A catalyst for producing alkyl aromatic hydrocarbons by alkylation reaction and a preparation method and application thereof
By using a catalyst supported by sulfonated polyether ether ketone (PEEK) additives, the stability and corrosivity issues of existing catalysts in aromatic alkylation reactions have been resolved, enabling efficient and low-cost production of alkyl aromatics.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- THE NORTHWEST RES INST OF CHEM IND
- Filing Date
- 2026-03-02
- Publication Date
- 2026-06-19
AI Technical Summary
Existing sulfonic acid resin catalysts suffer from sulfonic acid group loss in styrene-type sulfonic acid resins and sensitivity to metal ions during aromatic alkylation reactions. Furthermore, the preparation of perfluorosulfonic acid resins is complex and costly, which limits their application.
Sulfonated polyether ether ketone is used as the catalyst substrate and supported with phosphotungstic acid, phosphomolybdic acid, ZrO2, TiO2, Nb2O5, SiO2 or Al2O3 additives. The catalyst is prepared through a specific process to improve thermal and chemical stability and reduce equipment corrosion.
The catalyst has high thermal stability, chemical stability and good mechanical properties, high catalytic activity, is easy to separate and recover, has strong reusability, and reduces equipment corrosion and production costs.
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Figure CN122230799A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of solid acid catalyst technology, specifically relating to a catalyst for the production of alkyl aromatics by alkylation reaction, its preparation method, and its application. Background Technology
[0002] Alkylation is an important technique for constructing C-C bonds in organic synthesis. It can introduce alkyl side chains onto aromatic hydrocarbons, adjust their physicochemical properties, and be used to synthesize pharmaceutical, pesticide, or dye chemical intermediates with specific functions. Typical applications include the production of ethylbenzene (used to prepare styrene), long-chain alkylbenzenes (used to prepare detergents), and alkylnaphthalenes (used to produce naphthyl lubricating oils).
[0003] Currently, the commonly used industrial route for producing alkyl aromatics involves the Friedel-Crafts alkylation reaction of aromatics with halogenated hydrocarbons, alcohols, or alkenes. The reaction process is as follows:
[0004] The catalysts used are mainly divided into two categories: traditional Lewis acid catalysts and solid acid catalysts. Traditional Lewis acid catalysts, such as anhydrous aluminum trichloride, have high activity but require hydrochloric acid for catalysis, are highly corrosive, and their spent catalysts and wastewater are difficult to treat. Therefore, the current mainstream industrial application is still solid acid catalysts, represented by molecular sieves, which have advantages such as low corrosivity, high selectivity, and recyclability.
[0005] Sulfonic acid resin is a special polymer material with sulfonic acid group -SO3H at the end of its side chain. Compared with molecular sieve catalysts, which require high temperature and high pressure conditions (usually about 250~350℃, 1.0~3.0 MPa) to catalyze the alkylation of aromatics, the reaction conditions for sulfonic acid resin catalyzing alkylation reactions are milder (room temperature to 200℃, atmospheric pressure), and its application prospects are better.
[0006] US Patent 5124299A discloses a method for catalyzing the alkylation of toluene with C2-C5 olefins using a sulfonic acid-functionalized perfluorinated ion-exchange polymer. The catalyst is a blend of NafionR Polymer (manufactured by DuPont) and the perfluorinated diluent polytetrafluoroethylene (PTFE). By optimizing the loading of sulfonic acid groups and the molecular structure of the polymer, the thermal and chemical stability of the catalyst is improved. Suitable reaction conditions are: 150-200°C, 0.1-75 atm.
[0007] Patent US4168390A discloses a continuous process for the alkylation of phenols and olefins using Lewatit SC series sulfonic acid resins. The multi-zone fixed-bed reactor design protects key parameters such as catalyst reaction temperature (80~120℃ in the first zone and 110~130℃ in the second zone) and catalyst exchange capacity.
[0008] Currently, the shortcomings of sulfonic acid resin-catalyzed aromatic alkylation reaction technology are as follows: styrene-type sulfonic acid resins (such as the Amberlyst series) will gradually lose sulfonic acid groups when used for a long time at high temperatures, and contact with water or metal ions such as iron ions will also cause a decrease in acidity. Therefore, the purity requirements of raw materials are high. In addition, although perfluorosulfonic acid resins (such as Nafion) have better thermal stability, their complex preparation process, high pollution, and high cost also limit their application.
[0009] Polyetheretherketone (PEEK) is a novel high-energy engineering plastic, produced by the condensation polymerization of hydroquinone and 4,4'-difluorobenzophenone. Its main chain structure contains repeating units with one ketone bond and two ether bonds, exhibiting excellent chemical and thermal stability (melting point above 380℃, heat distortion temperature above 300℃). Sulfonated polyetheretherketone (SPEEK) introduces sulfonic acid groups into its main chain or side chains, retaining high stability while improving the material's hydrophilicity and ion exchange capacity. The structure of sulfonated polyetheretherketone is shown below:
[0010] Patent CN110483711A discloses a crosslinking modification method for sulfonated polyether ether ketone (PEEK) to improve thermal stability and methanol resistance. Patent CN115260422A optimizes the sulfonation process using p-chlorophenol and o-dichlorobenzene solvents to improve the controllability of sulfonation. Patent CN113527333A discloses a surface-modified PEEK method that improves the hydrophilicity and cell adhesion of the material through sulfonation and polypyrrole loading. Patent CN112792648A optimizes the surface structure of sulfonated PEEK through hydrothermal-low-temperature treatment to improve its biocompatibility with bone tissue. These patents mainly focus on material preparation and biomedical modification, and none of them involve the catalytic application of SPEEK in aromatic alkylation reactions. Summary of the Invention
[0011] To address the shortcomings of existing technologies, this invention provides a catalyst for the alkylation reaction to produce alkyl aromatics, its preparation method, and its application. The catalyst can catalyze the alkylation reaction of alcohols or olefins with benzene or naphthalene to produce the corresponding alkyl aromatic products. The catalyst has high thermal stability, chemical stability, and good mechanical properties, high catalytic activity, is easy to separate and recover, and has low corrosiveness to equipment.
[0012] A catalyst for the alkylation reaction to produce alkyl aromatics, the catalyst comprising sulfonated polyether ether ketone and an auxiliary agent supported on the sulfonated polyether ether ketone, wherein the auxiliary agent is any one of phosphotungstic acid, phosphomolybdic acid, ZrO2, TiO2, Nb2O5, SiO2, and Al2O3; the auxiliary agent accounts for 0.1-30% of the mass of the catalyst.
[0013] Preferably, the degree of sulfonation of the catalyst is 25-85 mol%.
[0014] Preferably, the catalyst has an ion exchange capacity of 1.0-2.5 mequiv / g and a specific surface area of 100-1200 m². 2 / g, with an average pore size of 5-30nm.
[0015] More preferably, the degree of sulfonation of the catalyst is 65-80 mol%.
[0016] More preferably, the catalyst has an ion exchange capacity of 1.5-1.9 mequiv / g and a specific surface area of 500-800 m². 2 / g.
[0017] More preferably, the catalyst has a degree of sulfonation of 78 mol%, an ion exchange capacity of 1.9 mequiv / g, and a specific surface area of 560 m². 2 / g, with an average pore size of 6.6nm.
[0018] The method for preparing the catalyst for the alkylation reaction to produce alkyl aromatics includes the following steps: (1) Vacuum dry polyether ether ketone, add it to concentrated sulfuric acid, and stir and reflux at 40-120℃ for 2-24h; (2) Add the additives and continue stirring and refluxing for 2-24 hours while maintaining the temperature; control the degree of sulfonation by adjusting the temperature and time. (3) Transfer the reaction slurry from step (2) to a constant pressure dropping funnel and drop it into a container containing coolant to stop the sulfonation. Wash the obtained product with water until pH=6-7, centrifuge, filter to further remove water, and vacuum dry.
[0019] Preferably, the mass ratio of the polyetheretherketone to concentrated sulfuric acid is 0.1-0.6; and the degree of crosslinking of the polyetheretherketone is 8-45%.
[0020] More preferably, the degree of crosslinking of the polyetheretherketone is 15-30%.
[0021] Preferably, the coolant is an aqueous solution of sodium chloride at a temperature of -10°C to 10°C, and the concentration of the aqueous solution of sodium chloride is less than or equal to 25 wt%; or the coolant is water at a temperature of 0°C to 10°C.
[0022] Preferably, the vacuum drying is performed at 40-80℃ for 12-48 hours; the stirring speed is 100-900 rpm.
[0023] A method for producing alkyl aromatics by alkylation reaction, the method comprising sequentially adding a raw material aromatic hydrocarbon, a solvent, and a catalyst to a batch reactor, replacing the air therein with nitrogen, stirring to suspend the catalyst, then adding an alkylating reagent, stirring the reaction at 80-150°C for 30-240 min, filtering, and recovering the catalyst; wherein the alkylating reagent is an alcohol or an olefin; and the catalyst is the above-mentioned catalyst.
[0024] Preferably, the molar ratio of the raw aromatic hydrocarbon to the alkylating agent is 1:1 to 1:5; the mass ratio of the catalyst to the raw aromatic hydrocarbon is 0.01 to 0.2; and the molar ratio of the solvent to the raw aromatic hydrocarbon is 1 to 5.
[0025] Preferably, the raw material aromatic hydrocarbon is any one of benzene, benzene homologues, naphthalene, and naphthalene homologues; The solvent is 1,2-dichloroethane, dichloromethane, or an aromatic solvent; the aromatic solvent is the same as the aromatic raw material. The alkylating agent is any one of methanol, ethanol, ethylene, tert-butanol, isobutene, 1-hexene, and 1-dodecene. The liquid raw material of the alkylating agent is pumped into the reactor by a liquid feed pump at a feed rate of 0.1-10 mL / min. The gaseous raw material of the alkylating agent is pumped into the reactor by a pressure reducing valve at a pressure of 0.1-3 MPa.
[0026] More preferably, the homologue of benzene is toluene, and the homologue of naphthalene is 2-methylnaphthalene.
[0027] Preferably, in the method for producing alkyl aromatics by alkylation reaction, the stirring speed is 100-600 rpm.
[0028] Preferably, the catalyst can be reused after being recovered and dried. After being used several times, it is regenerated. The regeneration method is as follows: first, elute with an elution solvent at 40-80℃ for 2-8 hours, then soak in a 1-10wt% dilute acid solution for 2-12 hours, then wash with deionized water until neutral, and vacuum dry at 40-80℃ for 12-24 hours.
[0029] Preferably, the elution solvent is acetone or toluene, and the dilute acid solution is dilute sulfuric acid or dilute hydrochloric acid.
[0030] Preferably, the catalyst needs to be regenerated when any of the following conditions are met: product selectivity is less than 90%, yield is less than 80%, catalyst is reused more than or equal to 10 times, or activity decreases by more than 15%.
[0031] Preferably, the yield recovery rate of the regenerated catalyst is ≥95%; otherwise, it cannot be recycled again.
[0032] The degree of sulfonation described in this invention is calculated based on NMR characterization results, and the degree of sulfonation DS satisfies the following formula: , Where DS represents the degree of sulfonation, expressed as a percentage (in moles); A Hr for 1 The peak area of characteristic hydrogen (Hr) in the 1H NMR spectrum is dimensionless. Since the sulfonic acid matrix sub-peak is easily broadened by water, the characteristic hydrogen is replaced by sulfonated ortho-hydrogen. ΣA Hi for 1 The sum of the peak areas of other hydrogen atoms in the H NMR spectrum is dimensionless.
[0033] Advantages of this invention: When the catalyst is used for alkylation to prepare alkyl aromatics, it has low corrosiveness to equipment, high product selectivity, is easy to separate and recover, has good thermal and chemical stability, can be reused multiple times, is simple to regenerate, and has a high activity recovery rate. Attached Figure Description
[0034] Figure 1 The NMR spectrum is that of the catalyst described in Example 1. Detailed Implementation Example 1
[0035] 1. A catalyst for the alkylation reaction to produce alkyl aromatics, said catalyst comprising sulfonated polyether ether ketone and an auxiliary agent supported on said sulfonated polyether ether ketone, said auxiliary agent being phosphotungstic acid; said auxiliary agent comprising 0.1% of the catalyst by mass; 2. The catalyst is prepared as follows: (1) The polyether ether ketone with a crosslinking degree of 8% was vacuum dried at 80°C for 12h, added to 98wt% concentrated sulfuric acid, and stirred and refluxed vigorously at 40°C for 24h. The stirring speed was 900rpm, and the mass ratio of the polyether ether ketone to concentrated sulfuric acid was 0.1. (2) Add additives to it, maintain the temperature and continue stirring and refluxing for 24 hours to obtain orange reaction slurry; (3) Transfer the reaction slurry from step (2) to a constant pressure dropping funnel and drop it into a beaker containing water at 10°C to stop the sulfonation process. A white spherical product is obtained. The product is washed with water until pH=7, centrifuged, filtered to further remove water, and then vacuum dried at 80°C for 12 hours to obtain the catalyst, which is a yellow spherical product. The catalyst was characterized by nuclear magnetic resonance (NMR). 1 The H-spectral results are shown below. Figure 1 As shown; Depend on Figure 1 It can be seen that characteristic hydrogen ( peak area =1, other hydrogens ( The sum of the peak areas of ) is 4.65 + 7.54, which is calculated using the sulfonation degree formula.
[0036] Therefore, DS = 84.6%. Example 2
[0037] The additive is phosphomolybdic acid, and the rest is the same as in Example 1. Example 3
[0038] The additive is zirconium oxide (ZrO2), and everything else is the same as in Example 1. Example 4
[0039] The additive is titanium dioxide (TiO2), and everything else is the same as in Example 1. Example 5
[0040] The additive is niobium pentoxide (Nb₂O₅), and the rest is the same as in Example 1. Example 6
[0041] The additive is silicon dioxide (SiO2), and the additive accounts for 30% of the mass of the catalyst. Other aspects are the same as in Example 1. Example 7
[0042] The additive is aluminum oxide (Al2O3), and everything else is the same as in Example 6. Example 8
[0043] The degree of crosslinking of polyetheretherketone is 45%, and the rest is the same as in Example 1. Example 9
[0044] The mass ratio of polyetheretherketone to concentrated sulfuric acid was 0.6, and everything else was the same as in Example 1. Example 10
[0045] In the preparation method, polyether ether ketone with a crosslinking degree of 45% is used. In step (1), the mixture is vigorously stirred and refluxed at 120°C for 2 hours. In step (2), the mixture is refluxed and stirred for 2 hours. The rest is the same as in Example 1. Example 11
[0046] The coolant was a 25 wt% sodium chloride aqueous solution at -10°C, and everything else was the same as in Example 1. Example 12
[0047] The vacuum drying process was carried out at 40°C for 48 hours, and other procedures were the same as in Example 1. Example 13
[0048] A method for producing alkyl aromatics via alkylation reaction, comprising sequentially adding raw aromatic hydrocarbons, solvent, and catalyst to a batch reactor, purging the air with nitrogen three times, stirring to suspend the catalyst, then adding an alkylating agent, and carrying out the alkylation reaction by stirring at 150°C for 240 min, filtering, recovering the catalyst, vacuum drying, and reusing it; after 10 uses, regeneration is performed. During regeneration, the catalyst is first eluted with acetone at 40°C for 8 h, then soaked in a 1 wt% dilute sulfuric acid solution for 8 h, then washed with deionized water until neutral, and vacuum dried; the stirring speed is 100 rpm, and the vacuum drying is carried out at 80°C for 12 h. Wherein, the raw material aromatic hydrocarbon is benzene; the solvent is the same as the raw material aromatic hydrocarbon; the catalyst is the catalyst according to claim 1; the alkylating agent is ethanol, which is pumped into the reaction vessel by a liquid feed pump at a feed rate of 0.1 mL / min; The molar ratio of the raw aromatic hydrocarbon to the alkylating agent is 1:1, the molar ratio of the solvent to the raw aromatic hydrocarbon is 1, and the mass ratio of the catalyst to the raw aromatic hydrocarbon is 0.01. Example 14
[0049] The molar ratio of the raw aromatic hydrocarbon to the alkylating agent is 1:5, the molar ratio of the solvent to the raw aromatic hydrocarbon is 5, and the mass ratio of the catalyst to the raw aromatic hydrocarbon is 0.2. The alkylating agent is fed at a rate of 10 mL / min; The alkylation reaction was carried out by stirring at 80°C for 30 min at a stirring speed of 600 rpm. Everything else is the same as in Example 13. Example 15
[0050] The alkylating agent is ethylene, which is injected into the reactor through a pressure reducing valve. The pressure of the ethylene is 0.1 MPa. Everything else is the same as in Example 13. Example 16
[0051] The alkylating agent is ethylene, which is injected into the reactor through a pressure reducing valve. The pressure of the ethylene is 3.0 MPa. Everything else is the same as in Example 14. Example 17
[0052] The alkylating agent is isobutylene, and the rest is the same as in Example 15. Example 18
[0053] The alkylating agent was 1-hexene, and the catalyst used was the catalyst prepared in Example 2. Everything else was the same as in Example 13. Example 19
[0054] The alkylating agent was 1-dodecene; the catalyst used was the catalyst prepared in Example 3; everything else was the same as in Example 13. Example 20
[0055] The alkylating agent was tert-butanol, and the catalyst used was the catalyst prepared in Example 4; everything else was the same as in Example 13. Example 21
[0056] The molar ratio of the solvent to the aromatic feedstock is 3, and the mass ratio of the catalyst to the aromatic feedstock is 0.05; the aromatic feedstock is naphthalene, the solvent is 1,2-dichloroethane, and the alkylating agent is ethanol; the catalyst used is the catalyst prepared in Example 5; everything else is the same as in Example 13. Example 22
[0057] The raw material aromatic hydrocarbon is toluene, the solvent is dichloromethane, and the alkylating agent is tert-butanol; the catalyst is the catalyst prepared in Example 6; everything else is the same as in Example 13. Example 23
[0058] The raw material aromatic hydrocarbon is 2-methylnaphthalene, and the alkylating agent is tert-butanol; the catalyst is the catalyst prepared in Example 7; everything else is the same as in Example 13. Example 24
[0059] During regeneration, the eluent toluene is first refluxed at 80°C for 2 hours, then soaked in 10wt% dilute hydrochloric acid solution for 2 hours, washed with deionized water until neutral, and then vacuum dried; the vacuum drying is carried out at 40°C for 24 hours. The catalyst used is the catalyst prepared in Example 8; Example 25
[0060] 1. A catalyst for the alkylation reaction to produce alkyl aromatics, said catalyst comprising sulfonated polyether ether ketone and an auxiliary agent supported on said sulfonated polyether ether ketone, said auxiliary agent being Nb2O5; said auxiliary agent comprising 4.8% of the catalyst by mass; 2. The catalyst is prepared as follows: (1) The polyether ether ketone with a crosslinking degree of 8% was vacuum dried at 80°C for 12h, added to 98wt% concentrated sulfuric acid, and stirred and refluxed vigorously at 40°C for 24h. The stirring speed was 900rpm, and the mass ratio of the polyether ether ketone to concentrated sulfuric acid was 0.1. (2) Add additives to it, maintain the temperature and continue stirring and refluxing for 24 hours to obtain orange reaction slurry; (3) Transfer the reaction slurry from step (2) to a constant pressure dropping funnel and drop it into a beaker containing water at 10°C to stop the sulfonation process. A white spherical product is obtained. The product is washed with water until pH=7, centrifuged, filtered to further remove water, and then vacuum dried at 80°C for 12 hours to obtain the catalyst, which is a yellow spherical product. 3. The obtained catalyst is used in the alkylation reaction of ethylene and benzene to produce ethylbenzene. Ethylene is injected into the reactor by a pressure reducing valve at a pressure of 3 MPa. The molar ratio of the raw material aromatic hydrocarbon to the alkylating agent ethylene is 1:1, the molar ratio of the solvent to the raw material aromatic hydrocarbon is 2, and the mass ratio of the catalyst to the raw material aromatic hydrocarbon is 0.01. Other aspects are the same as in Example 13.
[0061] Performance testing 1. The degree of sulfonation, ion exchange capacity, specific surface area, and average pore size of the catalysts in each example were measured. The results are shown in Table 1. The calculation method for the degree of sulfonation is the same as that for Example 1. Table 1 Test Results .
[0062] 2. The catalytic reaction results of Examples 13-25 are shown in Table 2; Table 2 Reaction Results , in, X: Conversion rate of the alkylating agent; Y1: Total yield of alkylation products when the catalyst is used for the first time; Y 10 : Total yield of alkylation products achieved when the catalyst is reused for the tenth time; Y 再生 The total yield of alkylation products when the regenerated catalyst is used for the first time; Z: Activity recovery rate of the regenerated catalyst during use, calculated using the following formula: .
Claims
1. A catalyst for the production of alkyl aromatics via alkylation reaction, characterized in that: The catalyst is composed of sulfonated polyether ether ketone and an auxiliary agent supported on the sulfonated polyether ether ketone. The auxiliary agent is any one of phosphotungstic acid, phosphomolybdic acid, ZrO2, TiO2, Nb2O5, SiO2, and Al2O3. The auxiliary agent accounts for 0.1-30% of the mass of the catalyst.
2. The catalyst for alkylation reaction to produce alkyl aromatics according to claim 1, characterized in that: The sulfonation degree of the catalyst is 25-85 mol.
3. The catalyst for alkylation reaction to produce alkyl aromatics according to claim 1, characterized in that: The catalyst has an ion exchange capacity of 1.0-2.5 mequiv / g and a specific surface area of 100-1200 m². 2 / g, with an average pore size of 5-30nm.
4. The method for preparing the catalyst for the alkylation reaction to produce alkyl aromatics according to claim 1, characterized in that: Includes the following steps: (1) Vacuum dry polyether ether ketone, add it to concentrated sulfuric acid, and stir and reflux at 40-120℃ for 2-24h; (2) Add the additives and continue stirring and refluxing for 2-24 hours while maintaining the temperature; (3) Transfer the reaction slurry from step (2) to a constant pressure dropping funnel and drop it into a container containing coolant to stop the sulfonation. Wash the obtained product with water until pH=6-7, centrifuge, filter, and vacuum dry.
5. The method for preparing the catalyst for alkylation reaction to produce alkyl aromatics according to claim 4, characterized in that: The mass ratio of polyetheretherketone to concentrated sulfuric acid is 0.1-0.6; the degree of crosslinking of the polyetheretherketone is 8-45%.
6. The method for preparing the catalyst for alkylation reaction to produce alkyl aromatics according to claim 4, characterized in that: The coolant is an aqueous solution of sodium chloride at a temperature of -10°C to 10°C, and the concentration of the aqueous solution of sodium chloride is less than or equal to 25 wt%; or the coolant is water at a temperature of 0°C to 10°C.
7. The method for preparing the catalyst for alkylation reaction to produce alkyl aromatics according to claim 4, characterized in that: The vacuum drying is performed at 40-80℃ for 12-48 hours; the stirring speed is 100-900 rpm.
8. A method for producing alkyl aromatics by alkylation reaction, characterized in that: The method involves sequentially adding aromatic hydrocarbons, solvent, and catalyst to a batch reactor, replacing the air with nitrogen, stirring to suspend the catalyst, then adding an alkylating agent, continuing the reaction at 80-150°C for 30-240 minutes, filtering, and recovering the catalyst; the alkylating agent is an alcohol or olefin; and the catalyst is the catalyst described in claim 1.
9. The method for producing alkyl aromatics by alkylation reaction according to claim 8, characterized in that: The molar ratio of the raw aromatic hydrocarbon to the alkylating agent is 1:1 to 1:5; the mass ratio of the catalyst to the raw aromatic hydrocarbon is 0.01 to 0.2; and the molar ratio of the solvent to the raw aromatic hydrocarbon is 1 to 5.
10. The method for producing alkyl aromatics by alkylation reaction according to claim 8, characterized in that: The raw material aromatic hydrocarbon is any one of benzene, benzene homologues, naphthalene, and naphthalene homologues; The solvent is 1,2-dichloroethane, dichloromethane, or an aromatic solvent; the aromatic solvent is the same as the aromatic raw material. The alkylating agent is any one of methanol, ethanol, ethylene, tert-butanol, isobutene, 1-hexene, and 1-dodecene. The liquid raw material of the alkylating agent is pumped into the reactor by a liquid feed pump at a feed rate of 0.1-10 mL / min. The gaseous raw material of the alkylating agent is pumped into the reactor by a pressure reducing valve at a pressure of 0.1-3 MPa.