CN115318280B - Method for regenerating and recovering catalyst and byproduct o-aminophenol from aniline tar - Google Patents
Method for regenerating and recovering catalyst and byproduct o-aminophenol from aniline tar Download PDFInfo
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- CN115318280B CN115318280B CN202210877075.2A CN202210877075A CN115318280B CN 115318280 B CN115318280 B CN 115318280B CN 202210877075 A CN202210877075 A CN 202210877075A CN 115318280 B CN115318280 B CN 115318280B
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J38/00—Regeneration or reactivation of catalysts, in general
- B01J38/48—Liquid treating or treating in liquid phase, e.g. dissolved or suspended
- B01J38/50—Liquid treating or treating in liquid phase, e.g. dissolved or suspended using organic liquids
- B01J38/56—Hydrocarbons
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- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
- B01J23/42—Platinum
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- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
- B01J23/44—Palladium
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/90—Regeneration or reactivation
- B01J23/96—Regeneration or reactivation of catalysts comprising metals, oxides or hydroxides of the noble metals
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J38/00—Regeneration or reactivation of catalysts, in general
- B01J38/02—Heat treatment
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J38/00—Regeneration or reactivation of catalysts, in general
- B01J38/04—Gas or vapour treating; Treating by using liquids vaporisable upon contacting spent catalyst
- B01J38/12—Treating with free oxygen-containing gas
- B01J38/40—Treating with free oxygen-containing gas and forming useful by-products
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C213/00—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton
- C07C213/10—Separation; Purification; Stabilisation; Use of additives
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/584—Recycling of catalysts
Abstract
The invention relates to a method for regenerating and recovering a catalyst from aniline tar and by-producing o-aminophenol. The invention separates the o-aminophenol from other organic components in the tar by utilizing the specific solvent, removes heavy components in the pore canal of the aniline catalyst in the tar, and solves the toxic effect of the tar on the activity of the catalyst. The solid phase o-aminophenol is purified by sublimation and desublimation to obtain the o-aminophenol product with bright appearance and purity of more than 99 percent and the aniline catalyst with good activity. The invention realizes the resource utilization of aniline production waste, successfully recovers the catalyst and the o-aminophenol with high added value, has simple and convenient operation, solves the problems of catalyst deactivation and loss in the aniline production process and high pollution and high carbon emission in the tar treatment process, and has the advantages that the recovery rate of the catalyst in the whole process is more than 95 percent, and the recovery rate of the o-aminophenol is more than 90 percent.
Description
Technical Field
The invention belongs to the field of recycling of chemical production waste materials, relates to comprehensive utilization of tar generated in an aniline industrial production process, and in particular relates to a method for regenerating and recovering a catalyst from aniline tar and by-producing o-aminophenol, and finally obtaining a high-purity o-aminophenol product and realizing aniline catalyst recovery.
Background
At present, aniline is produced by the reaction of nitrobenzene and hydrogen under the catalytic action of noble metal palladium-platinum catalyst. In the process of producing aniline by nitrobenzene hydrogenation, byproducts such as cyclohexanone, o-aminophenol, diphenylamine, 4-aminodiphenylamine and the like can be generated. In order to reduce the influence of byproducts such as cyclohexanone on the quality of aniline products, light components such as cyclohexanone and aniline substances are generally reacted in a subsequent refining section to be converted into Schiff base heavy components with higher boiling points, so that the influence on the quality of the products is reduced. However, heavy components generated during aniline production and purification process may block the channels of noble metal catalyst, resulting in deactivation of the catalyst. And in the process of refining the aniline product, part of noble metal catalyst inevitably runs off from the tower kettle along with aniline tar. Because the production flow lacks of a catalyst self-cleaning and regeneration process, and the tar has high viscosity and complex composition, the catalyst is difficult to separate and difficult to regenerate and recycle. The national productivity of the process for preparing aniline by liquid-phase hydrogenation of nitrobenzene is 134 ten thousand tons/year, and the annual consumption cost of the noble metal platinum/palladium catalyst in the form of inactivation, loss and the like reaches more than 6000 ten thousand.
The aniline tar is a black viscous liquid at normal temperature, and contains 20wt% of o-aminophenol and other long-chain polymers such as aniline, methylaniline, diphenylamine and polycyclic aromatic amines except for noble metal catalysts. Wherein the o-aminophenol with the largest proportion is an acid-base amphoteric compound, and simultaneously has Lewis acid (hydroxyl) and Lewis basic groups (amino), has strong self-interaction, so that the o-aminophenol is distinguished from other organic components only containing amino in tar, and has the possibility of separation. In addition, the o-aminophenol is an important chemical intermediate, is mainly used for fluorescent whitening agents, 8-hydroxyquinoline, dyes, medical intermediates and the like, has wide market prospect and high price, and has great recovery value.
At present, aniline tar is mainly subjected to incineration treatment, and precious metal is recovered in a mode of recovering precious metal palladium and platinum from furnace dust, so that the treatment mode not only causes great resource waste. The incineration mode damages the self carbon carrier structure of the noble metal catalyst, requires additional processing, and has complex flow and high noble metal loss rate. In the incineration process, high value-added products in tar such as o-aminophenol, p-aminodiphenylamine and the like are not effectively utilized as resources, so that great economic loss is caused. And a large amount of carbon dioxide and nitrogen oxides can be generated in a burning mode, so that environmental pollution is caused and carbon emission is increased.
The noble metal catalyst activation and regeneration direction is basically the petroleum cracking hydrogenation catalyst direction at home and abroad, and the noble metal catalyst regeneration and activation of aniline is not studied. The current research is basically in laboratory research stage, and the process route is complex and the industrialization difficulty is great.
Patent CN113121311a describes a comprehensive recovery process of aniline tar in aniline production. The aniline tar and the organic acid solvent are mixed and introduced into a rectifying tower for reaction and hydrotreatment, and the tar is decomposed into micromolecular substances through hydrocracking, so that high-added-value products such as alcohol amine and the like are produced, the toxic effect of the tar on the activity of the catalyst is solved, and the aniline catalyst is recovered. However, the technology relates to reactive distillation, the industrial application is difficult, substances outside an aniline production system are introduced, the risk of recycling the aniline device by the catalyst is unknown, and the further evaluation is needed.
Patent CN108047051a describes a method for producing aniline and diphenylamine by catalytic cracking of aniline tar produced in industrial production of aniline and a catalyst used in the method, wherein aniline tar is used as a raw material, and aniline and diphenylamine are produced by catalytic cracking reaction under the action of high temperature and the catalyst. The method can react aniline tar to produce high value added products of aniline and diphenylamine. However, the catalyst development difficulty is high, the reaction conditions relate to high temperature and high pressure, the energy consumption is high, the safe production is not facilitated, and the industrialization difficulty is high.
At present, few patents and literature reports related to recovery of noble metal catalysts and high added value products in aniline tar are provided, a small number of factories directly sell the tar at low price in consideration of production cost and other reasons, and most of factories treat the aniline tar in an incineration mode, so that environmental pollution is caused, and a large amount of resources such as noble metal catalysts, o-aminophenol and the like are wasted. Therefore, a reasonable aniline tar recycling route is designed, the noble metal catalyst is recovered from the aniline tar recycling route, and the high-purity o-aminophenol product is extracted, so that the environmental pollution can be reduced, waste materials can be changed into valuable materials, and the economic and social benefits are remarkable.
Disclosure of Invention
In view of the above problems in the prior art, the present invention provides a method for regenerating and recovering a catalyst from aniline tar and by-producing o-aminophenol, which includes the processes of extraction separation, activation, sublimation, solvent recovery, etc., and separates the catalyst, o-aminophenol and other substances in the tar through relevant operating conditions and methods, so as to achieve regeneration and recovery of aniline catalyst, especially noble metal catalyst, and effective extraction of high-purity o-aminophenol.
According to the method, firstly, the o-aminophenol is separated from other organic components in the tar through the selection of a specific solvent, and heavy components in the pore canal of the aniline catalyst in the tar are removed, so that the toxic effect of the tar on the activity of the catalyst is solved. Then the white powdery refined o-aminophenol with the purity of more than 99 percent and the aniline catalyst with the activity recovered are obtained through means such as drying, sublimation separation and the like, and the catalyst can be directly returned to a device for application.
In order to achieve the above purpose, the invention adopts the following technical scheme:
the invention provides a method for regenerating and recovering a catalyst from aniline tar and by-producing o-aminophenol, which comprises the following steps:
(1) And (3) extraction and separation: mixing aniline tar with an extraction solvent comprising benzene, short chain aliphatic hydrocarbons and optionally benzene derivatives, extracting with stirring, and then separating the liquid and solid phases by filtration;
(2) Catalyst activation: mixing the solid phase obtained in the step (1) with an activator, wherein the activator comprises benzene, short-chain aliphatic hydrocarbon and optional benzene derivatives, heating and activating under high-speed stirring, and then separating a liquid phase and a solid phase through filtration, wherein the solid phase is dried in inert gas to obtain a dry solid;
(3) Sublimation separation catalyst: adding the dried solid obtained in the step (2) into a sublimation desublimation machine, and adding the dried solid into N 2 Heating to 120-220 ℃ in the atmosphere for sublimation, obtaining white powdery o-aminophenol by sublimating sublimated gas, and recycling the catalyst by residual solid at the bottom of a sublimator.
In the step (1), the aniline tar is byproduct tar of aniline production, is black viscous liquid with pungent smell at normal temperature, and mainly comprises o-aminophenol, a catalyst, aniline, 4-aminodiphenylamine, and a small amount of impurities (including methylaniline, diphenylamine, phenylenediamine, other tricyclic recombination and the like). The aniline tar is derived from waste materials generated in the rectification process of the process for preparing aniline by hydrogenating nitrobenzene under the action of an aniline catalyst (preferably a noble metal catalyst); the noble metal catalyst is preferably selected from platinum catalysts, palladium catalysts, such as winning palladium metal supported powder catalysts, winning palladium platinum carbon noble metal supported powder catalysts, noble lapping palladium platinum dual supported noble metal catalysts, kelvin palladium platinum supported powder catalysts, and the like.
In the aniline tar obtained in some production processes, the catalyst content is greater than 10ppm, preferably 50-250ppm, and the ortho-aminophenol content is greater than 8wt%, preferably 15-30wt%.
Specifically, the aniline tar comprises the following components: 10-250ppm of catalyst, preferably 50-250ppm, 8-30wt% of o-aminophenol, preferably 15-30wt%, 13-20wt% of aniline, 25-45wt% of 4-aminodiphenylamine and the balance of impurities, wherein the impurities comprise methylaniline, diphenylamine, phenylenediamine, other tricyclic or higher components and the like.
In step (1) of the present invention, the extraction solvent comprises benzene, a short chain aliphatic hydrocarbon and optionally a benzene derivative;
wherein the short chain aliphatic hydrocarbon is selected from C6-C7 aliphatic hydrocarbons, preferably any one or a combination of at least two of methylpentane, dimethylpentane, hexane, cyclohexane, methylcyclohexane, methylcyclopentane, dimethylcyclopentane, more preferably any one or a combination of at least two of methylpentane, dimethylpentane, cyclohexane;
wherein the benzene derivative is selected from any one or a combination of at least two of toluene, xylene and nitrobenzene, and preferably toluene;
preferably, the mass ratio of benzene, short chain aliphatic hydrocarbon and benzene derivative is 1:0.1-0.5:0-0.1, preferably 1:0.1-0.2:0.01-0.05;
in some embodiments, most preferably, the extraction solvent is nitrobenzene waste benzene liquid, which is waste benzene discharged from a nitrobenzene production device, and is derived from a nitrobenzene product refining process.
The nitrobenzene waste benzene liquid comprises the following components in percentage by mass: benzene 85-92%, C6-C7 aliphatic hydrocarbon 7-15%, toluene 0.5-1%, wherein the C6-C7 aliphatic hydrocarbon comprises any one or a combination of at least two of methylpentane, dimethylpentane, hexane, cyclohexane, methylcyclohexane, methylcyclopentane, dimethylcyclopentane, etc.
In the step (1) of the invention, the mixing mass ratio of the aniline tar to the extraction solvent is 1:0.6-10, e.g. 1:1, 1:3, 1:4, 1:8, preferably 1:3-6.
In step (1) of the present invention, the stirring is carried out at a rotational speed of 50 to 800rpm, for example 200rpm, 400rpm, 600rpm, preferably 500 to 700rpm.
In step (1) of the present invention, the extraction temperature is 20-40 ℃, such as 25 ℃, 35 ℃, preferably 20-30 ℃, and the extraction time is 10-180min, such as 30min, preferably 20-40min; the extraction separation step utilizes the characteristic that the o-aminophenol is insoluble in a specific extractant to extract substances except the o-aminophenol and the catalyst in the aniline tar into a solvent, thereby realizing the extraction of the o-aminophenol in the tar.
In the step (1), the filtration is preferably carried out in a filter pressing mode, and a solid phase and a liquid phase are obtained through separation of a filter press;
the solid phase is crude o-aminophenol containing a catalyst, the content of the o-aminophenol in the composition is 90-98wt% after residual extractant is removed, the content of the catalyst is 0.05-0.2wt%, and the balance is impurities such as trace aniline and other aniline tar components;
the liquid phase contains an extraction solvent, a trace amount of o-aminophenol, and substances other than the o-aminophenol and the catalyst in the aniline tar.
In the step (2), the selection range of the activating agent and the extraction solvent in the step (1) is the same, but the specific compositions of the activating agent and the extraction solvent can be the same or different; i.e. the activator in step (2) comprises benzene, short chain aliphatic hydrocarbons and optionally derivatives of benzene;
wherein the short chain aliphatic hydrocarbon is selected from C6-C7 aliphatic hydrocarbons, preferably any one or a combination of at least two of methylpentane, dimethylpentane, hexane, cyclohexane, methylcyclohexane, methylcyclopentane, dimethylcyclopentane, more preferably any one or a combination of at least two of methylpentane, dimethylpentane, cyclohexane;
wherein the benzene derivative is selected from any one or a combination of at least two of toluene, xylene and nitrobenzene, and preferably toluene;
preferably, 1 of benzene, short chain aliphatic hydrocarbons and benzene derivatives: 0.1-0.5:0-0.1, preferably 1:0.1-0.2:0.01-0.05;
most preferably, the activator is nitrobenzene waste benzene liquid.
In step (2) of the present invention, the mass ratio of activator to solid phase is 4-8:1, e.g. 4:1, 6:1, 8:1, preferably 5-6:1.
In step (2) of the present invention, the high-speed stirring is carried out at a rotation speed of 500 to 3000rpm, for example 1000rpm, 2000rpm, 2500rpm, preferably 2000 to 3000rpm.
In step (2) of the present invention, the activation is carried out at a temperature of 50 to 80℃such as 55℃and 65℃and 75℃and preferably 60 to 65℃for a time of 60 to 200 minutes such as 110 minutes and preferably 100 to 120 minutes. And (3) the solid phase obtained in the step (1) is heated and stirred at a high speed in an activating agent, so that heavy components in a catalyst pore canal can be dissolved out, and meanwhile, the o-aminophenol is further purified. A condenser is arranged during activation, and the volatilized activating agent is condensed and refluxed.
In the step (2), the solid phase and the liquid phase are obtained through filtration and separation;
the solid phase is the catalyst-containing ortho-aminophenol, the ortho-aminophenol content in the composition of the dry solid is not less than 96%, such as 98%, 99%, preferably up to more than 99% by weight, and the noble metal catalyst content is 0.05-0.2% by weight;
the liquid phase contains an activator, trace amounts of o-aminophenol, trace amounts of 4-aminodiphenylamine, trace amounts of impurities such as aniline and other aniline tar components, and the like.
In the step (2), the temperature is 80-100 ℃ (not exceeding the sublimation temperature of the o-aminophenol), preferably 90 ℃, and the drying time is 30-120min; the inert shielding gas is preferably nitrogen. In the whole drying process, inert gas is introduced to protect, so that on one hand, the oxidation discoloration of the o-aminophenol in contact with air is avoided, and on the other hand, the high-temperature gas can effectively remove residual trace activator in the catalyst pore canal.
In step (3) of the present invention, the sublimation temperature is 120-220 ℃, such as 130 ℃, 180, 220 ℃, preferably 150-180 ℃; the sublimation time is 40-180min, preferably 60-90min. Heating the dried solid obtained in the step (2) in a sublimation desublimation device, and using the characteristic that the o-aminophenol is easy to sublimate at high temperature, removing a very small amount of 4-aminodiphenylamine which is a dyeing substance by sublimation in a specific temperature range, separating the 4-aminodiphenylamine from an aniline noble metal catalyst, so that white powdery refined o-aminophenol with the purity of more than 99 weight percent can be obtained, and the recovery rate of the o-aminophenol can be up to more than 90 percent;
preferably, the sublimation process is conducted with an inert gas, preferably nitrogen. The inert gas plays a role of shielding gas on one hand, and on the other hand, the inert gas serves as a conveying fluid of sublimated gas, and sublimated gas at the top is collected and cooled by a sublimator to obtain an o-aminophenol product.
In the step (3) of the invention, the sublimation desublimation machine is in a jacket stirring mode, circulating water is used as a cooling medium in the jacket, and before sublimation operation, the desublimation machine is filled with o-aminophenol particles with volume fractions of 10-30%, such as 15%, 20% and 25%, which are used as crystal nuclei, and the stirring is carried out to enable the solid particles to be in a mechanical fluidization state; the stirring speed is preferably 2000-3000rpm. The o-aminophenol sublimated gas is condensed on the surface of the particles, and the particles reach a certain weight and overflow to a product tank through sedimentation.
In the step (3), the residual solid at the bottom of the sublimator is a noble metal catalyst, the catalytic activity can be effectively recovered after the activation and drying treatment in the step (2), and the catalyst can be reused after being separated from the o-aminophenol by an aniline feeding device, and the recovery rate of the catalyst is more than 95%.
In the method, the liquid phase obtained by filtering in the step (1) and the step (2) can be used for separating and recovering benzene, derivatives thereof and short-chain aliphatic hydrocarbon through rectification.
The rectification separation method is conventional in the art, the invention has no special requirement, a technical person can adopt any disclosed method capable of realizing to design the rectification tower in detail according to the nature of the solvent, the solvent fraction is extracted from the top for recycling, and the residual tar in the tower bottom is sent to be burnt or the derivative of benzene and short-chain aliphatic hydrocarbon (such as aniline, 4-aminodiphenylamine and the like) are further extracted. For example, in some embodiments, when used for rectifying and separating nitrobenzene waste benzene liquid, the rectifying tower has a tray number of 30-85; the number of the side collecting plates is 20-50, the operating pressure of the tower top is controlled to be normal pressure-0.35 Mpa (G), the temperature of the tower bottom is 100-200 ℃, the reflux ratio of the tower top is 0.5-6, and the extraction temperature of the tower top is 50-60 ℃. The mixed solvent is fed at normal temperature, the feeding position of the mixed solvent is positioned at the upper part of the rectifying tower, the position of a feeding plate is preferably 15-30 plates, the side extraction position of the recovered benzene is positioned at the middle part of the rectifying tower, the position of the side extraction is preferably 10-25 plates, and the side extraction temperature is 80-85 ℃.
In the process of producing aniline by continuous hydrogenation of nitrobenzene, the aniline can undergo side reactions such as cyclohexanone, diphenylamine, benzidine and the like by hydrogenation, and the activity of the catalyst can be gradually reduced along with long-period operation of the device. According to analysis, toxic substances in the pore canal of the aniline catalyst mainly comprise two types, wherein one type is formed by introducing enriched long-chain alkane substances into nitrobenzene raw materials, and the other type is formed by reacting compounds with benzene rings and amino groups, such as aniline, diphenylamine, benzidine and the like, with cyclohexanone to form a viscous high polymer. Due to the pore selectivity of the aniline catalyst, the two substances are enriched on the surface of the catalyst after hydrogenation reaction, so that the pore of the catalyst is blocked, and the activity of the catalyst is reduced. Therefore, the core of the catalyst and the process for extracting the o-aminophenol from the aniline waste is how to separate the o-aminophenol from the aniline tar with complex composition and the capability of activating the catalyst.
In order to solve the problems, the experiment of the invention discovers that the separation and catalyst activation can be realized through the selection of specific solvents, wherein the most critical solvent selection and product refining process. More specifically, by mixing aniline tar and a specific solvent containing benzene, short-chain aliphatic hydrocarbon and optional benzene derivatives, the o-aminophenol and the regenerated catalyst can be separated and purified simultaneously, the solvent is slightly soluble or insoluble to the o-aminophenol, has strong solubility to long alkane which is a toxic substance in the pore canal of the aniline tar and the catalyst and a high molecular nitrogen-containing polymer, does not occupy the pore canal of the catalyst, has low boiling point and is easy to volatilize, and separation and recovery are easy. And then regenerating the catalyst by a physical separation means and purifying the o-aminophenol.
Meanwhile, in order to avoid the influence of newly introduced substances on the stable operation of the aniline device, a large number of experiments prove that unexpected discoveries of the invention adopt waste benzene liquid discharged from the nitrobenzene device in the aniline production system, and can realize more excellent effects.
Analysis shows that the main reason is that benzene has extremely strong capability of cleaning heavy tar in the aniline catalyst, and meanwhile, C6 and C7 aliphatic hydrocarbons have specific adsorption cleaning capability on long-chain alkane in the pore canal of the aniline catalyst. And the externally discharged waste benzene in the aniline industry chain is used as a cleaning agent, the cost is almost negligible, the whole process cost is extremely low, and the effect of introducing new substances on stable operation of the aniline system while the waste preparation of the aniline industry chain is realized.
Compared with the prior art, the technical scheme of the invention has the beneficial effects that:
the specific solvent selected in the catalyst separation and activation process is especially nitrobenzene waste benzene, and because the specific solvent contains short-chain aliphatic hydrocarbon and benzene, the removal of the long-chain alkane heavy component and the Schiff base heavy component blocked in the catalyst pore canal can be simultaneously realized, and in addition, the separation of the o-aminophenol and other substances in tar can be realized because of the difference of the specific solubility of benzene to tar components. On the premise of not damaging the catalyst structure, the toxic action of heavy components on the catalyst is solved, the catalyst can be directly returned to the device for use after activation, the catalyst unit consumption in the aniline production process is greatly reduced, and meanwhile, the extraction of the high value-added product o-aminophenol in tar is realized.
In the catalyst separation process, the characteristic that the o-aminophenol is easy to sublimate is utilized to remove a small amount of residual dyeing substance 4-aminodiphenylamine, the purity and crystal structure of the o-aminophenol are improved, the obtained o-aminophenol is white refined solid, the purity is more than 99%, and the requirement of superior products is met. Meanwhile, the o-aminophenol is separated from the insoluble impurity aniline noble metal catalyst by a physical means, the conditions are mild, the carbon-supported structure and activity of the catalyst are not affected, and the separated catalyst can be directly returned to an aniline device for application.
The waste liquid used in the dissolution and extraction is recovered in a rectification mode, so that the recycling of the waste liquid in an aniline production chain is realized, the recovery rate of the solvent is more than 85%, and the production cost can be effectively reduced.
The process has the advantages of simple operation, less three wastes, high production efficiency, low cost and simple industrialized amplification, realizes the comprehensive recycling of the waste materials, and has great economic and social benefits.
Drawings
FIG. 1 is a schematic flow chart of an embodiment of the invention for regenerating and recovering catalyst from aniline tar and by-producing o-aminophenol.
Detailed Description
So that the technical features and content of the present invention can be understood in detail, preferred embodiments of the present invention will be described in more detail below. While the preferred embodiments of the present invention have been described in the examples, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein.
< raw material information >
Aniline tar: the catalyst is waste materials generated in the rectification process of the aniline preparation process by nitrobenzene hydrogenation, wherein the content of a noble metal catalyst (a Kaili palladium platinum double-load carbon carrier powder catalyst) is 100ppm, the content of o-aminophenol is 27wt%, the content of aniline is 15wt%, the content of 4-aminodiphenylamine is 36wt%, and the balance is impurities (including methylaniline, diphenylamine, phenylenediamine and other tricyclic heavy components); is produced by a nifedipine device in Ningbo Wanhua industrial park and is an industrial product.
Nitrobenzene waste benzene liquid: the method is used for discharging waste benzene from a nitrobenzene production device and is derived from a nitrobenzene product refining process, and comprises the following components in percentage by mass: 91% of benzene, 8.5% of C6-C7 aliphatic hydrocarbon and 0.5% of toluene, wherein the C6-C7 aliphatic hydrocarbon comprises methylpentane, dimethylpentane, hexane, cyclohexane and methylcyclohexane; is produced by a nifedipine device in Ningbo Wanhua industrial park and is an industrial product.
Aniline catalyst: the Kaili palladium platinum double-loaded carbon carrier powder catalyst is purchased from the New materials Co., ltd.
The other conventional chemical reagents used in each example and comparative example are commercially available and will not be described in detail herein.
< detection method >
The composition of each obtained substance is determined by gas chromatography;
the method for measuring the yield of the obtained o-aminophenol is carried out by adopting a gas chromatography external standard combined with a weighing method;
the activity of the catalyst is evaluated by using an intermittent hydrogenation-reduction time evaluation device provided by DuPont company.
Example 1
(1) And (3) extraction and separation: 500g of aniline tar and nitrobenzene waste benzene liquid are mixed in an extraction separation kettle according to the mass ratio of 1:4. The extraction was stirred at 25℃for 30min at a stirring rate of 600rpm. Separating by a filter press to obtain a black solid phase, and collecting a liquid phase and sending the liquid phase to a solvent recovery process.
The solid phase is crude o-aminophenol containing a noble metal catalyst, and after the residual extractant is scraped, the content of the o-aminophenol in the composition is 96wt% and the content of the noble metal catalyst is 0.1wt%.
(2) Catalyst activation: and (3) adding the solid phase obtained in the step (1) into a catalyst activation kettle, mixing with nitrobenzene waste benzene liquid according to a mass ratio of 1:6, stirring and activating for 120min at 50 ℃, and stirring at a speed of 2000rpm. Filtering and separating to obtain solid phase, and feeding into an oven to obtain N 2 Drying in atmosphere at 90 deg.c for over 60min to obtain grey dry solid, and conveying the liquid phase to solvent recovering step.
The gray dry solid is an ortho-aminophenol comprising a noble metal catalyst having a composition of 98.5wt% ortho-aminophenol and 0.1wt% noble metal catalyst.
(3) Sublimation separation catalyst: adding the dried solid obtained in the step (2) into a sublimation desublimation machine to obtain a solid N 2 Heating and refining in atmosphere, filling o-aminophenol particles with the volume fraction of 20% in a sublimator as crystal nucleus before sublimation operation, stirring at the rotation speed of 2500rpm to enable solid particles to be in a fluidized state, heating the sublimator at 160 ℃ for 90min, sublimating sublimated gas to obtain white powdery o-aminophenol, and recovering the catalyst from residual solids at the bottom of the sublimator.
(4) And (3) recovering a solvent: continuously feeding the liquid phases obtained by filtering in the step (1) and the step (2) into a benzene rectification recovery tower for rectification, and recovering solvent benzene. And (3) operating a 5-layer packed tower, wherein the heating temperature of a tower kettle is 155 ℃, the reflux ratio is 5, the 2 nd layer of packing is fed to the feeding position, the third layer of packing is used for side production of products, the side production temperature is 82 ℃, benzene recovered by side production rectification is recycled as nitrobenzene production raw materials, and residual liquid of the tower kettle enters an incineration system for treatment.
The recovered noble metal catalyst was subjected to nitrobenzene batch hydrogenation and o-aminophenol product gas phase analysis, in this example, the catalyst recovery was 96%, and the noble metal catalyst activity after regeneration was 92% (based on 100% of fresh catalyst activity). The purity of the o-aminophenol product obtained by sublimation is 99.3 percent, and the recovery rate of the o-aminophenol is calculated to be 95 percent according to the content of the o-aminophenol in the tar waste material and the quality of the recovered o-aminophenol, and the recovery rate of the solvent benzene is calculated to be 90 percent (calculated by the benzene content in the nitrobenzene waste benzene liquid).
Example 2
(1) And (3) extraction and separation: 500g of aniline tar and nitrobenzene waste benzene liquid are mixed in an extraction separation kettle according to the mass ratio of 1:10. The extraction was stirred at 40℃for 60min at a stirring rate of 800rpm. Separating by a filter press to obtain a black solid phase, and collecting a liquid phase and sending the liquid phase to a solvent recovery process.
The solid phase is crude o-aminophenol containing a noble metal catalyst, and after the residual extractant is scraped, the content of the o-aminophenol in the composition is 98wt% and the content of the noble metal catalyst is 0.1wt%.
(2) Catalyst activation: and (3) adding the solid phase obtained in the step (1) into a catalyst activation kettle, mixing with nitrobenzene waste benzene liquid according to a mass ratio of 1:8, stirring and activating for 180min at 80 ℃, and stirring at a speed of 2000rpm. Filtering and separating to obtain solid phase, and feeding into an oven to obtain N 2 Drying in atmosphere at 80deg.C for more than 100min until the solid phase quality is unchanged, and collecting gray dry solid, and conveying the liquid phase to solvent recovery process.
The gray dry solid is an ortho-aminophenol comprising a noble metal catalyst having a composition of 99wt% ortho-aminophenol and 0.1wt% noble metal catalyst.
(3) Sublimation separation catalyst: adding the dried solid obtained in the step (2) into a sublimation desublimation machine to obtain a solid N 2 Heating and refining in atmosphere, filling o-aminophenol particles with the volume fraction of 10% in a sublimator as crystal nucleus before sublimation operation, stirring at the rotating speed of 2200rpm to enable solid particles to be in a fluidized state, heating the sublimator at 160 ℃ for 200min, sublimating sublimated gas to obtain white powdery o-aminophenol, and recovering the catalyst from residual solids at the bottom of the sublimator.
(4) And (3) recovering a solvent: continuously feeding the liquid phases obtained by filtering in the step (1) and the step (2) into a benzene rectification recovery tower for rectification, and recovering solvent benzene. And (3) operating a 5-layer packed tower, wherein the heating temperature of a tower kettle is 155 ℃, the reflux ratio is 5, the 2 nd layer of packing is fed to the feeding position, the third layer of packing is used for side production of products, the side production temperature is 82 ℃, benzene recovered by side production rectification is recycled as nitrobenzene production raw materials, and residual liquid of the tower kettle enters an incineration system for treatment.
The recovered noble metal catalyst was subjected to nitrobenzene batch hydrogenation and o-aminophenol product gas phase analysis, and in this example, the catalyst recovery was 95%, and the noble metal catalyst activity after regeneration was 95% (based on 100% of the fresh catalyst activity). The purity of the o-aminophenol product obtained by sublimation is 99.7%, and the recovery rate of the o-aminophenol is calculated to be 92% according to the content of the o-aminophenol in the tar waste material and the quality of the recovered o-aminophenol, and the recovery rate of the solvent benzene is 88% (calculated by the benzene content in the nitrobenzene waste benzene liquid).
Example 3
(1) And (3) extraction and separation: 500g of aniline tar was mixed with an extraction solvent (benzene 85wt%, 2-dimethylpentane 15 wt%) in a mass ratio of 1:2 in an extraction separation kettle. The extraction was stirred at 20℃for 20min at a stirring rate of 500rpm. Separating by a filter press to obtain a black solid phase, and collecting a liquid phase and sending the liquid phase to a solvent recovery process.
The solid phase is crude o-aminophenol containing a noble metal catalyst, and after the residual extractant is scraped, the content of the o-aminophenol in the composition is 94wt% and the content of the noble metal catalyst is 0.1wt%.
(2) Catalyst activation: adding the solid phase obtained in the step (1) into a catalyst activation kettle, mixing with an activating agent (85 wt% of benzene and 15wt% of 2, 2-dimethylpentane) according to a mass ratio of 1:4, stirring and activating for 90min at 50 ℃, and stirring at a speed of 1000rpm. Filtering and separating to obtain solid phase, and feeding into an oven to obtain N 2 Drying in atmosphere at 100deg.C for more than 40min until the solid phase quality is unchanged, and collecting gray dry solid, and conveying the liquid phase to solvent recovery process.
The gray dry solid is an ortho-aminophenol comprising a noble metal catalyst having a composition of 98wt% ortho-aminophenol and 0.1wt% noble metal catalyst.
(3) Sublimation separation catalyst: adding the dried solid obtained in the step (2) into a sublimation desublimation machine to obtain a solid N 2 Heating and refining in atmosphere, filling 30% of o-aminophenol particles with volume fraction as crystal nucleus in a sublimator before sublimation operation, stirring at 2500rpm to make solid particles in fluidized state, heating at 170deg.C for 180min, sublimating sublimated gas to obtain white powdery o-aminophenol, and recovering catalyst from residual solid at bottom of sublimator.
(4) And (3) recovering a solvent: continuously feeding the liquid phases obtained by filtering in the step (1) and the step (2) into a benzene rectification recovery tower for rectification, and recovering solvent benzene. And (3) operating a 5-layer packed tower, wherein the heating temperature of a tower kettle is 155 ℃, the reflux ratio is 5, the 2 nd layer of packing is fed to the feeding position, the third layer of packing is used for side production of products, the side production temperature is 82 ℃, benzene recovered by side production rectification is recycled as nitrobenzene production raw materials, and residual liquid of the tower kettle enters an incineration system for treatment.
The recovered noble metal catalyst was subjected to nitrobenzene batch hydrogenation and o-aminophenol product gas phase analysis, and in this example, the catalyst recovery was 95%, and the noble metal catalyst activity after regeneration was 90% (based on 100% of fresh catalyst activity). The purity of the o-aminophenol product obtained by sublimation is 99.2%, the recovery rate of the o-aminophenol is calculated to be 97% according to the content of the o-aminophenol in the tar waste material and the quality of the o-aminophenol obtained by recovery, and the recovery rate of the solvent benzene is calculated to be 85% (calculated by the benzene content in the nitrobenzene waste benzene liquid).
Comparative example 1
The preparation method of reference example 1 only differs in that: the extraction solvent in the step (1) and the activator in the step (2) are replaced by the configuration solvent with equal mass, the composition is 99.5 weight percent of 2-methylpentane and 0.5 weight percent of toluene, and other operations and conditions are unchanged.
The catalyst recovery rate in this comparative example was 95%, and the noble metal catalyst activity after regeneration was 75% (based on 100% of the fresh catalyst activity). The purity of the o-aminophenol product obtained by sublimation is 90%, and the recovery rate of the o-aminophenol is calculated to be 90% according to the content of the o-aminophenol in the tar waste and the quality of the recovered o-aminophenol.
Comparative example 2
The preparation method of example 1 was referred to, except that the extraction solvent in step (1) and the activator in step (2) were replaced with the same mass of the solvent, and the composition was 91wt% of benzene, 8.5wt% of n-nonane (long chain fat), 0.5wt% of toluene, and the other operations and conditions were unchanged.
In this comparative example, the catalyst recovery rate was 95%, and the noble metal catalyst activity after regeneration was 80% (based on 100% of the fresh catalyst activity). The purity of the o-aminophenol product obtained by sublimation is 99%, and the recovery rate of the o-aminophenol is calculated to be 90% according to the content of the o-aminophenol in the tar waste and the quality of the recovered o-aminophenol.
Comparative example 3
The preparation method of reference example 1 only differs in that: in the step (1), the extraction solvent and the activator in the step (2) are replaced by the configuration solvent with equal mass, and the components are 99wt% of benzene and 0.5wt% of toluene, and other operations and conditions are unchanged.
In this comparative example, the catalyst recovery was 95%, and the noble metal catalyst activity after regeneration was 85% (based on 100% of the fresh catalyst activity). The purity of the o-aminophenol product obtained by sublimation is 99%, and the recovery rate of the o-aminophenol is calculated to be 90% according to the content of the o-aminophenol in the tar waste and the quality of the recovered o-aminophenol.
Comparative example 4
The preparation method of reference example 1 only differs in that: in the step (1), the extraction solvent and the activator in the step (2) are replaced by the configuration solvent with equal mass, and the components are 91wt% of nitrobenzene, 8.5wt% of 2-methylpentane and 0.5wt% of toluene, and other operations and conditions are unchanged.
In this comparative example, the catalyst recovery was greater than 95% and the noble metal catalyst activity after regeneration was 85% (based on 100% fresh catalyst activity). The purity of the o-aminophenol product obtained by sublimation is 85%, and the recovery rate of the o-aminophenol is calculated to be 90% according to the content of the o-aminophenol in the tar waste and the quality of the recovered o-aminophenol.
Comparative example 5
The preparation method of reference example 1 only differs in that: and (3) changing the sublimation temperature to 280 ℃ and the sublimation time to 120min, and keeping other operations and conditions unchanged.
In this comparative example, the catalyst recovery was greater than 95% and the noble metal catalyst activity after regeneration was 90% (based on 100% fresh catalyst activity). The purity of the o-aminophenol product obtained by sublimation is 98.7%, and the recovery rate of the o-aminophenol is calculated to be 90% according to the content of the o-aminophenol in the tar waste and the quality of the recovered o-aminophenol.
Claims (30)
1. A method for regenerating and recovering a catalyst from aniline tar and by-producing o-aminophenol, which is characterized by comprising the following steps:
(1) And (3) extraction and separation: mixing aniline tar with an extraction solvent comprising benzene, short chain aliphatic hydrocarbons and optionally benzene derivatives, extracting with stirring, and then separating the liquid and solid phases by filtration; wherein the short-chain aliphatic hydrocarbon is selected from C6-C7 aliphatic hydrocarbon, the benzene derivative is selected from any one or a combination of at least two of toluene, xylene and nitrobenzene, and the mass ratio of benzene, short-chain aliphatic hydrocarbon and benzene derivative is 1:0.1-0.5:0-0.1;
(2) Catalyst activation: mixing the solid phase obtained in the step (1) with an activator, wherein the activator comprises benzene, short-chain aliphatic hydrocarbon and optional benzene derivatives, heating and activating under high-speed stirring, and then separating a liquid phase and a solid phase through filtration, wherein the solid phase is dried in inert gas to obtain a dry solid; wherein the short-chain aliphatic hydrocarbon is selected from aliphatic hydrocarbons of C6-C7, and the benzene derivative is selected from any one or a combination of at least two of toluene, xylene and nitrobenzene;
(3) Sublimation separation catalyst: adding the dried solid obtained in the step (2) into a sublimation desublimation machine, and adding the dried solid into N 2 Heating to 120-220 deg.C in atmosphere for sublimation, sublimating the sublimated gas to obtain white powdery o-aminophenol, and obtaining residual solid from the bottom of sublimatorTo recovery of the catalyst.
2. The method according to claim 1, wherein in the step (1), the aniline tar is a byproduct tar of aniline production, and the catalyst content in the aniline tar is more than 10ppm, and the ortho-aminophenol content is more than 8wt%.
3. The method according to claim 2, wherein the catalyst content in the aniline tar is 50-250ppm and the ortho-aminophenol content is 15-30wt%.
4. The method of claim 2, wherein the aniline tar is comprised of: 10-250ppm of catalyst, 8-30wt% of o-aminophenol, 13-20wt% of aniline, 25-45wt% of 4-aminodiphenylamine and the balance of impurities.
5. The method of claim 4, wherein the aniline tar is comprised of: 50-250ppm of catalyst, 15-30wt% of o-aminophenol, 13-20wt% of aniline, 25-45wt% of 4-aminodiphenylamine and the balance of impurities.
6. The method of claim 1, wherein in step (1), the short chain aliphatic hydrocarbon is selected from any one or a combination of at least two of methylpentane, dimethylpentane, hexane, cyclohexane, methylcyclohexane, methylcyclopentane, dimethylcyclopentane;
wherein the benzene derivative is toluene.
7. The method of claim 6, wherein the short chain aliphatic hydrocarbon is selected from any one or a combination of at least two of methylpentane, dimethylpentane, and cyclohexane.
8. The method of claim 1, wherein in step (1), the mass ratio of benzene, short chain aliphatic hydrocarbon and benzene derivative is 1:0.1-0.2:0.01-0.05.
9. The method of claim 1, wherein in step (1), the extraction solvent is nitrobenzene waste benzene liquid, and the nitrobenzene waste benzene liquid is waste benzene discharged from a nitrobenzene production device;
the nitrobenzene waste benzene liquid comprises the following components in percentage by mass: benzene 85-92%, C6-C7 aliphatic hydrocarbon 7-15%, toluene 0.5-1%, wherein the C6-C7 aliphatic hydrocarbon comprises any one or a combination of at least two of methylpentane, dimethylpentane, hexane, cyclohexane, methylcyclohexane, methylcyclopentane, dimethylcyclopentane.
10. The method according to claim 1, wherein in the step (1), the mixing mass ratio of the aniline tar to the extraction solvent is 1:0.6-10; and/or
In the step (1), stirring is carried out at a rotating speed of 50-800rpm; and/or
In the step (1), the extraction temperature is 20-40 ℃ and the extraction time is 10-180min.
11. The method according to claim 10, wherein the mixing mass ratio of aniline tar to extraction solvent is 1:3-6.
12. The method of claim 10, wherein the stirring is at 500-700rpm.
13. The method according to claim 10, wherein the extraction temperature is 20-30 ℃ and the extraction time is 20-40min.
14. The process of claim 1, wherein in step (2), the activator is the same as or different from the extraction solvent in step (1);
the short-chain aliphatic hydrocarbon is selected from any one or a combination of at least two of methylpentane, dimethylpentane, hexane, cyclohexane, methylcyclohexane, methylcyclopentane and dimethylcyclopentane;
the benzene derivative is toluene.
15. The method of claim 14, wherein the short chain aliphatic hydrocarbon is selected from any one or a combination of at least two of methylpentane, dimethylpentane, and cyclohexane.
16. The method of claim 1, wherein in step (2), 1 of benzene, short chain aliphatic hydrocarbons and benzene derivatives: 0.1-0.5:0-0.1.
17. The method of claim 1, wherein the benzene, short chain aliphatic hydrocarbon and benzene derivative is 1:0.1-0.2:0.01-0.05.
18. The method of claim 1, wherein in step (2), the activator is nitrobenzene waste benzene liquid.
19. The method of claim 1, wherein in step (2), the mass ratio of activator to solid phase is 4-8:1; and/or
In the step (2), the high-speed stirring is carried out, and the rotating speed is 500-3000rpm; and/or
In the step (2), the activation is carried out at the activation temperature of 50-80 ℃ for 60-200 min; and/or
In the step (2), the drying is carried out at the temperature of 80-100 ℃ for 30-120min; the inert shielding gas is nitrogen.
20. The method of claim 19, wherein the mass ratio of activator to solid phase is 5-6:1.
21. The method of claim 19, wherein the high speed agitation is at 2000-3000rpm.
22. The method of claim 19, wherein the activating is performed at a temperature of 60-65 ℃ for a time of 100-120 minutes.
23. The method of claim 19, wherein the drying is at a temperature of 90 ℃.
24. The method according to claim 1, wherein in step (3), the sublimation temperature is 120-220 ℃ and the sublimation time is 40-180min.
25. The method of claim 24, wherein the sublimation temperature is 150-180 ℃ and the sublimation time is 60-90min.
26. The method of claim 1, wherein in step (3), the sublimation process is conducted with an inert gas.
27. The method of claim 26, wherein the inert gas is nitrogen.
28. The method according to claim 1, wherein in step (3), the sublimation is preceded by filling the sublimation machine with 10 to 30% by volume of the o-aminophenol particles as nuclei and stirring the solid particles in a mechanically fluidized state.
29. The method of claim 28, wherein the agitation speed is 2000-3000rpm.
30. The method according to claim 1, wherein the liquid phase obtained by filtration in step (1) and step (2) is separated by distillation to recover benzene and its derivatives and short chain aliphatic hydrocarbons.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1553389A (en) * | 1976-12-17 | 1979-09-26 | Graesser Salicylates Ltd | Purification of aminophenols |
| CN1290689A (en) * | 2000-09-05 | 2001-04-11 | 华东理工大学 | Method for separating and refining para-aminophenol from electrolyte |
| CN1721391A (en) * | 2004-07-15 | 2006-01-18 | 王农跃 | Process for preparing 4-amino diphenylamine |
| CN110563069A (en) * | 2018-06-06 | 2019-12-13 | 中国石油化工股份有限公司 | Comprehensive utilization method of nitrobenzene tar and aniline wastewater |
| CN113121311A (en) * | 2019-12-31 | 2021-07-16 | 万华化学集团股份有限公司 | Comprehensive recovery treatment process of aniline tar |
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- 2022-07-25 CN CN202210877075.2A patent/CN115318280B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1553389A (en) * | 1976-12-17 | 1979-09-26 | Graesser Salicylates Ltd | Purification of aminophenols |
| CN1290689A (en) * | 2000-09-05 | 2001-04-11 | 华东理工大学 | Method for separating and refining para-aminophenol from electrolyte |
| CN1721391A (en) * | 2004-07-15 | 2006-01-18 | 王农跃 | Process for preparing 4-amino diphenylamine |
| CN110563069A (en) * | 2018-06-06 | 2019-12-13 | 中国石油化工股份有限公司 | Comprehensive utilization method of nitrobenzene tar and aniline wastewater |
| CN113121311A (en) * | 2019-12-31 | 2021-07-16 | 万华化学集团股份有限公司 | Comprehensive recovery treatment process of aniline tar |
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