Method for preparing isobutylbenzene from toluene and isopropanol

Abstract

The invention discloses a method for preparing isobutylbenzene from toluene and isopropanol, which comprises the following steps: raw materials including toluene, isopropanol and hydrogen react in the presence of a catalyst to obtain isobutylbenzene, the catalyst contains a modified montmorillonite component, and the modified montmorillonite is alkali metal ion exchange montmorillonite. The method has the advantages of simple conditions and small safety risk, and can realize continuous synthesis of isobutylbenzene. Therefore, the process route for synthesizing the isobutylbenzene has a wide market application prospect.

Description

Technical Field

[0001] The present invention belongs to the field of isobutylbenzene preparation, and particularly relates to the preparation of isobutylbenzene using toluene and isopropyl alcohol. Background Art

[0002] Isobutylbenzene (IBB for short) is the main intermediate for synthesizing ibuprofen (Profe or Brufen), an anti-inflammatory, antipyretic, and analgesic drug for human use. As an anti-inflammatory, antipyretic, and analgesic drug, ibuprofen can treat rheumatoid arthritis, degenerative arthritis, toothache, neuralgia, etc., and also has good curative effects on inflammation, fever, and pain after obstetrics and gynecology surgery, and has few adverse reactions and can be taken for a long time. At present, there are still many problems with other current antipyretic and analgesic drugs. For example, some domestic acetaminophen oral preparations have unstable effects and are not very effective for high fever, and the antipyretic effect time is short; aspirin and its compound preparations have large side effects on the digestive tract and blood system, and may also cause Reye's syndrome in children, etc. Therefore, the market application prospect of ibuprofen is very broad.

[0003] Among the numerous synthetic routes for synthesizing ibuprofen, almost all routes require the use of the intermediate isobutylbenzene. So far, there are more than a dozen synthetic process routes for isobutylbenzene, but most are laboratory preparation methods, and some can be industrialized, but the raw materials are not easily obtained. The existing synthetic process of isobutylbenzene is mainly the side-chain alkylation reaction process of toluene and propylene catalyzed by alkali metals.

[0004] In 1950, scientists such as Pines first proposed that strong-base-catalyzed side-chain alkylation reactions occur between alkyl aromatic hydrocarbons and small-molecule olefins. The strong-base catalyst is composed of an alkali metal or an alkali metal hydride and a promoter. The promoter can be an aromatic hydrocarbon, benzonitrile, pyridine, or chloroalkane, etc. Its main role is to induce the formation of a metal organic compound by an alkali metal or its oxide to attack the alkylbenzene. Currently, industry mainly synthesizes isobutylbenzene by reacting toluene and propylene under the action of an alkali metal potassium-sodium catalyst, and a kettle reaction is used in the synthesis. However, since the catalyst contains free alkali metal potassium or sodium, and water or ethanol needs to be added as a terminator during the synthesis process, and the reaction conditions use high temperature and high pressure, the operation requirements for synthesizing isobutylbenzene under such conditions are harsh and the safety risk is very high. At the same time, under such conditions, industry generally uses an intermittent kettle reaction to synthesize isobutylbenzene and cannot achieve continuous production. Currently, industry urgently needs a synthetic process route for isobutylbenzene that is simple to operate, has a small safety risk, and can be continuously synthesized. Summary of the Invention

[0005] In order to overcome the problems existing in the prior art (such as complex process, high safety risks, etc.), the present invention provides a method for preparing isobutylbenzene using toluene and isopropanol. The method has simple conditions, low safety risks, and can achieve continuous synthesis of isobutylbenzene. Therefore, using this process route to synthesize isobutylbenzene has broad market application prospects.

[0006] The object of the present invention is to provide a method for preparing isobutylbenzene using toluene and isopropanol, which includes: reacting raw materials containing toluene, isopropanol, and hydrogen in the presence of a catalyst, and the catalyst contains a modified montmorillonite component, and the modified montmorillonite is an alkali metal ion-exchanged montmorillonite.

[0007] Among them, the alkali metal ions are present in the interlayer of the montmorillonite.

[0008] In a preferred embodiment, before toluene and isopropanol are mixed with hydrogen to form the raw materials, toluene and isopropanol are first vaporized.

[0009] In a preferred embodiment, the molar ratio of toluene to isopropanol is (0.1 - 2.0):1, and / or the molar ratio of toluene to hydrogen is (0.01 - 1.2):1.

[0010] For example, the molar ratio of toluene to isopropanol is 0.1:1, 0.2:1, 0.4:1, 0.5:1, 0.6:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 1.8:1 or 2:1, and / or the molar ratio of toluene to hydrogen is 0.01:1, 0.05:1, 0.1:1, 0.2:1, 0.4:1, 0.6:1, 0.8:1, 1:1 or 1.2:1.

[0011] In a further preferred embodiment, the molar ratio of toluene to isopropanol is preferably (0.1 - 0.5):1, and the molar ratio of toluene to hydrogen is preferably (0.01 - 0.07):1.

[0012] In a preferred embodiment, the reaction conditions include: the reaction temperature is 350 - 550 °C, the reaction pressure is atmospheric pressure - 1.0 MPa, and the weight hourly space velocity of the raw materials is 0.1 - 4 h -1 .

[0013] For example, the reaction conditions include: the reaction temperature is 350 °C, 360 °C, 380 °C, 400 °C, 420 °C, 440 °C, 460 °C, 480 °C, 500 °C, 520 °C, 540 °C or 550 °C, the reaction pressure is 0 MPa, 0.2 MPa, 0.4 MPa, 0.6 MPa, 0.8 MPa or 1.0 MPa, and the weight hourly space velocity of the raw materials is 0.1 h -1 , 0.5 h -1 , 1 h-1 、1.5 hours -1 、2 hours -1 、2.5 hours -1 、3 hours -1 、3.5 hours -1 or 4 hours -1 。

[0015] In a further preferred embodiment, the conditions of the reaction include: the reaction temperature is 375 - 500 °C, the reaction pressure is 0 - 0.5 MPa, and the weight hourly space velocity of the raw materials is 0.2 - 2.5 hours -1 。

[0016] In a preferred embodiment, the ion exchange capacity of the montmorillonite is 0.4 - 1.6 meq / g, preferably 0.6 - 1.6 meq / g, for example 0.6 meq / g, 0.8 meq / g, 1.0 meq / g, 1.2 meq / g, 1.4 meq / g or 1.6 meq / g.

[0017] In a preferred embodiment, the alkali metal ion is selected from one or more of potassium ion, rubidium ion, and cesium ion.

[0018] Among them, the inventors found through experiments that the effect of using sodium ion is slightly worse than that of potassium ion, rubidium ion, and cesium ion.

[0019] In a further preferred embodiment, the alkali metal ion is selected from a combination of one, two, or three of potassium ion, rubidium ion, and cesium ion, preferably a combination of two or three of potassium ion, rubidium ion, and cesium ion.

[0020] Among them, the inventors found through experiments that when the montmorillonite ion-exchanged with two or three of potassium ion, rubidium ion, and cesium ion is used in the reaction, the catalytic effect is better.

[0021] In a still further preferred embodiment, based on the weight of the catalyst being 100 wt%, the weight of the alkali metal ion is 1.5 - 20 wt%, preferably 2.5 - 15 wt%, where it is based on the weight of the alkali metal element.

[0022] For example, based on the catalyst being 100 wt%, the weight of the alkali metal ion is 2.5 wt%, 3 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt% or 15 wt%, where it is based on the weight of the alkali metal element.

[0023] In a preferred embodiment, the catalyst further contains phosphorus element.

[0024] In a further preferred embodiment, the phosphorus element is derived from a phosphate salt, preferably from at least one of potassium phosphate, sodium phosphate, and ammonium phosphate, more preferably from sodium phosphate and / or ammonium phosphate, such as ammonium phosphate.

[0025] For example, it is derived from at least one of tripotassium phosphate, potassium hydrogen phosphate, potassium dihydrogen phosphate, triammonium phosphate, ammonium hydrogen phosphate, ammonium dihydrogen phosphate, trisodium phosphate, sodium hydrogen phosphate, and sodium dihydrogen phosphate.

[0026] Among them, the inventors found through experiments that introducing a phosphorus element into the catalyst can improve the activity of the catalyst.

[0027] In a still further preferred embodiment, based on the weight of the catalyst being 100 wt%, the weight of the phosphorus element is 0.1 - 4.5 wt%, preferably 0.3 - 3.5 wt%, such as 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, or 4.5 wt%.

[0028] In a preferred embodiment, the preparation of the catalyst includes: Step (1): Mix montmorillonite with an ion exchange solution containing the alkali metal ions for ion exchange, filter, and then dry and calcine to obtain an ion exchange product; Optionally, Step (2): Load the phosphorus element onto the ion exchange product and calcine; to obtain the catalyst.

[0029] In a further preferred embodiment, the ion exchange solution is an aqueous solution, preferably an aqueous solution containing a water-soluble alkali metal compound, and the water-soluble alkali metal salt is selected from one or two or three of water-soluble potassium compounds, water-soluble rubidium compounds, and water-soluble cesium compounds.

[0030] In a still further preferred embodiment, the alkali metal compound is selected from at least one of alkali metal hydroxides, alkali metal nitrates, alkali metal chlorides, and alkali metal acetates, and / or, the water-soluble potassium compound is selected from at least one of potassium hydroxide, potassium nitrate, potassium chloride, and potassium acetate, and / or, the water-soluble rubidium compound is selected from at least one of rubidium hydroxide, rubidium nitrate, rubidium chloride, and rubidium acetate, and / or, the water-soluble cesium compound is selected from at least one of cesium hydroxide, cesium nitrate, cesium chloride, and cesium acetate

[0031] In a still further preferred embodiment, in the ion exchange solution, the total concentration of the alkali metal ions is 0.1 - 3.0 mol / L, preferably 0.25 - 2.5 mol / L, such as 0.25, 0.5, 0.8, 1, 1.2, 1.5, 1.8, 2, 2.2, or 2.5 mol / L.

[0032] In a preferred embodiment, the temperature of the ion exchange is 20 to 80 °C, for example, 20 °C, 30 °C, 40 °C, 50 °C, 60 °C, 70 °C or 80 °C.

[0033] In a preferred embodiment, the weight ratio of the montmorillonite to the volume of the ion exchange solution is 1:(5 to 20) [g / mL], for example, 1:5 [g / mL], 1:6 [g / mL], 1:8 [g / mL], 1:10 [g / mL], 1:12 [g / mL], 1:14 [g / mL], 1:16 [g / mL], 1:18 [g / mL] or 1:20 [g / mL].

[0034] In a preferred embodiment, when the alkali metal ions are selected from a combination of two or three, each alkali metal ion independently contacts the montmorillonite at least once for ion exchange. After an alkali metal ion contacts the montmorillonite at least once for ion exchange, it is washed to obtain an ion exchange intermediate, and then another kind of alkali metal ion contacts the ion exchange intermediate at least once for ion exchange.

[0035] In a further preferred embodiment, when the alkali metal ions are selected from A and B, the montmorillonite is ion-exchanged with A first and then with B. Preferably, the ion exchange includes: (a) A ion exchange, first contacting A with the montmorillonite for ion exchange, the number of exchanges being 1 to 3 times, and after the exchange is completed, it is washed with water; (b) B ion exchange, contacting the montmorillonite after A ion exchange with B for ion exchange, the number of exchanges being 1 to 3 times, and after the exchange is completed, it is washed with water. When the alkali metal ions further contain C, after B ion exchange, it further includes: (c) C ion exchange, contacting the montmorillonite after B ion exchange with C for ion exchange, the number of exchanges being 1 to 3 times, and after the exchange is completed, it is washed with water. Among them, A, B, and C are independently selected from potassium ions, rubidium ions, and cesium ions and are different from each other.

[0036] In a preferred embodiment, the exchange order of potassium ions, rubidium ions, and cesium ions is preferably potassium ions first, then rubidium ions, and finally cesium ions.

[0037] In a further preferred embodiment, the montmorillonite is ion-exchanged with at least one of potassium ions and rubidium ions, or the montmorillonite is ion-exchanged with potassium ions and rubidium ions separately at least once in sequence, or the montmorillonite is ion-exchanged with potassium ions and cesium ions separately at least once in sequence, or the montmorillonite is ion-exchanged with rubidium ions and cesium ions separately at least once in sequence, or the montmorillonite is ion-exchanged with potassium ions, rubidium ions, and cesium ions separately at least once in sequence.

[0038] In a preferred embodiment, the drying temperature after the ion exchange is 90 - 130 °C, and the calcination temperature is 500 - 600 °C.

[0039] For example, the drying temperature after the ion exchange is 90 °C, 100 °C, 110 °C, 120 °C or 130 °C, and the calcination temperature is 500 °C, 520 °C, 540 °C, 560 °C, 580 °C or 600 °C.

[0040] In a preferred embodiment, the loading of the phosphorus element is carried out as follows: the ion exchange product is impregnated in an aqueous phosphate solution, the water therein is evaporated to dryness after impregnation, and then dried and calcined.

[0041] In this way, all the phosphorus elements in the aqueous phosphate solution can be loaded onto the ion exchange product.

[0042] In a further preferred embodiment, the ratio of the volume (ml) of the aqueous phosphate solution to the weight (g) of the ion exchange product is controlled to be (3 - 20):1, preferably (5 - 15):1, such as 3:1, 4:1, 6:1, 8:1, 10:1, 12:1, 14:1 or 15:1.

[0043] Among them, the concentration of phosphate in the aqueous phosphate solution is controlled according to the amount of phosphorus element to be loaded on the catalyst.

[0044] In a still further preferred embodiment, the impregnation time is 5 - 120 minutes, such as 5 minutes, 10 minutes, 20 minutes, 40 minutes, 60 minutes, 80 minutes, 100 minutes or 120 minutes.

[0045] In a preferred embodiment, the method is carried out in at least two parallel fixed - bed reactors, and the catalyst is filled in each fixed - bed reactor independently. Among them, one fixed - bed reactor is in an online state, and the rest of the fixed - bed reactors are in a non - online state.

[0046] In a further preferred embodiment, when the online fixed - bed reactor is deactivated, it is cut out for regeneration, and one fixed - bed reactor is switched into the remaining fixed - bed reactors.

[0047] For example, the method is carried out in two parallel fixed - bed reactors, one is in an online state, and the other is in a non - online state. When the online fixed - bed reactor is deactivated, it is cut out for regeneration and the other fixed - bed reactor is switched in.

[0048] The method of the present invention includes: vaporizing toluene and isopropanol and then mixing them with hydrogen, and then passing through two parallel fixed-bed reactors. Under the condition of contacting with a catalyst in the reactors, toluene and isopropanol can be converted into isobutylbenzene; in the parallel fixed-bed reactors, in one reactor, toluene and isopropanol contact with the catalyst to generate isobutylbenzene at the same time, and in the other reactor, the catalyst is regenerated. The two parallel fixed-bed reactors are automatically switched back and forth through valves to enable one reactor to carry out the reaction of synthesizing isobutylbenzene from toluene and isopropanol, and the other reactor to carry out catalyst regeneration.

[0049] In a further preferred embodiment, it is judged whether the fixed-bed reactor is deactivated according to the reaction time, and it is preferably cut out after reacting for 20 to 100 h, such as 20 h, 30 h, 40 h, 50 h, 60 h, 70 h, 80 h, 90 h or 100 h.

[0050] In a preferred embodiment, the regeneration includes: first introducing air into the (cut-out) fixed-bed reactor at 450 - 600 °C for 10 - 40 minutes, then introducing nitrogen at the reaction temperature for 10 - 30 minutes, and then introducing hydrogen at the reaction temperature for 10 - 30 minutes.

[0051] In a further preferred embodiment, the regeneration includes: first introducing air into the (cut-out) fixed-bed reactor at 500 - 550 °C for 15 - 30 minutes, then introducing nitrogen at the reaction temperature for 20 - 25 minutes, and then introducing hydrogen at the reaction temperature for 15 - 20 minutes.

[0052] For example, the regeneration includes: first introducing air into the (cut-out) fixed-bed reactor at 500 °C, 510 °C, 520 °C, 530 °C, 540 °C or 550 °C for 15 minutes, 18 minutes, 20 minutes, 22 minutes, 25 minutes, 28 minutes or 30 minutes, then introducing nitrogen at the reaction temperature for 20 minutes, 21 minutes, 22 minutes, 23 minutes, 24 minutes or 25 minutes, and then introducing hydrogen at the reaction temperature for 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes or 20 minutes. Among them, the reaction temperature refers to the reaction temperature for preparing isobutylbenzene from toluene and isopropanol, that is, the temperature of the reaction of the present invention.

[0053] In the present invention, the inventors found through a large number of experimental studies that after the modified montmorillonite after specific ion exchange is applied to the reaction of preparing isobutylbenzene from toluene and isopropanol, the reaction conditions are simple, the safety risk is small, and the continuous synthesis of isobutylbenzene can be realized. The reaction conversion rate of this method can reach up to 10%, and the isobutylbenzene selectivity reaches 65%.

[0054] Traditional side-chain alkylation of toluene and propylene uses metal potassium and sodium catalysts. Due to the presence of metal potassium and sodium in the catalyst, the entire catalytic system requires anhydrous and anaerobic conditions as well as high-pressure reaction conditions to be controlled. These conditions are harsh and there are also significant safety hazards. In contrast, the reaction conditions of the present method are mild and the safety risks are small.

[0055] In the ranges disclosed in the present invention, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein. In the following text, in principle, the various technical solutions can be combined with each other to obtain new technical solutions, which should also be regarded as specifically disclosed herein.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] (1) The reaction for preparing isobutylbenzene from toluene and isopropanol has simple conditions, small safety risks, and can achieve continuous synthesis of isobutylbenzene.

[0058] (2) The reaction conversion rate of this method reaches 10%, and the selectivity of isobutylbenzene reaches 65%. Detailed implementation manners

[0059] The present invention will be specifically described below in conjunction with specific embodiments. It is necessary to point out here that the following embodiments are only for further illustration of the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the protection scope of the present invention.

[0060] In addition, it should be noted that, among the various specific technical features described in the following detailed implementation manners, without contradiction, they can be combined in any suitable way. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0061] In addition, any combination can be made among the various different implementation manners of the present invention as long as it does not violate the idea of the present invention. The technical solutions thus formed belong to a part of the original public content of this specification and also fall within the protection scope of the present invention.

[0062] If there is no special limitation on the raw materials used in the examples and comparative examples, they are all disclosed in the prior art. For example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0063] The content of the exchange ions in the catalyst was obtained by detection with inductively coupled plasma atomic emission spectrometry (ICP), and the content of phosphorus in the catalyst was obtained by detection with inductively coupled plasma atomic emission spectrometry (ICP).

[0064] Toluene conversion rate = (moles of toluene converted / moles of toluene fed) * 100%;

[0065] Isobutylbenzene selectivity = (moles of isobutylbenzene formed / moles of toluene converted) * 100%.

[0066]

Example 1

[0067] Take 20 g of montmorillonite with an ion exchange capacity of 0.8 meq / g and perform ion exchange on it at 50 °C. The ion exchange solution used is 200 mL of 1 mol / L potassium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. After the exchange, it is washed with deionized water, then dried at 110 °C and calcined at 550 °C for 6 hours. A potassium ion-modified montmorillonite catalyst is obtained, and the elemental content of the exchange ions in the catalyst is 2.8 wt%.

[0068] The catalyst obtained above is tableted into 40 - 60 mesh granular catalysts and loaded into two parallel reactors. Toluene and isopropanol are vaporized and mixed with hydrogen, and then passed through the above-mentioned parallel fixed-bed reactors (one of which is in the on-line state) to synthesize isobutylbenzene. The conditions of the on-line reactor are normal pressure, the molar ratio of toluene to isopropanol is 0.25:1, at a liquid hourly space velocity of 0.5 h -1 and at 400 °C, the molar ratio of toluene to hydrogen is 0.5:1.

[0069] After the on-line reactor runs for 50 h, it is taken out for regeneration and another reactor is cut in. The conditions of the regeneration reactor are: air is introduced at 530 °C for 20 minutes, nitrogen is introduced at 400 °C for 25 minutes, and then hydrogen is introduced at 400 °C for 15 minutes for activity evaluation. The results are listed in Table 1.

[0070]

Example 2

[0071] Take 20 g of montmorillonite with an ion exchange capacity of 1.5 meq / g and perform ion exchange on it at 50 °C. The ion exchange solution used is 200 mL of 1 mol / L rubidium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. After the exchange, it is washed with deionized water, then dried at 110 °C and calcined at 550 °C for 6 hours. A rubidium ion-modified montmorillonite catalyst is obtained, and the elemental content of the exchange ions in the catalyst is 10.2 wt%.

[0072] The obtained catalyst was pressed into 40-60 mesh granular catalyst and loaded into two parallel reactors. Toluene and isopropanol were vaporized and mixed with hydrogen, and then isobutylbenzene was synthesized through the above-mentioned parallel fixed-bed reactors (one of which was in the online state). The conditions of the online reactor were normal pressure, the molar ratio of toluene to isopropanol was 0.25:1, and at a liquid hourly space velocity of 0.5 h -1 , at 400 °C, and the molar ratio of toluene to hydrogen was 0.5:1.

[0073] After the online reactor ran for 50 h, it was taken out for regeneration and another reactor was switched in. The conditions of the regeneration reactor were: air was introduced at 530 °C for 20 minutes, nitrogen was introduced at 400 °C for 25 minutes, and then hydrogen was introduced at 400 °C for 15 minutes for activity evaluation. The results are listed in Table 1.

[0074]

Example 3

[0075] 20 g of montmorillonite with an ion exchange capacity of 1.5 meq / g was taken and ion-exchanged at 50 °C. The first ion exchange solution used was 200 mL of 1 mol / L potassium nitrate solution, and the exchange was carried out 2 times, with each ion exchange time being 2 hours. Then the ion exchange solution used was 200 mL of 1 mol / L rubidium nitrate solution, and the exchange was carried out 2 times, with each ion exchange time being 2 hours. After the exchange, it was washed with deionized water, then dried at 110 °C and calcined at 550 °C for 6 hours. A potassium ion-rubidium ion modified montmorillonite catalyst was obtained, and the elemental content of the exchanged ions in the catalyst was 11.5 wt%.

[0076] The obtained catalyst was pressed into 40-60 mesh granular catalyst and loaded into two parallel reactors. Toluene and isopropanol were vaporized and mixed with hydrogen, and then isobutylbenzene was synthesized through the above-mentioned parallel fixed-bed reactors (one of which was in the online state). The conditions of the online reactor were normal pressure, the molar ratio of toluene to isopropanol was 0.25:1, and at a liquid hourly space velocity of 0.5 h -1 , at 400 °C, and the molar ratio of toluene to hydrogen was 0.5:1.

[0077] After the online reactor ran for 50 h, it was taken out for regeneration and another reactor was switched in. The conditions of the regeneration reactor were: air was introduced at 530 °C for 20 minutes, nitrogen was introduced at 400 °C for 25 minutes, and then hydrogen was introduced at 400 °C for 15 minutes for activity evaluation. The results are listed in Table 1.

[0078]

Example 4

[0079] Take 20 g of montmorillonite with an ion exchange capacity of 1.5 meq / g and conduct ion exchange on it at 50 °C. The first ion exchange solution used is 200 mL of 1 mol / L potassium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. Then the ion exchange solution used is 200 mL of 1 mol / L cesium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. After the exchange is completed, wash with deionized water, then dry at 110 °C and calcine at 550 °C for 6 hours. Obtain a potassium ion - cesium ion modified montmorillonite catalyst, and the elemental content of the exchanged ions in the catalyst is 12.5 wt%.

[0080] Tablet the catalyst obtained above into particulate catalysts with a mesh size of 40 - 60 and load them into two parallel reactors. Gasify toluene and isopropanol and mix them with hydrogen, and then synthesize isobutene through the above - mentioned parallel fixed - bed reactors (one of which is in the on - line state). The conditions of the on - line reactor are normal pressure, the molar ratio of toluene to isopropanol is 0.25:1, and at a liquid hourly space velocity of 0.5 h -1 , at 400 °C, and the molar ratio of toluene to hydrogen is 0.5:1.

[0081] After the on - line reactor operates for 50 h, cut it out for regeneration and switch to another reactor. The conditions of the regeneration reactor are: introduce air at 530 °C for 20 minutes, introduce nitrogen at 400 °C for 25 minutes, and then conduct activity evaluation under the condition of introducing hydrogen at 400 °C for 15 minutes. The results are listed in Table 1.

[0082]

Example 5

[0083] Take 20 g of montmorillonite with an ion exchange capacity of 1.5 meq / g and conduct ion exchange on it at 50 °C. The first ion exchange solution used is 200 mL of 1 mol / L rubidium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. Then the ion exchange solution used is 200 mL of 1 mol / L cesium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. After the exchange is completed, wash with deionized water, then dry at 110 °C and calcine at 550 °C for 6 hours. Obtain a rubidium ion - cesium ion modified montmorillonite catalyst, and the elemental content of the exchanged ions in the catalyst is 13.6 wt%.

[0084] Tablet the catalyst obtained above into particulate catalysts with a mesh size of 40 - 60 and load them into two parallel reactors. Gasify toluene and isopropanol and mix them with hydrogen, and then synthesize isobutene through the above - mentioned parallel fixed - bed reactors (one of which is in the on - line state). The conditions of the on - line reactor are normal pressure, the molar ratio of toluene to isopropanol is 0.25:1, and at a liquid hourly space velocity of 0.5 h -1 , at 400 °C, and the molar ratio of toluene to hydrogen is 0.5:1.

[0085] After the on-line reactor has been operating for 50 h, it is taken out for regeneration and another reactor is switched in. The conditions for the regenerated reactor are as follows: air is introduced at 530 °C for 20 minutes, nitrogen is introduced at 400 °C for 25 minutes, and then hydrogen is introduced at 400 °C for 15 minutes for activity evaluation. The results are listed in Table 1.

[0086]

Example 6

[0087] Take 20 g of montmorillonite with an ion exchange capacity of 1.5 meq / g and carry out ion exchange on it at 50 °C. The first ion exchange solution used is 200 mL of 1 mol / L potassium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. Then the ion exchange solution used is 200 mL of 1 mol / L rubidium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. Finally, the ion exchange solution used is 200 mL of 1 mol / L cesium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. After the exchange is completed, it is washed with deionized water, then dried at 110 °C and calcined at 550 °C for 6 hours. A potassium ion-rubidium ion-cesium ion modified montmorillonite catalyst is obtained, and the elemental content of the exchanged ions in the catalyst is 14.8 wt%.

[0088] The catalyst obtained above is pressed into particles with a size of 40 - 60 mesh and loaded into two parallel reactors. Toluene and isopropanol are vaporized and mixed with hydrogen, and then isobutylbenzene is synthesized through the above-mentioned parallel fixed-bed reactors (one of which is in the on-line state). The conditions for the on-line reactor are normal pressure, the molar ratio of toluene to isopropanol is 0.25:1, at a liquid hourly space velocity of 0.5 h -1 and at 400 °C, the molar ratio of toluene to hydrogen is 0.5:1.

[0089] After the on-line reactor has been operating for 50 h, it is taken out for regeneration and another reactor is switched in. The conditions for the regenerated reactor are as follows: air is introduced at 530 °C for 20 minutes, nitrogen is introduced at 400 °C for 25 minutes, and then hydrogen is introduced at 400 °C for 15 minutes for activity evaluation. The results are listed in Table 1.

[0090]

Example 7

[0091] Take 20 g of montmorillonite with an ion exchange capacity of 1.5 meq / g and perform ion exchange on it at 50 °C. The first ion exchange solution used is 200 mL of 1 mol / L potassium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. The next ion exchange solution used is 200 mL of 1 mol / L rubidium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. The last ion exchange solution used is 200 mL of 1 mol / L cesium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. After the exchange is completed, wash with deionized water, then dry at 110 °C and calcine at 550 °C for 6 hours to obtain the ion exchange product, where the elemental content of the exchanged ions is 14.8 wt%. Subsequently, add 15 g of the above ion exchange product to 75 mL of ammonium dihydrogen phosphate aqueous solution for impregnation, then evaporate the water in it, dry again, and calcine at 550 °C for 6 hours to obtain a potassium ion-rubidium ion-cesium ion and phosphorus-modified montmorillonite catalyst, and the phosphorus element content in the catalyst is 0.3 wt%.

[0092] Tablet the catalyst obtained above into 40 - 60 mesh granular catalysts and load them into two parallel reactors. Gasify toluene and isopropanol and mix them with hydrogen, and then synthesize isobutylbenzene through the above parallel fixed-bed reactors (one of which is in the online state). The conditions of the online reactor are normal pressure, the molar ratio of toluene to isopropanol is 0.25:1, at a liquid hourly space velocity of 0.5 h -1 and at 400 °C, with the molar ratio of toluene to hydrogen being 0.5:1.

[0093] After the online reactor runs for 50 h, cut it out for regeneration and switch to another reactor. The conditions of the regeneration reactor are: introduce air at 530 °C for 20 minutes, introduce nitrogen at 400 °C for 25 minutes, and then carry out activity evaluation under the condition of introducing hydrogen at 400 °C for 15 minutes. The results are listed in Table 1.

[0094]

Example 8

[0095] Take 20 g of montmorillonite with an ion exchange capacity of 1.5 meq / g and conduct ion exchange on it at 50 °C. The first ion exchange solution used is 200 mL of 1 mol / L potassium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. Then the ion exchange solution used is 200 mL of 1 mol / L rubidium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. Subsequently, the ion exchange solution used is 200 mL of 1 mol / L cesium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. After the exchange, wash with deionized water, then dry at 110 °C and calcine at 550 °C for 6 hours to obtain the ion exchange product, where the elemental content of the exchanged ions is 14.8 wt%. Subsequently, add 15 g of the above ion exchange product to 150 mL of an aqueous sodium hydrogen phosphate solution for impregnation, then evaporate the water in it, dry again, and calcine at 550 °C for 6 hours to obtain a potassium ion-rubidium ion-cesium ion and phosphorus-modified montmorillonite catalyst, and the phosphorus element content in the catalyst is 2.1 wt%.

[0096] Press the catalyst obtained above into 40 - 60 mesh granular catalysts and load them into two parallel reactors. Gasify toluene and isopropanol and mix them with hydrogen, and then synthesize isobutylbenzene through the above parallel fixed-bed reactors (one of which is in the online state). The conditions of the online reactor are normal pressure, the molar ratio of toluene to isopropanol is 0.25:1, at a liquid hourly space velocity of 0.5 h -1 and at 400 °C, the molar ratio of toluene to hydrogen is 0.5:1.

[0097] After the online reactor operates for 50 h, cut it out for regeneration and switch to another reactor. The conditions of the regeneration reactor are: introduce air at 530 °C for 20 minutes, introduce nitrogen at 400 °C for 25 minutes, and then conduct activity evaluation under the condition of introducing hydrogen at 400 °C for 15 minutes. The results are listed in Table 1.

[0098]

Example 9

[0099] Take 20 g of montmorillonite with an ion exchange capacity of 1.5 meq / g and perform ion exchange on it at 50 °C. The first ion exchange solution used is 200 mL of 1 mol / L potassium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. Then, the ion exchange solution used is 200 mL of 1 mol / L rubidium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. Subsequently, the ion exchange solution used is 200 mL of 1 mol / L cesium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. After the exchange is completed, wash it with deionized water, then dry it at 110 °C and calcine it at 550 °C for 6 hours to obtain the ion exchange product, and the elemental content of the exchanged ions is 14.8 wt%. Subsequently, add 15 g of the above ion exchange product to 225 mL of an aqueous potassium phosphate solution for impregnation, then evaporate the water in it, and then dry it and calcine it at 550 °C for 6 hours to obtain a potassium ion-rubidium ion-cesium ion and phosphorus-modified montmorillonite catalyst, and the phosphorus element content in the catalyst is 3.5 wt%.

[0100] Press the catalyst obtained above into 40 - 60 mesh granular catalysts and load them into two parallel reactors. Gasify toluene and isopropanol and mix them with hydrogen, and then synthesize isobutylbenzene through the above parallel fixed-bed reactors (one of which is in the online state). The conditions of the online reactor are normal pressure, the molar ratio of toluene to isopropanol is 0.25:1, and at a liquid hourly space velocity of 0.5 h -1 and at 400 °C, the molar ratio of toluene to hydrogen is 0.5:1.

[0101] After the online reactor operates for 50 h, cut it out for regeneration and switch to another reactor. The conditions of the regeneration reactor are: introduce air at 530 °C for 20 minutes, introduce nitrogen at 400 °C for 25 minutes, and then carry out activity evaluation under the condition of introducing hydrogen at 400 °C for 15 minutes, and the results are listed in Table 1.

[0102]

Example 10

[0103] Take 20 g of montmorillonite with an ion exchange capacity of 1.5 meq / g and perform ion exchange on it at 25 °C. The first ion exchange solution used is 120 mL of 2.4 mol / L potassium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. Then, the ion exchange solution used is 120 mL of 2.4 mol / L rubidium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. Subsequently, the ion exchange solution used is 120 mL of 2.4 mol / L cesium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. After the exchange is completed, wash it with deionized water, then dry it at 110 °C and calcine it at 500 °C for 6 hours. Obtain a potassium ion-rubidium ion-cesium ion-modified montmorillonite catalyst, and the elemental content of the exchanged ions in the catalyst is 11.7 wt%.

[0104] The obtained catalyst was tableted into 40-60 mesh granular catalyst and loaded into two parallel reactors. Toluene and isopropanol were vaporized and mixed with hydrogen, and then isobutylbenzene was synthesized through the above-mentioned parallel fixed-bed reactors (one of which was in the on-line state). The conditions of the on-line reactor were normal pressure, the molar ratio of toluene to isopropanol was 0.1:1, and at a liquid hourly space velocity of 2.5 h -1 and at 375 °C, the molar ratio of toluene to hydrogen was 0.01:1.

[0105] After the on-line reactor had been operating for 50 h, it was taken out for regeneration and another reactor was put into operation. The conditions of the regeneration reactor were as follows: air was introduced at 530 °C for 20 minutes, nitrogen was introduced at 400 °C for 25 minutes, and then hydrogen was introduced at 400 °C for 15 minutes for activity evaluation. The results are listed in Table 1.

[0106]

Example 11

[0107] 20 g of montmorillonite with an ion exchange capacity of 1.5 meq / g was taken and subjected to ion exchange at 40 °C. The first ion exchange solution used was 375 mL of 0.25 mol / L potassium nitrate solution, and the exchange was carried out 2 times, with each ion exchange time being 2 h. Then the ion exchange solution used was 375 mL of 0.25 mol / L rubidium nitrate solution, and the exchange was carried out 2 times, with each ion exchange time being 2 h. Subsequently, the ion exchange solution used was 375 mL of 0.25 mol / L cesium nitrate solution, and the exchange was carried out 2 times, with each ion exchange time being 2 h. After the exchange was completed, it was washed with deionized water, then dried at 110 °C and calcined at 600 °C for 6 h. A potassium ion-rubidium ion-cesium ion modified montmorillonite catalyst was obtained, and the elemental content of the exchanged ions in the catalyst was 11.5 wt%.

[0108] The obtained catalyst was tableted into 40-60 mesh granular catalyst and loaded into two parallel reactors. Toluene and isopropanol were vaporized and mixed with hydrogen, and then isobutylbenzene was synthesized through the above-mentioned parallel fixed-bed reactors (one of which was in the on-line state). The conditions of the on-line reactor were normal pressure, the molar ratio of toluene to isopropanol was 0.5:1, and at a liquid hourly space velocity of 0.2 h -1 and at 450 °C, the molar ratio of toluene to hydrogen was 1.2:1.

[0109] After the on-line reactor had been operating for 50 h, it was taken out for regeneration and another reactor was put into operation. The conditions of the regeneration reactor were as follows: air was introduced at 530 °C for 20 minutes, nitrogen was introduced at 400 °C for 25 minutes, and then hydrogen was introduced at 400 °C for 15 minutes for activity evaluation. The results are listed in Table 1.

[0110]

Example 12

[0111] Take 20 g of montmorillonite with an ion exchange capacity of 1.5 meq / g and conduct ion exchange on it at 80 °C. The first ion exchange solution used is 180 mL of 1.5 mol / L potassium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. Then the ion exchange solution used is 180 mL of 1.5 mol / L rubidium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. Subsequently, the ion exchange solution used is 180 mL of 1.5 mol / L cesium nitrate solution, and the exchange is carried out 2 times, with each ion exchange time being 2 hours. After the exchange, wash with deionized water, then dry at 110 °C and calcine at 550 °C for 6 hours. A potassium ion-rubidium ion-cesium ion modified montmorillonite catalyst is obtained, and the elemental content of the exchanged ions in the catalyst is 13.7 wt%.

[0112] Tablet the catalyst obtained above into granular catalysts with a mesh size of 40 - 60, and load them into two parallel reactors. Vaporize toluene and isopropanol and mix them with hydrogen, and then synthesize isobutylbenzene through the above-mentioned parallel fixed-bed reactors (one of which is in the online state). The conditions of the online reactor are 0.5 MPa, the molar ratio of toluene to isopropanol is 0.1:1, and at a liquid hourly space velocity of 1.0 h -1 , at 500 °C, and the molar ratio of toluene to hydrogen is 0.6:1.

[0113] After the online reactor operates for 50 h, cut it out for regeneration and switch to another reactor. The conditions of the regeneration reactor are: introduce air at 530 °C for 20 minutes, introduce nitrogen at 400 °C for 25 minutes, and then conduct activity evaluation under the condition of introducing hydrogen at 400 °C for 15 minutes. The results are listed in Table 1.

[0114]

Comparative Example

[0115] Repeat the process of Example 1, with the difference that: use 200 mL of 1 mol / L sodium nitrate solution to replace the potassium nitrate solution, and other conditions remain unchanged. The results are listed in Table 1.

[0116] Table 1

[0117]

[0118]

[0119] The present invention has been described in detail above in combination with specific embodiments and exemplary examples, but these descriptions should not be construed as limiting the present invention. Those skilled in the art understand that without departing from the spirit and scope of the present invention, various equivalent substitutions, modifications or improvements can be made to the technical solutions of the present invention and their implementation manners, and these all fall within the scope of the present invention. The protection scope of the present invention is subject to the appended claims.

Claims

1. A method for preparing isobutylbenzene using toluene and isopropanol, comprising: Raw materials including toluene, isopropanol, and hydrogen react in the presence of a catalyst to obtain isobutylbenzene. The catalyst contains a modified montmorillonite component, and the modified montmorillonite is an alkali metal ion-exchanged montmorillonite.

2. The method according to claim 1, wherein The molar ratio of toluene to isopropanol is (0.1 - 2.0):1, preferably (0.1 - 0.5):1; and / or, the molar ratio of toluene to hydrogen is (0.01 - 1.2):1, preferably (0.01 - 0.07):

1.

3. The method according to claim 1, wherein, The conditions of the reaction include: the reaction temperature is 350 to 550 °C, preferably 375 to 500 °C; and / or, the reaction pressure is atmospheric pressure to 1.0 MPa, preferably atmospheric pressure to 0.5 MPa; and / or, the weight hourly space velocity of the raw materials is 0.1 to 4 h -1 , preferably 0.2 to 2.5 h -1 .

4. The method according to claim 1, wherein The alkali metal ions are selected from one or more of potassium ions, rubidium ions, and cesium ions; preferably, based on 100 wt% of the weight of the catalyst, the weight of the alkali metal ions is 1.5 - 20 wt%, preferably 2.5 - 15 wt%, where it is based on the weight of the alkali metal element.

5. The method according to claim 1, characterized in that, The catalyst further contains a phosphorus element; preferably, the phosphorus element is derived from a phosphate salt, preferably from at least one of potassium phosphate, sodium phosphate, and ammonium phosphate; more preferably, based on 100 wt% of the catalyst, the weight of the phosphorus element is 0.1 - 4.5 wt%, preferably 0.3 - 3.5 wt%.

6. The method according to any one of claims 1 to 5, characterized in that The preparation of the catalyst includes: Step (1): Mix montmorillonite with an ion exchange solution containing the alkali metal ions for ion exchange, filter, and then dry and calcine to obtain an ion exchange product; Optionally, Step (2): Load the phosphorus element onto the ion exchange product and calcine.

7. The method according to claim 6, characterized in that, In Step (1), In the ion exchange solution, the total concentration of the alkali metal ions is 0.1 - 3.0 mol / L, preferably 0.25 - 2.5 mol / L; and / or, The temperature of the ion exchange is 20 - 80 °C; and / or, The weight ratio of the montmorillonite to the volume of the ion exchange solution is 1:(5 - 20).

8. The method according to claim 6, wherein The loading of the phosphorus element is carried out as follows: Immerse the ion exchange product in an aqueous phosphate solution, evaporate the water after impregnation, and then dry and calcine.

9. The method according to claim 6, wherein The drying temperature after the ion exchange is 90 - 130 °C, and the calcination temperature is 500 - 600 °C.

10. The method according to any one of claims 1 to 5, characterized in that The method is carried out in at least two parallel fixed-bed reactors. Each fixed-bed reactor is independently filled with the catalyst. Among them, one fixed-bed reactor is in an online state, and the remaining fixed-bed reactors are in an offline state; Preferably, when the online fixed-bed reactor is deactivated, it is cut out for regeneration, and one fixed-bed reactor is cut into the remaining fixed-bed reactors.

11. The method according to claim 10, wherein Judge whether the fixed-bed reactor is deactivated according to the reaction time, and preferably cut it out after reacting for 20 - 100 h.

12. The method according to claim 10, wherein The regeneration includes: First, introduce air into the fixed-bed reactor at 450 - 600 °C for 10 - 40 minutes, then introduce nitrogen at the reaction temperature for 10 - 30 minutes, and then introduce hydrogen at the reaction temperature for 10 - 30 minutes.

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