阅读说明：本技术 一种分子筛膜、膜反应器及在制备对叔丁基苯酚中的应用 (Molecular sieve membrane, membrane reactor and application in preparation of p-tert-butylphenol ) 是由 姜志成 刘运海 赵欣 方子来 张鹏 何光文 杨国忠 代红涛 林少宁 于 2020-07-16 设计创作，主要内容包括：本发明提供了一种分子筛膜、膜反应器及在制备对叔丁基苯酚中的应用。所述分子筛膜,膜内侧附着一层转烷基化催化剂；优选地,所述转烷基化催化剂为Beta分子筛、TS-1、SAPO-5中的至少一种。在本发明中,该分子筛膜主要应用于PTBP的制备工艺中,一方面通过膜分离提高产物选择性,另一方面将吸附在膜孔径及表面的少量副产OTBP、2,4-DTBP通过烷基转移反应进一步生成产物PTBP后再进行膜分离,具有产物选择性高的优点。(The invention provides a molecular sieve membrane, a membrane reactor and application in preparation of p-tert-butylphenol. A layer of transalkylation catalyst is attached to the inner side of the molecular sieve membrane; preferably, the transalkylation catalyst is at least one of Beta molecular sieve, TS-1, SAPO-5. In the invention, the molecular sieve membrane is mainly applied to the preparation process of PTBP, on one hand, the selectivity of the product is improved through membrane separation, on the other hand, a small amount of by-products OTBP and 2,4-DTBP adsorbed on the pore diameter and the surface of the membrane are subjected to transalkylation reaction to further generate the PTBP product, and then the PTBP product is subjected to membrane separation, so that the molecular sieve membrane has the advantage of high selectivity of the product.)

1. A molecular sieve membrane, wherein a layer of a transalkylation catalyst is attached to the inside of said membrane; preferably, the transalkylation catalyst is at least one of Beta molecular sieve, TS-1, SAPO-5.

2. The molecular sieve membrane of claim 1, wherein the membrane pore size is 0.55-0.75 nm.

3. The molecular sieve membrane according to claim 1 or 2, characterized in that the preparation method of the molecular sieve membrane comprises the following steps:

1) coating a layer of Al on the inner side of the steel wire mesh₂O₃As the adhesive, baking at 500-600 ℃ for 3-5h to prepare the alpha-Al with the thickness of 0.5-1.5mm₂O₃An inert support;

2) immersing an inert support body into a low-temperature synthesis mother solution of a molecular sieve, and adding an organic template agent to control the aperture of a film to be 0.55-0.75 nm;

3) stirring for 10-30 min, crystallizing, washing, drying, roasting, and removing the organic template; preferably, the roasting temperature is 550-600 ℃, and the time is 2-6 h;

4) uniformly attaching a transalkylation catalyst to the inner surface of the molecular sieve membrane through an adhesive, and roasting at 500-600 ℃ for 12-24h to obtain the molecular sieve membrane; preferably, the coating thickness of the transalkylation catalyst is from 0.5 to 1 mm; preferably, the adhesive is at least one of aluminum oxide, silicon oxide and zinc oxide.

4. The molecular sieve membrane of claim 3, wherein the addition amount of the organic template in the step 2) is 1-2 wt% of the mass of the molecular sieve low-temperature synthesis mother liquor;

preferably, the organic template agent is at least one of tetrapropylammonium hydroxide, tetraethylammonium hydroxide and triethylamine.

5. The molecular sieve membrane of claim 4, wherein the molecular sieve in step 2) is at least one of MCM-22, ZSM-5 and Silct-1.

6. A membrane reactor characterized in that the inside of the membrane reactor is provided with a molecular sieve membrane according to any of claims 1-5 that matches the shape of its inner wall.

7. A preparation method of p-tert-butylphenol, characterized in that in the membrane reactor of claim 6, phenol and isobutylene are used as raw materials, and the reaction is carried out under the action of hydrogen type molecular sieve catalyst to prepare p-tert-butylphenol;

preferably, the catalyst is at least one of HZSM-5 molecular sieve, HMCM-22 molecular sieve and HY zeolite molecular sieve in a powder state;

preferably, the catalyst loading is 20-50%, more preferably 30-40% of the reactor volume;

preferably, the phenol to isobutylene feed ratio is from 6 to 14:1 molar ratio, more preferably from 8 to 12:1 feed ratio;

preferably, the reaction temperature is 80-120 ℃, more preferably 100-.

8. The preparation method of claim 7, wherein the pressure difference between the inside and the outside of the molecular sieve membrane in the membrane reactor is controlled to be 30-45 KpaG;

preferably, the pressure in the molecular sieve membrane in the membrane reactor is 40-50kPaG, and the pressure outside the membrane is 5-10 kPaG.

9. The preparation method according to claim 7 or 8, wherein after the reaction is finished, the reaction liquid is sent to a rectifying device for separation, unreacted phenol recovered from the tower top is sent to a reactor for reuse, and p-tert-butylphenol is obtained from the tower bottom;

preferably, the rectifying device is a packed tower or a plate tower, and the number of the plate is 10-20; more preferably, the number of said rectifying means is only 1.

10. The preparation method of claim 9, wherein after the membrane reactor is filled with the catalyst, preheated phenol is introduced to establish a liquid level, a stirrer is started to stir uniformly, the system is heated to an initial reaction temperature, preferably 60-100 ℃, phenol and isobutene are continuously introduced into the reactor according to a molar feed ratio of 6-14:1, preferably 8-12:1, the reaction is started, meanwhile, the product is continuously fed into a rectifying device to carry out continuous rectification separation, unreacted phenol recovered from the top of the tower is fed into the reactor to be recycled, and p-tert-butylphenol is obtained from the bottom of the tower.

Technical Field

The invention relates to a molecular sieve membrane, in particular to a molecular sieve membrane, a membrane reactor and application in preparation of p-tert-butylphenol.

Background

P-tert-butylphenol (PTBP) has antioxidant properties, can be used as a polymerization inhibitor and a stabilizer, and is an important intermediate for the production of fine chemicals, particularly for the synthesis of pesticides, medicines, liquid crystals and perfumes. The p-tert-butylphenol is prepared by mainly using phenol and isobutene as raw materials, but the traditional preparation process has low product selectivity and raw material conversion rate, a large amount of byproducts, namely, o-tert-butylphenol (OTBP), 2, 4-di-tert-butylphenol (2,4-DTBP) and excessive phenol are not easy to remove, and subsequent separation is required to be continuously carried out by a plurality of rectifying devices, so that the separation process is complex and the device investment cost is high.

Patent CN110721732A discloses a method for producing p-tert-butylphenol, which adopts a continuous reaction process of a molecular sieve catalyst and a fixed bed reactor, and although the process improves the stability of the catalyst, the product selectivity can only reach 85% at most, the number of byproducts is still more, the separation of the product is difficult, and the separation cost is very high; in addition, the method has high reaction temperature and certain industrial application risks.

Patent CN108558611A discloses an industrial continuous method for preparing p-tert-butylphenol, which adopts a multi-kettle series operation process, wherein phenol is directly added from a first kettle, isobutylene is continuously added through each kettle, and a reaction device is directly connected with a rectifying device to separate raw materials and products. The conversion rate of phenol and the selectivity of p-tert-butylphenol are both about 90 percent, and still have great promotion space. In addition, although a specific rectification mode is not mentioned in the patent, the traditional rectification separation of PTBP according to boiling point gradient at least needs 3-4 rectification towers due to more by-product components, and the defects of long product separation flow, high cost and the like exist.

Disclosure of Invention

Aiming at the problem that a large amount of byproducts, namely, ortho-tert-butylphenol (OTBP) and 2, 4-di-tert-butylphenol (2,4-DTBP), are generated by the conventional preparation method of p-tert-butylphenol (PTBP) and the separation of the products is difficult, the invention provides a molecular sieve membrane, a membrane reactor and application thereof in the preparation of the p-tert-butylphenol, which are beneficial to improving the conversion rate and the selectivity of raw materials of the products and greatly reducing the investment of devices and the operation cost.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a molecular sieve membrane, wherein a layer of transalkylation catalyst is attached to the inner side of the membrane; preferably, the transalkylation catalyst is at least one of Beta molecular sieve, TS-1, SAPO-5.

In the invention, the molecular sieve membrane is mainly applied to the preparation process of PTBP, on one hand, the selectivity of the product is improved through membrane separation, on the other hand, a small amount of by-products OTBP and 2,4-DTBP adsorbed on the pore diameter and the surface of the membrane are subjected to transalkylation reaction to further generate the PTBP product, and then the PTBP product is subjected to membrane separation, so that the molecular sieve membrane has the advantage of high selectivity of the product. The transalkylation reaction expression of OTBP and 2,4-DTBP is as follows:

furthermore, in order to realize the purpose of separating the PTBP product from the OTBP and the 2,4-DTBP byproducts, the pore diameter of the membrane is 0.55-0.75 nm.

The molecular sieve membrane with the transalkylation catalyst attached thereto of the present invention can be prepared by various methods such as an in-situ hydrothermal synthesis method, a seed crystal method, a pore blocking method, a microwave heating method, etc., and in the following preferred embodiment, the present invention is prepared by an in-situ hydrothermal synthesis method in the presence of an organic template having a membrane-forming pore diameter of 0.55 to 0.75 nm.

In a preferred embodiment of the present invention, the method for preparing the molecular sieve membrane comprises the following steps:

1) coating a layer of Al on the inner side of the steel wire mesh₂O₃As the adhesive, baking at 500-600 ℃ for 3-5h to prepare the alpha-Al with the thickness of 0.5-1.5mm₂O₃An inert support;

2) immersing an inert support body into a low-temperature synthesis mother solution of a molecular sieve, and adding an organic template agent to control the aperture of a film to be 0.55-0.75 nm; the addition amount of the organic template agent is 1-2 wt% of the mass of the molecular sieve low-temperature synthesis mother liquor; preferably, the organic template is at least one of tetrapropylammonium hydroxide (TPAOH), tetraethylammonium hydroxide (TEAOH) and triethylamine; preferably, the molecular sieve is at least one of MCM-22, ZSM-5 and Silcte-1;

3) stirring for 10-30 min, crystallizing, washing, drying, roasting, and removing the organic template; preferably, the roasting temperature is 550-600 ℃, and the time is 2-6 h;

4) uniformly attaching a transalkylation catalyst to the inner surface of the molecular sieve membrane through an adhesive, and roasting at 500-600 ℃ for 12-24h to obtain the molecular sieve membrane; preferably, the coating thickness of the transalkylation catalyst is from 0.5 to 1 mm; preferably, the adhesive is at least one of aluminum oxide, silicon oxide and zinc oxide.

In a preferred embodiment of the invention, the low-temperature synthesis mother liquor of the MCM-22 molecular sieve in the step 2) is obtained by mixing and stirring 30-180 parts by mass of a sodium source, 1200-2000 parts by mass of a silicon source, 12-48 parts by mass of an aluminum source, 120-360 parts by mass of a template agent and 3000-6000 parts by mass of water to obtain a gel, and then crystallizing the gel at the temperature of 80-150 ℃ for 4-10 hours;

the sodium source is at least one of sodium hydroxide, sodium bicarbonate and sodium peroxide;

the silicon source is at least one of silica sol, silicic acid and sodium silicate; wherein, the mass concentration of the silicon dioxide in the silica sol is 20-50%;

the aluminum source is at least one of aluminum oxide, aluminum hydroxide and sodium metaaluminate;

the template agent is at least one of cycloheximide (HMI), piperidine and Cetyl Trimethyl Ammonium Bromide (CTAB).

In a preferred embodiment of the invention, the low-temperature synthesis mother liquor of the ZSM-5 molecular sieve is obtained by mixing and stirring 1000 parts by mass of a sodium source 200-;

the sodium source is at least one of sodium hydroxide, sodium bicarbonate and sodium peroxide;

the template agent is at least one of tetrapropylammonium hydroxide and tetraethylammonium hydroxide;

the silicon source is at least one of silica sol, silicic acid and sodium silicate; wherein the mass concentration of the silicon dioxide in the silica sol is 34-50%;

the aluminum source is at least one of aluminum oxide, aluminum hydroxide and sodium metaaluminate.

In a preferred embodiment of the invention, the low-temperature synthesis mother liquor of the Silcite-1 molecular sieve is obtained by mixing and stirring 1000 parts by mass of a sodium source, 16000-22000 parts by mass of a silicon source, 3000-5000 parts by mass of a template agent and 400-4000 parts by mass of water to obtain a gel, and then crystallizing the gel at 80-150 ℃ for 4-10 hours;

the sodium source is at least one of sodium hydroxide, sodium bicarbonate and sodium peroxide;

the template agent is at least one of tetrapropylammonium hydroxide and tetraethylammonium hydroxide;

the silicon source is at least one of silica sol, silicic acid and sodium silicate; wherein the mass concentration of the silicon dioxide in the silica sol is 34-50%;

the membrane reactor is internally provided with the molecular sieve membrane matched with the shape of the inner wall of the membrane reactor. As a preferred technical scheme, the molecular sieve membrane and the wall of the reactor cylinder are fixed through a bracket and a bolt. The reactor is preferably a batch tank reactor.

In the invention, the membrane reactor is applied to the preparation of p-tert butyl phenol. As the reaction for preparing the p-tert-butylphenol from the phenol is an exothermic reaction, as a preferred technical scheme, an inner coil cooling pipe is arranged in the membrane reactor and is used for controlling the reaction temperature. Furthermore, in the preparation process of the p-tert-butylphenol, different pressure control systems are arranged in the membrane inner part and the membrane outer reactor, and the pressure control systems are controlled by two independent cascade control loops, so that a certain pressure difference is formed between the membrane inner part and the membrane outer part, and the product separation is facilitated.

In the membrane reactor, phenol and isobutene are used as raw materials and react under the action of a hydrogen type molecular sieve catalyst to prepare the p-tert-butylphenol; the method utilizes a membrane separation method to separate the product and the by-product in a reactor through an oriented molecular sieve membrane, and meanwhile, the by-product OTBP and 2,4-DTBP can continuously react to generate the product PTBP under the action of a transalkylation catalyst loaded on the inner side of the membrane, so that the selectivity of the reaction can be obviously improved.

Preferably, the catalyst is at least one of HZSM-5 molecular sieve, HMCM-22 molecular sieve and HY zeolite molecular sieve in a preferred powder state;

preferably, the catalyst loading is 20-50%, more preferably 30-40% of the reactor volume;

preferably, the phenol to isobutylene feed ratio is from 6 to 14:1 molar ratio, more preferably from 8 to 12:1 feed ratio;

preferably, the reaction temperature is 80-120 ℃, more preferably 100-.

Further, controlling the pressure difference between the inside and the outside of the molecular sieve membrane in the membrane reactor to be 30-45 KpaG; by setting the pressure difference between the inside and the outside of the membrane, the PTBP product can be separated out in time, and the reaction conversion rate is improved.

Preferably, the pressure in the molecular sieve membrane in the membrane reactor is 40-50kPaG, and the pressure outside the membrane is 5-10 kPaG.

Further, after the reaction is finished, feeding the reaction liquid into a rectifying device for separation, recovering unreacted phenol at the top of the tower, feeding the unreacted phenol into a reactor for recycling, and obtaining p-tert-butylphenol at the bottom of the tower;

preferably, the rectifying device is a packed tower or a plate tower, the plate number is 10-20, the operation pressure is preferably 2-5kPaA, the temperature of a tower bottom is preferably 135 ℃, and the temperature of a tower top is preferably 79.89 ℃; more preferably, the number of said rectifying means is only 1. The method can obtain the product PTBP with high selectivity, avoids the step-by-step purification of the product by adopting a plurality of rectifying devices and accessory equipment thereof, and can separate the product PTBP and the raw material phenol by only 1 rectifying device.

Further, after filling a catalyst in the membrane reactor, introducing preheated phenol to establish a liquid level, starting a stirrer to stir uniformly, heating the system to an initial reaction temperature, preferably 60-100 ℃, continuously introducing phenol and isobutene into the reactor according to a molar feed ratio of 6-14:1, preferably 8-12:1, starting a reaction, simultaneously continuously feeding a product into a rectifying device to perform continuous rectification separation, recovering unreacted phenol from the top of the tower, feeding the unreacted phenol into the reactor for recycling, and obtaining p-tert-butylphenol from the bottom of the tower.

In the method, the purpose of phenol excess is to completely convert isobutene, and the isobutene conversion rate can reach more than 99.9%; the excess phenol can be recycled, but the amount of phenol cannot be too great, too much phenol increases the subsequent recycling cost, and therefore a feed ratio of 8-12:1 is more preferred.

Compared with the existing method, the preparation method of p-tert-butylphenol has the characteristics of simple process, high product selectivity, high isobutene conversion rate, small quantity of rectifying equipment, low investment cost, simple operation, high safety and the like.

Detailed Description

The present invention is further illustrated by the following specific examples, which are intended to be illustrative of the invention and are not to be construed as limiting the scope of the invention.

The main raw material sources are as follows:

CTAB (cetyl trimethyl ammonium bromide), Shanghai weft lifting chemical industry

TPAOH (tetrapropylammonium hydroxide), Anhui Siapo chemical technology Co., Ltd

TEAOH (tetraethylammonium hydroxide), Shanghai Allantin Biotechnology Ltd

Beta molecular sieve, Fuhao chemical industry

TS-1 molecular sieve, deep Hao chemical industry

HMCM-22 molecular sieve, deep Hao chemical industry

HZSM-5 molecular sieve, Fuhao chemical industry

Phenol, Nantong Runfeng petrochemical Co., Ltd

Isobutylene Shanghai Ji to Biochemical technology Limited products

Al₂O₃The adhesive is prepared from the following components in percentage by mass of 1: 5 of Al₂O₃And water.

Other starting materials and reagents are commercially available unless otherwise specified.

The kettle type reactor in the embodiment of the invention is provided by the chemical machinery Limited company of Wanhua wood village on a cigarette platform, and the product model is Parr 4523; the p-tert-butylphenol reaction liquid prepared in the embodiments 1 to 8 of the invention is refined and separated from the product by a rectifying tower, and the rectifying tower is provided with the same number of plates and operation parameters, and specifically comprises the following steps: 10 trays, an operating pressure of 2kPaA, a column bottom temperature of 135 ℃ and a column top temperature of 79.89 ℃.

[ PREPARATION EXAMPLE 1 ]

(1) Preparing a low-temperature synthesis mother solution of the MCM-22 molecular sieve:

adding 5400g of water and 72g of NaOH into the container in sequence, and stirring for 30 min; then, 33.7g of alumina was added, 1830g of silica sol (silica concentration: 30% by weight) was stirred for 2 hours, and finally 350g of CTAB was added and stirred for 3 hours to obtain a gel. And transferring the gel into a reaction kettle, and crystallizing for 8 hours at the low temperature of 100 ℃ to prepare the low-temperature synthesis mother liquor of the MCM-22 molecular sieve. In the synthesis mother solution, the molar ratio of each component is as follows: SiO 2₂:Al₂O₃:Na⁺:CTAB＝9.14：0.33：1.8：0.96。

(2) Preparation of the molecular sieve membrane:

preparing a cylindrical steel wire mesh (aperture 1 μm) with diameter of 20cm and height of 30cm, and coating a layer of Al on the inner side of the steel wire mesh₂O₃Adhesive with a thickness of about 1mm, and roasting at 600 deg.C for 4 hr in a high-temperature roasting furnace to obtain alpha-Al₂O₃An inert support; alpha-Al is added₂O₃Immersing the inert support body into 2kg of MCM-22 molecular sieve low-temperature synthesis mother liquor, and adding 0.03kg of TEAOH as an organic template agent; stirring for 20min under electric power, and crystallizing at 200 deg.C for 12 hr; taking out, washing with water for 15min, and ultrasonic washing for 10 min; drying the steel wire mesh wrapping the molecular sieve at 100 ℃ for 8h, then roasting at 600 ℃ for 3h, removing the organic template agent, and opening a pore channel of the molecular sieve membrane to prepare the composite structure oriented molecular sieve membrane;

coating a layer of Al with the thickness of about 0.5mm on the inner surface of the molecular sieve membrane₂O₃Coating a layer of Beta molecular sieve catalyst with the thickness of about 0.5mm on the adhesive, and roasting the mixture for 24 hours at 550 ℃ to obtain the molecular sieve membrane with the Beta molecular sieve catalyst attached to the inner surface.

(3) And (3) fixing the prepared molecular sieve membrane on the wall of the kettle type reactor through a bracket and a bolt to obtain the membrane reactor. Separate pressure control systems are respectively arranged in the inner part and the outer part of the membrane reactor; the membrane reactor was designated MR-1.

[ PREPARATION EXAMPLE 2 ]

(1) Preparing a low-temperature synthesis mother solution of a ZSM-5 molecular sieve:

weighing 400g of NaOH, adding the NaOH into 1600g of deionized water, stirring until the NaOH is completely dissolved, adding 15290g of 25% TPAOH solution, and stirring for 20 min; then, 14120g of 34% silica sol solution is slowly dropped into the solution and stirred for 4 hours; adding 695g of alumina, and stirring for 4h to obtain gel; transferring the gel to a stainless steel hydrothermal kettle, carrying out a first stage of crystallization reaction in an oven at 100 ℃, and carrying out rapid cooling on crystallized mother liquor at 20 ℃ for 8 hours to obtain a first stage of crystallized liquor; under the condition of water bath at 20 ℃, 3530g of 34% silica sol and 1300g of water are added into the first-stage crystallization liquid, the mixture is stirred for 20min, the mixture is put into a stainless steel crystallization kettle again, second-stage crystallization reaction is carried out at 180 ℃, and after 20h, second-stage crystallization liquid, namely the low-temperature synthesis mother liquid of the ZSM-5 molecular sieve, is obtained. The molar ratio of each component in the embodiment is as follows: SiO 2₂：Al₂O₃：Na⁺:TPAOH＝99.85：6.82：10：25.95。

(2) Preparation of the molecular sieve membrane:

a molecular sieve membrane was prepared according to the method of example 1, with the only difference that: 1) alpha-Al is added₂O₃After the inert support body is immersed into 2kg of low-temperature synthesis mother liquor of a ZSM-5 molecular sieve, 0.04kg of TPAOH is added to be used as an organic template agent; 2) after the composite structure orientation molecular sieve membrane is prepared, a layer of Al is coated on the inner surface of the membrane₂O₃And (3) coating a layer of TS-1 molecular sieve on the adhesive, and roasting to obtain the molecular sieve membrane with the TS-1 molecular sieve catalyst attached to the inner surface.

(3) And (3) fixing the prepared molecular sieve membrane on the wall of the kettle type reactor through a bracket and a bolt to obtain the membrane reactor. Separate pressure control systems are respectively arranged in the inner part and the outer part of the membrane reactor; the membrane reactor was designated MR-2.

[ example 1 ] production of p-tert-butylphenol by means of a Membrane reactor MR-1

Phenol and isobutene are used as raw materials and are continuously reacted through a membrane reactor MR-1 under the action of an HMCM-22 molecular sieve catalyst. Wherein the loading amount of the catalyst accounts for 20% of the volume of the reactor in the membrane, the molar feeding ratio of the phenol to the isobutene is 6:1, the reaction temperature is 100 ℃, the reaction pressure in the membrane is set to be 40KPaG, the pressure outside the membrane is set to be 5KPaG, the reaction liquid is sent to a rectifying tower after the reaction, the unreacted phenol is recovered from the top of the tower, and the p-tert-butylphenol (the product purity is 99.68%) is obtained from the bottom of the tower. In this example, the conversion of isobutylene was 99.9% and the selectivity to p-tert-butylphenol was 99.74%.

[ example 2 ] production of p-tert-butylphenol by means of a Membrane reactor MR-1

Phenol and isobutene are used as raw materials and are continuously reacted through a membrane reactor MR-1 under the action of an HMCM-22 molecular sieve catalyst. Wherein the loading amount of the catalyst accounts for 40% of the volume of the reactor in the membrane, the molar feeding ratio of the phenol to the isobutene is 8:1, the reaction temperature is 80 ℃, the reaction pressure in the membrane is set to be 50KPaG, the pressure outside the membrane is set to be 10KPaG, the reaction liquid is sent to a rectifying tower after the reaction, the unreacted phenol is recovered from the top of the tower, and the p-tert-butylphenol (the product purity is 99.53%) is obtained from the bottom of the tower. In this example, the conversion of isobutylene was 99.91% and the selectivity to p-tert-butylphenol was 99.31%.

[ example 3 ] production of p-tert-butylphenol by Membrane reactor MR-1

Phenol and isobutene are used as raw materials and are continuously reacted through a membrane reactor MR-1 under the action of an HMCM-22 molecular sieve catalyst. Wherein the loading amount of the catalyst accounts for 50% of the volume of the reactor in the membrane, the molar feeding ratio of the phenol to the isobutene is 10:1, the reaction temperature is 120 ℃, the reaction pressure in the membrane is set to be 50KPaG, the pressure outside the membrane is set to be 5KPaG, the reaction liquid is sent to a rectifying tower after the reaction, the unreacted phenol is recovered from the top of the tower, and the p-tert-butylphenol (the product purity is 99.77%) is obtained from the bottom of the tower. In this example, the conversion of isobutylene was 99.92% and the selectivity to p-tert-butylphenol was 99.92%.

[ example 4 ] production of p-tert-butylphenol by means of a Membrane reactor MR-1

Phenol and isobutene are used as raw materials and are continuously reacted through a membrane reactor MR-1 under the action of an HMCM-22 molecular sieve catalyst. Wherein the loading amount of the catalyst accounts for 30 percent of the volume of the reactor in the membrane, the molar feeding ratio of the phenol to the isobutene is 12:1, the reaction temperature is 110 ℃, the reaction pressure in the membrane is set to be 40KPaG, the pressure outside the membrane is set to be 10KPaG, the reaction liquid is sent to a rectifying tower after the reaction, the unreacted phenol is recovered at the top of the tower, and the p-tert-butylphenol (the product purity is 99.70 percent) is obtained at the bottom of the tower. In this example, the conversion of isobutylene was 99.93%, and the selectivity to p-tert-butylphenol was 99.85%.

[ example 5 ] production of p-tert-butylphenol by Membrane reactor MR-2

Phenol and isobutene are used as raw materials and are continuously reacted through a membrane reactor MR-2 under the action of an HZSM-5 molecular sieve catalyst. Wherein the loading amount of the catalyst accounts for 30 percent of the volume of the reactor in the membrane, the molar feeding ratio of the phenol to the isobutene is 6:1, the reaction temperature is 100 ℃, the reaction pressure in the membrane is set to be 40KPaG, the pressure outside the membrane is set to be 5KPaG, the reaction liquid is sent to a rectifying tower after the reaction, the unreacted phenol is recovered at the top of the tower, and the p-tert-butylphenol (the product purity is 99.83 percent) is obtained at the bottom of the tower. In this example, the conversion of isobutylene was 99.92% and the selectivity to p-tert-butylphenol was 99.91%.

[ example 6 ] production of p-tert-butylphenol by Membrane reactor MR-2

Phenol and isobutene are used as raw materials and are continuously reacted through a membrane reactor MR-2 under the action of an HZSM-5 molecular sieve catalyst. Wherein the loading amount of the catalyst accounts for 20% of the volume of the reactor in the membrane, the molar feeding ratio of the phenol to the isobutene is 8:1, the reaction temperature is 90 ℃, the reaction pressure in the membrane is set to be 50KPaG, the pressure outside the membrane is set to be 5KPaG, the reaction liquid is sent to a rectifying tower after the reaction, the unreacted phenol is recovered from the top of the tower, and the p-tert-butylphenol (the product purity is 99.71%) is obtained from the bottom of the tower. In this example, the conversion of isobutylene was 99.93%, and the selectivity to p-tert-butylphenol was 99.63%.

[ example 7 ] production of p-tert-butylphenol by Membrane reactor MR-2

Phenol and isobutene are used as raw materials and are continuously reacted through a membrane reactor MR-2 under the action of an HZSM-5 molecular sieve catalyst. Wherein the loading amount of the catalyst accounts for 40% of the volume of the reactor in the membrane, the molar feeding ratio of the phenol to the isobutene is 9:1, the reaction temperature is 100 ℃, the reaction pressure in the membrane is set to be 40KPaG, the pressure outside the membrane is set to be 10KPaG, the reaction liquid is sent to a rectifying tower after the reaction, the unreacted phenol is recovered from the top of the tower, and the p-tert-butylphenol (the product purity is 99.79%) is obtained from the bottom of the tower. In this example, the conversion of isobutylene was 99.92% and the selectivity to p-tert-butylphenol was 99.73%.

[ example 8 ] production of p-tert-butylphenol by Membrane reactor MR-2

Phenol and isobutene are used as raw materials and are continuously reacted through a membrane reactor MR-2 under the action of an HZSM-5 molecular sieve catalyst. Wherein the loading amount of the catalyst accounts for 50% of the volume of the reactor in the membrane, the molar feeding ratio of the phenol to the isobutene is 14:1, the reaction temperature is 110 ℃, the reaction pressure in the membrane is set to be 50KPaG, the pressure outside the membrane is set to be 10KPaG, the reaction liquid is sent to a rectifying tower after the reaction, the unreacted phenol is recovered at the top of the tower, and the p-tert-butylphenol (the product purity is 99.75%) is obtained at the bottom of the tower. In this example, the conversion of isobutylene was 99.93%, and the selectivity to p-tert-butylphenol was 99.89%.

[ COMPARATIVE EXAMPLES ]

Under the action of HZSM-5 molecular sieve catalyst, phenol and isobutene are fed into a kettle type reactor without a molecular sieve membrane for continuous reaction. Wherein the loading amount of the catalyst accounts for 30% of the volume of the reactor in the membrane, the molar feeding ratio of the phenol to the isobutene is 8:1, the reaction temperature is 100 ℃, the pressure in the reactor is set to be 40KPaG, the reaction liquid is sequentially sent to 3 rectifying towers for separation after the reaction, wherein the pressure of the first rectifying tower is controlled to be 2KpaA, the temperature of the bottom of the tower is 135 ℃, the temperature of the top of the tower is 79.89 ℃, the first rectifying tower is used for separating the phenol which is not completely reacted, and the purity of the PTBP is determined for the first time to be 90.75% after the phenol is removed; the pressure of the second rectifying tower is controlled to be 2KPaA, the temperature of the tower kettle is 140 ℃, the temperature of the tower top is 120 ℃, the second rectifying tower is used for separating a byproduct OTBP, and the second determination of the PTBP purity after removing the OTBP is 98.5%; the pressure of the third rectifying tower is controlled at 2KPaA, the temperature of the tower kettle is 140.7 ℃, the temperature of the tower top is 126 ℃, the third rectifying tower is used for separating heavy components, and finally the PTBP with the product purity of 99.65 percent is obtained. In this comparative example, the isobutylene conversion was 99.92% and the p-tert-butylphenol selectivity was 85.79%.

According to the test results of the above examples and comparative examples, the product purity of PTBP prepared by the traditional molecular sieve catalytic method can reach more than 99% only after at least 3 times of rectification and purification, and the method has the defects of long process flow and high equipment cost; according to the invention, the kettle type reactor is improved, the molecular sieve membrane is additionally arranged, and the layer of transalkylation catalyst is attached to the inner side of the membrane, so that the selectivity of PTBP is obviously improved by more than 10% compared with a comparative example, and therefore, a pure product PTBP can be separated by only one rectifying tower, and the product purity is up to more than 99.5%.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and additions can be made without departing from the method of the present invention, and these modifications and additions should also be regarded as the protection scope of the present invention.