Catalyst for synthesizing isobutylbenzene, preparation method and application thereof, and method for preparing isobutylbenzene through side chain alkylation of toluene and acetone

Abstract

The invention relates to the technical field of isobutylbenzene synthesis processes, and provides a catalyst for synthesizing isobutylbenzene, a preparation method and application thereof, and a method for preparing isobutylbenzene through side chain alkylation of toluene and acetone. The catalyst comprises a cesium ion-exchanged X-type molecular sieve and barium and / or strontium loaded on the X-type molecular sieve. The catalyst provided by the invention is used in isobutylbenzene synthesis, isobutylbenzene can be synthesized through a toluene and acetone side chain alkylation fixed bed reaction process, and a new isobutylbenzene synthesis route is provided; the process route is simple in process condition and small in safety risk, continuous synthesis of the isobutylbenzene can be realized, and the process route for synthesizing the isobutylbenzene has a wide market application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of isobutylbenzene synthesis process, and more specifically, to a catalyst for synthesizing isobutylbenzene, a preparation method and application thereof, and a method for preparing isobutylbenzene by side chain alkylation of toluene and acetone. Background Art

[0002] As an anti-inflammatory, antipyretic and analgesic drug, ibuprofen can treat rheumatoid arthritis, deforming arthritis, toothache, neuralgia, etc. It also has good effects on inflammation, fever and pain after gynecological and obstetric surgery, and has few adverse reactions and can be taken for a long time. However, there are still many problems with other types of antipyretic and analgesic drugs. For example, some domestic oral preparations of acetaminophen are unstable, and the effect on high fever is not very ideal, and the antipyretic effect time is short; aspirin and its compound preparations have great side effects on the digestive tract and blood system, and may cause Reye's syndrome in children. Therefore, the market application prospects of ibuprofen are very broad.

[0003] Isobutylbezene (IBB) is the main intermediate of the synthetic drug ibuprofen (Profe or Brufen). Among the many synthetic routes for synthesizing ibuprofen, almost all routes require the intermediate isobutylbezene. So far, there are more than a dozen synthetic process routes for isobutylbezene, but most of them are laboratory preparation methods. Although some can be industrialized, the raw materials are not easy to obtain. The existing industrial synthesis process of isobutylbezene is mainly the side chain alkylation reaction process of toluene and propylene under alkali metal catalysis.

[0004] In 1950, scientists such as Pines first proposed the use of strong bases to catalyze the side chain alkylation reaction of alkyl aromatic hydrocarbons and small molecule olefins. Strong base catalysts are composed of alkali metals or alkali metal hydrides and promoters. Promoters can be aromatic hydrocarbons, benzocyanate, pyridine or chloroalkane, etc., and their main function is to induce alkali metals or their oxides to form metal organic compounds to attack alkylbenzenes. At present, toluene and propylene are mainly used in the industry to synthesize isobutylene under the action of alkali metal potassium and sodium catalysts, and a kettle reaction is used in the synthesis. However, since the catalyst contains free alkali metal potassium and sodium, and water or ethanol needs to be added as a terminator during the synthesis process, the reaction conditions use high temperature and high pressure. Therefore, the operation requirements for synthesizing isobutylene using this process route are harsh and the safety risk is very high. In addition, when synthesizing isobutylene using this process route, intermittent kettle reactions are generally used in industry, and continuous production cannot be achieved. At present, the industry is in urgent need of a process synthesis route that is simple to operate, has low safety risks, and can continuously synthesize isobutylene. Summary of the invention

[0005] The purpose of the present invention is to provide a catalyst for synthesizing isobutylbenzene and a method for preparing isobutylbenzene by side chain alkylation of toluene and acetone, so as to solve the technical problems of complex process and high safety risk in the prior art for preparing isobutylbenzene.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a catalyst for synthesizing isobutylene, comprising a cesium ion-exchanged X-type molecular sieve and barium and / or strontium supported on the cesium ion-exchanged X-type molecular sieve.

[0008] In the present invention, the cesium ion-exchanged X-type molecular sieve refers to an X-type molecular sieve obtained by exchanging sodium ions in the X-type molecular sieve with cesium ions.

[0009] According to some embodiments of the present invention, the X-type molecular sieve is a nano X-type molecular sieve.

[0010] In the present invention, the particle size of the X-type molecular sieve will significantly affect the catalytic performance of the catalyst. Using a nano-scale X-type molecular sieve with smaller particles can make the catalyst have better catalytic performance.

[0011] The nanometer X-type molecular sieve used in the present invention can be prepared by using the existing nanometer X-type molecular sieve preparation method.

[0012] According to some embodiments of the present invention, the particle size of the X-type molecular sieve is 10 to 100 nm.

[0013] According to some embodiments of the present invention, the particle size of the X-type molecular sieve is 20 to 90 nm.

[0014] According to some embodiments of the present invention, the SiO 2 / Al 2 O 3 It is 2 to 3.

[0015] According to some embodiments of the present invention, the preparation method of the nano X-type molecular sieve includes: obtaining a mixed solution including tetramethylammonium bromide, aluminum isopropoxide, sodium silicate, tetraethyl silicate and water, crystallizing, filtering, drying, and calcining to obtain the nano X-type molecular sieve.

[0016] According to some embodiments of the present invention, the method for preparing the mixed solution comprises: dissolving tetramethylammonium bromide, aluminum isopropoxide, sodium silicate, and tetraethyl silicate in water, and stirring at 10 to 20° C. for 1 to 5 hours.

[0017] According to some embodiments of the present invention, the crystallization temperature is 80 to 170° C. and the time is 10 to 100 hours.

[0018] According to some embodiments of the present invention, the crystallization temperature is 100-150° C. and the time is 15-60 hours.

[0019] According to some embodiments of the present invention, the drying temperature in the preparation of nano X-type molecular sieve is 90-120°C.

[0020] According to some embodiments of the present invention, the calcination temperature in the preparation of nano X-type molecular sieve is 500-600° C. and the calcination time is 3-10 h.

[0021] According to some embodiments of the present invention, the molar ratio of sodium silicate to aluminum isopropoxide is (0.0001-0.001):1, the molar ratio of tetraethyl silicate to aluminum isopropoxide is (0.85-1.7):1, the molar ratio of tetramethylammonium bromide to aluminum isopropoxide is (0.15-0.3):1, and the molar ratio of water to aluminum isopropoxide is (30-45):1.

[0022] According to some embodiments of the present invention, the mass percentage of cesium ions in the catalyst is 15-35%, for example, it can be 15%, 15.5%, 16%, 17.5%, 18%, 20%, 21%, 22%, 25%, 28%, 30%, 32%, 33%, 35%, etc.

[0023] According to some embodiments of the present invention, the mass percentage of barium and / or strontium in the catalyst is 0.5-5.0%, for example, it can be 0.5%, 0.8%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, etc.

[0024] In a second aspect, the present invention provides a method for preparing the catalyst described in the first aspect, comprising: subjecting the X-type molecular sieve to ion exchange with a solution containing cesium ions, washing, drying for the first time, then impregnating with a solution comprising a barium salt and / or a strontium salt, drying for a second time, and calcining to obtain the catalyst.

[0025] In the present invention, the solution containing cesium ions can be prepared by any soluble cesium-containing compound; the solution containing barium salts and / or strontium salts can be prepared by any soluble barium salts and / or strontium salts; and the ion exchange of the X-type molecular sieve with the solution containing cesium ions can be carried out in a conventional manner in the art.

[0026] According to some embodiments of the present invention, the cesium ion concentration in the cesium ion-containing solution is 0.5 to 3.0 mol / L.

[0027] According to some embodiments of the present invention, the mass volume ratio of the X-type molecular sieve and the solution containing cesium ions is 1 g: (5-50) mL.

[0028] According to some embodiments of the present invention, the temperature of the ion exchange is 10-95°C.

[0029] According to some embodiments of the present invention, the ion exchange time is 1 to 3 hours.

[0030] According to some embodiments of the present invention, the number of ion exchanges is 1 to 5 times.

[0031] According to some embodiments of the invention, the barium salt comprises barium nitrate or barium chloride.

[0032] According to some embodiments of the invention, the strontium salt comprises strontium nitrate or strontium chloride.

[0033] According to some embodiments of the present invention, the solution containing cesium ions includes a cesium hydroxide solution or a cesium nitrate solution.

[0034] According to some embodiments of the present invention, the temperature of the first drying is 90-140°C.

[0035] According to some embodiments of the present invention, the temperature of the second drying is 90-140°C.

[0036] According to some embodiments of the present invention, the calcination temperature is 500-600° C. and the calcination time is 3-10 h.

[0037] In a third aspect, the present invention provides the use of the catalyst described in the first aspect in the synthesis of isobutylbenzene, especially in the side chain alkylation of toluene and acetone to produce isobutylbenzene.

[0038] In a fourth aspect, the present invention provides a method for preparing isobutylbenzene by side chain alkylation of toluene and acetone, comprising: gasifying toluene and acetone, mixing with hydrogen, contacting with the catalyst described in the first aspect to react, and preparing isobutylbenzene.

[0039] According to some embodiments of the present invention, the reaction is carried out in a fixed bed reactor.

[0040] According to some embodiments of the present invention, the molar ratio of toluene to acetone is (0.1-10):1, the molar ratio of toluene to hydrogen is (0.01-1):1, the reaction temperature is 300-600°C, the reaction pressure is 0-0.5 MPa, and the raw material weight space velocity is 0.05-5 h -1 .

[0041] According to some embodiments of the present invention, the molar ratio of toluene to acetone is (0.8-8).

[0042] According to some embodiments of the present invention, the molar ratio of toluene to hydrogen is (0.01-0.05):1.

[0043] According to some embodiments of the present invention, the reaction temperature is 350-450°C.

[0044] According to some embodiments of the present invention, the reaction pressure is 0 to 0.3 MPa.

[0045] According to some embodiments of the present invention, the raw material weight space velocity is 0.05 to 2 h -1 .

[0046] The beneficial effects of the present invention are at least:

[0047] The catalyst provided by the present invention is used in the synthesis of isobutylbenzene, and can synthesize isobutylbenzene through a fixed-bed reaction process of toluene and acetone side chain alkylation, providing a new isobutylbenzene synthesis route; the process route has simple process conditions, low safety risks, and can realize continuous synthesis of isobutylbenzene. The synthesis of isobutylbenzene by using the process route has broad market application prospects. DETAILED DESCRIPTION

[0048] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain this patent in detail and do not limit the scope of protection of the present invention in any way.

[0049] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, etc., can all be purchased on the market or can be obtained by existing methods; the reagent amounts, unless otherwise specified, are the reagent amounts used in conventional experimental operations; the experimental methods, unless otherwise specified, are all conventional methods.

[0050] Preparation Example 1-4

[0051] Preparation of Nano-X Molecular Sieve:

[0052] Weigh the amounts of the components in Table 1, add aluminum isopropoxide and tetramethylammonium bromide into water and stir until dissolved, then add sodium silicate (Na 2 SiO 3 9H 2 O) and tetraethyl silicate are slowly added to the mixed solution and stirred at 15°C for 3 hours; then the mixed solution is transferred to a polytetrafluoroethylene stainless steel reactor for crystallization, and the crystallization temperature and time are shown in Table 1; the crystallized product is filtered and washed until the pH drops to 9; it is dried at 100°C and calcined at 550°C for 6h to obtain nano X-type molecular sieves X-1 to X-4, whose particle size and silicon-aluminum ratio are shown in Table 2.

[0053] Table 1

[0054]

[0055] Table 2

[0056]

[0057] Examples 1-10

[0058] Preparation of catalyst:

[0059] Take 20g of X-type molecular sieve and perform ion exchange at 50°C. The ion exchange liquid used is 160mL of cesium nitrate solution (the concentration of cesium nitrate solution in Example 8 is 1.25mol / L, and the concentration of cesium nitrate solution in other examples is 1mol / L). The ion exchange time is 2h each time, and the exchange is 1 to 4 times (the number of ion exchanges in Example 5 is 1 time, the number of ion exchanges in Example 6 is 2 times, the number of ion exchanges in Example 7 is 3 times, and the number of ion exchanges in other examples is 4 times); then wash with sufficient deionized water, and then dry at 110°C; dissolve barium nitrate and / or strontium nitrate in water, and load barium and / or strontium onto the above-mentioned X-type molecular sieve by equal amount impregnation method, and finally dry at 110°C and roast at 550°C for 6h to obtain catalysts A1 to A10. The mass content of Cs ions after ion exchange of X-type molecular sieve of each catalyst, the type of catalyst-loaded metal, and the loading amount are shown in Table 3.

[0060] Embodiment 11

[0061] The preparation method of the catalyst is similar to that of Example 3, except that the X-type molecular sieve is replaced by X-3 with a NaX-type molecular sieve 5-X (SiO 2 / Al 2 O 3 =2.2).

[0062] Catalyst A11 was obtained.

[0063] Comparative Example 1

[0064] The preparation method of the catalyst is similar to that of Example 3, except that no cesium nitrate solution is used to perform ion exchange on the X-type molecular sieve.

[0065] Catalyst D1 was obtained.

[0066] Comparative Example 2

[0067] The preparation method of the catalyst is the same as that of Example 3, except that the cesium nitrate solution is replaced with 160 mL of 1 mol / L potassium nitrate solution.

[0068] Catalyst D2 was obtained.

[0069] Comparative Example 3

[0070] The preparation method of the catalyst is similar to that of Example 3, except that barium nitrate is replaced by magnesium nitrate.

[0071] Catalyst D3 was obtained.

[0072] Comparative Example 4

[0073] The preparation method of the catalyst is similar to that of Example 3, except that barium nitrate is replaced by calcium nitrate.

[0074] Catalyst D4 was obtained.

[0075] Catalyst performance evaluation

[0076] Each catalyst was pressed into a 40-60 mesh granular catalyst, loaded into a fixed bed reactor, and heated at normal pressure, 420°C, a molar ratio of toluene to acetone of 1:4, and a liquid space velocity of 0.5 h -1 , enter H 2 (Toluene and H 2 The catalytic activity was evaluated under the condition of a molar ratio of 0.24:1), and the results are shown in Table 3.

[0077] Catalyst A3 was pressed into 40-60 mesh granular catalysts and loaded into a fixed bed reactor at normal pressure, 420°C, a molar ratio of toluene to acetone of 1:4, and a liquid space velocity of 0.5 h -1 , no access to H 2 The catalytic activity was evaluated under the conditions of , and the results are shown in Table 3.

[0078] Table 3

[0079]

[0080] Among them, the exchange ion mass content and element content are detected by atomic emission spectrometry (ICP), and the detection instrument model is Varian 725-ES.

[0081] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A catalyst for synthesizing isobutylene, characterized in that: The catalyst comprises a cesium ion-exchanged X-type molecular sieve and barium and / or strontium supported on the cesium ion-exchanged X-type molecular sieve.

2. The catalyst according to claim 1, characterized in that The X-type molecular sieve is a nano X-type molecular sieve; preferably, the particle size of the X-type molecular sieve is 10 to 100 nm, preferably 20 to 90 nm; And / or, the SiO2 / Al2O3 of the X-type molecular sieve is 2-3.

3. The catalyst according to claim 1 or 2, characterized in that The mass percentage of cesium ions in the catalyst is 15-35%; And / or, the mass percentage of barium and / or strontium in the catalyst is 0.5-5.0%.

4. The method for preparing the catalyst according to any one of claims 1 to 3, characterized in that: include: The X-type molecular sieve is subjected to ion exchange with a solution containing cesium ions, washed, dried for the first time, and then impregnated with a solution containing barium salt and / or strontium salt, dried for the second time, and calcined to obtain the catalyst.

5. The preparation method according to claim 4, characterized in that: The cesium ion concentration in the cesium ion-containing solution is 0.5 to 3.0 mol / L; and / or, the mass volume ratio of the X-type molecular sieve and the solution containing cesium ions is 1 g: (5-50) mL; And / or, the ion exchange temperature is 10-95°C.

6. The preparation method according to claim 4 or 5, characterized in that: The barium salt includes barium nitrate or barium chloride; and / or, the strontium salt comprises strontium nitrate or strontium chloride; and / or, the solution containing cesium ions comprises a cesium hydroxide solution or a cesium nitrate solution; And / or, the temperature of the first drying is 90-140°C; And / or, the temperature of the second drying is 90-140°C; And / or, the calcination temperature is 500-600° C. and the calcination time is 3-10 hours.

7. Use of the catalyst according to any one of claims 1 to 3 in the synthesis of isobutylbenzene, especially in the side chain alkylation of toluene and acetone to produce isobutylbenzene.

8. A method for preparing isobutylbenzene by side chain alkylation of toluene and acetone, characterized in that: include: Toluene and acetone are gasified and then mixed with hydrogen, and then contacted with the catalyst described in any one of claims 1 to 3 to react to prepare isobutylene.

9. The method according to claim 8, characterized in that The reaction is carried out in a fixed bed reactor.

10. The method according to claim 9, characterized in that The molar ratio of toluene to acetone is (0.1-10):1, the molar ratio of toluene to hydrogen is (0.01-1):1, the reaction temperature is 300-600°C, the reaction pressure is 0-0.5 MPa, and the raw material weight space velocity is 0.05-5 h -1 ; Preferably, The molar ratio of toluene to acetone is (0.8-8):1; and / or the molar ratio of toluene to hydrogen is (0.01-0.05):1; and / or the reaction temperature is 350-450°C; and / or the reaction pressure is 0-0.3 MPa; and / or the raw material weight space velocity is 0.05-2h -1 .

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