%, respectively.

[0108] Step 3: Demethylation to produce high-purity 5-indanol

[0109] Add 280.1 parts of 99.6% 5-methoxyindane and 300 parts of mixed trimethylbenzene into the reactor, heat to 125-130°C, add 47% hydrobromic acid dropwise for reaction, add dropwise for 2 hours, the methyl bromide gas generated by the reaction is cooled to -10°C through a condenser and a second cold trap and enters a bromoalkane storage tank (-15°C), keep warm for 2.5 hours, take a sample for analysis, 0.08% of 5-methoxyindane is qualified, stop collecting bromoalkane, add 560.2 parts of 47% hydrobromic acid dropwise, collect 1 bromomethylbenzene, and add 1 bromomethylbenzene. 76.9 parts, with a recovery rate of 98.5%; then the reaction solution was cooled slightly to separate the hydrobromic acid aqueous solution, the solvent layer was washed once with 21.5 parts of water, the layers were separated, and the water layers were combined to obtain 421.6 parts of 25.4% hydrobromic acid solution (sent to the recovery section for heating and recovery of 47% hydrobromic acid), 294.2 parts of trimethylbenzene were recovered in the material layer distillation kettle, and then vacuum distillation (-0.095MPa, reflux ratio 5:1) was performed to obtain 251.1 parts of 99.87% 5-indanol, with a yield of 98.6%.

[0110] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means 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 application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0111] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for separating diphenol isomers and 5-indanol in a crude phenolic product, characterized in that: include: The crude phenolic product is distilled to obtain a mixed diphenol with a distillation range of 240 to 300°C; The mixed diphenol with a distillation range of 240 to 300° C. obtained by distilling the crude phenol distillation residue by an etherification reaction is treated as follows: the mixed diphenol is subjected to an etherification reaction with an etherification agent under the action of a catalyst, and after the reaction, the excess etherification agent in the reactant is recovered and distilled to obtain an etherified product and a first kettle residue; The hydroquinone dialkyl ether with a purity of not less than 98% in the etherified product is crystallized and purified by melt crystallization or solvent crystallization; and / or part of the etherified product is reduced by mixed trimethylbenzene and hydrobromic acid to obtain a plurality of hydroquinone isomers and 5-indanol.

2. The method according to claim 1, characterized in that The mixed catechol with a distillation range of 240-300°C includes a mixed catechol full distillation section with a distillation range of 240-290°C; or a catechol distillation section with a distillation range of 240-260°C and a m- / hydroquinone distillation section with a distillation range of 260-290°C.

3. The method according to claim 2, characterized in that The catechol fraction with a distillation range of 240 to 260° C. includes an independent catechol fraction with a distillation range of 240 to 250° C. and an independent 5-indanol fraction with a distillation range of 250 to 260° C.; the fraction contains 30 to 90% catechol, 0 to 30% 4-methylcatechol, 0 to 60% 5-indanol and 0 to 10% 3,4,5-trimethylphenol; The isoquinone / hydroquinone section with a distillation range of 260 to 290° C. includes an independent section with a distillation range of 260 to 275° C. and an independent section with a distillation range of 275 to 290° C., which contains 10 to 80% of hydroquinone, 10 to 80% of resorcinol, 0 to 5% of 5,6,7,8-tetrahydro-1-naphthol, 0 to 5% of 5,6,7,8-tetrahydro-2-naphthol, 0 to 10% of o-phenylphenol, 0 to 5% of 1-naphthol, and 0 to 5% of 2-naphthol.

4. The method according to claim 3, characterized in that The catechol fraction with a distillation range of 240 to 260° C. contains 70 to 90% of catechol, 0 to 30% of 4-methylcatechol, 0 to 20% of 5-indanol, and 0 to 2% of 3,4,5-trimethylphenol.

5. The method according to claim 3, characterized in that: The resorcinol / hydroquinone fraction with a distillation range of 260 to 290° C. contains 10 to 80% hydroquinone, 10 to 80% resorcinol, 0 to 5% 5,6,7,8-tetrahydro-1-naphthol, 0 to 5% 5,6,7,8-tetrahydro-2-naphthol, 0 to 10% o-phenylphenol, 0 to 5% 1-naphthol, and 0 to 5% 2-naphthol.

6. The method according to any one of claims 1 to 5, characterized in that: The catalyst is present in an amount of 0 to 100% of the weight of the mixed hydroquinone; the catalyst comprises sodium fatty alcohol, inorganic base, pyridine, methylaminopyridine and 1,8-diazabicyclo[5.4.0]undec-7-ene.

7. The method according to claim 6, characterized in that The etherification agent is an alkyl etherification agent, including fatty alcohol, halogenated alkane, difatty sulfate or difatty carbonate; the conditions of the etherification reaction include: a certain temperature of 0 to 250° C. and a certain pressure of 0 to 10 MPa, and the heat preservation reaction is carried out for 2 to 20 hours.

8. The method according to claim 6, characterized in that The parameters for obtaining a plurality of etherified products and the first still residue by distillation include: a distillation temperature of 50 to 200° C. and a distillation pressure of -0.01 to -0.1 MPa.

9. The method according to claim 6, characterized in that The etherified compounds include various kinds of catechol dialkyl ether, hydroquinone dialkyl ether, resorcinol dialkyl ether, 5-alkoxyindan, catechol monoalkyl ether, hydroquinone monoalkyl ether and resorcinol monoalkyl ether.

10. The method according to claim 6, characterized in that The etherified product that is partially reduced includes at least one of catechol monoalkyl ether, catechol dialkyl ether, hydroquinone monoalkyl ether, hydroquinone dialkyl ether, resorcinol monoalkyl ether, resorcinol dialkyl ether, 5-indenyl alkyl ether, 1-naphthalene alkyl ether, 2-naphthalene alkyl ether and 5,6,7,8-tetrahydro-1-naphthalene alkyl ether, 5,6,7,8-tetrahydro-2-naphthalene alkyl ether.

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