CN105668580B - Composite molecular sieves and its synthetic method - Google Patents

Abstract

The present invention relates to a kind of composite molecular sieves and its synthetic method, essentially consists in and solves the problems, such as that the aperture of porous material of prior art synthesis is not single, acid weaker, active high.The present invention includes the composition of following molar relationship by using a kind of composite molecular sieves ZSM 5/ZnVPI 8：n(ZnO):n(SiO₂):n(Al₂O₃)=1~100:10~1000:1, n represents molal quantity in formula, and its XRD diffracting spectrum is 6.64 ± 0.1,9.83 ± 0.07,20.21 ± 0.1,21.14 ± 0.1,22.07 ± 0.1,23.22 ± 0.1,25.06 ± 0.01,26.64 ± 0.1,28.37 ± 0.1,7.96 ± 0.05,8.83 ± 0.05,13.23 ± 0.05,15.91 ± 0.01,25.91 ± 0.04,26.96 ± 0.02, there is the technical scheme of diffraction maximum at 45.05 ± 0.01,45.52 ± 0.01 angstroms, preferably solve above mentioned problem.The composite molecular sieves can be applied in the industrial production of Downstream Products of Methanol.

Description

Composite molecular sieves and its synthetic method

Technical field

The present invention relates to a kind of composite molecular sieves and its synthetic method.

Background technology

Because interior bore size distribution ranges are wide and the rich and varied property of topology, zeolite molecular sieve material are wide Apply generally in fields such as absorption, heterogeneous catalysis, the carrier of all kinds of guest molecules and ion exchanges.They are with selective absorption For principal character, its unique pore canal system makes it have the ability for sieving different sized molecules, and this is also that this kind of material is claimed Be " molecular sieve " the reason for.Only possesses the material of adsorption capacity (guest molecule water or template can be removed) in theory Poromerics or molecular sieve can be referred to as.

With the continuous exploration applied to zeolite, and scientific research development is to its new property, the needs of new capability, people Substantial amounts of energy has been put into synthesis artificial zeolite's molecular sieve.Artificial zeolite is synthesized first from Barrer the 1940s etc. Afterwards, thereafter enter in more than ten years, Milton, Breck and Sand et al. are added using hydrothermal technique in aluminosilicate gels Alkali metal or alkaline earth metal hydroxide, A types, X-type, L-type and y-type zeolite and modenite etc. are synthesized；Twentieth century six In the ten's, with the introducing of organic base cation, a series of brand new zeolite molecular sieves are prepared out, such as ZSM-n series (ZSM-1, ZSM-5, ZSM-11, ZSM-22, ZSM-48 etc.) zeolite molecular sieve, this kind of molecular sieve have preferable catalytic activity, The advantages that hydrothermal stability and higher corrosion resistance, it is widely used in the fields such as PETROLEUM PROCESSING, fine chemistry industry, for many years The always focus of people's research.In numerous ZSM-n Series Molecules sieves, ZSM-5 is most widely used, and it is The zeolite molecular sieve of Pentasil type two-dimensional channel systems, by oval ten-ring straight hole road (0.54nm × 0.56nm) and sine Shape duct (0.51nm × 0.54nm) forms.ZSM-5 zeolite has excellent catalytic performance, is widely used in catalytic cracking (US 4980052nd, CN 102423718), aromatisation (US 4590321, USP4615995, US4665251), alkylation (US7635793B2), it is disproportionated very important industrial chemical processes such as (CN 1340486).

Based on the good catalytic performances of ZSM-5, largely closed using ZSM-5 as the composite type zeolite molecular sieve for participating in primitive Come out into report, particularly the symbiosis zeolitic material of ZSM-5 molecular sieve and modenite MOR porous materials, contain multistage pore canal Structure, strong acid weak acid distribution is wider, can handle molecular diameter complex component not of uniform size, and can play their association Same catalytic effect.

Chinese patent CN 1565967 reports the method that one kind prepares modenite/ZSM-5 mixed crystal materials, and mercerising is boiled Masonry be crystal seed be added in ZSM-5 synthesis reaction mixture, it is to be mixed uniformly after, hydrothermal crystallizing both product.The material Mercerising with compared with mechanical mixture/ZSM-5 better performances.But need to add different crystal seeds in building-up process as induction Agent, further need exist for adding fluoride.

Chinese patent CN1393403 reports have synthesized middle mesoporous-microporous composite molecular sieve composition using the method for segmentation crystallization, For processing of heavy oil.Synthetic method is first to prepare the reaction mixture gel of synthetic microporous molecular sieve, then in 30~300 DEG C of bars The crystallization of first stage is carried out under part, for crystallization after 3~300 hours, the pH value for adjusting reactant mixture is 9.5~12, and is added The template used in mesoporous molecular sieve is synthesized, then carries out the hydrothermal crystallizing of second stage, crystallization from pressure at 30~170 DEG C again Time is 15~480 hours, obtains middle mesoporous-microporous composite molecular sieve composition, but the building-up process of molecular sieve needs to be segmented crystallization, And centre will also adjust pH value, synthetic method is also complex.

The G of Chinese patent 100586565 passes through selection suitable template, and adjust suitable pH value range, control simultaneously Suitable silica alumina ratio and crystallization temperature is prepared for the complex type molecular sieve class material of ZSM-5 and modenite.

And the document of other multiple types composite molecular screens is prepared using ZSM-5 molecular sieve as synthesis unit also through a large amount of reports Road.

Chinese patent CN03133557.8, which reports to have synthesized under static conditions, has the compound of two kinds of structures of TON and MFI Structure molecular screen, the molecular sieve add a small amount of crystal seed and salt in gel process is prepared, and controlling crystallizing parameter can obtain To the molecular sieve of two kinds of crystal formation different proportions, silica alumina ratio is more than 50 on the lattice of molecular sieve, and obtaining composite molecular screen of the present invention can Course of reaction for mixture such as petroleum distillate.

The A of Chinese patent CN 110722035 are used by using ZSM-5, ZSM-11, ZSM-35, ZSM-48 etc. as nuclear phase To coat the continuous fine and close ZSM-5 crystal grain of shell, fully wrapped around core-shell type zeolite molecular sieve is synthesized, the molecular sieve has Type selectivity is preferably selected, there is preferable catalytic activity when being reacted for toluene disproportionation, toluene methylation etc..

Chinese patent CN 101081370A are prepared for a kind of ZSM-5/SAPO-11 complex type molecular sieves using two-step method, should Molecule and match can be applied in the reaction of catalytic gasoline hydrogenation.

The method that Chinese patent CN 1772611A are used as synthetic reaction thing by adding molecular sieve in advance, it was recently reported that a kind of A kind of composite molecular sieve in ten-element cyclic structure and its synthetic method, several complex type molecular sieves prepared by this method can be applied to lubricate Oily hydrogenation process.

And constantly the widening to zeolite application field with people, and scientific research development is to its new property, new capability Needs, substantial amounts of energy be put to New-type Zeolite Molecular Sieves synthesis with preparation work in, wherein, use hetero atom (atom Measure heavier metallic element) substitution backbone element to prepare the zeolite molecular sieve with novel skeleton structure and special properties into Synthesized for New-type Zeolite Molecular Sieves with preparing one of effective means.Zinc si molecular sieves VPI-7 is prepared out within 1991, Annen Then the good high silicon zinc si molecular sieves VPI-8 of first heat endurance has been synthesized, and there is twelve-ring channel system, in stone There is application potential in the cracking industry of oily macromolecular.The VPI-8 mentioned in Camblor synthesis needs to add expensive organic mould Plate agent (such as TEAOH), this has very big limitation to further practical application.

Up to now, there is not been reported for the document about ZSM-5/VPI-8 complex type molecular sieve and its synthetic method.

The content of the invention

One of technical problems to be solved by the invention be prior art synthesis aperture of porous material it is single, it is acid compared with The problem of weak, active not high.A kind of new composite molecular sieves are provided, the composite molecular sieves have the hole of multistage distribution The characteristics of road structure, strong acid weak acid distribution is wider, and activity is higher；The two of the technical problems to be solved by the invention are existing A kind of the problem of above-mentioned composite molecular sieves preparation method is not directed in technology, there is provided preparation of new composite molecular sieves Method.

To solve one of above-mentioned technical problem, the technical solution adopted by the present invention is as follows：A kind of composite molecular sieves, bag Include the composition of following molar relationship：x(ZnO)：y(SiO₂)∶z(Al₂O₃)=1~100:10~1000:1, n is represented mole in formula Number, it is characterised in that the composite molecular sieves include two kinds of thing phases of ZSM-5 and VPI-8 simultaneously, and its XRD diffracting spectrum exists 6.64 ± 0.1,9.83 ± 0.07,20.21 ± 0.1,21.14 ± 0.1,22.07 ± 0.1,23.22 ± 0.1,25.06 ± 0.01, 26.64 ± 0.1,28.37 ± 0.1,7.96 ± 0.05,8.83 ± 0.05,13.23 ± 0.05,15.91 ± 0.01,25.91 ± There is diffraction maximum at 0.04,26.96 ± 0.02,45.05 ± 0.01,45.52 ± 0.01 angstroms.

In above-mentioned technical proposal, preferable technical scheme is the composition of molar relationship：x(ZnO)：y(SiO₂)∶z(Al₂O₃) =10~50:50~500:1.

To solve the two of above-mentioned technical problem, the technical solution adopted by the present invention is as follows：A kind of composite molecular sieves Synthetic method, comprise the following steps：

(1) by silicon source, zinc source, alkali source, template M and water mix, formed mixture I, mixture I using molar ratio computing as： SiO₂/ ZnO=0.1~100, OH^-/SiO₂=0.01~10.0, M/SiO₂=0.01~10.0, H₂O/SiO₂=10~1000, It is 8~12 with dilute acid soln regulation pH value；

(2) SiO to contain in silicon source in said mixture I₂On the basis of weight, added in said mixture I appropriate Crystal seed, formed mixture II, amount of seed SiO₂The 0.01~20% of weight, crystal seed SiO₂/Al₂O₃Mol ratio is 10 Amorphous substance of the crystal grain of~1000 presoma containing ZSM-5 zeolite in 10~500nm；

(3) said mixture II is stirred after forming uniform crystallization mixture, be put into enclosed high pressure kettle 80~220 Crystallization 8~200 hours in DEG C baking oven；

(4) the good product of crystallization is taken out, after washing, filtering and dry, composite molecular sieves is made；

Silicon source wherein used be selected from organosilicon, amorphous silica, Ludox, solid oxidation silicon, silica gel, diatomite or At least one of waterglass；Zinc source used is selected from least one of zinc nitrate, zinc acetate, zinc sulfate, zinc chloride；Alkali used Source is at least one of hydroxide selected from alkali metal；Template used dose of M be in organic amine or Inorganic Ammonium at least It is a kind of.

In above-mentioned technical proposal, mixture I is with molar ratio computing, preferred scope：SiO₂/ ZnO=1~50, OH^-/SiO₂= 0.1~5.0, M/SiO₂=0.1~5.0, H₂O/SiO₂=50~500, crystal seed SiO₂/Al₂O₃Mol ratio preferred scope is 20 Amorphous substance of the crystal grain of~500 presoma containing ZSM-5 at 50~300 nanometers, amount of seed preferred scope are in raw material SiO₂The 0.1~10% of weight.Control ph preferred scope is 8~12, and more preferably scope is 9~11.Organic amine used is preferred Scheme is selected from 4-propyl bromide, TPAOH, tetraethylammonium bromide, tetraethyl ammonium hydroxide, tetrabutyl phosphonium bromide At least one of ammonium, TBAH, triethylamine, n-butylamine, ethylenediamine or ethamine；Inorganic Ammonium preferred scheme be selected from At least one of ammoniacal liquor, ammonium salt；Dilute acid soln preferred scheme used be selected from watery hydrochloric acid, dilute sulfuric acid, dust technology, phosphoric acid,diluted, At least one of oxalic acid or acetic acid.Crystallization temperature preferred scope is 100~200 DEG C, and crystallization time preferred scope is 12~120 Hour.

The synthetic method concrete operations of composite molecular sieves are to take the desired amount of silicon source and zinc source by material proportion, point Solution is not made with distilled water dissolving, then two kinds of solution are mixed, strong stirring, the desired amount of template is then added, stirs PH value is adjusted in 9~11 scopes with dilute alkaline soln after mixing 30 minutes, then is supplied distilled water while added appropriate ZSM-5 crystal seeds, Strong stirring is to forming uniform crystallization mixture again.Crystallization mixture is placed in autoclave, controls required temperature, it is brilliant After changing 12~120 hours, washing is taken out, alcohol is washed each 2 times, 120 DEG C and dried 6 hours, 550 DEG C and is calcined 6 hours, you can obtain described Composite molecular sieves.

Metallic element Zn contents are in plasma P erkin-Elmer 3300DV icp analysis in composite molecular sieves It is measured on instrument, concrete operation method is as follows：

Sample is placed in 100 DEG C of oven for drying 2 hours, weigh afterwards 0.2~0.5 gram of sample after drying in platinum crucible or In King crucible, add 10 drops 1：1 sulfuric acid, 8 milliliters of hydrofluoric acid, heating, often shake and accelerate sample to decompose, treat solution in crucible It is clear it is thorough after, solution is steamed to white cigarette and emitted to the greatest extent, cooling is removed, adds 1:15 milliliters of hydrochloric acid and suitable quantity of water.Dissolve by heating residue, Ran Houyi In 100 milliliters of volumetric flasks of people, crucible is eluted with water and dilute to scale, shakes up, the solution configured is introduced into ICP spectrometers point Analysis, record percentage composition.

By the present invention in that sieve nucleation process with ZSM-5 crystal seeds inducing molecule, regulation is adapted to involved thing phase nucleation and crystallization PH value range, control be adapted to the zinc silicon ratio and crystallization temperature of growth, be prepared under hydrothermal conditions simultaneously containing ZSM-5 and The composite molecular sieves of VPI-8 crystalline phases, because the surface of composite molecular sieves is with interface, acidity and than surface and simple thing Mechanical kilowatt mixing has bigger difference, and its acid amount is larger, acid stronger, containing multistage pore canal, so have preferable catalytic performance, Be advantageous to the separation and diffusion of different molecular diameter product, can be applied to the course of reaction that methanol converts hydrocarbon processed.In commenting for setting In valency condition and range, methanol conversion 100%, the once through yield of product isobutene and aromatic hydrocarbons reaches as high as 89.9%, aromatic hydrocarbons Middle BTX selectivity is up to 66.8%, while catalyst has good stability, achieves preferable technique effect.

Below by embodiment, the present invention is further elaborated.

Embodiment

【Embodiment 1】

The synthesis of ZSM-5/ZnVPI-8 composite molecular screens

94.7 grams of sodium metasilicates and 15.5 grams of sodium hydroxides are taken, solution A is dissolved into 380 grams of distilled water, takes 21 grams of nitre Sour zinc, solution B is made with 35 grams of distilled water, B solution is poured slowly into solution A, strong stirring, then add 9.8 grams of tetrems Base ammonium hydroxide and 4.2 grams of ethylenediamines (mixed templates are designated as M), after stirring a period of time, pH value is adjusted 11 with dilute sulfuric acid, The mol ratio of controlling crystallizing mixed liquor is：SiO₂∶ZnO∶NaOH：M∶H₂O=1: 0.1: 0.5: 0.4: 30, add 1.0 grams of ZSM- 5 zeolite seed crystal (SiO₂/Al₂O₃=50, grain size 100nm), mixed solution is put into autoclave, in 120 DEG C of insulations 100 hours, take out washing, alcohol wash each 2 times, 120 DEG C dry 6 hours, 550 DEG C be calcined 6 hours, obtained ZSM-5/ZnVPI-8 is answered Molecular sieve (wherein ZSM-5 and ZnVPI-8 thing are in a ratio of 75/25) is closed, is designated as ZV-1, the n of ICP test compound molecular sieves (ZnO)：n(SiO₂)：n(Al₂O₃)=1.5：70：1.

【Embodiment 2】

The synthesis of ZSM-5/ZnVPI-8 composite molecular screens

245 grams of sodium metasilicates and 2.4 grams of lithium hydroxides are taken, solution A is dissolved into 2000 grams of distilled water, takes 542 grams of nitre Sour zinc, solution B is made with 1600 grams of distilled water, B solution is poured slowly into solution A, strong stirring, then add 2101 gram four Ethyl phosphonium bromide ammonium (template is designated as M), after stirring a period of time, pH value is adjusted 9 with dust technology, controlling crystallizing mixed liquor rubs You are at proportioning：SiO₂∶ZnO∶LiOH：M∶H₂O=1: 1: 0.05: 5: 100, add 5.0 grams of ZSM-5 zeolite crystal seed (SiO₂/Al₂O₃ =20, grain size 300nm), mixed solution is put into autoclave, 200 hours are incubated at 80 DEG C, takes out washing, alcohol is washed Dry 6 hours, 550 DEG C for each 2 times, 120 DEG C and to be calcined 6 hours, be made ZSM-5/ZnVPI-8 composite molecular screens (wherein ZSM-5 with 59/41) ZnVPI-8 thing is in a ratio of, be designated as ZV-2, the n (ZnO) of ICP test compound molecular sieves：n(SiO₂)：n(Al₂O₃)= 4：35：1.

【Embodiment 3】

The synthesis of ZSM-5/ZnVPI-8 composite molecular screens

189.4 grams of sodium metasilicates and 80 grams of sodium hydroxides are taken, solution A is dissolved into 1400 grams of distilled water, takes 210 grams of nitre Sour zinc, solution B is made with 400 grams of distilled water, B solution is poured slowly into solution A, strong stirring, then add 84 grams of tetrems Base ammonium bromide and 25.2 grams of ethylenediamines (mixed templates are designated as M), after stirring a period of time, pH value is adjusted 12 with dilute sulfuric acid, The mol ratio of controlling crystallizing mixed liquor is：SiO₂∶ZnO∶NaOH：M∶H₂O=1: 1: 0.5: 2.4: 50, add 2.5 grams of ZSM-5 Zeolite seed crystal (SiO₂/Al₂O₃=200, grain size 30nm), mixed solution is put into autoclave, 54 are incubated at 160 DEG C Hour, take out washing, alcohol wash each 2 times, 120 DEG C dry 6 hours, 550 DEG C be calcined 6 hours, be made compound point of ZSM-5/ZnVPI-8 Son sieve (wherein ZSM-5 and ZnVPI-8 thing are in a ratio of 44/56), is designated as ZV-3, the n (ZnO) of ICP test compound molecular sieves：n (SiO₂)：n(Al₂O₃)=45：270：1.

【Embodiment 4】

The synthesis of ZSM-5/ZnVPI-8 composite molecular screens

122.5 grams of sodium metasilicates and 239.5 grams of lithium hydroxides are taken, solution A is dissolved into 1300 grams of distilled water, takes 813 Gram zinc nitrate, is made solution B with 860 grams of distilled water, B solution is poured slowly into solution A, strong stirring, then adds 420.2 Gram tetraethylammonium bromide (template is designated as M), after stirring a period of time, pH value is adjusted 10 with dust technology, controlling crystallizing mixing The mol ratio of liquid is：SiO₂∶ZnO∶LiOH：M∶H₂O=1: 3: 10: 2: 120, add 3.0 grams of ZSM-5 zeolite crystal seed (SiO₂/ Al₂O₃=500, grain size 200nm), mixed solution is put into autoclave, 10 hours are incubated at 200 DEG C, taking-up washing, Alcohol, which is washed each 2 times, 120 DEG C and dried 6 hours, 550 DEG C, to be calcined 6 hours, and ZSM-5/ZnVPI-8 composite molecular screens (wherein ZSM-5 is made It is in a ratio of 64/36) with ZnVPI-8 thing, is designated as ZV-4, the n (ZnO) of ICP test compound molecular sieves：n(SiO₂)：n(Al₂O₃) =70：320：1.

【Embodiment 5~20】

It is raw materials used as shown in table 1 according to the method for embodiment 3, control reaction sorting different ratio (table 2), close respectively Into going out ZSM-5/ZnVPI-8 composite molecular screens, ZSM-5/ZnVPI-8 and n (ZnO) in material：n(SiO₂)：n(Al₂O₃) be shown in Table 3。

Table 1

【Embodiment 21】

Application of the ZSM-5/ZnVPI-8 composite molecular screens in methanol converts hydrocarbon reaction processed

The ZV-1 molecular sieves that Example 1 synthesizes, carry out ammonium at 80 DEG C with 5wt% ammonium nitrate solutions and exchange 3 hours.Product Filtered, washing, after drying 3 hours at 130 DEG C, repeat ammonium of progress and exchange, filtered, washing, dry 3 at 130 DEG C After hour, be calcined 3 hours at 550 DEG C, obtained Hydrogen coexisting molecular sieve, then tabletting, break into pieces, sieve, take 12~20 purposes Particle is standby, is designated as M₁.Using methanol as raw material, with a diameter of 15 millimeters of fixed bed reactors, in 450 DEG C, mass space velocity 1.5h^-1, pressure be 0.02MPa under conditions of check and rate, isobutene mass yield reaches 21.9%, and aromatics quality yield reaches 50.1%, BTX selectivity is up to 58.3% in aromatic hydrocarbons, achieves preferable technique effect.

Table 2

Embodiment	Sample number into spectrum	Reactant ratio forms	Crystal seed/SiO2
				5	ZV-5	SiO2∶ZnO∶NaOH：M∶H2O=1：0.01：2：9：255	0.1%
6	ZV-6	SiO2∶ZnO∶KOH：M∶H2O=1：4：0.03：3：400	4%
				7	ZV-7	SiO2∶ZnO∶LiOH：M∶H2O=1：8：7.5：1：25	0.9%
8	ZV-8	SiO2∶ZnO∶KOH：M∶H2O=1：0.1：2：7：120	20%
				9	ZV-9	SiO2∶ZnO∶LiOH：M∶H2O=1：5：0.02：1：625	1%
10	ZV-10	SiO2∶ZnO∶KOH：M∶H2O=1：10：10：10：1000	7.3%
				11	ZV-11	SiO2∶ZnO∶LiOH：M∶H2O=1：1.5：0.2：4.6：100	6.1%
12	ZV-12	SiO2∶ZnO∶NaOH：M∶H2O=1：1.9：1.2：7.2：447	2.9%
				13	ZV-13	SiO2∶ZnO∶LiOH：M∶H2O=1：2.5：4.3：6.5：200	4.7%
14	ZV-14	SiO2∶ZnO∶KOH：M∶H2O=1：3.8：1.7：8：800	0.01%
				15	ZV-15	SiO2∶ZnO∶NaOH：M∶H2O=1：1：1：5：70	18.5%
16	ZV-16	SiO2∶ZnO∶LiOH：M∶H2O=1：0.6：2：1.5：190	10.9%
				17	ZV-17	SiO2∶ZnO∶NaOH：M∶H2O=1：4.3：1.1：0.5：70	16.4%
18	ZV-18	SiO2∶ZnO∶KOH：M∶H2O=1：3.1：9.9：7.5：390	0.05%
				19	ZV-19	SiO2∶ZnO∶LiOH：M∶H2O=1：2.2：1.6：4.5：700	13.3%
20	ZV-20	SiO2∶ZnO∶KOH：M∶H2O=1：6：9：5：190	8.7%

Table 3

Sample number into spectrum	ZSM-5/ZnVPI-8	n(ZnO)：n(SiO2)：n(Al2O3)
			ZV-5	7/93	1：77：1
ZV-6	42/58	42：155：1
			ZV-7	27/73	79：332：1
ZV-8	99/1	3：482：1
			ZV-9	30/70	53：223：1
ZV-10	65/35	100：371：1
			ZV-11	49/51	17：442：1
ZV-12	36/64	23：201：1
			ZV-13	53/47	29：266：1
ZV-14	1/99	41：1000：1
			ZV-15	89/11	15：774：1
ZV-16	75/25	10：111：1
			ZV-17	83/27	48：419：1
ZV-18	4/96	36：565：1

ZV-19	80/20	26：117：1
			ZV-20	71/29	61：67：1

【Embodiment 22】

Example it is 2-in-1 into ZV-2 molecular sieves, using embodiment 21 catalyst preparation side's method be made catalyst, note For M₂.Using methanol as raw material, with a diameter of 15 millimeters of fixed bed reactors, in 400 DEG C, mass space velocity 2.5h^-1, pressure be Checked and rated under conditions of 1MPa, isobutene mass yield reaches 29.9%, and aromatics quality yield reaches 43.5%, BTX in aromatic hydrocarbons Selectively up to 53.6%.

【Embodiment 23】

The ZV-3 molecular sieves that Example 3 synthesizes, catalyst, note are made using catalyst preparation side's method of embodiment 21 For M₃.Using methanol as raw material, with a diameter of 15 millimeters of fixed bed reactors, in 350 DEG C, mass space velocity 3.0h^-1, pressure be Checked and rated under conditions of 2MPa, isobutene mass yield reaches 32.2%, and aromatics quality yield reaches 40.5%, BTX in aromatic hydrocarbons Selectively up to 50.3%.

【Embodiment 24】

The ZV-4 molecular sieves that Example 4 synthesizes, catalyst, note are made using catalyst preparation side's method of embodiment 21 For M₄.Using methanol as raw material, with a diameter of 15 millimeters of fixed bed reactors, in 500 DEG C, mass space velocity 0.5h^-1, pressure be Checked and rated under conditions of 4MPa, isobutene mass yield reaches 27.9%, and aromatics quality yield reaches 41.1%, BTX in aromatic hydrocarbons Selectively up to 40.9%.

【Embodiment 25】

ZSM-5/ZnVPI-8 composite molecular screens acid measures examination

The ZV-20 molecular sieves that Example 3 synthesizes, by the method for embodiment 21, it is compound that Hydrogen ZSM-5/ZnVPI-8 is made Molecular sieve.With the desorption curve of temperature programmed desorption device measure ammonia, acid strength is represented with strong, weak acid position desorption temperature. The ammonia being desorbed out is absorbed with the dilution heat of sulfuric acid of excess, then dripped with standard solution of sodium hydroxide is counter after chromatogram It is fixed, thus calculate the acid amount of tested molecular sieve.Measurement result such as table 4.

【Comparative example 1】

The β zeolites that the silica alumina ratio for taking Shanghai Petroleum Chemical Engineering Institute to produce is 39.9, it is measured by the method for embodiment 21 Acidity, as a result as shown in table 4.

【Comparative example 2】

The mordenite molecular sieve that the silica alumina ratio for taking Shanghai Petroleum Chemical Engineering Institute to produce is 22.6, by the side of embodiment 21 Method measures its acidity, as a result as shown in table 4.

【Comparative example 3】

The ZSM-5 molecular sieve that the silica alumina ratio for taking Shanghai Petroleum Chemical Engineering Institute to produce is 18.8, by the method for embodiment 21 It is acid to measure it, as a result as shown in table 4.

Table 4

Claims (10)

1. a kind of composite molecular sieves, include the composition of following mol ratio：x(ZnO)：y(SiO₂)∶z(Al₂O₃)=1~100: 10~1000:1, x, y, z represents molal quantity respectively in formula, it is characterised in that the composite molecular sieves include ZSM-5 simultaneously With two kinds of thing phases of VPI-8, its XRD diffracting spectrum 6.64 ± 0.1,9.83 ± 0.07,20.21 ± 0.1,21.14 ± 0.1, 22.07 ± 0.1,23.22 ± 0.1,25.06 ± 0.01,26.64 ± 0.1,28.37 ± 0.1,7.96 ± 0.05,8.83 ± 0.05,13.23 ± 0.05,15.91 ± 0.01,25.91 ± 0.04,26.96 ± 0.02,45.05 ± 0.01,45.52 ± 0.01 Occurs diffraction maximum at angstrom.

2. composite molecular sieves according to claim 1, it is characterised in that the group of composite molecular sieves molar relationship Into：x(ZnO)：y(SiO₂)∶z(Al₂O₃)=10~50:50~500:1.

3. the synthetic method of composite molecular sieves according to claim 1, comprises the following steps：

(1) by silicon source, zinc source, alkali source, template M and water mix, formed mixture I, mixture I using molar ratio computing as：SiO₂/ ZnO=0.1~100, OH^-/SiO₂=0.01~10.0, M/SiO₂=0.01~10.0, H₂O/SiO₂=10~1000, use diluted acid Solution regulation pH value is 8~12；

(2) SiO to contain in silicon source in said mixture I₂On the basis of weight, appropriate crystalline substance is added in said mixture I Kind, form mixture II, amount of seed SiO₂The 0.01~20% of weight, crystal seed SiO₂/Al₂O₃Mol ratio be 10~ Amorphous substance of the crystal grain of 1000 presoma containing ZSM-5 zeolite in 10~500nm；

(3) said mixture II is stirred after forming uniform crystallization mixture, be put into enclosed high pressure kettle in 80~220 DEG C of bakings Crystallization 8~200 hours in case；

(4) the good product of crystallization is taken out, after washing, filtering and dry, composite molecular sieves is made；

Silicon source wherein used is selected from organosilicon, amorphous silica, Ludox, solid oxidation silicon, silica gel, diatomite or water glass At least one of glass；Zinc source used is selected from least one of zinc nitrate, zinc acetate, zinc sulfate, zinc chloride；Alkali source used is At least one of hydroxide selected from alkali metal；Template used dose of M is selected from least one of organic amine or Inorganic Ammonium.

4. the synthetic method of composite molecular sieves according to claim 3, it is characterised in that reactant mixture I with mole Than being calculated as：SiO₂/ ZnO=1~50, OH^-/SiO₂=0.1~5.0, M/SiO₂=0.1~5.0, H₂O/SiO₂=50~500, it is brilliant Kind dosage is SiO in raw material₂The 0.1~10% of weight.

5. the synthetic method of composite molecular sieves according to claim 3, it is characterised in that dilute acid soln used is dilute At least one of hydrochloric acid, dilute sulfuric acid, dust technology, phosphoric acid,diluted, oxalic acid or acetic acid, between regulation pH value is 9~11.

6. the synthetic method of composite molecular sieves according to claim 3, it is characterised in that the organic amine is selected from four Propyl group ammonium bromide, TPAOH, tetraethylammonium bromide, tetraethyl ammonium hydroxide, TBAB, tetrabutyl hydrogen-oxygen Change at least one of ammonium, triethylamine, n-butylamine, ethylenediamine or ethamine；Inorganic Ammonium is selected from least one of ammoniacal liquor, ammonium salt.

7. the synthetic method of composite molecular sieves according to claim 3, it is characterised in that the crystal seed is SiO₂/ Al₂O₃Mol ratio is amorphous substance of the crystal grain of 20~500 presoma containing ZSM-5 at 50~300 nanometers.

8. the synthetic method of composite molecular sieves according to claim 3, it is characterised in that crystallization temperature be 100~ 200 DEG C, crystallization time is 12~120 hours.

9. the synthetic method of composite molecular sieves according to claim 3, it is characterised in that the crystal seed is SiO₂/ Al₂O₃Mol ratio is amorphous substance of the crystal grain of 40~400 presoma containing ZSM-5 at 100~300 nanometers.

10. any composite molecular sieves described in claims 1 to 3 are used for the reaction of methanol hydro carbons as catalyst In.