Method for reducing by-product in reaction system of bisphenol a

Abstract

To provide a method for reducing a by-product in a reaction system of bisphenol A.SOLUTION: A method for reducing a by-product in a reaction system of bisphenol A includes the steps of: sending mother liquid generated by reacting, concentrating, crystallizing and separating phenol and acetone to a mother liquid recovery system; bringing the mother liquid obtained by the mother liquid recovery system into contact with a sulfonic acid group-containing metal organic skeleton catalyst and performing isomerization reaction; and sending a product obtained by the isomerization reaction to the mother liquid recovery system, and obtaining bisphenol A through crystallization and dephenolization. In an isomerization reaction catalyst of a by-product of bisphenol A, an amount of a sulfonic acid and a pore size of a catalyst can be adjusted, a conversion ratio of the by-product of the bisphenol A in a catalyst reaction is high and the conversion ratio can reach 28% to 55%, a selection ratio of the bisphenol A is high and the selection ratio can achieve 80% to 90%, and the by-product of the bisphenol A can be efficiently converted into the bisphenol A.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for reducing by-products in a bisphenol A reaction system, and in particular to a method and catalyst for producing bisphenol A by catalyzing the isomerization of by-products 2,4-BPA, trisphenols, and chromans in a bisphenol A reaction system, and also to a method for reducing by-products in a bisphenol A reaction system. [Background technology]

[0002] Bisphenol A (BPA), whose chemical name is 2,2-bis(4-hydroxyphenyl)propane, is a widely used organic chemical raw material produced by the condensation reaction of phenol and acetone in the presence of a catalyst. It is primarily used in the production of polymeric materials such as polycarbonate and epoxy resin.

[0003] The bisphenol A reaction produces 2,4-bisphenol A (abbreviated as 2,4-BPA) as a by-product. The p-isopropenylphenol produced by the condensation reaction of phenol with acetone continues to react with the main product, bisphenol A, to produce 4-(2,2,4-trimethylchroman-4-yl)phenol (abbreviated as trisphenol). The raw phenol also contains small amounts of mesityl acetone, which is produced by acetone itself under acidic catalytic conditions. This condensation reaction with phenol produces 2-2-4-trimethyl-4-(4'-hydroxyphenyl)-chroman and 1,1,3-trimethyl-1-(4'-hydroxyphenyl)indan-6-ol (abbreviated as chroman). These by-products affect the purity and color of the bisphenol A product, affecting its quality and downstream uses. Therefore, treatment of the crystallization mother liquor is a critical step to ensure the quality of the final product and the raw materials.

[0004] To solve the above problems, efforts have been made to isomerize bisphenol A by-products to obtain a larger amount of bisphenol A product. Patent Document 1 discloses a method for producing bisphenol A from phenol and acetone via a catalytic condensation reaction in the presence of a sulfonated ion exchange resin. The concentrated bisphenol A crystallization stream is targeted and isomerized in the presence of a macroporous sulfonated ion exchange catalyst. Patent Document 2 discloses a method for producing bisphenol A in which a mixture obtained after the reaction of phenol and acetone is concentrated, crystallized, and subjected to solid-liquid separation, and a portion of the resulting mother liquor is isomerized, followed by crystallization and solid-liquid separation to obtain bisphenol A. Patent Document 3 discloses an isomerization method in which a product obtained by the condensation reaction of ketone and phenol to produce bisphenol is isomerized under aqueous conditions with an ion exchange resin having sulfonic acid groups, followed by separation to obtain bisphenol.

[0005] Currently, the catalysts commonly used industrially to catalyze the isomerization of 2,4-BPA, a by-product of bisphenol A, are acidic ion exchange resins. However, these resins have relatively low catalytic selectivity and poor catalytic stability, prone to deactivation due to pore blockage and coke accumulation. This is primarily due to the large molecular size of the bisphenol A by-product, which requires a larger reaction space. The resins are limited by the degree of cross-linking and swelling, resulting in poor pore size control, which adversely affects the mass transfer and diffusion of by-products during the catalytic reaction. Furthermore, the sulfonic acid and thiol groups that are active in the isomerization reaction are prone to leaching from the resin, reducing catalytic performance and corroding equipment, affecting subsequent separation and product quality.

[0006] In short, the current reaction process for synthesizing bisphenol A using a resin catalyst does not consider an appropriate method scheme for isomerizing and converting the by-products in the reaction to obtain bisphenol A. In particular, the crystallization mother liquor after the reaction does not take into account maximum recovery and concentration of the by-products, and an appropriate operating scheme for isomerization treatment of multi-component and high-molecular by-products is lacking. Therefore, it is necessary to develop a process for efficiently reducing by-products in the bisphenol A reaction system and to obtain a catalyst suitable for the by-product isomerization reaction in the bisphenol A reaction system using a manufacturing method that can adjust the pore structure and control the acidity points.

[0007] Therefore, the present invention focuses on the problems of poor concentration of by-products and low isomerization activity during the catalysis of the isomerization of bisphenol A by-products, and has developed a new isomerization method and a suitable isomerization catalyst for the method. The main novelty is that the isomerization method proposes an isomerization method in which the bisphenol A-containing by-products produced after the reaction, concentration, crystallization, and separation of phenol and acetone are collected to obtain a mother liquor rich in bisphenol A by-products, which is then sent to an isomerization reactor. The isomerization of bisphenol A by-products is catalyzed using a sulfonic acid group-containing metal organic framework catalyst, which can adjust the sulfonic acid content and thiol content and is suitable for the reaction of bisphenol A polymer by-products, thereby achieving a high conversion rate of bisphenol A by-products and a high yield of bisphenol A. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Chinese Patent No. CN 200880004965.0 Publication [Patent Document 2] Chinese Patent No. CN 201380033378.5 [Patent Document 3] Chinese Patent No. CN 202080047470.7 Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a method for reducing by-products in a bisphenol A reaction system, in which the mother liquor produced after the reaction, concentration, crystallization, and separation of phenol and acetone is partially sent to a cracking / rearrangement reactor and an isomerization reactor, respectively, and then the mother liquor is brought into contact with a sulfonic acid group-containing metal-organic framework catalyst to carry out an isomerization reaction, and the resulting product is crystallized and separated to obtain bisphenol A. This method treats the by-products in the bisphenol A reaction system, efficiently converting them to bisphenol A, resulting in a high conversion rate of the bisphenol A by-products and a high yield of the resulting product, bisphenol A.

[0010] The isomerization reaction formula is as follows:

[0011] [ka] [Means for solving the problem]

[0012] In order to achieve the above object, the technical means adopted by the present invention are as follows.

[0013] This method reduces by-products in a bisphenol A reaction system, in which a mother liquor produced after phenol and acetone are reacted, concentrated, crystallized, and separated is partially sent to a cracking and rearrangement reactor and an isomerization reactor, respectively. The mother liquor is then brought into contact with a sulfonic acid group-containing metal organic framework catalyst to carry out an isomerization reaction, and the resulting product is crystallized and separated to obtain bisphenol A.

[0014] A method for reducing by-products in a reaction system of bisphenol A, comprising: (a) a step of sending the mother liquor produced after reacting, concentrating, crystallizing, and separating phenol and acetone to a mother liquor recovery system; (b) contacting the mother liquor obtained by the mother liquor recovery system with a sulfonic acid group-containing metal organic framework catalyst to carry out an isomerization reaction; and (c) The product obtained by the isomerization reaction is sent to a mother liquor recovery system, where it is crystallized and dephenolated to obtain bisphenol A. The above method, characterized in that it comprises:

[0015] In the step (a), phenol and acetone are synthesized in a bisphenol A reactor (101) to obtain bisphenol A, the reaction liquid at the outlet of the bisphenol A reactor (101) is sent to a concentration column (102) to be concentrated, and the light components obtained at the top of the concentration column (102) are of Recovered by solvent recovery system, As a light component The obtained phenol and acetone are sent to a bisphenol A reactor (101), and the concentrated reaction liquid obtained from the bottom of the concentration column (102) is sent to a crystallization reactor (103) where it is crystallized with phenol to obtain a bisphenol A adduct and a crystallization mother liquor from the reactor. The bisphenol A adduct is sent to a dephenolization reactor (104) where phenol is removed to obtain the product bisphenol A. The dephenolized product is sent to a mother liquor recovery system (106), and the crystallization mother liquor from the reactor is sent to the mother liquor recovery system (106) to recover the mother liquor. The phenol recovered by the mother liquor recovery system (106) is sent to the bisphenol A reactor (101), and the bisphenol A adduct recovered by the mother liquor recovery system (106) is sent to the crystallization reactor (103).

[0016] The step (b): A part of the crystallization mother liquor of the recovery system obtained after the mother liquor recovery system (106) recovers the phenol and bisphenol A adduct is sent to an isomerization reactor (107) containing a sulfonic acid group-containing metal organic framework catalyst to carry out an isomerization reaction, a part of the crystallization mother liquor of the recovery system obtained after the mother liquor recovery system (106) recovers the phenol and bisphenol A adduct is sent to a cracking and rearrangement reactor (108) to carry out a cracking and rearrangement reaction, and the resulting cracking and rearrangement product is sent to the mother liquor recovery system (106). In the isomerization reaction, the catalyst and the mother liquor are contacted in a fixed bed reaction, the reaction temperature is 50 to 90°C, the reaction pressure is 0.1 to 1.0 MPaA, and the liquid hourly space velocity is 0.1 to 10 h -1 is.

[0017] In the step (c), the isomerized product at the outlet of the isomerization reactor (107) is sent to a mother liquor recovery system (106), where it is crystallized with phenol via a crystallization reactor (103) to obtain a bisphenol A adduct, which then enters a dephenolization reactor (104) to remove phenol and obtain the product bisphenol A.

[0018] The crystallization mother liquor in the recovery system in the step (a) is a mixture containing 2,4-bisphenol A, phenol, and bisphenol A adducts, and the isomerization reactor is a fixed-bed reactor.

[0019] The sulfonic acid group-containing metal organic framework catalyst in the step (b) is formed by bonding a metal ion or a metal cluster to an organic ligand via a coordinate bond, the metals contained are a combination of one or more of Al, Mg, Ti, Cr, Fe, Cu, Zn, Zr, Ce, and Hf, and the organic ligands contained are a combination of one or more of terephthalic acid, trimesic acid, and an imidazole compound, and the pore diameter of the catalyst is 0.5 nm to 10 nm and the specific surface area is 100 m 2 / g~5000m 2 / g, and the content of sulfonic acid groups is 0.01 mmol / g to 8.0 mmol / g.

[0020] The sulfonic acid group-containing metal organic framework catalyst can be obtained by one of the preparation methods of one-step synthesis, post-synthesis acid treatment, or post-synthesis oxidation treatment.

[0021] One-step synthesis of a sulfonic acid group-containing metal-organic framework catalyst: A metal precursor salt and a sulfonic acid group-containing organic ligand are dissolved in N,N-dimethylformamide, stirred, and then allowed to crystallize in a crystallizer at 140-160°C for 24-36 hours. The resulting crystallized product is filtered, washed with methanol and N,N-dimethylformamide, and dried to obtain a sulfonic acid group-containing metal-organic framework. The metal precursor salt is a combination of one or more of oxides, nitrates, chlorides, and acetylacetonates of one or more of Al, Mg, Ti, Cr, Fe, Cu, Zn, Zr, Ce, and Hf. The sulfonic acid group-containing organic ligand is a combination of one or more of sulfonic acid group-containing benzoic acid, sulfonic acid group-containing terephthalic acid, sulfonic acid group-containing trimesic acid, and sulfonic acid group-containing imidazole compounds.

[0022] The method for preparing the sulfonic acid group-containing metal organic framework catalyst by post-synthesis acid treatment is as follows: a metal precursor salt and an organic ligand are dissolved in N,N-dimethylformamide, stirred, and then allowed to stand in a crystallizer at 120°C to 160°C for 24 to 48 hours for crystallization; the resulting crystallized product is filtered, washed with methanol and N,N-dimethylformamide, and dried to obtain a metal organic framework precursor; the resulting metal organic framework material is placed in a polytetrafluoroethylene-lined reactor, an acidic liquid is added, and sulfonation treatment is carried out at 100°C to 180°C for 24 hours; the resulting product is filtered, washed, dried, and then used as a catalyst for preparing the sulfonic acid group-containing metal organic framework. The metal precursor salt is a combination of one or more of oxides, nitrates, chlorides, and acetylacetonates of one or more of Al, Mg, Ti, Cr, Fe, Cu, Zn, Zr, Ce, and Hf; the organic ligand is a combination of one or more of terephthalic acid, trimesic acid, and imidazole compounds that do not contain amino acids or that contain amino acids; the metal-organic framework precursor is formed by bonding a metal ion or a metal cluster to an organic ligand via a coordinate bond; and the acidic liquid is a combination of one or more of sulfuric acid, chlorosulfonic acid, and 1,3-propane sultone.

[0023] The method for preparing the sulfonic acid group-containing metal organic framework catalyst by post-synthesis oxidation treatment is as follows: a metal precursor salt and a thiol group-containing organic ligand are dissolved in N,N-dimethylformamide, stirred, and then allowed to stand in a crystallizer at 110°C to 140°C for 24 to 48 hours for static crystallization; the resulting crystallized product is filtered, washed with ethanol, and dried to obtain a metal organic framework precursor; the resulting metal organic framework material is placed in a polytetrafluoroethylene-lined reactor, an oxidizing liquid is added, and oxidation treatment is carried out at 50°C to 60°C for 2 to 6 hours; the resulting product is filtered, washed, dried, and then subjected to oxidation treatment with sulfonic acid group-containing metal organic framework catalyst. An acid group-containing metal organic framework is obtained, wherein the metal precursor salt is a combination of one or more of oxides, nitrates, chlorides, and acetylacetonates of one or more of Al, Mg, Ti, Cr, Fe, Cu, Zn, Zr, Ce, and Hf; the organic ligand is a combination of one or more of alkylthiol, terephthalic acid containing aminothiol, trimesic acid, and imidazole compounds; the metal organic framework precursor is formed by bonding metal ions or metal clusters to the organic ligands via coordinate bonds; and the oxidizing liquid is hydrogen peroxide. [Effects of the Invention]

[0024] The advantages and benefits of the present invention are as follows:

[0025] (1) The novel method for reducing by-products in a bisphenol A reaction system according to the present invention invents an isomerization reaction process for bisphenol A by-products, which efficiently converts bisphenol A by-products into bisphenol A. The catalytic reaction has a high conversion rate of 2,4-BPA, a by-product of bisphenol A, of 28% to 55%, and a high selectivity to bisphenol A, of 80% to 90%.

[0026] (2) The novel method for reducing by-products in a bisphenol A reaction system according to the present invention invents a catalyst for the isomerization of bisphenol A by-products, which is capable of adjusting the amount of sulfonic acid and the pore size of the catalyst. The catalyst reaction has a high conversion rate of bisphenol A by-products, reaching 28% to 55%, and a high selectivity to bisphenol A, reaching 80% to 90%.

[0027] (3) The novel method for reducing by-products in the reaction system of bisphenol A according to the present invention is characterized by the invention of a catalyst for the isomerization reaction of bisphenol A by-products, which reduces the outflow of acidic functional groups, sulfonic acid groups, and thiol groups of the catalyst, thereby mitigating corrosion of equipment. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a schematic flow chart showing the reduction of by-products in a reaction system of bisphenol A according to the present invention. [Figure 2] 1 is an X-ray diffraction spectrum of sample S1 prepared in Example 1. [Figure 3] 1 is an X-ray diffraction spectrum of sample S2 prepared in Example 2. [Figure 4] 1 is an X-ray diffraction spectrum of sample S3 prepared in Example 3. [Figure 5] 1 is an X-ray diffraction spectrum of sample S4 prepared in Example 4. [Figure 6] 1 is an X-ray diffraction spectrum of sample S5 prepared in Example 5. [Figure 7] 1 is an X-ray diffraction spectrum of sample S6 prepared in Example 6. [Figure 8] 1 is an X-ray diffraction spectrum of sample S7 prepared in Example 7. [Figure 9] 1 is an X-ray diffraction spectrum of sample S8 prepared in Example 8. [Figure 10] 1 is an X-ray diffraction spectrum of sample S9 prepared in Example 9. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, the present invention will be described in more detail through specific examples with reference to the accompanying drawings. However, the following examples are merely illustrative and do not limit the present invention, and are not intended to limit the scope of protection of the present invention.

[0030] The specific steps of implementing the method of the present invention will be described below using specific examples. [Example]

[0031] Example 1 In this example, the process for producing bisphenol A is as follows (FIG. 1).

[0032] (a) Phenol and acetone are synthesized in a bisphenol A reactor (101) to obtain bisphenol A, and the reaction liquid at the outlet of the bisphenol A reactor (101) is sent to a concentration tower (102) to be concentrated, and the light components obtained at the top of the concentration tower (102) are of Recovered by solvent recovery system, As a light component The obtained phenol and acetone are sent to a bisphenol A reactor (101), and the concentrated reaction liquid obtained from the bottom of the concentration column (102) is sent to a crystallization reactor (103) where it is crystallized with phenol to obtain a bisphenol A adduct and a crystallization mother liquor from the reactor. The bisphenol A adduct is sent to a dephenolization reactor (104) where phenol is removed to obtain the product bisphenol A. The dephenolized product is sent to a mother liquor recovery system (106), and the crystallization mother liquor from the reactor is sent to the mother liquor recovery system (106) to recover the mother liquor. The phenol recovered by the mother liquor recovery system (106) is sent to the bisphenol A reactor (101), and the bisphenol A adduct recovered by the mother liquor recovery system (106) is sent to the crystallization reactor (103).

[0033] (b) A portion of the crystallization mother liquor of the recovery system obtained after the mother liquor recovery system (106) recovers phenol and bisphenol A adducts is sent to an isomerization reactor (107) containing a sulfonic acid group-containing metal organic framework catalyst to carry out an isomerization reaction, a portion of the crystallization mother liquor of the recovery system is obtained after the mother liquor recovery system (106) recovers phenol and bisphenol A adducts, and a portion of the crystallization mother liquor of the recovery system is sent to a cracking / rearrangement reactor (108) to carry out a cracking / rearrangement reaction, the resulting cracking / rearrangement product is sent to the mother liquor recovery system (106), and the isomerization product at the outlet of the isomerization reactor (107) is sent to the mother liquor recovery system (106).

[0034] (c) The isomerized product at the outlet of the isomerization reactor (107) is sent to the mother liquor recovery system (106), where it is crystallized and dephenolated to obtain bisphenol A.

[0035] In this example, a one-step synthesis preparation process for the sulfonic acid group-containing metal organic framework catalyst was carried out: a metal precursor salt (10 g of zinc tetrachloride) and a ligand (11.6 g of 2-sulfoterephthalic acid) were dissolved in 800 mL of N,N-dimethylformamide, stirred thoroughly, and poured into a crystallizer for static crystallization at 140°C for 24 hours. The resulting crystallized product was filtered, washed with methanol and N,N-dimethylformamide, and dried to obtain sulfonic acid group-containing metal organic framework material S1. XRD analysis of the resulting product S1 revealed the XRD spectrum shown in Figure 2, indicating that this product is a sulfonic acid group-containing metal organic framework catalyst having the structure. Table 1 shows that the specific surface area of ​​the resulting sample S1 was 960 m 2 / g, the average pore diameter is 4.5 nm, and the sulfonic acid group content is 2.85 mmol / g.

[0036] In this example, the prepared sulfonic acid group-containing metal organic framework S1 is introduced into an isomerization reactor, and the catalyst and mother liquor are contacted in a fixed-bed reaction. The reaction temperature is 50°C, the reaction pressure is 0.1 MPaA, and the liquid hourly space velocity is preferably 0.1 h -1The isomerization reaction of the mother liquor was catalyzed by a sample of the sulfonic acid group-containing metal organic framework catalyst S1 obtained in Example 1, and the 2,4-BPA conversion was 28% and the bisphenol A selectivity was 80%.

[0037] Example 2 In this example, the bisphenol A production process is the same as that of Example 1.

[0038] In this example, the one-step synthesis preparation process for the sulfonic acid group-containing metal organic framework catalyst was as follows: A metal precursor salt (10 g of hafnium chloride) and a ligand (7.4 g of 4,8-disulfo-2,6-naphthalenedicarboxylic acid) were dissolved in 960 mL of N,N-dimethylformamide, stirred thoroughly, and poured into a crystallizer for static crystallization at 160°C for 36 hours. The resulting crystallized product was filtered, washed with ethanol, and dried to obtain sulfonic acid group-containing metal organic framework material S2. XRD analysis of the resulting product S2 revealed the XRD spectrum shown in Figure 3, indicating that this product is a sulfonic acid group-containing metal organic framework catalyst having the structure. Table 1 shows that the specific surface area of ​​the resulting sample S2 was 821 m. 2 / g, the average pore diameter is 6.8 nm, and the sulfonic acid group content is 3.46 mmol / g.

[0039] In this example, the prepared sulfonic acid group-containing metal organic framework material S2 is introduced into an isomerization reactor, and the catalyst and mother liquor are contacted in a fixed-bed reaction. The reaction temperature is 70°C, the reaction pressure is 0.2 MPaA, and the liquid hourly space velocity is preferably 10 h -1 The isomerization reaction of the mother liquor was catalyzed by a sample of the sulfonic acid group-containing metal organic framework catalyst S2 obtained in Example 2, and the 2,4-BPA conversion was 38% and the bisphenol A selectivity was 82%.

[0040] Example 3 In this example, the bisphenol A production process is the same as that of Example 1.

[0041] In this example, the one-step synthesis preparation process for the sulfonic acid group-containing metal organic framework catalyst was as follows: The metal precursor salt (10 g of aluminum nitrate) and the ligand (8.8 g of 1-sulfonic acid trimesic acid) were dissolved in 780 mL of N,N-dimethylformamide, stirred thoroughly, and poured into a crystallizer for static crystallization at 150°C for 30 hours. The resulting crystallized product was filtered, washed with ethanol, and dried to obtain sulfonic acid group-containing metal organic framework material S3. The XRD spectrum of the resulting product S3 was shown in Figure 4, indicating that this product was a sulfonic acid group-containing metal organic framework catalyst having the structure. As shown in Table 1, the specific surface area of ​​the resulting sample S3 was 803 m 2 / g, the average pore diameter is 6.5 nm, and the sulfonic acid group content is 3.33 mmol / g.

[0042] In this example, the prepared sulfonic acid group-containing metal organic framework S3 is introduced into an isomerization reactor, and the catalyst and mother liquor are contacted in a fixed-bed reaction. The reaction temperature is 65°C, the reaction pressure is 0.2 MPaA, and the liquid hourly space velocity is preferably 10 h -1 The isomerization reaction of the mother liquor was catalyzed by a sample of the sulfonic acid group-containing metal organic framework catalyst S3 obtained in Example 3, and the 2,4-BPA conversion was 39% and the bisphenol A selectivity was 84%.

[0043] Example 4 In this example, the bisphenol A production process is the same as that of Example 1.

[0044] The post-synthesis acid treatment preparation process for the sulfonic acid group-containing metal-organic framework catalyst in this example was as follows: The metal precursor salt (10.5 g of zirconium tetrachloride) and the ligand (10.5 g of terephthalic acid) were dissolved in 800 mL of N,N-dimethylformamide, stirred thoroughly, and poured into a crystallizer for 24 hours at 120 °C for static crystallization. The resulting crystallized product was filtered, washed with methanol and N,N-dimethylformamide, and dried to obtain a metal-organic framework material. The resulting metal-organic framework material was placed in a polytetrafluoroethylene-lined reactor, and an acidic liquid (100 mL of chlorosulfonic acid) was added. The sulfonation treatment was carried out at 100 °C for 24 hours. The resulting product was filtered, washed, and dried to obtain sulfonic acid group-containing metal-organic framework material S4. XRD analysis of the resulting product S4 revealed the XRD spectrum shown in Figure 5, indicating that this product is a sulfonic acid group-containing metal-organic framework catalyst having the structure. From Table 1, the specific surface area of ​​the obtained sample S4 is 793 m 2 / g, the average pore diameter is 8.5 nm, and the sulfonic acid group content is 5.57 mmol / g.

[0045] In this example, the bisphenol A production process is the same as that of Example 1.

[0046] In this example, the prepared sulfonic acid group-containing metal organic framework material S4 is introduced into an isomerization reactor, and the catalyst and mother liquor are contacted in a fixed-bed reaction. The reaction temperature is 90°C, the reaction pressure is 0.5 MPaA, and the liquid hourly space velocity is preferably 0.5 h -1 The isomerization reaction of the mother liquor was catalyzed by a sample of the sulfonic acid group-containing metal organic framework catalyst S4 obtained in Example 4, and the 2,4-BPA conversion was 37% and the bisphenol A selectivity was 90%.

[0047] Example 5 In this example, the bisphenol A production process is the same as that of Example 1.

[0048] The post-synthesis acid treatment preparation process for the sulfonic acid group-containing metal-organic framework catalyst in this example was as follows: A metal precursor salt (7.6 g of ferric nitrate nonahydrate) and a ligand (6.5 g of trimesic acid) were dissolved in 700 mL of N,N-dimethylformamide, stirred thoroughly, and poured into a crystallizer for static crystallization at 160 °C for 48 hours. The resulting crystallized product was filtered, washed with ethanol, and dried to obtain a metal-organic framework material. The resulting metal-organic framework material was placed in a polytetrafluoroethylene-lined reactor, and an acidic liquid (100 mL of 1,3-propane sultone) was added. The sulfonation treatment was carried out at 180 °C for 24 hours. The resulting product was filtered, washed, and dried to obtain a sulfonic acid group-containing metal-organic framework material S5. XRD analysis of the resulting product S5 revealed the XRD spectrum shown in Figure 6, indicating that the product was a sulfonic acid group-containing metal-organic framework catalyst having the structure. Table 1 indicates that the specific surface area of ​​the resulting sample S5 was 755 m. 2 / g, the average pore diameter is 9.2 nm, and the sulfonic acid group content is 4.22 mmol / g.

[0049] In this example, the bisphenol A production process is the same as that of Example 1.

[0050] In this example, the prepared sulfonic acid group-containing metal organic framework S5 is introduced into an isomerization reactor, and the catalyst and mother liquor are contacted in a fixed-bed reaction. The reaction temperature is 60°C, the reaction pressure is 1.0 MPaA, and the liquid hourly space velocity is preferably 0.2 h -1 The isomerization reaction of the mother liquor was catalyzed by a sample of the sulfonic acid group-containing metal organic framework catalyst S5 obtained in Example 5, and the 2,4-BPA conversion was 43% and the bisphenol A selectivity was 90%.

[0051] Example 6 In this example, the bisphenol A production process is the same as that of Example 1.

[0052] The post-synthesis acid treatment preparation process for the sulfonic acid group-containing metal-organic framework catalyst in this example was as follows: A metal precursor salt (10 g of copper nitrate) and a ligand (6.5 g of trimesic acid) were dissolved in 700 mL of N,N-dimethylformamide, stirred thoroughly, and poured into a crystallizer for 48 hours of static crystallization at 130 °C. The resulting crystallized product was filtered, washed with ethanol, and dried to obtain a metal-organic framework material. The resulting metal-organic framework material was placed in a polytetrafluoroethylene-lined reactor, and an acidic liquid (100 mL of 1,3-propane sultone) was added. The sulfonation treatment was carried out at 180 °C for 24 hours. The resulting product was filtered, washed, and dried to obtain a sulfonic acid group-containing metal-organic framework material S6. XRD analysis of the resulting product S6 revealed the XRD spectrum shown in Figure 7, indicating that the product was a sulfonic acid group-containing metal-organic framework catalyst having the structure. As shown in Table 1, the specific surface area of ​​the resulting sample S6 was 783 m. 2 / g, the average pore diameter is 9.4 nm, and the sulfonic acid group content is 4.36 mmol / g.

[0053] In this example, the bisphenol A production process is the same as that of Example 1.

[0054] In this example, the prepared sulfonic acid group-containing metal organic framework S6 is introduced into an isomerization reactor, and the catalyst and mother liquor are contacted in a fixed-bed reaction. The reaction temperature is 65°C, the reaction pressure is 1.0 MPaA, and the liquid hourly space velocity is preferably 0.2 h -1 The isomerization reaction of the mother liquor was catalyzed by a sample of the sulfonic acid group-containing metal organic framework catalyst S6 obtained in Example 6, and the 2,4-BPA conversion was 47% and the bisphenol A selectivity was 88%.

[0055] Example 7 In this example, the bisphenol A production process is the same as that of Example 1.

[0056] The post-synthesis oxidation process for the sulfonic acid group-containing metal-organic framework catalyst in this example was as follows: A metal precursor salt (10 g of chromium nitrate) and a ligand (8.3 g of 2,5-dimercaptoterephthalic acid) were dissolved in 660 mL of N,N-dimethylformamide, stirred thoroughly, and poured into a crystallizer for 24 hours of static crystallization at 110 °C. The resulting crystallized product was filtered, washed with ethanol, and dried to obtain a metal-organic framework material. The resulting metal-organic framework material was placed in a polytetrafluoroethylene-lined reactor, and an oxidizing liquid (20 mL of hydrogen peroxide) was added. The oxidation treatment was carried out at 50 °C for 2 hours. The resulting product was filtered, washed, and dried to obtain sulfonic acid group-containing metal-organic framework material S7. XRD analysis of the resulting product S7 revealed the XRD spectrum shown in Figure 8, indicating that the product was a sulfonic acid group-containing metal-organic framework catalyst having the structure. Table 1 indicates that the specific surface area of ​​the resulting sample S7 was 726 m. 2 / g, the average pore diameter is 10.5 nm, and the sulfonic acid group content is 6.02 mmol / g.

[0057] In this example, the bisphenol A production process is the same as that of Example 1.

[0058] In this example, the prepared sulfonic acid group-containing metal organic framework material S7 is introduced into an isomerization reactor, and the catalyst and mother liquor are contacted in a fixed-bed reaction. The reaction temperature is 80°C, the reaction pressure is 0.7 MPaA, and the liquid hourly space velocity is preferably 3.0 h -1 The isomerization reaction of the mother liquor was catalyzed by a sample of the sulfonic acid group-containing metal organic framework catalyst S7 obtained in Example 7, and the 2,4-BPA conversion was 55% and the bisphenol A selectivity was 87%.

[0059] Example 8 In this example, the bisphenol A production process is the same as that of Example 1.

[0060] The post-synthesis oxidation process for the sulfonic acid group-containing metal-organic framework catalyst in this example was as follows: A metal precursor salt (10 g of titanium chloride) and a ligand (7.4 g of 4,8-dimercapto-2,6-naphthalenedicarboxylic acid) were dissolved in 850 mL of N,N-dimethylformamide, stirred thoroughly, and poured into a crystallizer for 48 hours of static crystallization at 140 °C. The resulting crystallized product was filtered, washed with ethanol, and dried to obtain a metal-organic framework material. The resulting metal-organic framework material was placed in a polytetrafluoroethylene-lined reactor, and an oxidizing liquid (35 mL of hydrogen peroxide) was added. The oxidation treatment was carried out at 60 °C for 6 hours. The resulting product was filtered, washed, and dried to obtain a sulfonic acid group-containing metal-organic framework material S8. XRD analysis of the resulting product S8 revealed the XRD spectrum shown in Figure 9, indicating that the product was a sulfonic acid group-containing metal-organic framework catalyst having the structure. Table 1 indicates that the specific surface area of ​​the resulting sample S8 was 866 m. 2 / g, the average pore diameter is 5.7 nm, and the sulfonic acid group content is 4.38 mmol / g.

[0061] In this example, the bisphenol A production process is the same as that of Example 1.

[0062] In this example, the prepared sulfonic acid group-containing metal organic framework material S8 is introduced into an isomerization reactor, and the catalyst and mother liquor are contacted in a fixed-bed reaction. The reaction temperature is 70°C, the reaction pressure is 0.5 MPaA, and the liquid hourly space velocity is preferably 7.0 h -1 The isomerization reaction of the mother liquor was catalyzed by a sample of the sulfonic acid group-containing metal organic framework catalyst S8 obtained in Example 8, and the 2,4-BPA conversion was 48% and the bisphenol A selectivity was 89%.

[0063] Example 9 In this example, the bisphenol A production process is the same as that of Example 1.

[0064] The post-synthesis oxidation process for the sulfonic acid group-containing metal-organic framework catalyst in this example was as follows: Metal precursor salts (6.6 g magnesium nitrate, 3.4 g cerium nitrate) and ligand (6.9 g 2,5-dimercaptoterephthalic acid) were dissolved in 820 mL of N,N-dimethylformamide, stirred thoroughly, and poured into a crystallizer for 36 hours of static crystallization at 120 °C. The resulting crystallized product was filtered, washed with ethanol, and dried to obtain a metal-organic framework material. The resulting metal-organic framework material was placed in a polytetrafluoroethylene-lined reactor, and an oxidizing liquid (40 mL hydrogen peroxide) was added. The oxidation treatment was carried out at 55 °C for 4 hours. The resulting product was filtered, washed, and dried to obtain sulfonic acid group-containing metal-organic framework material S9. XRD analysis of the resulting product S9 revealed the XRD spectrum shown in Figure 10, indicating that this product is a sulfonic acid group-containing metal-organic framework catalyst having the structure. From Table 1, the specific surface area of ​​the obtained sample S9 is 833 m 2 / g, the average pore diameter is 5.3 nm, and the sulfonic acid group content is 4.06 mmol / g.

[0065] In this example, the bisphenol A production process is the same as that of Example 1.

[0066] In this example, the prepared sulfonic acid group-containing metal organic framework material S9 is introduced into an isomerization reactor, and the catalyst and mother liquor are contacted in a fixed-bed reaction. The reaction temperature is 65°C, the reaction pressure is 0.5 MPaA, and the liquid hourly space velocity is preferably 6.0 h -1 The isomerization reaction of the mother liquor was catalyzed by a sample of the sulfonic acid group-containing metal organic framework catalyst S9 obtained in Example 9, and the 2,4-BPA conversion was 45% and the bisphenol A selectivity was 87%.

[0067] In the above examples, the 2,4-BPA conversion rate and bisphenol A selectivity were calculated as follows:

[0068] (Number 1) 2,4-BPA conversion rate = (charged amount of 2,4-BPA - amount of unreacted 2,4-BPA) / charged amount of 2,4-BPA x 100%.

[0069] (Number 2) Bisphenol A selectivity = amount of bisphenol A produced / amount of 2,4-BPA product × 100%.

[0070] The method described in this invention proposes a method for converting 2,4-bisphenol A, a by-product of bisphenol A production, into bisphenol A by isomerizing a mixture containing 2,4-bisphenol A, phenol, and bisphenol A adducts as a raw material. To demonstrate the effectiveness of the method described in this invention in catalyzing the conversion of 2,4-bisphenol A to bisphenol A, the isomerization reaction was carried out using 2,4-bisphenol A as a raw material in Examples 1 to 9, and the results are shown in Table 2. Table 2 shows that the sulfonic acid group-containing metal-organic framework catalyst samples S1 to S9 obtained in Examples 1 to 9 had good 2,4-BPA conversion rates (28% to 55%) and high bisphenol A selectivity (80% to 90%) in the product. This demonstrates that the sulfonic acid group-containing metal-organic framework catalyst described in this invention can be used to efficiently catalyze the isomerization of 2,4-BPA to produce bisphenol A. In terms of the effect of catalyzing the isomerization reaction of 2,4-bisphenol A with a catalyst to produce bisphenol A, the method described in the present invention can catalytically convert the by-product 2,4-BPA in bisphenol A, significantly reducing the content of the by-product 2,4-BPA and converting 2,4-BPA to bisphenol A with high selectivity. In summary, from the above analysis, it can be seen that the method described in the present invention can significantly reduce the amount of the by-product 2,4-bisphenol A in the production of bisphenol A, and can also convert 2,4-bisphenol A with high selectivity, thereby improving the yield of bisphenol A.

[0071] [Table 1]

[0072] [Table 2]

[0073] Although preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the present disclosure is not limited to the above embodiments, and various simple modifications can be made to the technical means of the present disclosure within the scope of the technical idea of ​​the present disclosure, and such simple modifications are equally included in the scope of protection of the present disclosure.

[0074] Furthermore, the specific technical features described in the above specific embodiments can be combined in any suitable manner if there is no contradiction, but to avoid unnecessary repetition, the present disclosure omits various possible combinations.

[0075] It should be noted that the various embodiments of the present disclosure can be combined in any manner, and as long as they do not contradict the spirit of the present disclosure, they should also be considered as the contents disclosed in the present disclosure. [Explanation of symbols]

[0076] 101 Bisphenol A Reactor 102 Concentration tower 103 Crystallization reactor 104 Dephenolization reactor 105 Solvent Recovery System 106 Mother Liquor Recovery System 107 Isomerization Reactor 108 Cracking and rearrangement reactor

Claims

1. A method for reducing by-products in a bisphenol A reaction system, comprising: (a) sending the mother liquor produced after reacting, concentrating, crystallizing, and separating phenol and acetone to a mother liquor recovery system; (b) contacting the mother liquor obtained by the mother liquor recovery system with a sulfonic acid group-containing metal organic framework catalyst to carry out an isomerization reaction; and (c) sending the product obtained by the isomerization reaction to the mother liquor recovery system, and obtaining bisphenol A through crystallization and dephenolation; The sulfonic acid group-containing metal organic framework catalyst in the step (b) is formed by bonding a metal ion or a metal cluster to an organic ligand via a coordinate bond, the metals contained are a combination of one or more of Al, Mg, Ti, Cr, Fe, Cu, Zn, Zr, Ce, and Hf, and the organic ligands contained are a combination of one or more of terephthalic acid, trimesic acid, and imidazole compounds, and the pore diameter of the catalyst is 0.5 nm to 10 nm and the specific surface area is 100 m. ２ / g to 5000m ２ / g, the content of sulfonic acid groups is 0.01 mmol / g to 8.0 mmol / g, The sulfonic acid group-containing metal organic framework catalyst is obtained by a preparation method including one-step synthesis, post-synthesis acid treatment, or post-synthesis oxidation treatment; a one-step synthesis method for the sulfonic acid group-containing metal organic framework catalyst: a metal precursor salt and a sulfonic acid group-containing organic ligand are dissolved in N,N-dimethylformamide, stirred, and then allowed to stand in a crystallizer at 140°C to 160°C for 24 to 36 hours for static crystallization; the resulting crystallized product is filtered, washed with methanol and N,N-dimethylformamide, and dried to obtain a sulfonic acid group-containing metal organic framework; the metal precursor salt is a combination of one or more of oxides, nitrates, chlorides, and acetylacetonates of one or more of Al, Mg, Ti, Cr, Fe, Cu, Zn, Zr, Ce, and Hf; and the sulfonic acid group-containing organic ligand is a combination of one or more of benzoic acid having a sulfonic acid group, terephthalic acid having a sulfonic acid group, trimesic acid having a sulfonic acid group, and imidazole compound having a sulfonic acid group; The method for preparing the sulfonic acid group-containing metal organic framework catalyst by post-synthesis acid treatment is as follows: the metal precursor salt and organic ligand are dissolved in N,N-dimethylformamide, stirred, and then placed in a crystallizer at 120°C to 160°C for 24 to 48 hours for static crystallization. The resulting crystallized product is filtered, washed with methanol and N,N-dimethylformamide, and dried to obtain a metal organic framework precursor. The resulting metal organic framework material is placed in a polytetrafluoroethylene-lined reactor, an acidic liquid is added, and sulfonation treatment is carried out at 100°C to 180°C for 24 hours. The resulting product is filtered, washed, dried, and then used as a sulfonic acid group-containing metal organic framework. a metal organic framework precursor is obtained, wherein the metal precursor salt is a combination of one or more of oxides, nitrates, chlorides, and acetylacetonates of one or more of Al, Mg, Ti, Cr, Fe, Cu, Zn, Zr, Ce, and Hf; the organic ligand is a combination of one or more of terephthalic acid, trimesic acid, and imidazole compounds that do not contain amino or contain amino; the metal organic framework precursor is formed by bonding a metal ion or a metal cluster to the organic ligand via a coordinate bond; and the acidic liquid is a combination of one or more of sulfuric acid, chlorosulfonic acid, and 1,3-propane sultone; The method for preparing the sulfonic acid group-containing metal organic framework catalyst by post-synthesis oxidation treatment is as follows: the metal precursor salt and the thiol group-containing organic ligand are dissolved in N,N-dimethylformamide, stirred, and then placed in a crystallizer at 110°C to 140°C for 24 to 48 hours for static crystallization. The resulting crystallized product is filtered, washed with ethanol, and dried to obtain a metal organic framework precursor. The resulting metal organic framework material is placed in a polytetrafluoroethylene-lined reactor, and an oxidizing liquid is added thereto. The resulting product is oxidized at 50°C to 60°C for 2 to 6 hours. The resulting product is filtered, washed, dried, and then subjected to sulfonation treatment. The metal organic framework material containing phosphoric acid groups is obtained, wherein the metal precursor salt is a combination of one or more of oxides, nitrates, chlorides, and acetylacetonates of one or more of Al, Mg, Ti, Cr, Fe, Cu, Zn, Zr, Ce, and Hf, and the organic ligand is a combination of one or more of alkylthiol, aminothiol-containing terephthalic acid, trimesic acid, and imidazole compounds, and the metal organic framework material precursor is formed by bonding metal ions or metal clusters to the organic ligands via coordinate bonds, and the oxidizing liquid is hydrogen peroxide. A method for reducing by-products in a reaction system of bisphenol A, comprising:

2. The step (a): Phenol and acetone are synthesized in a bisphenol A reactor (101) to obtain bisphenol A, the reaction liquid at the outlet of the bisphenol A reactor (101) is sent to a concentration tower (102) to be concentrated, the light components obtained at the top of the concentration tower (102) are recovered by a solvent recovery system, and the obtained phenol and acetone are sent to the bisphenol A reactor (101), the concentrated reaction liquid obtained from the bottom of the concentration tower (102) is sent to a crystallization reactor (103) to be crystallized with the phenol to obtain a bisphenol A adduct, and the crystallization mother liquor of the reactor is obtained, and the bisphenol A adduct is obtained.

2. The method for reducing by-products in a bisphenol A reaction system according to claim 1, wherein the A adduct is sent to a dephenolation reactor (104) to remove the phenol to obtain a product bisphenol A, the dephenolated product is sent to a mother liquor recovery system (106), the crystallization mother liquor of the reactor is sent to the mother liquor recovery system (106) to recover the mother liquor, the phenol recovered by the mother liquor recovery system (106) is sent to the bisphenol A reactor (101), and the bisphenol A adduct recovered by the mother liquor recovery system (106) is sent to the crystallization reactor (103).

3. The step (b): A portion of the crystallization mother liquor of the recovery system obtained after the mother liquor recovery system (106) recovers the phenol and the bisphenol A adduct is sent to an isomerization reactor (107) containing the sulfonic acid group-containing metal organic framework catalyst to carry out an isomerization reaction, a portion of the crystallization mother liquor of the recovery system obtained after the mother liquor recovery system (106) recovers the phenol and the bisphenol A adduct is sent to a cracking / rearrangement reactor (108) to carry out a cracking / rearrangement reaction, and the resulting cracking / rearrangement product is sent to the mother liquor recovery system (106). In the isomerization reaction, the catalyst and the mother liquor are contacted in a fixed bed reaction, at a reaction temperature of 50 to 90°C, a reaction pressure of 0.1 to 1.0 MPaA, and a liquid hourly space velocity of 0.1 to 10 h ‐１ The method for reducing by-products in a reaction system of bisphenol A according to claim 2, characterized in that:

4. 4. The method for reducing by-products in a bisphenol A reaction system according to claim 3, characterized in that in step (c): the isomerized product at the outlet of the isomerization reactor (107) is sent to the mother liquor recovery system (106), and crystallized with the phenol via the crystallization reactor (103) to obtain the bisphenol A adduct, which then enters the dephenolization reactor (104) to remove the phenol and obtain the product bisphenol A.

5. 4. The method for reducing by-products in a bisphenol A reaction system according to claim 3, wherein the crystallization mother liquor in the recovery system in step (a) is a mixture containing 2,4-bisphenol A, the phenol, and the bisphenol A adduct, and the isomerization reactor is a fixed-bed reactor.

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