Refining process method and refining device for oxidation product

Abstract

The invention discloses a refining process method and a refining device of an oxidation product. The oxidation product is a phenol hydrogen peroxide oxidation reaction product. The refining separation process method comprises the steps of gas-liquid separation, segregation rectification, full-condensation rectification I, full-condensation rectification II and full-condensation rectification III which are carried out in sequence. The hydroquinone product and byproducts of catechol, circulating phenol, light / heavy impurity oil and wastewater are obtained through the technological process of gas-liquid separation, condensation recovery, crystallization separation and temperature control rectification of a reaction product obtained through phenol hydrogen peroxide oxidation, the separation difficulty is low, the product purity is high, the process is continuous and easy to operate, and industrial feasibility is achieved.

Description

Technical Field

[0001] The present application relates to a refining process method and a refining device for oxidation products, belonging to the field of chemical engineering technology. Background Art

[0002] Hydroquinone is a fine chemical raw material widely used in the fields of chemical engineering, medicine, pesticides, fragrances, rubber, etc. Among them, the demand for catechol accounts for 50% in the flavor and fragrance field and 40% in the pharmaceutical field; the demand for hydroquinone accounts for 31% in the rubber auxiliaries field, 14% and 5% in the fields of photosensitive materials and pharmaceutical intermediates respectively, and the application fields of special engineering plastics represented by PEK and PEEK have great development potential. At present, the hydroquinone industry is developing rapidly and the application fields are constantly expanding.

[0003] The output of hydroquinone in China continues to grow, but the production enterprises generally have the disadvantages of small scale and uneven technical levels. Moreover, the current hydroquinone synthesis technology generally uses volatile, flammable and explosive compounds as solvents, forming a high fire hazard environment in the oxygen atmosphere generated by the decomposition of hydrogen peroxide. Therefore, it is necessary to develop a green and safe hydroquinone synthesis technology. Summary of the Invention

[0004] The present application develops a corresponding product refining and separation method based on the reaction technology of hydroxyl oxidation of phenol with hydrogen peroxide in a water-based solvent. The process is continuous and easy to operate, and has industrial feasibility.

[0005] In one aspect of the present application, a refining process method for oxidation products is provided. The reaction products of the oxidation of phenol with hydrogen peroxide are subjected to a process flow of gas-liquid separation - condensation recovery - crystallization separation - temperature-controlled rectification - to obtain hydroquinone products, by-product catechol, recycled phenol, light / heavy impurity oils and wastewater. The separation difficulty is low, the product purity is high, the process is continuous and easy to operate, and has industrial feasibility.

[0006] The oxidation product is the reaction product of the oxidation of phenol with hydrogen peroxide;

[0007] The refining and separation process method includes gas-liquid separation, partial condensation rectification, total condensation rectification I, total condensation rectification II, and total condensation rectification III carried out in sequence;

[0008] Among them, crystallization separation is also included after the rectification I;

[0009] The gas-liquid separation includes: the gas phase of the oxidation product obtained in the reaction kettle is subjected to gas-liquid separation to obtain condensate and non-condensable gas;

[0010] The fractional condensation rectification includes: after the condensate and the liquid phase of the oxidation product obtained in the reaction kettle are subjected to fractional condensation rectification in a dehydration tower, non-condensable waste gas and rectified water are obtained at the top of the dehydration tower, and dehydrated material is obtained at the bottom of the dehydration tower;

[0011] The total condensation rectification I includes: the dehydrated material undergoes total condensation rectification I through a dephenolization tower, a material containing phenol is obtained at the top of the dephenolization tower, and dephenolized material is obtained at the bottom of the dephenolization tower;

[0012] The total condensation rectification II includes: the dephenolized material undergoes total condensation rectification II through a light component removal tower, o-diphenol is obtained at the top of the light component removal tower, and light component-removed material is obtained at the bottom of the light component removal tower;

[0013] The total condensation rectification III includes: the light component-removed material undergoes total condensation rectification III through a product tower, p-diphenol is obtained at the top of the product tower, and heavy impurity oil is obtained at the bottom of the product tower;

[0014] The crystallization separation includes: the material containing phenol passes through a phenol-quinone crystallizer to separate and obtain phenol.

[0015] Optionally, the gas-liquid separation includes: the gas phase of the oxidation product obtained in the reaction kettle successively passes through a condenser and a condensate tank for gas-liquid separation;

[0016] Among them, the operating temperature of the condenser and the condensate tank is 30 to 100 °C;

[0017] The operating pressure of the condensate tank is 100 to 300 kPa(A).

[0018] Optionally, the operating temperature is independently selected from any value of 30 °C, 50 °C, 80 °C, 100 °C or the range value between any two of the above;

[0019] Optionally, the operating pressure of the condensate tank is independently selected from any value of 100 kPa(A), 150 kPa(A), 200 kPa(A), 250 kPa(A), 300 kPa(A) or the range value between any two of the above;

[0020] Optionally, the gas phase generated by the reaction kettle is condensed by a tail gas condenser and then phase-separated, and the condensate is recovered through a tail gas liquid separation tank. The condensate of the tail gas liquid separation tank and the liquid phase of the reaction kettle are jointly sent to a dehydration tower for separation, and the dehydration tower separates non-condensable gas and waste water through fractional condensation rectification.

[0021] Optionally, the dehydration product at the bottom of the dehydration tower is separated into phenol and high-melting-point impurities through total condensation rectification in a dephenolization tower.

[0022] Optionally, the top of the dephenolization tower is connected to a phenol-quinone crystallizer, and recycled phenol is separated by crystallization.

[0023] Optionally, the light - removing tower separates the o - diphenol by - product through total condensation rectification.

[0024] Optionally, a phenol - quinone crystallizer 5 is used to separate a small amount of high - boiling - point impurities such as benzoquinone in phenol.

[0025] Optionally, in the partial condensation rectification process, the top temperature of the dehydration tower is 40 - 130°C, and the operating pressure is 0.1 - 150 kPa(A).

[0026] Optionally, the top temperature of the dehydration tower is independently selected from any value of 40°C, 50°C, 75°C, 100°C, 130°C or the range values between any two of the above.

[0027] Optionally, the operating pressure of the dehydration tower is independently selected from any value of 0.1 kPa(A), 10 kPa(A), 50 kPa(A), 100 kPa(A), 150 kPa(A) or the range values between any two of the above.

[0028] Optionally, in the total condensation rectification I process, the top temperature of the phenol - removing tower is 120 - 220°C, and the operating pressure is 1 - 90 kPa(A).

[0029] Optionally, the top temperature of the phenol - removing tower is independently selected from any value of 120°C, 151°C, 180°C, 200°C, 220°C or the range values between any two of the above.

[0030] Optionally, the operating pressure of the phenol - removing tower is independently selected from any value of 1 kPa(A), 40 kPa(A), 70 kPa(A), 90 kPa(A) or the range values between any two of the above.

[0031] Optionally, in the total condensation rectification II process, the top temperature of the light - removing tower is 120 - 220°C, and the operating pressure is 0.1 - 30 kPa(A).

[0032] Optionally, the top temperature of the light - removing tower is independently selected from any value of 120°C, 140°C, 160°C, 180°C, 200°C, 220°C or the range values between any two of the above.

[0033] Optionally, the operating pressure of the light - removing tower is independently selected from any value of 0.1 kPa(A), 5 kPa(A), 10 kPa(A), 15 kPa(A), 20 kPa(A), 25 kPa(A), 30 kPa(A) or the range values between any two of the above.

[0034] Optionally, in the total condensation rectification III process, the top temperature of the product tower is 150 to 250 °C, and the operating pressure is 0.1 to 30 kPa(A).

[0035] Optionally, the top temperature of the product tower is independently selected from any value of 150 °C, 170 °C, 190 °C, 210 °C, 230 °C, 250 °C or the range value between any two of the above.

[0036] Optionally, the operating pressure of the product tower is independently selected from any value of 0.1 kPa(A), 5 kPa(A), 10 kPa(A), 15 kPa(A), 20 kPa(A), 25 kPa(A), 30 kPa(A) or the range value between any two of the above.

[0037] As a specific embodiment, the refining process method of the oxidation product uses the phenol hydrogen peroxide oxidation reaction product as the separation raw material, and mainly includes the following equipment: tail gas condenser 1, tail gas liquid separation tank 2, dehydration tower 3, dephenolization tower 4, phenol quinone crystallizer 5, light component removal tower 6, and product tower 7. The gas phase obtained from the reaction kettle enters the tail gas condenser 1, and the material after low-temperature condensation is sent to the tail gas liquid separation tank 2. The non-condensable gas is discharged as waste gas, and the condensate is sent to the dehydration tower 3. The liquid phase reaction product obtained from the reaction kettle is also sent to the dehydration tower 3. The dehydration tower 3 performs partial condensation rectification to obtain non-condensable waste gas and rectified water at the top of the tower. The waste gas is discharged, and part of the rectified water is discharged as wastewater and part is recycled as a solvent. The dehydrated material obtained at the bottom of the dehydration tower 3 is sent to the dephenolization tower 4. The dephenolization tower 4 obtains phenol and high-melting-point impurities at the top of the tower through rectification operation and sends them to the phenol quinone crystallizer 5 to separate and recycle the phenol. The material at the bottom of the dephenolization tower 4 is sent to the light component removal tower 6, and by-product o-diphenol is separated at the top of the tower. The material at the bottom of the tower is sent into the product tower 7. The product tower 7 obtains hydroquinone product at the top of the tower through negative pressure total condensation rectification, and heavy impurity oil is separated at the bottom of the tower.

[0038] Another aspect of the present application provides a refining device for an oxidation product, and the refining device includes a condensation unit, a dehydration tower, a dephenolization tower, a light component removal tower, a product tower, and a phenol quinone crystallizer;

[0039] The liquid phase outlet of the condensation unit is connected to the dehydration tower;

[0040] The bottom of the dehydration tower is provided with a dehydrated material outlet, which is connected to the dephenolization tower. The top of the dehydration tower is provided with a non-condensable gas outlet and a rectified water outlet;

[0041] The bottom of the dephenolization tower is provided with a dephenolized material outlet, which is connected to the light component removal tower. The top of the dephenolization tower is provided with a phenol material outlet. The phenol material outlet is connected to the phenol quinone crystallizer, and the phenol quinone crystallizer is provided with a phenol outlet;

[0042] The bottom of the light component removal column is provided with a light component removal material outlet, which is connected to the product column, and the top of the light component removal column is provided with an o-diphenol outlet;

[0043] The bottom of the product column is provided with a heavy impurity oil outlet, and the top of the product column is provided with a hydroquinone outlet;

[0044] The condensation unit is connected to the gas-phase outlet of the oxidation product of the reaction kettle;

[0045] The dehydration column is connected to the liquid-phase outlet of the oxidation product of the reaction kettle.

[0046] Optionally, the condensation unit includes a condenser and a condensate tank connected in sequence;

[0047] The inlet of the condenser is connected to the gas-phase outlet of the oxidation product.

[0048] Optionally, the reflux ratio of the dehydration column is 0.5 to 15, and the number of theoretical plates is 15 to 90.

[0049] Optionally, the reflux ratio of the dehydration column is independently selected from any value of 0.5, 3, 6, 9, 12, 15 or the range value between any two of the above.

[0050] Optionally, the number of theoretical plates of the dehydration column is independently selected from any value of 15, 30, 45, 60, 75, 90 or the range value between any two of the above.

[0051] Optionally, the reflux ratio of the phenol removal column is 0.1 to 10, and the number of theoretical plates is 10 to 80.

[0052] Optionally, the reflux ratio of the phenol removal column is independently selected from any value of 0.1, 2, 4, 6, 8, 10 or the range value between any two of the above.

[0053] Optionally, the number of theoretical plates of the phenol removal column is independently selected from any value of 10, 32, 50, 80 or the range value between any two of the above.

[0054] Optionally, the reflux ratio of the light component removal column is 0.1 to 5, and the number of theoretical plates is 10 to 80.

[0055] Optionally, the reflux ratio of the light component removal column is independently selected from any value of 0.1, 1.8, 3.6, 4.5, 5 or the range value between any two of the above.

[0056] Optionally, the number of theoretical plates of the light component removal column is independently selected from any value of 10, 20, 40, 60, 80 or the range value between any two of the above.

[0057] Optionally, the reflux ratio of the product column is 0.1 to 5, and the number of theoretical plates is 10 to 80.

[0058] Optionally, the reflux ratio of the product column is independently selected from any value of 0.1, 0.5, 1, 2, 3, 4, 5 or a range value between any two of the above.

[0059] Optionally, the number of theoretical plates of the product column is independently selected from any value of 10, 30, 50, 80 or a range value between any two of the above.

[0060] The beneficial effects that can be produced by this application include:

[0061] It can be used for the separation and purification of hydroquinone produced by the hydroxylation of phenol with hydrogen peroxide. The process is continuous and easy to operate, and has industrial feasibility. Description of the Drawings

[0062] Figure 1 It is a schematic process flow diagram of a refining process method for an oxidation product of this application.

[0063] List of Components and Reference Numerals:

[0064] 1. Tail gas condenser; 2. Tail gas liquid separator; 3. Dehydration column; 4. Dephenolization column; 5. Phenol - quinone crystallizer; 6. Light - ends column; 7. Product column. Detailed Embodiments

[0065] The following describes this application in detail with reference to the embodiments, but this application is not limited to these embodiments.

[0066] Unless otherwise specified, the raw materials in the embodiments of this application are all purchased through commercial channels.

[0067] Example 1

[0068] The gas phase obtained from the reactor enters the tail gas condenser 1. After being condensed to 50 °C, the material is sent to the tail gas liquid separation tank 2, where gas-liquid separation is carried out at a pressure of 150 kPa(A). The non-condensable gas is discharged as waste gas, and the condensate is sent to the dehydration tower 3. The liquid-phase reaction product obtained from the reactor is also sent to the dehydration tower 3. The operating pressure of the dehydration tower 3 is 50 kPa(A), with 60 theoretical plates, a reflux ratio of 6, and a top temperature of 75 °C. Through partial condensation rectification, non-condensable waste gas and rectified water are obtained at the top of the tower. The waste gas is discharged, and 52.2% of the rectified water is discharged as wastewater, while the rest is recycled as a solvent. The dehydrated material obtained at the bottom of the dehydration tower 3 is sent to the phenol removal tower 4. The operating pressure of the phenol removal tower 4 is 40 kPa(A), with 32 theoretical plates, a reflux ratio of 2, and a top temperature of 151 °C. Through rectification operation, phenol and high-melting-point impurities are obtained at the top of the tower and sent to the phenol-quinone crystallizer 5, where phenol with a purity of 99.5% is crystallized and separated for recycling. The material at the bottom of the phenol removal tower 4 is sent to the light component removal tower 6. The operating pressure of the light component removal tower 6 is 15 kPa(A), with 40 theoretical plates, a reflux ratio of 1.8, and a top temperature of 180 °C. Para-dihydroxybenzene with a molar purity of 99.9% as a by-product is separated at the top of the tower, and the bottom material is sent to the product tower 7. The operating pressure of the product tower 7 is 5 kPa(A), with 30 theoretical plates, a reflux ratio of 0.5, and a top temperature of 190 °C. Through vacuum total condensation rectification, para-dihydroxybenzene product with a molar purity of 99.9% is obtained at the top of the tower, and heavy impurity oil is separated at the bottom of the tower.

[0069] As described above, these are only several embodiments of the present application and do not impose any form of limitation on the present application. Although the present application is disclosed with preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the relevant art can make some changes or modifications within the scope of the technical solution of the present application by using the disclosed technical content, which are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. A refining process method for an oxidation product, characterized in that, The oxidation product is the product of the oxidation reaction of phenol with hydrogen peroxide; The refined separation process method includes gas-liquid separation, partial condensation rectification, total condensation rectification I, total condensation rectification II, and total condensation rectification III carried out in sequence; Among them, after the rectification I, crystallization separation is also included; The gas-liquid separation includes: the gas phase of the oxidation product obtained in the reaction kettle is subjected to gas-liquid separation to obtain condensate and non-condensable gas; The partial condensation rectification includes: the condensate and the liquid phase of the oxidation product obtained in the reaction kettle are subjected to partial condensation rectification in a dehydration tower, non-condensable waste gas and rectified water are obtained at the top of the dehydration tower, and dehydrated material is obtained at the bottom of the dehydration tower; The total condensation rectification I includes: the dehydrated material is subjected to total condensation rectification I through a phenol removal tower, a material containing phenol is obtained at the top of the phenol removal tower, and phenol-removed material is obtained at the bottom of the phenol removal tower; The total condensation rectification II includes: the phenol-removed material is subjected to total condensation rectification II through a light component removal tower, o-diphenol is obtained at the top of the light component removal tower, and light component-removed material is obtained at the bottom of the light component removal tower; The total condensation rectification III includes: the light component-removed material is subjected to total condensation rectification III through a product tower, p-diphenol is obtained at the top of the product tower, and heavy impurity oil is obtained at the bottom of the product tower; The crystallization separation includes: the material containing phenol passes through a phenol-quinone crystallizer to separate and obtain phenol.

2. The refining process method according to claim 1, characterized in that, The gas-liquid separation includes: the gas phase of the oxidation product obtained in the reaction kettle is subjected to gas-liquid separation successively through a condenser and a condensate tank; Among them, the operating temperature of the condenser and the condensate tank is 30-100 °C; The operating pressure of the condensate tank is 100-300 kPa(A).

3. The refining process method according to claim 1, characterized in that, During the partial condensation rectification process, the top temperature of the dehydration tower is 40-130 °C, and the operating pressure is 0.1-150 kPa(A).

4. The refining process method according to claim 1, characterized in that, During the total condensation rectification I process, the top temperature of the phenol removal tower is 120-220 °C, and the operating pressure is 1-90 kPa(A).

5. The refining process method according to claim 1, characterized in that, During the total condensation rectification II process, the top temperature of the light component removal tower is 120-220 °C, and the operating pressure is 0.1-30 kPa(A).

6. The refining process method according to claim 1, characterized in that, During the total condensation rectification III process, the top temperature of the product tower is 150-250 °C, and the operating pressure is 0.1-30 kPa(A).

7. A refining device for an oxidation product, characterized in that, The refining device includes a condensation unit, a dehydration tower, a phenol removal tower, a light component removal tower, a product tower, and a phenol-quinone crystallizer; The liquid phase outlet of the condensation unit is connected to the dehydration tower; The bottom of the dehydration tower is provided with a dehydrated material outlet, which is connected to the phenol removal tower. The top of the dehydration tower is provided with a non-condensable gas outlet and a rectified water outlet; The bottom of the phenol removal tower is provided with a phenol-removed material outlet, which is connected to the light component removal tower. The top of the phenol removal tower is provided with a phenol material outlet, the phenol material outlet is connected to the phenol-quinone crystallizer, and the phenol-quinone crystallizer is provided with a phenol outlet; The bottom of the light component removal tower is provided with a light component-removed material outlet, which is connected to the product tower. The top of the light component removal tower is provided with an o-diphenol outlet; The bottom of the product tower is provided with a heavy impurity oil outlet, and the top of the product tower is provided with a hydroquinone outlet; The condensation unit is connected to the gas phase outlet of the oxidation product of the reaction kettle; The dehydration tower is connected to the liquid-phase outlet of the oxidation product of the reaction kettle.

8. The refining device according to claim 7, characterized in that, The condensation unit includes a condenser and a condensation tank connected in sequence; The inlet of the condenser is connected to the gas-phase outlet of the oxidation product.

9. The refining device according to claim 7, characterized in that, The reflux ratio of the dehydration tower is 0.5 to 15, and the number of theoretical plates is 15 to 90; Preferably, the reflux ratio of the phenol removal tower is 0.1 to 10, and the number of theoretical plates is 10 to 80.

10. The refining device according to claim 7, wherein, The reflux ratio of the light component removal tower is 0.1 to 5, and the number of theoretical plates is 10 to 80; Preferably, the reflux ratio of the product tower is 0.1 to 5, and the number of theoretical plates is 10 to 80.

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