CN105983437B - A kind of catalyst of the structure molecular screen containing MWW, preparation method and applications - Google Patents

Abstract

The invention discloses a kind of catalyst for alkylation reaction, it is characterized in that catalytic activity constituent element contains a kind of MWW structure molecular screen, it is 0.01~0.10cm that nitrogen adsorption-desorption BJH curve of the MWW structure molecular screen, which is shown in the nitrogen desorption rate at 3.8 ± 0.5nm,³/ g, and the adsorbance of 2,4,6- trimethylpyridines after its 20 DEG C absorption, 200 DEG C of desorptions is >=35 μm of ol/g.When the catalyst is for ethylene and benzene liquid phase alkylation reaction, while maintaining high ethylbenzene selectivity, it is remarkably improved conversion of ethylene, compared with current industrial widely applied BEA molecular sieve catalyst, there is better ethylbenzene selectivity.

Description

A kind of catalyst of the structure molecular screen containing MWW, preparation method and applications

Technical field

The present invention relates to a kind of catalyst containing molecular sieve, preparation method and applications, are about one more specifically Catalyst, preparation method and its application in the chemical reaction processes such as alkylation of kind structure molecular screen containing MWW.

Background technique

Ethylbenzene is mainly used for dehydrogenation production styrene as important industrial chemicals, and then produces styrene series resin Such as polystyrene (PS), acrylonitrile-butadiene-styrene (ABS) (ABS), styrene-acrylonitrile (SAN) and butadiene-styrene rubber (SBR) Etc..In addition, a small amount of ethylbenzene is also used for solvent, diluent and generation diethylbenzene etc..In recent years, the development of styrene is more To be rapid, market has driven the sustainable growth of ethylbenzene yield to the thriving demand of styrene；From 1998 to 2015 year, global second The demand of benzene will be increased with 3.7% speed.Industrially, ethylbenzene is mainly to be synthesized by ethylene and benzene alkylation reaction, only About 2% ethylbenzene is to pass through C₈The separation method production of fraction.

Currently, the production technology of ethylbenzene mainly has: AlCl₃Method, Alkar vapor phase method, catalytic distillation technology molecular sieve gas phase Method and molecular sieve liquid phase method etc.；And first two method due to environmental pollution, corrosion equipment, energy consumption is high the disadvantages of, by gradually It eliminates.From the 1980s, the production of ethylbenzene starts from traditional AlCl₃Catalyst Friedel-Crafts benzene hydrocarbon chemical industry Skill is to molecular sieve catalytic process changeover.Molecular sieve catalytic ethylbenzene synthesis technology is divided into vapor phase method and two kinds of liquid phase method again.Molecular sieve Vapor phase method catalyzes and synthesizes ethylbenzene primary disadvantage is that xylene content is high, influences the quality of product；To a certain extent, it may be said that Molecular sieve liquid phase method is the deficiency for vapor phase method and the technique that grows up, since reaction temperature is low, to reduce secondary anti- The production quantity of product is answered, the production quantity of dimethylbenzene is especially greatly reduced, improves the quality of ethylbenzene product.Currently, liquid phase Synthesizing ethyl benzene technique has realized that industrialized catalyst has Y, Beta and MCM-22 molecular sieve catalyst.

Currently, the production technology of ethylbenzene mainly has: AlCl₃Method, Alkar vapor phase method, catalytic distillation technology molecular sieve gas phase Method and molecular sieve liquid phase method etc..AlCl₃Method and Alkar vapor phase method due to environmental pollution, corrosion equipment, energy consumption is high the disadvantages of, It is phased out.From the 1980s, the production of ethylbenzene starts from traditional AlCl₃Catalyst Friedel-Crafts benzene Hydrocarbylation process is to molecular sieve catalytic process changeover.Molecular sieve catalytic ethylbenzene synthesis technology is divided into vapor phase method and two kinds of liquid phase method again. The major defect of molecular sieve vapor phase method is xylene content height, influences the quality of product.Molecular sieve liquid phase method reaction temperature is low, secondary The production quantity of reaction product is reduced, and especially greatly reduces the production quantity of dimethylbenzene, the quality of ethylbenzene product can be improved.Mesh Before, it has realized in industrialized molecular sieve liquid phase method synthesizing ethyl benzene technique, has used Y, Beta and MCM-22 molecular sieve for catalyst Active component.

Mobli company Cheng etc. (Studies in Surface Science and Catalysis, 1999,121: 53-60.) by 220 DEG C of reaction temperature, reaction pressure 3.44MPa, benzene is found with the Experimental comparison under ethylene molar ratio 4:1, Beta molecular sieve activity highest, MCM-22 molecular sieve ethylbenzene, ethylization selectivity are best, and Y type molecular sieve is due to its cellular structure In there are supercage, selectivity is worst, inactivation is very fast.

The MWW such as MCM-22, MCM-49, MCM-56 structure molecular screen is all urging for extraordinary alkene and benzene alkylation reaction Agent, such catalyst have the characteristics that reaction temperature is mild, benzene alkene is than low, environmental-friendly.US 5600048 (1997) research The liquid-phase alkylation performance of MWW structure molecular screen, as the result is shown under conditions of identical conversion of ethylene, MWW structural molecule Sieve catalyst has better ethylbenzene selectivity, but its treating capacity is less than Beta molecular sieve catalyst.

MWW structure molecular screen includes MCM-22, MCM-49, MCM-36, MCM-56, SSZ-25, ITQ-1 and ITQ-2 equal part Son sieve.Nineteen ninety, Mobil company for the first time using hexamethylene imine as template hydrothermal synthesis go out MCM-22 molecular sieve (US, 4954325,1990) its structure, and in 1994 is parsed for the first time, and MWW structure molecular screen is named as with this, therefore have The lamellar zeolite of MWW topological structure is also known as MCM-22 family molecular sieves.MWW structure molecular screen have two sets it is non-cross only Vertical duct: the sinusoidal duct of oval 10MR two dimension that layer internal orifice dimension is 0.40 × 0.59nm；Interlayer be 0.71 × 0.71 × The 12MR supercage of 1.82nm, and communicated with the outside world with the 10MR of 0.40 × 0.54nm opening；In addition it is also distributed on its surface The hole 12MR, is the half of supercage, and depth is about 0.91nm (Science, 1994,264:1910).MWW structure molecular screen is because of it Unique cellular structure and physico-chemical property alkylation (US 5600048,1997), aromatisation (catalysis journal, 2002,23: 24), have in the reaction such as catalytic cracking (J.Catal., 1997,167:438) and isomerization (J.Catal., 1996,158:561) Have broad application prospects.

Although MWW structure molecular screen micropore specific area with higher, due to the limitation in ten-ring aperture, in supercage Acidic site hardly result in utilization.In order to make the acidic site in supercage be fully used, many researchs are dedicated in MWW molecule It introduces mesoporous in sieve or communicates ten-ring sine duct and interlayer supercage in layer, so as to improve inside diffusion.

Compared with three-dimensional molecular sieve, the lamellar zeolites such as MWW are not because Coating combination is close, to show various structures Property and plasticity, and after composition still can further progress structural modification.For example interlayer swelling, stripping are carried out to MCM-22P From (be partially stripped or be completely exfoliated) and intercalation, reaming and the post-processing such as pillared, available holding MWW basic layer structure Unit, and the catalysis material such as MCM-56 homologue with large aperture and high-specific surface area, MCM-36, ITQ-2 and IEZ series point Son sieve.

For MWW structure molecular screen, Wu Peng etc. is protected using the MCM-22 molecular sieve after roasting as raw material using organic amine The method of the selectively molten silicon of MWW skeleton, has been successfully prepared mesoporous MCM-22 molecular sieve.With individually will cause with the molten silicon of NaOH Structure collapse is compared, and this method introduces aperture in the crystalline substance of 20nm or so while three-dimensional structure and two-dimensional layered structure convert Interior mesoporous, molecular sieve crystallinity also remains intact.Xu Long childs etc. carry out merely with MCM-22 molecular sieve of the NaOH to roasting front and back Processing, can also equally dramatically increase the mesoporous of MCM-22 molecular sieve, improve it in ethylene and benzene liquid phase alkylation reaction Performance.

Summary of the invention

Inventor has been surprisingly found that MWW structure molecular screen is different from the prior art in experience on the basis of a large number of experiments The sieve sample that alkaline matter for processing process obtains, " flower shape " is tightly packed is changed into the loose heap of sheet by former for pattern Product, confusion degree dramatically increase, and zeolite crystal more disperses, and specific surface area and pore volume increased, while having lower Na⁺Content, show as with different from routine MWW structure molecular screen specific nitrogen adsorption-desorption BJH curve 3.8 ± The adsorbance of nitrogen desorption rate and specific 2,4,6- trimethylpyridine at 0.5nm, using it as the catalyst of active component, Compared with current industrial widely applied BEA molecular sieve catalyst, there is comparable conversion of ethylene and better ethylbenzene to select Selecting property is more able to satisfy the operating condition of low benzene alkene ratio.Based on this, the present invention is formed.

An object of the present invention is to provide a kind of catalyst of structure molecular screen containing MWW, the second purpose is to provide its system Preparation Method, the third purpose are to provide it in the application of the chemical reactions such as alkylation.

In order to realize the first purpose, catalyst provided by the invention, it is characterised in that catalytic activity constituent element contains a kind of MWW Nitrogen adsorption-desorption BJH curve of structure molecular screen, the MWW structure molecular screen is shown in the nitrogen at 3.8 ± 0.5nm Gas desorption rate is 0.01~0.10cm³/ g, and the adsorbance of 2,4,6- trimethylpyridines after its 20 DEG C absorption, 200 DEG C of desorptions For >=35 μm of ol/g.

Described MWW structure molecular screen has special nitrogen adsorption-desorption parameter attribute and 2,4,6- trimethylpyridines Adsorbance.Molecular sieve nitrogen adsorption-desorption BJH curve be shown in the nitrogen desorption rate at 3.8 ± 0.5nm be 0.1~ 0.10cm³/ g, and 2, adsorbance of 4, the 6- trimethylpyridines after 20 DEG C of absorption and in 200 DEG C of desorptions is >=35 μm of ol/g, and The MWW molecular sieve BJH curve of prior art conventional hydrothermal synthesis is shown in the desorption rate of the nitrogen at 3.8nm >=0.20cm³/g、2, The adsorbance of 4,6- trimethylpyridine is respectively less than 35 μm of ol/g.

It is fewer that nitrogen adsorption-desorption BJH curve is shown in the desorption magnitude at 3.8 ± 0.5nm, then illustrates molecular sieve crystalline substance Grain more disperses；2,4,6- trimethylpyridine adsorbances are more, show that the accessibility in molecular sieve activated centre is better.Therefore, originally Invention provides the MWW structure molecular screen in catalyst, has crystal grain more dispersed and better accessibility.

BJH curve is shown in the test of the nitrogen desorption rate at 3.8nm: using the production of Quantachrome instrument company AS-3 static state n2 absorption apparatus；Test condition: being placed in sample processing system for sample, is evacuated to 1.33 × 10 at 300 DEG C^{- 2}Pa, heat-insulation pressure keeping 4h purify sample；Test process: at -196 DEG C of liquid nitrogen temperature, measurement purification sample is not pressing p/p on year-on-year basis₀ Under the conditions of to the adsorbance of nitrogen, utilize the distribution of BJH formula calculated hole diameters.

The adsorbance characterisitic parameter of 2,4,6- trimethylpyridines be sieve sample is pressed into 10 to 20mg from blade, set In pond in situ, in 20 DEG C of 2,4,6- trimethylpyridines of absorption, and in 2,4,6- trimethyl pyrroles of 200 DEG C of removing physical absorptions Pyridine is measured by Fourier transform infrared spectroscopy.

It can be seen that the MWW structure molecular screen in catalyst of the present invention with the prior art using normal by SEM electromicroscopic photograph The accumulation pattern for the MWW structure molecular screen that rule hydrothermal synthesis process obtains is very different.MWW structural molecule in the present invention It sieves pattern and sheet loosely-packed is presented, this will provide more activated centres and more contact activated centres for catalytic conversion process Chance.And the accumulation pattern for the MWW structure molecular screen that prior art conventional hydrothermal synthesis process obtains, for more rule Based on " flower " shape and " lotus throne " shape, accumulation degree it is more regular.

Catalyst of the invention, the MWW structure molecular screen containing 30~70 weight %, in terms of oxide 1~40 weight % Inorganic oxide carrier；Preferably, the inorganic oxygen of MWW structure molecular screen and 10~30 weight % containing 50~70 weight % Compound carrier；It is furthermore preferred that the inorganic oxide of the MWW structure molecular screen containing 60~70 weight % and 20~30 weight % carry Body.

In order to realize the second purpose, the present invention also provides the preparation method of the catalyst of the above-mentioned structure molecular screen containing MWW, Including MWW structure molecular screen is mixed with inorganic oxide carrier, molding, drying, roasting obtain the process of catalyst, it is special Sign is that the MWW structure molecular screen is obtained through following processing: by raw material MWW structure molecular screen, nitrogenous organic base R1, It is H that organic amine R2, deionized water, which are uniformly mixed and obtain molar ratio,₂O/SiO₂=5~100, R1/SiO₂=0.01~5, R2/SiO₂ =0~1 mixture, and the mixture 5~72h of Crystallizing treatment and is recycled at 100~180 DEG C, wherein described is nitrogenous Organic base R1 is selected from tetramethylammonium hydroxide, tetraethyl ammonium hydroxide, tetrapropylammonium hydroxide, dimethyl diethyl hydroxide Ammonium, monomethyl triethylammonium hydroxide, monomethyl tripropyl ammonium hydroxide, dimethyl dipropyl ammonium hydroxide, an ethyl front three Base ammonium hydroxide, diethyl dipropyl ammonium hydroxide, an ethyl tripropyl ammonium hydroxide, an oxypropyl trimethyl ammonium hydroxide and one At least one of propyl triethylammonium hydroxide, described organic amine R2, selected from pentamethylene imines, hexamethylene imine, In heptamethylene imines, 1,4- phenodiazine cycloheptane, cycloheptyl alkanamine, hexamethylene alkanamine, cyclopentamine, aniline, piperidines and piperazine at least It is a kind of.

Described mixture, preferred molar ratio are H₂O/SiO₂=5~50, R1/SiO₂=0.05~0.5, R2/SiO₂ =0~0.5, preferred molar ratio is H₂O/SiO₂=10~25, R1/SiO₂=0.05~0.2, R2/SiO₂=0.1~ 0.3；Described crystallization is 8~36h of progress preferably at for 140~160 DEG C, more preferably in 150 DEG C of crystallization times 8~for 24 hours.

Described nitrogenous organic base R1, selected from tetramethylammonium hydroxide, tetraethyl ammonium hydroxide, tetrapropylammonium hydroxide, Dimethyl diethyl ammonium hydroxide, monomethyl triethylammonium hydroxide, monomethyl tripropyl ammonium hydroxide, dimethyl dipropyl hydrogen Amine-oxides, an ethyl-trimethyl ammonium hydroxide, diethyl dipropyl ammonium hydroxide, an ethyl tripropyl ammonium hydroxide, a propyl At least one of quaternary ammonium bases such as trimethylammonium hydroxide and a propyl triethylammonium hydroxide, preferred nitrogenous organic base R1 are At least one of tetraethyl ammonium hydroxide, dimethyl diethyl ammonium hydroxide.

Described organic amine R2 is selected from pentamethylene imines, hexamethylene imine, heptamethylene imines ,-two azo-cycle of Isosorbide-5-Nitrae At least one of heptane, cycloheptyl alkanamine, hexamethylene alkanamine, cyclopentamine, aniline, piperidines, piperazine, preferred organic amine R2 are six sub- At least one of methylene imine, aniline, piperidines, piperazine.

In a more preferred case, described nitrogenous organic base R1 is tetraethyl ammonium hydroxide and/or dimethyl diethyl Ammonium hydroxide, while organic amine R2 is hexamethylene imine and/or piperidines.

In preparation method of the invention, described raw material MWW structural molecule screened from without roasting removed template method and/or By roasting the MWW structure molecular screen of removed template method, wherein it is preferred that not being fired removed template method.Described raw material MWW structure molecular screen can be MCM-22 (US4954325, Mobil/CN103771435A, RIPP), MCM-49 (US5236575, Mobil), MCM-56 (US 5362697, Mobil), SSZ-25 (US5202014, Chevron) and UZM-8 The MWW structure Si-Al molecular sieve of various direct hydrothermal synthesis such as (US 6756030B1, UOP), is also possible to ITQ-2 and MCM-36 Deng MWW structure molecular screen obtained from handling MCM-22P.Although can also be carried out to ITQ-2 and MCM-36 molecular sieve Treatment process provided by the invention, but from the viewpoint of simple process, described raw material MWW structure molecular screen is directly to locate The MWW structure molecular screen of reason hydrothermal synthesis can obtain better effect and simple process.

Preparation method of the invention, R1/SiO in described mixture₂=0.05~0.5, R2/SiO₂=0~0.5, i.e., R2/SiO₂Ends of range point value be zero in the case where, expression can individually use nitrogenous organic base R1.Individually using nitrogenous organic The mode of alkali R1 is particularly suitable for the complete situation of raw material MWW crystallization of molecular sieves, such as generally requires raw material MWW structure molecular screen Relative crystallinity be >=100%.Which can realize MWW structure molecular screen product under the premise of crystallinity is declined slightly Specific surface area, pore volume and the 2,4,6- trimethylpyridine adsorbance of sample dramatically increase.

In preparation method of the invention, it is particularly suitable in such a way that nitrogenous organic base R1 is handled simultaneously with organic amine R2 Crystallize the lossy raw material MWW structure molecular screen of imperfect or crystallinity, such as the relative crystallinity MWW structure lower than 90% point Son sieve, which can promote secondary crystallization, significantly improve crystallinity at least 5% or more.Described relative crystallinity is less than 90% MWW structure molecular screen may include incomplete because crystallizing caused by crystallization time is inadequate or template dosage is too low MWW molecular sieve is also possible to crystallize MWW structure molecular screen of the complete MWW structure molecular screen after having lost crystallinity.It adopts Under the mode handled simultaneously with nitrogenous organic base R1 and organic amine R2, MWW structure molecular screen Product samples are obviously mentioned in crystallinity Realize that specific surface area, pore volume and 2,4,6- trimethylpyridine adsorbance dramatically increase under the premise of height.In addition, ion exchange Degree can be more obvious, Na⁺Be down to 0.05 weight % hereinafter, Product samples can without ammonium exchange process, can roasting direct be H- Type molecular sieve uses as acidic catalyst active component for being alkylated, aromatisation, cracking, the reaction such as isomerization.

The recovery product, process are known to those skilled in the art, including separation of solid and liquid, washing, drying and Roasting, it is no longer numerous herein to state.The process of the specific recovery product of implementable one that but it is not limited to this of the present invention is described After the completion of 5~72h of crystallization, temperature of reaction system is down to room temperature, crystallization product is separated through solid with mother liquor, and wherein solid is through going Ion water washing is to pH value close to 7, and after 100 DEG C of drying, it is de- to be warming up to 550 DEG C of roasting 10h with the heating rate of 2 DEG C/min Template agent removing, the product after being roasted.

The preparation method of catalyst of the invention can also include optionally by the above-mentioned MWW structure with special parameter point Son sieve, which first carries out ammonium, which to be handed over, reduces alkali metal content to the process for being less than 0.05 weight % in terms of alkali metal oxide.Wherein, described Inorganic oxide carrier the 1~40% of catalyst weight, preferably 20~30% are accounted in terms of oxide.

The preparation method of catalyst of the invention, including MWW structure molecular screen are mixed with inorganic oxide carrier, molding, Dry, roasting obtains the process of catalyst.As it is known to those skilled in the art that further including being added to help in order to facilitate kneading and compacting Squeeze the substance conventionally used for preparing catalyst such as agent and water.The extrusion aid is in sesbania powder, starch, nitric acid and citric acid One or several kinds, wherein preferably nitric acid.By taking nitric acid as an example, additional amount is 0.5~5 weight %, preferably 1~3 weight Measure %.

The inorganic oxide carrier comes from silica, aluminium oxide, magnesia, titanium oxide or zirconium oxide.Preferably, institute The inorganic oxide carrier stated carrys out self-alumina, such as selected from SB powder, dry glue powder, Aluminum sol or boehmite, wherein more excellent Select dry glue powder.

In order to realize the third purpose, the present invention also provides a kind of ethylene and benzene liquid phase alkylation reaction, it is characterised in that Ethylene and benzene exist in a kind of catalyst and reaction temperature is 180~280 DEG C, and reaction pressure is 2.0~4.0MPa, benzene weight 1~5h of air speed^-1, benzene is alkylated under conditions of being 2~12 with ethylene molar ratio to react, wherein the catalyst is above-mentioned Catalyst of the invention；More preferably process conditions are as follows: reaction temperature be 200~260 DEG C, reaction pressure be 3.0~ 3.5MPa, 3~5h of benzene weight space velocity^-1, benzene and ethylene molar ratio are 2~12.

Alkylation provided by the invention has better conversion of ethylene and ethylbenzene selectivity in synthesizing ethyl benzene.? While maintaining high ethylbenzene selectivity, it is remarkably improved conversion of ethylene.With current industrial widely applied BEA molecular sieve Catalyst is compared, and is had better ethylbenzene selectivity, is more able to satisfy the operating condition of low benzene alkene ratio, before having application well Scape.

Catalyst provided by the invention, while can also be used in Alkylation benzene with propylene reaction, it is other aromatisation, cracking, different The reactions such as structure can also use the catalyst.

Detailed description of the invention

Fig. 1 is that comparative example 1, comparative example 2, embodiment 1, the ethylene of 2 gained catalyst of embodiment and benzene liquid-phase alkylation are anti- The conversion of ethylene (%) and ethylbenzene selectivity (%) answered compare figure.

Fig. 2 is that comparative example 1, comparative example 2, embodiment 3, the ethylene of 4 gained catalyst of embodiment and benzene liquid-phase alkylation are anti- The conversion of ethylene (%) and ethylbenzene selectivity (%) answered compare figure.

Fig. 3 is that comparative example 1, comparative example 3, embodiment 5, the ethylene of 6 gained catalyst of embodiment and benzene liquid-phase alkylation are anti- The conversion of ethylene (%) and ethylbenzene selectivity (%) answered compare figure.

Specific embodiment

Catalyst and preparation method thereof of the invention is described further below by embodiment, this is described with reference to the drawings The alkylation performance of the catalyst provided, but range not thereby limiting the invention are provided.

In embodiment and comparative example, X-ray diffraction (XRD) crystalline phase figure of sample is spread out in Siemens D5005 type X-ray It penetrates on instrument and is measured.With sample and authentic specimen at the diffracted intensity (peak that 2 θ are diffractive features peak between 22.5 °~25.0 ° It is high) the sum of ratio indicate crystallinity of the sample relative to authentic specimen, i.e., relative crystallinity is (using 2 sample of comparative example as base 100%) quasi- sample, crystallinity are calculated as.

In embodiment and comparative example, the test that BJH curve is shown in the nitrogen desorption rate at 3.8nm is used The AS-3 static state n2 absorption apparatus of Quantachrome instrument company production is in test condition: sample is placed in sample processing system, 1.33 × 10 are evacuated at 300 DEG C^-2Pa, heat-insulation pressure keeping 4h purify sample；Test process: at -196 DEG C of liquid nitrogen temperature, Measurement purification sample is not pressing p/p on year-on-year basis₀Under the conditions of to the adsorbance of nitrogen.

In embodiment and comparative example, the adsorbance characterisitic parameter of 2,4,6- trimethylpyridines is that sieve sample is pressed into 10 It to 20mg from blade, is placed in pond in situ, in 20 DEG C of 2,4,6- trimethylpyridines of absorption, and in 200 DEG C of removing physical absorptions 2,4,6- trimethylpyridines, measured by Fourier transform infrared spectroscopy.

In embodiment and comparative example, alkylation properties evaluation: Solid Bed micro-reactor, catalyst breakage are 16~20 Mesh particle, loadings 8mL.Process conditions are as follows: reaction temperature is 200~260 DEG C, reaction pressure 3MPa, benzene weight space velocity 3h^-1, benzene and ethylene molar ratio are 12.

To ensure data reliability and repeatability, take 7 temperature spots: 200 DEG C, 210 DEG C, 220 DEG C, 230 DEG C, 240 DEG C, 250 DEG C and 260 DEG C, each temperature spot adopts three instantaneous samples, its product of chromatography composition, then calculate conversion of ethylene and Ethylbenzene selectivity takes its average value.

Provided in embodiment and comparative example 220 DEG C of temperature spot of stable reaction each catalyst of explanation conversion of ethylene and Ethylbenzene selectivity.

Comparative example 1

This comparative example illustrate to use it is industrial it is widely applied using Beta molecular sieve as the catalyst of catalytic activity group member with And ethylene and benzene liquid phase alkylation reaction performance evaluation.

Beta molecular sieve (SiO₂/Al₂O₃=25) ammonium exchanges: under 90 DEG C of water bath conditions, ammonium exchanges 2h, takes out, filtering, It is dried for standby.Wherein ammonium ion precursor is ammonium nitrate, exchange liquid proportion: 1g molecular sieve: 1g ammonium nitrate: 20g deionized water.

Beta molecular sieve (butt 80%) after ammonium is handed over is uniformly mixed with carrier dry gel powder (butt 70%), then by nitre Acid and appropriate amount of deionized water are slowly added to after being mixed into uniform liquid, are uniformly mixed when being added.The mass ratio of gained mixture Are as follows: 70% molecular sieve butt: 30% dry glue powder butt: 3% nitric acid: (catalyst butt=molecular sieve is dry for 100% deionized water 100%) base+carrier butt, is defined as.Then mixture is further uniformly mixed on banded extruder, and then is squeezed into item, dried Dry, roasting obtains comparative catalyst, number D-1.

Conversion of ethylene (%) and ethylbenzene selectivity (%) the result is shown in Figure 1, at 220 DEG C of reaction temperature, conversion of ethylene is 100%, ethylbenzene selectivity 92.8%.

Comparative example 2

MCM-22 molecular sieve is prepared according to the method applied for a patent in publication CN103771435A.

Solid sea mound silica gel (butt 90%) is dissolved in deionized water, hexamethylene imine and aniline is added, stirring is extremely It is completely dissolved, above-mentioned solution, then sodium metaaluminate (analysis is pure) and sodium hydroxide (analysis is pure), after mixing evenly, gained will be added Mixture colloid mol ratio are as follows: 0.18NaOH:SiO₂: 0.033Al₂O₃: 0.10HMI:0.20AN:15H₂O.Then by gained Mixture colloid is transferred in closed crystallizing kettle, the dynamic crystallization 72h at 145 DEG C, takes out product after cooling, be filtered, washed, After dry and roasting, it is spare to obtain sieve sample.XRD analysis product is MCM-22 molecular sieve, and crystallinity is defined as 100%, Na₂O content is 0.55wt.%, and pattern is assembled with 2~4 μm of " flower shape "；Specific surface area and pore volume are respectively 450m²/ g and 0.55cm³/g.Nitrogen adsorption-desorption BJH curve is shown in the nitrogen desorption rate at 3.8 ± 0.5nm 0.20cm³/ g, and the adsorbance of 2,4,6- trimethylpyridines after its 20 DEG C absorption, 200 DEG C of desorptions is 28.7 μm of ol/g.

Ammonium exchange, catalyst preparation and alkylation performance evaluation are the same as comparative example 1, comparative catalyst's number D-2.

Alkylation properties are evaluated with comparative example 1.

Conversion of ethylene (%) and ethylbenzene selectivity (%) the result is shown in Figure 1, at 220 DEG C of reaction temperature, conversion of ethylene is 96.9%, ethylbenzene selectivity 95.2%.

Embodiment 1

This example demonstrates that catalyst provided by the invention and alkylation performance evaluation.

With sieve sample in the comparative example 2 before tetraethyl ammonium hydroxide (TEAOH, content 25%) modification roasting: By MCM-22 molecular sieve (SiO₂/Al₂O₃=25, Na₂O wt.%=0.55), tetraethyl ammonium hydroxide and deionized water mixing, It stirs evenly.Gained mixture colloid mol ratio are as follows: SiO₂: 0.10TEAOH:15H₂O.Then gained mixture is transferred to In closed crystallizing kettle, 150 DEG C, dynamic crystallization 16h, product is taken out after cooling, after being filtered, washed, dried and being roasted, is obtained everywhere MCM-22 sieve sample after reason is spare, relative crystallinity 100%；XRF surveys its NaO wt.%=0.23；SEM morphology analysis Show the accumulation of sheet loosely-packed；The specific surface area and pore volume of molecular sieve are respectively 500m²/ g and 0.67cm³/ g, nitrogen are inhaled It is 0.05cm that the BJH curve of attached-desorption, which is shown in the nitrogen desorption rate at 3.8 ± 0.5nm,³/ g, and its 20 DEG C absorption, 200 DEG C The adsorbance of 2,4,6- trimethylpyridine after desorption is 46.1 μm of ol/g；Ammonium ion exchange system is for H- type molecular sieve and urges Agent is spare, number A-1.

Conversion of ethylene (%) and ethylbenzene selectivity (%) the result is shown in Figure 1, at 220 DEG C of temperature, conversion of ethylene is 100%, as a result ethylbenzene selectivity 95.6% illustrates that the catalyst can improve conversion of ethylene and ethylbenzene selectivity simultaneously.

Embodiment 2

This example demonstrates that catalyst provided by the invention and alkylation performance evaluation.

With sieve sample in the comparative example 2 after tetraethyl ammonium hydroxide (TEAOH, content 25%) modification roasting: By MCM-22 molecular sieve (SiO₂/Al₂O₃=25, Na₂O wt.%=0.55), tetraethyl ammonium hydroxide and deionized water mixing, It stirs evenly.Gained mixture colloid mol ratio are as follows: SiO₂: 0.10TEAOH:15H₂O.Then gained mixture is transferred to In closed crystallizing kettle, 150 DEG C, dynamic crystallization 16h, product is taken out after cooling, after being filtered, washed, dried and being roasted, is obtained everywhere Sample is that MCM-49 molecular sieve is spare after reason, relative crystallinity 96%；XRF surveys its NaO wt.%=0.21；SEM morphology analysis Show sheet loosely-packed；The specific surface area and pore volume of molecular sieve are respectively 495m²/ g and 0.65cm³/g；Nitrogen adsorption- It is 0.05cm that the BJH curve of desorption, which is shown in the nitrogen desorption rate at 3.8 ± 0.5nm,³/ g, and its 20 DEG C absorption, 200 DEG C of desorptions The adsorbance of 2,4,6- trimethylpyridine afterwards is 43.4 μm of ol/g；Ammonium ion exchange system is for H- type molecular sieve and catalyst It is spare, number A-2.

Conversion of ethylene (%) and ethylbenzene selectivity (%) the result is shown in Figure 1, at 220 DEG C of temperature, conversion of ethylene is 99.8%, as a result ethylbenzene selectivity 95.6% illustrates that the catalyst can improve conversion of ethylene and ethylbenzene selectivity simultaneously.

Embodiment 3

This example demonstrates that catalyst provided by the invention and alkylation performance evaluation.

With molecular sieve in the comparative example 2 before tetraethyl ammonium hydroxide (TEAOH, content 25%) and piperidines modification roasting Sample: by MCM-22 molecular sieve (SiO₂/Al₂O₃=25, Na₂O wt.%=0.55), tetraethyl ammonium hydroxide, piperidines and go from Sub- water mixing, stirs evenly.Gained mixture colloid mol ratio are as follows: SiO₂: 0.10TEAOH:0.30PI:15H₂O.Then will Gained mixture is transferred in closed crystallizing kettle, 150 DEG C, dynamic crystallization 16h, is taken out product after cooling, is filtered, washed, is done After dry and roasting, obtaining that treated, MCM-22 sieve sample is spare, relative crystallinity 112%；XRF surveys its NaO wt.% =0.03；SEM morphology analysis shows sheet loosely-packed；The specific surface area and pore volume of molecular sieve are respectively 485m²/ g and 0.72cm³/g；It is 0.08cm that nitrogen adsorption-desorption BJH curve, which is shown in the nitrogen desorption rate at 3.8 ± 0.5nm,³/ g, and its The adsorbance of 2,4,6- trimethylpyridine after 20 DEG C of absorption, 200 DEG C of desorptions is 43.1 μm of ol/g.

The molecular sieve does not need ammonium ion exchange, is directly made into catalyst and roasts spare, number A-3.

Conversion of ethylene (%) and ethylbenzene selectivity (%) result are shown in Fig. 2, and at 220 DEG C of temperature, conversion of ethylene is 99.7%, as a result ethylbenzene selectivity 95.6% illustrates that the catalyst can improve conversion of ethylene and ethylbenzene selectivity simultaneously.

Embodiment 4

This example demonstrates that catalyst provided by the invention and alkylation performance evaluation.

With molecular sieve in the comparative example 2 after tetraethyl ammonium hydroxide (TEAOH, content 25%) and piperidines modification roasting Sample: by MCM-22 molecular sieve (SiO₂/Al₂O₃=25, Na₂O wt.%=0.55), tetraethyl ammonium hydroxide, piperidines and go from Sub- water mixing, stirs evenly.Gained mixture colloid mol ratio are as follows: SiO₂: 0.10TEAOH:0.30PI:15H₂O.Then will Gained mixture is transferred in closed crystallizing kettle, 150 DEG C, dynamic crystallization 16h, is taken out product after cooling, is filtered, washed, is done After dry and roasting, sample is that MCM-22 molecular sieve is spare after being handled, relative crystallinity 110%；XRF surveys its NaO wt%= 0.02；SEM morphology analysis shows sheet loosely-packed；The specific surface area and pore volume of molecular sieve are respectively 494m²/ g and 0.63cm³/g；It is 0.07cm that nitrogen adsorption-desorption BJH curve, which is shown in the nitrogen desorption rate at 3.8 ± 0.5nm,³/ g, and its The adsorbance of 2,4,6- trimethylpyridine after 20 DEG C of absorption, 200 DEG C of desorptions is 41.5 μm of ol/g.

The molecular sieve does not need ammonium ion exchange, and it is spare to be directly made into catalyst roasting.Number A-4.

Conversion of ethylene (%) and ethylbenzene selectivity (%) result are shown in Fig. 2, and at 220 DEG C of temperature, conversion of ethylene is 99.5%, as a result ethylbenzene selectivity 95.9% illustrates that the catalyst can improve conversion of ethylene and ethylbenzene selectivity simultaneously.

Comparative example 3

This comparative example illustrates that according to the MCM-22 molecular sieve of the method synthesis in CN103771435A be urging for active component Agent and its alkylation performance evaluation.

A certain amount of sodium metaaluminate (Chinese medicines group is analyzed pure) and sodium hydroxide (Beijing Reagent Company,

Analyze pure) it is dissolved in deionized water, it stirs to being completely dissolved, by extra large mound silica gel (Haiyang Chemical Plant, Qingdao, SiO₂Contain Amount for above-mentioned solution 97%) is added, add hexamethylene imine (Japanese TCI company analyzes pure), aniline (Beijing Chemical Plant, It analyzes pure).Mixture colloid mol ratio are as follows: 0.18NaOH:SiO₂: 0.033Al₂O₃: 0.05HMI:0.25AN:15H₂O, it is brilliant Change 145 DEG C of temperature, under self-generated pressure, with 300 turns per minute mixing speed crystallization 72 hours, take out product after cooling, pass through After filter, washing and dry and roasting, sample is obtained.

Test obtains XRD diffraction pattern, 25 to 35 ° of the angles θ.Product is MCM-22 molecular sieve, is labeled as D-4, relative crystallinity It is 83%；

SEM test display grain size is about 2.0~4.0 μm；

BET analyzes its specific surface area and pore volume is respectively 375m²/ g and 0.44cm³/g；

XRF analysis Na₂O content is 1.36wt.%.

It is 0.18cm that nitrogen adsorption-desorption BJH curve, which is shown in the nitrogen desorption rate at 3.8 ± 0.5nm,³/ g, and its The adsorbance of 2,4,6- trimethylpyridine after 20 DEG C of absorption, 200 DEG C of desorptions is 18 μm of ol/g.

Ammonium exchange, catalyst preparation and alkylation evaluation are the same as comparative example 1.Catalyst number D-3.

Conversion of ethylene (%) and ethylbenzene selectivity (%) the result is shown in Figure 1, at 220 DEG C of temperature, conversion of ethylene is 87.4%, ethylbenzene selectivity 96.5%.The catalyst causes its activity too low since crystallization is low.

Embodiment 5

This example demonstrates that catalyst provided by the invention and alkylation performance evaluation.

With molecular sieve sample in the comparative example 3 before tetraethyl ammonium hydroxide (TEAOH, content 25%) and piperidines processing roasting Product: by MCM-22 molecular sieve (SiO₂/Al₂O₃=25, Na₂O wt.%=1.32), tetraethyl ammonium hydroxide, piperidines and deionization Water mixing, stirs evenly.Gained mixture colloid mol ratio are as follows: SiO₂: 0.10TEAOH:0.30PI:15H₂O.Then by institute It obtains mixture to be transferred in closed crystallizing kettle, 150 DEG C, dynamic crystallization 16h, takes out product after cooling, be filtered, washed, dried After roasting, obtaining that treated, MCM-22 sieve sample is spare；Relative crystallinity 110%, XRF survey its NaO wt.%= 0.11；SEM morphology analysis shows sheet loosely-packed；The specific surface area and pore volume of the molecular sieve are respectively 471m²/ g and 0.62cm³/ g, it is 0.05cm that nitrogen adsorption-desorption BJH curve, which is shown in the nitrogen desorption rate at 3.8 ± 0.5nm,³/ g, and its The adsorbance of 2,4,6- trimethylpyridine after 20 DEG C of absorption, 200 DEG C of desorptions is 46.2 μm of ol/g.

Ammonium exchange, catalyst preparation and alkylation evaluation are the same as comparative example 1.Catalyst number A-5.

Conversion of ethylene (%) and ethylbenzene selectivity (%) result are shown in Fig. 3, and at 220 DEG C of temperature, conversion of ethylene is 100%, as a result ethylbenzene selectivity 95.8% illustrates that the catalyst can improve conversion of ethylene and ethylbenzene selectivity simultaneously.

Embodiment 6

This example demonstrates that the synthetic method and alkylation performance of catalyst provided by the invention are evaluated.

With molecular sieve sample in the comparative example 1 after tetraethyl ammonium hydroxide (TEAOH, content 25%) and piperidines processing roasting Product: by MCM-22 molecular sieve (SiO₂/Al₂O₃=25, Na₂O wt.%=1.32), tetraethyl ammonium hydroxide, piperidines and deionization Water, after mixing evenly, gained mixture colloid mol ratio are as follows: SiO₂: 0.033Al₂O₃: 0.10TEAOH:0.30PI:15H₂O。 Then gained mixture is transferred in closed crystallizing kettle, 150 DEG C, dynamic crystallization 16h, takes out product after cooling, is filtered, washed After washing, dry and roasting, obtaining that treated, MCM-22 sieve sample is spare.Relative crystallinity 101%, XRF survey its NaO Wt.%=0.25, SEM morphology analysis show sheet loosely-packed；The specific surface area and pore volume of the molecular sieve be respectively 485m²/ g and 0.60cm³/g.Nitrogen adsorption-desorption BJH curve is shown in the nitrogen desorption rate at 3.8 ± 0.5nm 0.05cm³/ g, and the adsorbance of 2,4,6- trimethylpyridines after its 20 DEG C absorption, 200 DEG C of desorptions is 46.1 μm of ol/g.

Ammonium exchange, catalyst preparation and alkylation evaluation are the same as comparative example 1.Catalyst number A-6.

Conversion of ethylene (%) and ethylbenzene selectivity (%) result are shown in Fig. 3, and at 220 DEG C of temperature, conversion of ethylene is 99.6%, as a result ethylbenzene selectivity 95.8% illustrates that the catalyst can improve conversion of ethylene and ethylbenzene selectivity simultaneously.

The catalyst and comparative example catalyst that Fig. 1, Fig. 2 and Fig. 3 provide embodiment are in ethylene and benzene liquid phase alkylation reaction Middle showed conversion of ethylene and ethylbenzene selectivity.It can be seen that industrial agent D-1 catalyst, conversion of ethylene 100%, best ethylbenzene selectivity is 93.2%, hence it is evident that is lower than MWW structure molecular screen；Conventional hydrothermal synthetic method synthesizes D-2 catalyst, about 2~5 μm of crystal grain, conversion of ethylene is lower；And comparative example D-3 molecular sieve table due to its lower crystallinity Reveal very low conversion of ethylene, ethylbenzene selectivity does not have reference significance then.It is endless for crystallizing complete or crystallization Whole MWW structure molecular screen, after nitrogenous organic base-organic amine modification, the MWW structure of available high-crystallinity Molecular sieve simultaneously improves its specific surface and pore volume, and pattern becomes sheet loosely-packed by original flower shape, this will be reactant The chance in more activated centres and more contact activated centres is provided.The liquid phase alkylation reaction performance of ethylene and benzene is than processing Preceding effect is good, and conversion of ethylene and ethylbenzene selectivity all increase；It is urged obtained by MWW structure molecular screen especially before processing roasting Agent, alkylation performance increase rate is bigger, has best conversion of ethylene and ethylbenzene selectivity.

Claims (24)

1. a kind of catalyst for alkylation reaction, it is characterised in that catalytic activity constituent element contains a kind of MWW structure molecular screen, described Nitrogen adsorption-desorption BJH curve of MWW structure molecular screen be shown in the nitrogen desorption rate at 3.8 ± 0.5nm be 0.01~ 0.10cm³/ g, and the adsorbance of 2,4,6- trimethylpyridines after its 20 DEG C absorption, 200 DEG C of desorptions is >=35 μm of ol/g.

2. according to the catalyst of claim 1, wherein nitrogen adsorption-desorption BJH curve of the MWW structure molecular screen 0.01~the 0.08cm of nitrogen desorption rate being shown at 3.8 ± 0.5nm³/ g, and 2,4 after its 20 DEG C absorption, 200 DEG C of desorptions, The adsorbance of 6- trimethylpyridine is 40~60 μm of ol/g.

3. according to the catalyst of claim 1, wherein nitrogen adsorption-desorption BJH curve of the MWW structure molecular screen Being shown in the nitrogen desorption rate at 3.8 ± 0.5nm is 0.01~0.05cm³/ g, and 2 after its 20 DEG C absorption, 200 DEG C of desorptions, The adsorbance of 4,6- trimethylpyridine is 40~50 μm of ol/g.

4. according to the catalyst of claim 1, wherein sheet loosely-packed is presented in the MWW structure molecular screen pattern.

5. according to the catalyst of claim 1, wherein the MWW structure molecular screen containing 30~70 weight %, 1~40 weight % The inorganic oxide carrier in terms of oxide.

6. according to the catalyst of claim 5, wherein the inorganic oxide carrier accounts for 20~30 weight % of catalyst.

7. according to the catalyst of claim 5 or 6, wherein the inorganic oxide is selected from silica, aluminium oxide, oxidation One of magnesium, zirconium oxide and titanium oxide.

8. a kind of preparation method of the catalyst for alkylation reaction of structure molecular screen containing MWW, including by MWW structure molecular screen and nothing Machine oxide carrier obtains the process of catalyst through mixing, molding, drying, roasting, it is characterised in that the MWW structural molecule Sieve is obtained through following processing:

It is H that raw material MWW structure molecular screen, nitrogenous organic base R1, organic amine R2, deionized water, which are uniformly mixed, and obtain molar ratio₂O/ SiO₂=5~100, R1/SiO₂=0.01~5, R2/SiO₂=0~1 mixture, and by the mixture at 100~180 DEG C 5~72h of Crystallizing treatment is simultaneously recycled, wherein described nitrogenous organic base R1 is selected from tetramethylammonium hydroxide, tetraethyl hydroxide Ammonium, tetrapropylammonium hydroxide, dimethyl diethyl ammonium hydroxide, monomethyl triethylammonium hydroxide, monomethyl tripropyl hydrogen-oxygen Change ammonium, dimethyl dipropyl ammonium hydroxide, an ethyl-trimethyl ammonium hydroxide, diethyl dipropyl ammonium hydroxide, an ethyl three At least one of propyl ammonium hydroxide, an oxypropyl trimethyl ammonium hydroxide and a propyl triethylammonium hydroxide, described has Machine amine R2 is selected from pentamethylene imines, hexamethylene imine, heptamethylene imines, homopiperazine, cycloheptyl alkanamine, ring At least one of hexane amine, cyclopentamine, aniline, piperidines and piperazine.

9. according to method for claim 8, wherein the raw material MWW structure molecular screen is not to be fired removed template method MWW structure molecular screen.

10. according to the method for claim 8 or 9, wherein the raw material MWW structural molecule screened from MCM-22, MCM-49, One of MCM-56, SSZ-25 and UZM-8 or different kinds of molecules sieve.

11. according to method for claim 8, wherein the relative crystallinity of the raw material MWW structure molecular screen is less than 90%.

12. according to method for claim 8, wherein the molar ratio of the mixture is H₂O/SiO₂=5~50, R1/SiO₂ =0.05~0.5, R2/SiO₂=0~0.5.

13. according to method for claim 8, wherein the molar ratio of the mixture is H₂O/SiO₂=10~25, R1/SiO₂ =0.05~0.2, R2/SiO₂=0.1~0.3.

14. according to method for claim 8, wherein the nitrogenous organic base R1 is tetraethyl ammonium hydroxide and/or dimethyl Diethyl ammonium hydroxide.

15. according to method for claim 8, wherein the organic amine R2 is hexamethylene imine, aniline, piperidines and piperazine At least one of.

16. according to method for claim 8, wherein the nitrogenous organic base R1 is tetraethyl ammonium hydroxide and/or dimethyl Diethyl ammonium hydroxide, while organic amine R2 is hexamethylene imine and/or piperidines.

17. according to the preparation method of claim 8, the inorganic oxide carrier, precursor be selected from SB powder, dry glue powder, One or more of Aluminum sol and boehmite.

18. a kind of ethylene and benzene liquid phase alkylation reaction method, it is characterised in that make second in the presence of the catalyst of claim 1 Alkene and benzene contact carry out liquid phase alkylation reaction.

19. according to the reaction method of claim 18, it is characterised in that reaction temperature is 180~280 DEG C, reaction pressure 2.0 ~4.0MPa, 1~6h of benzene weight space velocity^-1, benzene and ethylene molar ratio are 2~12.

20. according to the reaction method of claim 18, wherein the reaction temperature is 200~260 DEG C, reaction pressure 3.0 ~3.5MPa, 3~5h of benzene weight space velocity^-1, benzene and ethylene molar ratio are 6~12.

21. application of the catalyst of claim 1 in Alkylation benzene with propylene reaction.

22. application of the catalyst of claim 1 in aromatisation.

23. application of the catalyst of claim 1 in cracking.

24. application of the catalyst of claim 1 in isomerization.