Catalyst for preparing ethylbenzene from ethanol and benzene, preparation therefor and use thereof

Patent metadata

Field	Value
Publication number	US-11434183-B2
Application number	US-201817262677-A
Country	US
Kind code	B2
Filing date	Jul 27, 2018
Priority date	Jul 23, 2018
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

Disclosed is a catalyst for producing ethylbenzene in one-step by vapor phase alkylation reaction of ethanol and benzene. The catalyst has the following features for the reaction: high alkylation reaction activity, high selectivity of ethylbenzene in an alkylation product, high hydrothermal stability and stable catalytic performance. The catalyst comprises a mesoporous-microporous composite TNU-9 molecular sieve and the silicon to aluminum molar ratio, SiO2/Al2O3, of the meso-microporous composite TNU-9 molecular sieve ranges from 50 to 200.

First claim

The invention claimed is:

1. A method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene comprising the following steps:
feeding raw materials comprising benzene and ethanol to a fixed bed reactor loaded with a molecular sieve catalyst to react to obtain ethylbenzene;
wherein the molecular sieve catalyst is mesoporous-microporous composite TNU-9 molecular sieve, wherein a silica to alumina molar ratio, SiO 2 /Al 2 O 3 , of the mesoporous-microporous composite TNU-9 molecular sieve ranges from 50 to 200; wherein the mesoporous-microporous composite TNU-9 molecular sieve comprises a mesopore channel, a diameter of which ranges from 3 to 50 nm; a reaction temperature ranges from 300 to 500° C., a reaction pressure ranges from 0.1 to 2 MPa, a molar ratio of benzene to ethanol in the raw materials ranges from 3:1 to 7:1, and a weight hourly space velocity of the raw materials ranges from 3 to 8 h −1 .

2. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 1 , wherein the silica to alumina molar ratio, SiO 2 /Al 2 O 3 , of the mesoporous-microporous composite TNU-9 molecular sieve ranges from 50 to 100.

3. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 1 , wherein the silica to alumina molar ratio, SiO 2 /Al 2 O 3 , of the mesoporous-microporous composite TNU-9 molecular sieve ranges from 60 to 100.

4. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 1 , wherein the silica to alumina molar ratio, SiO 2 /Al 2 O 3 , of the mesoporous-microporous composite TNU-9 molecular sieve ranges from 60 to 80.

5. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 1 , wherein the mesoporous-microporous composite TNU-9 molecular sieve is in a form of crystal grain accumulation, and a diameter of a single crystal grain ranges from 100 to 1000 nm.

6. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 1 , wherein a preparation method for the molecular sieve catalyst comprises the following steps:
(1) adding an aluminum source, an alkali source, and a silicon source comprising mesopore structure to an aqueous solution containing a template and then stirring to obtain a gel-like precursor;
(2) crystallizing hydrothermally the gel-like precursor obtained in step (1);
(3) washing a product obtained in step (2) to be neutral and drying the product; and
(4) calcining the product obtained in step (3) to obtain the molecular sieve catalyst.

7. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 6 , wherein a molar ratio of the aluminum source, alkali source, silicon source comprising mesopore structure, and template in step (1) satisfies: SiO 2 :Al 2 O 3 :M 2 O:R:H 2 O=(5˜100):1:(1˜30):(5˜20):(1000˜4000);
wherein, R represents the template and is calculated by a molar number of the template itself, a molar number of the aluminum source is calculated by a molar number of Al 2 O 3 , a molar number of the alkali source is calculated by a molar number of its corresponding alkali metal oxide M 2 O, a molar number of the silicon source is calculated by a molar number of SiO 2 , and a molar number of water is calculated by a molar number of H 2 O itself;
the template in step (1) comprises at least one of 1,4-MPB, glucose and activated carbon.

8. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 7 , wherein a method for preparing 1,4-MPB comprises: subjecting a solution comprising 1,4-dibromobutane and N-methyltetrahydropyrrole to refluxing, recrystallizing and drying to obtain 1,4-MPB.

9. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 8 , wherein the solution comprising 1,4-dibromobutane and N-methyltetrahydropyrrole is obtained by placing 1,4-dibromobutane and N-methyltetrahydropyrrole in acetone;
the refluxing is performed at a temperature ranging from 30 to 80° C. in water bath, and a time for the refluxing in water bath ranges from 6 to 48 h;
a step of extraction by acetone occurs before the recrystallization;
a solvent for recrystallization includes a mixed solvent of methanol and diethyl ether, wherein a volume ratio of methanol and diethyl ether is (0.05˜50):(1˜20);
the drying is performed at a temperature ranging from 60 to 120° C. for a time ranging from 5 to 20 h.

10. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 6 , wherein the silicon source comprising mesopore structure in step (1) is at least one of silica comprising mesopore structure, MCM-48, and SBA-15.

11. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 6 , wherein the aluminum source in step (1) is at least one of sodium metaaluminate, aluminum powder, aluminum nitrate and aluminum hydroxide;
the alkali source is at least one of sodium hydroxide and potassium hydroxide.

12. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 6 , wherein a time for stirring in step (1) ranges from 5 to 24 h.

13. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 6 , wherein a hydrothermal crystallization in step (2) is hydrothermal dynamic crystallization, and the hydrothermal dynamic crystallization is performed at a temperature ranging from 120 to 260° C. for a time ranging from 100 to 360 h.

14. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 13 , wherein the dynamic crystallization in step (2) is rotational crystallization, and the rotation speed ranges from 5 to 30 rpm.

15. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 6 , wherein step (3) comprises filtering and washing a product obtained in step (2) until a washing liquid is neutral, and then drying the product at a temperature ranging from 60 to 110° C.

16. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 6 , wherein a temperature for calcining in step (4) ranges from 200 to 600° C., and the time for calcining ranges from 1 to 20 h.

17. The method for producing ethylbenzene by vapor-phase alkylation of ethanol and benzene according to claim 6 , wherein the preparation method for the molecular sieve catalyst comprises the following steps:
1) synthesis of 1,4-MPB template R
dissolving 1,4-dibromobutane and N-methyltetrahydropyrrole in acetone, heating them to a temperature ranging from 30 to 80° C., refluxing for a time ranging from 6 to 48 h; extracting a reaction solution obtained by acetone, and recrystallizing the obtained product by a mixed solvent of methanol and diethyl ether, drying the recrystallized product in a vacuum drying oven at a temperature ranging from 60 to 120° C. for a time ranging from 5 to 20 h to obtain the template R;
2) preparation of TNU-9 molecular sieve
dissolving the template R obtained in step 1) in water, and then adding sequentially an aluminum source, an alkali source and a silicon source comprising mesopore structure to obtain a solution I, wherein a molar ratio of raw materials in the solution I was SiO2:Al 2 O 3 :M 2 O:R: H2O=(5˜100):1:(1˜30):(5˜20):(1000˜4000); after stirring for a time ranging from 5 to

Assignees

• Dalian Inst Chem & Physics Cas

Inventors

• Su Xiong
• Yang Xiaoli
• Huang Yanqiang
• Zhang Tao

Classifications

• B01J35/45

  Nanoparticles · CPC title

• B01J37/0018 Primary

  Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat) · CPC title

• B01J29/041 Primary

  Mesoporous materials having base exchange properties, e.g. Si/Al-MCM-41 · CPC title

• B01J29/70

  of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 · CPC title

• B01J37/04

  Mixing {(B01J37/0009, B01J37/0018 take precedence)} · CPC title