CN109746037B

CN109746037B - Side chain alkylation composite pore molecular sieve catalyst and application thereof

Info

Publication number: CN109746037B
Application number: CN201711058553.2A
Authority: CN
Inventors: 蒋见; 缪长喜; 卢媛娇; 孙清
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2017-11-01
Filing date: 2017-11-01
Publication date: 2022-04-05
Anticipated expiration: 2037-11-01
Also published as: CN109746037A

Abstract

The invention mainly relates to a composite molecular sieve catalyst for preparing ethylbenzene and styrene by toluene and methanol side chain alkylation, which mainly solves the problems that the catalyst used in the prior art is easy to inactivate and the utilization rate of methanol is low when the catalyst is used for toluene and methanol side chain alkylation reaction. In the invention, a mesoporous guiding agent is introduced in the process of a hydrothermal synthesis method to synthesize a microporous-mesoporous composite pore X molecular sieve as a catalyst material; the catalyst is used for exchanging alkali metal ions for the composite hole X molecular sieve before use and well solves the problem by adopting the technical scheme of loading rare earth and aluminum reagents, and can be used for the industrial production of preparing ethylbenzene and styrene by the side alkylation reaction of methylbenzene and methanol.

Description

Side chain alkylation composite pore molecular sieve catalyst and application thereof

Technical Field

The invention relates to a composite molecular sieve catalyst for preparing ethylbenzene and styrene, in particular to a composite molecular sieve catalyst for preparing ethylbenzene styrene by toluene and methanol side chain alkylation.

Background

Styrene monomer is an important organic chemical raw material, and is mainly used for producing products such as polystyrene, (ABS) resin, styrene-butadiene rubber, unsaturated resin and the like. In addition, the method can also be used for pharmacy, dyes or preparation of pesticide emulsifiers, mineral dressing agents and the like, and has wide application. The yield of the styrene series resin is second to PE and PVC in the synthetic resin and is named as the third. At present, most industrial styrene is obtained by carrying out Friedel-Craft reaction on benzene and ethylene to generate ethylbenzene and then carrying out catalytic dehydrogenation. The method has the advantages of longer process, more side reactions, high energy consumption, raw material cost accounting for 85% of the variable production cost, and higher production cost. The alkylation of toluene and methanol is a potential application prospect route for producing styrene, and Sidorenko and the like successfully synthesize ethylbenzene and styrene by using toluene and methanol as catalysts by using X-type and Y-type zeolites exchanged by alkali metal ions for the first time in 1967. Compared with the traditional process, the method has the advantages of wide raw material source, low cost, low energy consumption, less pollution and the like. Therefore, the response has been reported to be regarded as important, and research on the response is increasing.

The catalyst for preparing styrene by toluene and methanol side chain alkylation belongs to a solid base catalyst, but the catalytic process is a one-acid-base concerted catalytic reaction and takes base active site catalysis as the leading factor. The acidic site of the catalyst can play a role in stabilizing toluene benzene ring, and the basic site can activate methyl groups of toluene and methanol. Firstly, methanol is decomposed into formaldehyde on an alkali center, toluene is adsorbed on an acid center, a side chain methyl group of the toluene is activated by the alkali center, then the formaldehyde and the activated methyl group react to produce styrene, and part of the styrene reacts with generated hydrogen to produce ethylbenzene. If the catalyst is too strong in alkalinity, the formaldehyde can be further decomposed, and more hydrogen and ethylbenzene are generated; if the catalyst is too strong in acidity, alkylation of benzene rings and toluene disproportionation can occur to generate benzene and xylene, so that the catalyst is required to have proper acid-base matching, and meanwhile, the existence of the benzene rings requires that the catalyst has a certain spatial pore structure.

The toluene methanol side alkylation reaction has been extensively studied over a variety of catalysts. Many molecular sieves such as X, Y, L, beta, ZSM-5, and some basic oxides such as MgO, MgO-TiO₂And CaO-TiO₂Are reported to be studied in the reactions catalyzing the alkylation OF the side chains OF toluene with methanol, such as JOURNAL OF CATALYSIS 173, 490-500 (1998) and CN101623649A, CN 101623650A. As a result of the studies, it was found that in order to achieve a better catalytic effect of side chain alkylation, the catalyst must satisfy the following four requirements: the catalyst must have sufficient basic sites to activate the conversion of methanol to the methylating agent formaldehyde; a weak Lewis acid center is required to stabilize toluene and polarize its methyl group; toluene and methanol have a good stoichiometric adsorption balance on the catalyst; the catalyst must have a microporous pore structure. Thus, the results of some studies of the catalytic activity of zeolites indicate that alkali metal cation exchanged type X zeolites are relatively effective catalysts. The reactivity of the type Y zeolite is inferior to that of the type X zeolite. While other zeolites such as L, beta, ZSM-5 type do not have ideal reactivity, and some alkaline oxides without microporous structure such as MgO, MgO-TiO₂And CaO-TiO₂Etc. have only low activity. At present, most Fau-type molecular sieve catalysts for toluene methanol side chain alkylation reported in literature are conventional X-type and Y-type molecular sieve catalysts, and the molecular sieves only contain micropores and do not have mesoporous channels.

There is no report in the prior art of the advantageous use of composite pore type molecular sieve catalyst materials for the side-chain alkylation reaction.

Disclosure of Invention

One of the technical problems to be solved by the invention is that the catalyst used in the prior art has the problems of low raw material utilization rate and easy inactivation of the catalyst when being used in the side chain alkylation reaction, and the invention provides a novel side chain alkylation catalyst which has the characteristics of high methanol utilization rate and difficult inactivation of the catalyst. The invention also provides a novel preparation method of the side chain alkylation catalyst, and the method has the advantages of simple preparation process and the like when being used for preparing the side chain alkylation catalyst.

In order to solve one of the above technical problems, the technical solution adopted by the present invention is as follows: a composite molecular sieve catalyst with alkylated side chain features that it is a rare-earth modified composite molecular sieve.

In the above technical scheme, preferably, the composite molecular sieve contains two pore channel structures of a micropore and a mesopore.

In the technical scheme, the volume ratio of micropores to mesopores of the composite molecular sieve is preferably 0.5-15, and more preferably 3-8.

In the technical scheme, preferably, the size range of mesoporous pores of the composite molecular sieve is 2-20 nm; more preferably 5 to 15 nm.

In the above technical scheme, preferably, the composite molecular sieve is modified by alkali metal ions; more preferably, the alkali metal ion exchange modification is completed before the rare earth modification, and the loading amount of the rare earth element is 0.3-5%, preferably 0.5-3%.

In the above technical scheme, preferably, the composite molecular sieve is modified by aluminum; more preferably, the aluminum modification is performed by using sodium metaaluminate; preferably, the content of the sodium metaaluminate used for modification is 2-5% in percentage by weight of the catalyst.

In the above technical scheme, preferably, the composite molecular sieve is modified by bismuth; preferably, the content of bismuth element for modification is 0.1-1.5% by weight of the catalyst; more preferably, the content of bismuth element used for modification is 0.2-1.2%.

In order to solve the second technical problem, the invention adopts the following technical scheme: a preparation method of a side chain alkylation catalyst comprises the following preparation steps: sodium aluminate, sodium silicate, sodium hydroxide, potassium hydroxide, a mesoporous directing agent hexadecyltrimethylammonium chloride (or a mesoporous directing agent such as hexadecyltrimethylammonium bromide, poly-dimethyldiallylammonium chloride) and water are used as raw materials and mixed according to a certain proportion, the mixture is crystallized for a certain time at the temperature of 60-150 ℃, and then the crystallized mixture is roasted to synthesize the composite porous X or Y molecular sieve material containing micropores and mesopores.

In order to solve the second technical problem, the invention also adopts the following technical scheme: a side chain alkylation catalyst is prepared by the following steps: the method comprises the steps of mixing aluminum hydroxide, silica sol, sodium hydroxide, potassium hydroxide, a mesoporous guiding agent cetyl trimethyl ammonium chloride (or a mesoporous guiding agent such as cetyl trimethyl ammonium bromide and poly dimethyl diallyl ammonium chloride) and water serving as raw materials according to a certain proportion, crystallizing for a certain time at the temperature of 60-150 ℃, and then roasting to synthesize the composite pore X or Y molecular sieve material containing micropores and mesopores.

The size of the micropore of the synthesized composite molecular sieve is 0.6-0.8 nm, the size of the mesopore is 2-20 nm, the volume ratio of the micropore to the mesopore is 0.5-15, and the ratio of silicon to aluminum is SiO₂/Al₂O₃The range is 1-7. In the above technical scheme, preferably, the composite molecular sieve material has a silica-alumina ratio of SiO₂/Al₂O₃The range is 2-3, and the more preferable silicon-aluminum ratio of the composite molecular sieve material SiO₂/Al₂O₃An X molecular sieve material in the range of 2-2.5;

in the above technical scheme, preferably, the mesoporous size of the composite molecular sieve material is between 5nm and 15 nm;

in the above technical scheme, preferably, the volume ratio of micropores to mesopores of the composite molecular sieve material is 3-8.

As can be seen from the figure, the adsorption and desorption isotherm of the molecular sieve of the composite pore has a hysteresis loop, which indicates that the molecular sieve contains mesopores, and the pore size distribution is obvious.

The process of the invention can be carried out in a fixed-bed continuous flow reactor, the process of which is briefly described below: the required amount of catalyst was taken and placed in the constant temperature zone of the reactor, and the lower part of the catalyst was filled with quartz sand. Under the set temperature and pressure, toluene and methanol are mixed, the mixture is pumped to a preheater by a micro pump to be mixed and gasified with nitrogen, the mixture enters the upper end of a reactor and flows through a catalyst bed layer to carry out catalytic reaction, and reaction products are directly injected by a valve to enter a gas chromatography for analysis.

The activity and selectivity of the catalyst were calculated according to the following formulas:

this indicator is more important than selectivity for methanol utilization.

The method of the invention selects the synthesized composite pore X-type molecular sieve as the catalyst material, which is beneficial to the diffusion of reaction molecules in the pore canal of the molecular sieve catalyst and reduces the decomposition of methanol, thereby effectively improving the utilization rate of methanol. Meanwhile, rare earth elements and aluminum reagents are modified, so that the decomposition of methanol in the toluene-methanol side-alkylation reaction is reduced, and the problems of low methanol utilization rate and easy catalyst inactivation in the toluene-methanol side-alkylation reaction are effectively solved. Particularly when Al is adopted for modification, the catalytic activity of the alkylation catalyst is further improved; the stability of the catalyst is greatly improved after the rare earth modification. By adopting the method of the invention, the molar ratio of toluene to methanol is 6: 1, the reaction temperature is 425 ℃, the reaction pressure is 0MPa, and the weight space velocity of the raw material is 2.5 hours^-1Under the condition, the utilization rate of the methanol can reach 54 percent, the total selectivity of the ethylbenzene styrene can reach 96 percent, the stability of the catalyst can reach 200 hours, and a better technical effect is obtained.

Drawings

FIG. 1 is an adsorption-desorption isotherm and pore size distribution diagram of a conventional X molecular sieve catalyst described in comparative example 1.

Fig. 2 is an adsorption-desorption isotherm and pore size distribution diagram of the composite pore X molecular sieve catalyst described in example 1.

The invention is further illustrated by the following examples.

Detailed Description

[ example 1 ]

Sodium aluminate, sodium silicate, sodium hydroxide and potassium hydroxideThe mesoporous guiding agent hexadecyltrimethylammonium chloride and water are mixed according to a certain proportion, the mixture is crystallized for 16 hours at the temperature of 100 ℃, and the synthesized product is filtered, washed and then roasted to obtain the composite porous X molecular sieve material. SiO for synthesizing composite hole X molecular sieve₂/Al₂O₃The ratio is 2.0, and the mesoporous size is about 7 nm.

Taking 10 g of the molecular sieve, and carrying out ion exchange in 100 ml of 1 mol/L KNO3 solution for 2 hours at 80 ℃ for 2 times; then 50 ml of 1 mol/l RbNO₃Carrying out ion exchange in the solution for 2 times; finally, ion exchange is carried out in 50 ml of 1 mol/L CsNO3 solution for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the alkali metal ion in the catalyst exchanged the sodium ion in the molecular sieve with an ion exchange degree of 82.3%.

Taking 10 g of the obtained molecular sieve, taking cerium nitrate and sodium metaaluminate as precursors, and loading cerium and aluminum on the catalyst by adopting a step-by-step impregnation method, wherein the content of the loaded cerium is 2%, and the content of the sodium metaaluminate is 4%.

Tabletting the obtained catalyst to form a 40-60-mesh granular catalyst, and loading the granular catalyst into a reactor, wherein the molar ratio of toluene to methanol is 5: 1. at 2.5 hours^-1Liquid space velocity of (2), 425 ℃, N₂The activity evaluation was carried out at a flow rate of 10 ml/min, and the catalyst was not deactivated for 200 hours, and the activity results are shown in Table 1.

[ example 2 ]

The method comprises the steps of mixing sodium aluminate, sodium silicate, sodium hydroxide, potassium hydroxide, a mesoporous guiding agent cetyl trimethyl ammonium bromide and water serving as raw materials according to a certain proportion, crystallizing for 16 hours at the temperature of 100 ℃, filtering, washing and roasting a synthetic product to obtain the composite porous X molecular sieve material. SiO for synthesizing composite hole X molecular sieve₂/Al₂O₃The ratio is 2.0, and the mesoporous size is about 8 nm.

Taking 10 g of the molecular sieve, and carrying out ion exchange in 100 ml of 1 mol/L KNO3 solution for 2 hours at 80 ℃ for 2 times; then ion exchange is carried out in 50 ml of RbNO3 solution with 1 mol/L for 2 times; finally, ion exchange is carried out in 50 ml of 1 mol/L CsNO3 solution for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the alkali metal ion in the catalyst exchanged the sodium ion in the molecular sieve with an ion exchange degree of 86.7%.

[ example 3 ]

The method comprises the steps of mixing sodium aluminate, sodium silicate, sodium hydroxide, potassium hydroxide, a mesoporous directing agent poly dimethyl diallyl ammonium chloride and water serving as raw materials according to a certain proportion, crystallizing for 16 hours at the temperature of 100 ℃, filtering, washing and roasting a synthetic product to obtain the composite porous X molecular sieve material. SiO for synthesizing composite hole X molecular sieve₂/Al₂O₃The ratio is 2.0, and the mesoporous size is about 5 nm.

Taking 10 g of the molecular sieve, and carrying out ion exchange in 100 ml of 1 mol/L KNO3 solution for 2 hours at 80 ℃ for 2 times; then ion exchange is carried out in 50 ml of RbNO3 solution with 1 mol/L for 2 times; finally, ion exchange is carried out in 50 ml of 1 mol/L CsNO3 solution for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the alkali metal ion in the catalyst exchanged the sodium ion in the molecular sieve with an ion exchange degree of 83.7%.

Tabletting the obtained catalyst to form 40-60 mesh granular catalyst, loading the granular catalyst into a reactor, and carrying out normal temperature treatmentThe molar ratio of pressure to toluene to methanol is 5: 1. at 2.5 hours^-1Liquid space velocity of (2), 425 ℃, N₂The activity evaluation was carried out at a flow rate of 10 ml/min, and the catalyst was not deactivated for 200 hours, and the activity results are shown in Table 1.

[ example 4 ]

The method comprises the steps of mixing sodium aluminate, sodium silicate, sodium hydroxide, a mesoporous guiding agent hexadecyltrimethylammonium chloride and water serving as raw materials according to a certain proportion, crystallizing for 16 hours at the temperature of 100 ℃, filtering, washing and roasting a synthetic product to obtain the composite porous X molecular sieve material. SiO for synthesizing composite hole X molecular sieve₂/Al₂O₃The ratio is 2.3, and the mesoporous size is about 12 nm.

Taking 10 g of the molecular sieve, and heating the molecular sieve at 80 ℃ in 100 ml of 1 mol/L KNO₃Ion exchange is carried out in the solution for 2 hours and 2 times; then 50 ml of 1 mol/l RbNO₃Carrying out ion exchange in the solution for 2 times; finally 50 ml of 1 mol/l CsNO₃Carrying out ion exchange in the solution for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the alkali metal ion in the catalyst exchanged the sodium ion in the molecular sieve with an ion exchange degree of 83.1%.

Tabletting the obtained catalyst to form a 40-60-mesh granular catalyst, and loading the granular catalyst into a reactor, wherein the molar ratio of toluene to methanol is 5: 1. at 2.5 hours^-1Liquid space velocity of (2), 425 ℃, N₂The activity evaluation was performed at a flow rate of 10 ml/min, and the activity results are shown in Table 1.

[ example 5 ]

The method comprises the steps of mixing sodium aluminate, sodium silicate, sodium hydroxide, a mesoporous guiding agent cetyl trimethyl ammonium bromide and water serving as raw materials according to a certain proportion, crystallizing for 16 hours at the temperature of 100 ℃, filtering, washing and roasting a synthetic product to obtain the composite pore X molecular sieve material. Synthesis of composite pore X moleculesSiO of sieve₂/Al₂O₃The ratio is 2.3, and the mesoporous size is about 14 nm.

Taking 10 g of the molecular sieve, and carrying out ion exchange in 100 ml of 1 mol/L KNO3 solution for 2 hours at 80 ℃ for 2 times; then ion exchange is carried out in 50 ml of RbNO3 solution with 1 mol/L for 2 times; finally, ion exchange is carried out in 50 ml of 1 mol/L CsNO3 solution for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the alkali metal ion in the catalyst exchanged the sodium ion in the molecular sieve with an ion exchange degree of 85.7%.

Taking 10 g of the obtained molecular sieve, taking cerium nitrate and sodium metaaluminate as precursors, and loading cerium and aluminum on the catalyst by adopting a step-by-step impregnation method, wherein the content of the loaded cerium is 2%, and the content of the sodium metaaluminate is 4%. Tabletting the obtained catalyst to form a 40-60-mesh granular catalyst, and loading the granular catalyst into a reactor, wherein the molar ratio of toluene to methanol is 5: 1. at 2.5 hours^-1Liquid space velocity of (2), 425 ℃, N₂The activity evaluation was carried out at a flow rate of 10 ml/min, and the catalyst was not deactivated for 200 hours, and the activity results are shown in Table 1.

[ example 6 ]

The method comprises the steps of mixing sodium aluminate, sodium silicate, sodium hydroxide, a mesoporous directing agent poly dimethyl diallyl ammonium chloride and water serving as raw materials according to a certain proportion, crystallizing for 16 hours at the temperature of 100 ℃, filtering, washing and roasting a synthetic product to obtain the composite porous X molecular sieve material. SiO for synthesizing composite hole X molecular sieve₂/Al₂O₃The ratio is 2.3, and the mesoporous size is about 10 nm.

[ example 7 ]

The method comprises the steps of mixing sodium aluminate, sodium silicate, sodium hydroxide, potassium hydroxide, a mesoporous guiding agent cetyl trimethyl ammonium bromide and water serving as raw materials according to a certain proportion, crystallizing for 16 hours at the temperature of 100 ℃, filtering, washing and roasting a synthetic product to obtain the composite porous Y molecular sieve material. SiO for synthesizing composite hole Y molecular sieve₂/Al₂O₃The ratio is 5.0, and the mesoporous size is about 8 nm.

Taking 10 g of the molecular sieve, and carrying out ion exchange in 100 ml of 1 mol/L KNO3 solution for 2 hours at 80 ℃ for 2 times; then ion exchange is carried out in 50 ml of RbNO3 solution with 1 mol/L for 2 times; finally, ion exchange is carried out in 50 ml of 1 mol/L CsNO3 solution for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the ion exchange degree of sodium ions in the alkali metal ion exchange molecular sieve in the catalyst was 85.8%.

[ example 8 ]

The method comprises the steps of mixing aluminum hydroxide, silica sol, sodium hydroxide, potassium hydroxide, a mesoporous guiding agent hexadecyltrimethylammonium chloride and water serving as raw materials according to a certain proportion, crystallizing for 16 hours at the temperature of 100 ℃, filtering, washing and roasting a synthesized product to obtain the composite porous X molecular sieve material. SiO for synthesizing composite hole X molecular sieve₂/Al₂O₃The ratio is 2.0, and the mesoporous size is about 7 nm.

[ example 9 ]

Taking 10 g of the molecular sieve, and heating the molecular sieve at 80 ℃ in 100 ml of 1 mol/L KNO₃Ion exchange is carried out in the solution for 2 hours and 2 times; then is at50 ml of 1 mol/l RbNO₃Carrying out ion exchange in the solution for 2 times; finally 50 ml of 1 mol/l CsNO₃Carrying out ion exchange in the solution for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the alkali metal ion in the catalyst exchanged the sodium ion in the molecular sieve with an ion exchange degree of 83.1%.

Taking 10 g of the obtained molecular sieve, taking cerium nitrate and sodium metaaluminate as precursors, and loading cerium and aluminum on the catalyst by adopting a step-by-step impregnation method, wherein the content of the loaded cerium is 2%, and the content of the sodium metaaluminate is 0.5%.

[ example 10 ]

Taking 10 g of the obtained molecular sieve, taking lanthanum nitrate and sodium metaaluminate as precursors, and loading lanthanum and aluminum on the catalyst by adopting a step-by-step impregnation method, wherein the content of the loaded lanthanum is 2%, and the content of the sodium metaaluminate is 3%.

[ example 11 ]

Taking 10 g of the obtained molecular sieve, taking lanthanum nitrate and sodium metaaluminate as precursors, and loading lanthanum and aluminum on the catalyst by adopting a step-by-step impregnation method, wherein the content of the loaded lanthanum is 2, and the content of the sodium metaaluminate is 5%.

[ example 12 ]

Sodium aluminate, sodium silicate, sodium hydroxide, mesoporous guiding agent hexadecyl trimethyl ammonium chloride and water are used as raw materials according to a certain proportionMixing the components in proportion, crystallizing for 16 hours at the temperature of 100 ℃, filtering and washing the synthesized product, and then roasting to obtain the composite porous X molecular sieve material. SiO for synthesizing composite hole X molecular sieve₂/Al₂O₃The ratio is 2.3, and the mesoporous size is about 12 nm.

Taking 10 g of the obtained molecular sieve, taking cerium nitrate and sodium metaaluminate as precursors, and loading cerium and aluminum on the catalyst by adopting a step-by-step impregnation method, wherein the content of the loaded cerium is 2%, and the content of the sodium metaaluminate is 7%.

[ example 13 ]

Taking 10 g of the molecular sieve, and heating the molecular sieve at 80 ℃ in 100 ml of 1 mol/L KNO₃Ion exchange is carried out in the solution for 2 hours and 2 times; then 50 ml of 1 mol/l RbNO₃Carrying out ion exchange in the solution for 2 times; finally 50 ml of 1 mol/l CsNO₃Solutions ofIon exchange is carried out for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the alkali metal ion in the catalyst exchanged the sodium ion in the molecular sieve with an ion exchange degree of 83.1%.

Taking 10 g of the obtained molecular sieve, taking cerium nitrate and sodium metaaluminate as precursors, and loading cerium and aluminum on the catalyst by adopting a step-by-step impregnation method, wherein the content of the loaded cerium is 0.3%, and the content of the sodium metaaluminate is 4%.

Tabletting the obtained catalyst to form a 40-60-mesh granular catalyst, and loading the granular catalyst into a reactor, wherein the molar ratio of toluene to methanol is 5: 1. at 2.5 hours^-1Liquid space velocity of (2), 425 ℃, N₂The activity evaluation was carried out at a flow rate of 10 ml/min, and the catalyst was not deactivated for 150 hours, and the activity results are shown in Table 1.

[ example 14 ]

Taking 10 g of the obtained molecular sieve, taking lanthanum nitrate and sodium metaaluminate as precursors, and loading lanthanum and aluminum on the catalyst by adopting a step-by-step impregnation method, wherein the content of the loaded lanthanum is 1%, and the content of the sodium metaaluminate is 4%.

Tabletting the obtained catalyst to form a 40-60-mesh granular catalyst, loading the granular catalyst into a reactor, and carrying out toluene methylation at normal pressureThe molar ratio of alcohol is 5: 1. at 2.5 hours^-1Liquid space velocity of (2), 425 ℃, N₂The activity evaluation was carried out at a flow rate of 10 ml/min, and the catalyst was not deactivated for 180 hours, and the activity results are shown in Table 1.

[ example 15 ]

Taking 10 g of the obtained molecular sieve, taking lanthanum nitrate and sodium metaaluminate as precursors, and loading lanthanum, cerium and aluminum on the catalyst by adopting a step-by-step impregnation method, wherein the content of lanthanum is 3% after loading, and the content of sodium metaaluminate is 4%.

[ example 16 ]

The method comprises the steps of mixing sodium aluminate, sodium silicate, sodium hydroxide, a mesoporous guiding agent hexadecyltrimethylammonium chloride and water serving as raw materials according to a certain proportion, crystallizing for 16 hours at the temperature of 100 ℃, filtering, washing and roasting a synthetic product to obtain the composite porous X molecular sieve material. Combination of Chinese herbsSiO for forming composite hole X molecular sieve₂/Al₂O₃The ratio is 2.3, and the mesoporous size is about 12 nm.

Taking 10 g of the obtained molecular sieve, taking cerium nitrate and sodium metaaluminate as precursors, and loading cerium and aluminum on the catalyst by adopting a step-by-step impregnation method, wherein the content of the loaded cerium is 5%, and the content of the sodium metaaluminate is 4%.

[ example 17 ]

The composite porous mordenite molecular sieve material is prepared by mixing sodium aluminate, sodium silicate, sodium hydroxide, a mesoporous directing agent cetyl trimethyl ammonium bromide and water according to a certain proportion, crystallizing for 24 hours at 160 ℃, filtering, washing and roasting a synthetic product. The mesoporous size of the synthesized composite pore mordenite molecular sieve is about 8 nm.

3 g of the above molecular sieve was mechanically mixed with 7 g of the molecular sieve synthesized in [ example 4 ] at 80 ℃ in 100 ml of 1 mol/l KNO₃Ion exchange is carried out in the solution for 2 hours and 2 times; then 50 ml of 1 mol/l RbNO₃Carrying out ion exchange in the solution for 2 times; finally 50 ml of 1 mol/l CsNO₃Carrying out ion exchange in the solution for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the alkali metal ion in the catalyst is exchangedThe ion exchange degree of sodium ions in the sub-sieve was 80.8%.

[ example 18 ]

Taking [ example 4 ] 7 g of X molecular sieve and 3 g of Y molecular sieve, mechanically mixing uniformly, and heating at 80 ℃ under the condition of 100 ml of KNO with the concentration of 1 mol/L₃Ion exchange is carried out in the solution for 2 hours and 2 times; then 50 ml of 1 mol/l RbNO₃Carrying out ion exchange in the solution for 2 times; finally 50 ml of 1 mol/l CsNO₃Carrying out ion exchange in the solution for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the alkali metal ion in the catalyst exchanged the sodium ion in the molecular sieve with an ion exchange degree of 80.8%.

[ example 19 ]

Taking [ example 4 ] 7 g of X molecular sieve and 3 g of Y molecular sieve, mechanically mixing uniformly, and heating at 80 ℃ under the condition of 100 ml of KNO with the concentration of 1 mol/L₃In solution for dissociationSub-exchange for 2 hours, exchange for 2 times; then 50 ml of 1 mol/l RbNO₃Carrying out ion exchange in the solution for 2 times; finally 50 ml of 1 mol/l CsNO₃Carrying out ion exchange in the solution for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the alkali metal ion in the catalyst exchanged the sodium ion in the molecular sieve with an ion exchange degree of 80.8%.

Taking 10 g of the obtained molecular sieve, taking cerium nitrate as a precursor, and loading cerium and aluminum on the catalyst by adopting a step-by-step impregnation method, wherein the content of the loaded cerium is 2%.

[ example 20 ]

The method comprises the steps of mixing sodium aluminate, sodium silicate, sodium hydroxide, potassium hydroxide, a mesoporous guiding agent hexadecyltrimethylammonium chloride and water according to a certain proportion, crystallizing for 16 hours at 100 ℃, filtering, washing and roasting a synthesized product to obtain the composite porous X molecular sieve material. SiO for synthesizing composite hole X molecular sieve₂/Al₂O₃The ratio is 2.0, and the mesoporous size is about 7 nm.

Taking 10 g of the obtained molecular sieve, taking cerium nitrate, bismuth nitrate and sodium metaaluminate as precursors, and loading cerium and aluminum on a catalyst by adopting a step-by-step impregnation method, wherein the content of cerium is 2% and the content of bismuth is 0.2% after loading; the content of sodium metaaluminate is 4%.

[ example 21 ]

Taking 10 g of the obtained molecular sieve, taking cerium nitrate, bismuth nitrate and sodium metaaluminate as precursors, and loading cerium and aluminum on a catalyst by adopting a step-by-step impregnation method, wherein the content of the loaded cerium is 2 percent, and the content of the bismuth is 1 percent; the content of sodium metaaluminate is 4%.

Comparative example 1

Taking a purchased common X molecular Sieve (SiO)₂/Al₂O₃2.0 without mesopores), 10 g, at 80 ℃ in 100 ml of 1 mol/l KNO₃Ion exchange is carried out in the solution for 2 hours and 2 times; then 50 ml of 1 mol/l RbNO₃Carrying out ion exchange in the solution for 2 times; finally 50 ml of 1 mol/l CsNO₃Carrying out ion exchange in the solution for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the alkali metal ion in the catalyst exchanged the sodium ion in the molecular sieve with an ion exchange degree of 82.9%.

Tabletting the obtained catalyst to form a 40-60-mesh granular catalyst, and loading the granular catalyst into a reactor, wherein the molar ratio of toluene to methanol is 5: 1. at 2.5 hours^-1Liquid space velocity of (2), 425 ℃, N₂The activity evaluation was performed at a flow rate of 10 ml/min, and the methanol utilization rate decreased by 50% in 70 hours of the catalyst, and the activity results are shown in Table 1.

Comparative example 2

Taking 10 g of the obtained molecular sieve, taking cerium nitrate as a precursor, and loading cerium on the catalyst by adopting an impregnation method, wherein the content of the loaded cerium is 2%.

Comparative example 3

Get and buyGeneral X molecular Sieve (SiO)₂/Al₂O₃2.0 without mesopores), 10 g, at 80 ℃ in 100 ml of 1 mol/l KNO₃Ion exchange is carried out in the solution for 2 hours and 2 times; then 50 ml of 1 mol/l RbNO₃Carrying out ion exchange in the solution for 2 times; finally 50 ml of 1 mol/l CsNO₃Carrying out ion exchange in the solution for 2 times; after filtration, the mixture was dried at 100 ℃ for 10 hours. After the exchange, the alkali metal ion in the catalyst exchanged the sodium ion in the molecular sieve with an ion exchange degree of 82.9%.

Taking 10 g of the obtained molecular sieve, taking sodium metaaluminate as a precursor, and loading aluminum on the catalyst by adopting an impregnation method, wherein the content of the loaded sodium metaaluminate is 4%.

Tabletting the obtained catalyst to form a 40-60-mesh granular catalyst, and loading the granular catalyst into a reactor, wherein the molar ratio of toluene to methanol is 5: 1. at 2.5 hours^-1Liquid space velocity of (2), 425 ℃, N₂The activity evaluation was performed at a flow rate of 10 ml/min, and the catalyst utilization rate of methanol was reduced by 50% at 70 hours, and the activity results are shown in table 1.

TABLE 1

Claims

1. A side chain alkylation composite molecular sieve catalyst is characterized in that the catalyst adopts a composite molecular sieve modified by rare earth, aluminum reagent and bismuth element; the composite molecular sieve contains two pore channel structures of micropores and mesopores, the volume ratio of the micropores to the mesopores is 0.5-15, and the size range of the mesopores is 2-20 nm; the molecular sieve is at least one of an X molecular sieve, a Y molecular sieve, an L molecular sieve and a mercerized molecular sieve, the loading capacity of the rare earth element is 0.3-5%, the aluminum reagent adopts meta-aluminate, the loading capacity of the meta-aluminate is 0.5-8%, and the content of the bismuth element is 0.1-1.5%.

2. The side-chain alkylated composite pore molecular sieve catalyst according to claim 1, characterized in that the volume ratio of micropores to mesopores is 3 to 8.

3. The side-chain alkylated composite pore molecular sieve catalyst of claim 1, characterized in that the mesopore size ranges from 2 to 15 nm.

4. The side-chain alkylated composite pore molecular sieve catalyst of claim 1, characterized in that the molecular sieve is modified by alkali metal ion exchange prior to use.

5. The side-chain alkylated composite pore molecular sieve catalyst of claim 1, wherein the loading of rare earth elements is in the range of 0.5% to 3%.

6. The side-chain alkylated composite pore molecular sieve catalyst of claim 1, wherein the loading of meta-aluminate is in the range of 2% to 5%.

7. The side-chain alkylated composite pore molecular sieve catalyst of claim 1, wherein the content of bismuth element is 0.2% to 1.2%.

8. The side-chain alkylated composite pore molecular sieve catalyst of claim 1, characterized in that the catalyst is synthesized by introducing a mesoporous directing agent in a hydrothermal synthesis method.

9. The side-chain alkylated composite pore molecular sieve catalyst of claim 1, characterized in that the mesopore directing agent is selected from at least one of cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, polydimethyldiallylammonium chloride.

10. The side-chain alkylated composite pore molecular sieve catalyst of claim 1, characterized in that the composite pore molecular sieve catalyst is prepared by the following method: the composite molecular sieve catalyst is synthesized by taking sodium aluminate, sodium silicate, sodium hydroxide, a mesoporous guiding agent and water as raw materials and mixing the raw materials according to a certain proportion, and crystallizing and roasting the mixture at the temperature of 60-150 ℃.

11. A side chain alkylation method, which adopts aromatic hydrocarbon and side chain alkylation reagent to react under the action of the catalyst of any one of claims 1 to 9 to obtain a side chain alkylation product.

12. A method for preparing ethylbenzene and styrene adopts methanol and toluene as raw materials, and ethylbenzene and styrene are obtained by reaction under the action of the catalyst of any one of claims 1-9.