CN104591209B - Small crystal grain Y-shaped molecular sieve and preparation method thereof - Google Patents

Abstract

The invention discloses a kind of small crystal grain Y-shaped molecular sieve and preparation method thereof.The character of this small crystal grain Y-shaped molecular sieve is as follows: SiO₂/ A1₂O₃Mol ratio is 10 less than 40, and average grain diameter is 200～700nm, and relative crystallinity is more than 100%, and lattice constant 2.430～2.450nm, specific surface area is 850～1000m²/ g, pore volume is 0.50～0.80mL/g, and the pore volume shared by the secondary pore of 1.7～10nm accounts for more than the 50% of total pore volume, Na₂O content≤0.15wt%, its preparation method be silica alumina ratio is higher, degree of crystallinity is high, the NaY type Molecular sieve raw material of good stability, sequentially passes through alkali cleaning, ammonium exchange, hydrothermal treatment consists and with obtaining after acid and the process of the mixed solution of ammonium salt.The Y type molecular sieve of gained of the present invention, suitably as the Cracking Component of light oil type hydrogen cracking catalyst, can make catalyst have good activity, heavy naphtha selectivity and the product property of excellence.

Description

Small crystal grain Y-shaped molecular sieve and preparation method thereof

Technical field

The present invention relates to a kind of Y type molecular sieve and preparation method thereof, particularly a kind of small crystal grain Y-shaped molecular sieve and preparation thereof Method.

Background technology

Y type molecular sieve is cracking active component that at present can be the most universal in residual oil cracking field, and crystal grain is generally About 1000nm, its crystal grain is relatively big, and duct is relatively long, and diffusional resistance is big, and macromole is difficult to inside entrance duct react, Afterproduct is the most difficult diffuses out, so the selectivity of its cracking activity and purpose product receives restriction in reaction.With conventional Y type Molecular sieve is compared, and small crystal grain Y-shaped molecular sieve has bigger external surface area and more outer surface active center, is conducive to improving big point Sub-hydrocarbon cracking capability, thus there is the most superior catalytic perfomance.Meanwhile, Y type molecular sieve crystallite dimension is reduced all right Improve inner surface active sites utilization rate.In general, reactant molecule diffusion in molecular sieve endoporus duct is referred to as intracrystalline expansion Dissipate.Molecular sieve inner surface to be made all is used for catalyzed conversion, it is necessary to make micropore diffusion speed more than endoporus catalyzed conversion Speed.Shortening the evolving path is the best way.The effective way overcoming micropore diffusion to limit is to reduce zeolite crystal Size.This not only can increase the external surface area of zeolite crystal, and shorten diffusion length simultaneously.EP0204236 is to little Crystal NaY molecular sieve and big crystal NaY molecular sieve compare, and result shows, RFCC is had higher by the former Active and preferable selectivity.Therefore the technology of preparing of small crystal grain molecular sieve increasingly causes the attention of people.

At present, the directed agents proposed in NaY molecular sieve substantially employing US 3639099 and US 3671191 Method.First the method is to prepare mole to consist of (15-17) Na₂O∶Al₂O₃∶(14-16)SiO₂∶(285-357)H₂The guiding of O Agent, then it is directed to the raw materials such as agent and waterglass, sodium metaaluminate, aluminum sulfate according to mol ratio (3-6) Na₂O∶Al₂O₃∶(8-12) SiO₂∶(120-200)H₂The ratio of O is mixed with gel, then by gel about 100 DEG C crystallization.The NaY of the method synthesis Framework of molecular sieve SiO₂/Al₂O₃Generally about 5.0, generally below 5.2, grain size is usually 500-800nm.

The method preparing fine grain Y type molecular sieve proposed in CN1081425A is first by the synthesis liquid 80 DEG C～180 of NaY Pre-crystallization l～10 hours at DEG C, add directed agents after being cooled to room temperature, then continues crystallization 5～25 at 80 DEG C～100 DEG C little Time, this processing step is more complicated and is difficult to control to, and the hydrothermal stability of the fine grain Y type molecular sieve prepared is poor.

The crystal grain of molecular sieve is reduced, such as by adding organic solvent miscible with water in synthetic system USP3516786 and USP4372931 uses and adds disperse medium, methanol, ethanol, dimethyl sulfoxide and the side of left-right rotary sugar Method, the grain size of its synthetic product is 10～100nm.The sial of the molecular sieve synthesized by the method is relatively low, is only capable of synthesizing X-type Molecular sieve, and organic solvent is readily volatilized under the conditions of hydrothermal crystallizing.

USP4587115 and USP4778666 uses and improves synthesis technique, such as high-speed stirred, the method for microwave heating, its The grain size of synthetic product is about 500nm.The method building-up process is complicated, and synthesis cost is high, and the silicon of gained molecular sieve Aluminum ratio is low, and hydrothermal stability has much room for improvement.

CN1789125A proposes the preparation method of the NaY molecular sieve of a kind of high silica alumina ratio, little crystal grain, is conventional method to be closed The gel become at 50～100 DEG C after static crystallization 0～70h, adds silicon source, then continue at 90～120 DEG C crystallization 0.5～ 50h.After the method needs, silicon reinsertion improves silica alumina ratio, and step is complicated.

The preparation method of a kind of high silicon aluminium ratio small crystal NaY molecular sieve that CN1785807A provides, in advance at 15～60 DEG C Lower stirring 0.5～48 hour prepared crystallization director of ageing, is then directed to agent, reactant mixture is made in water, silicon source, aluminum source, By reactant mixture crystallization in two steps, first step dynamic crystallization, second step static crystallization after stirring, eventually pass filter, wash Wash, be dried, prepare the relative crystallinity high silicon aluminium ratio small crystal NaY molecular sieve more than 80%.But hydrothermal stability is bad, HY divides It is relatively low that son sieve crystallizes reservation degree after 750 DEG C of hydrothermal treatment consists 2 hours.

The preparation method of small crystal grain NaY molecular sieve disclosed in CN92105661.3, its preparation process is: first will be without leading To the silica-alumina gel of agent in the input orientation agent again in 1 ~ 10 hour of 80 ~ 180 DEG C of crystallization, then continue crystallization 5 ~ 25 at 90 ~ 100 DEG C Hour, until crystallization is complete.The NaY molecular sieve that the small crystal grain NaY molecular sieve that the method prepares prepares with conventional method compares, and has Identical silica alumina ratio and degree of crystallinity, simply crystal grain less is 0.1 ~ 0.5 micron.Therefore, the fine grain NaY molecule of the method gained The silica alumina ratio of sieve is the most relatively low, and generally less than 5, and also its degree of crystallinity also awaits improving further.

CN101722023A discloses a kind of fine grain NaY type molecular sieve and preparation method thereof.This fine grain NaY type molecule The SiO of sieve₂/Al₂O₃Mol ratio is 4.0～6.0, and mean diameter, 100～700nm, is to use low temperature synthesis directed agents, low temperature Prepared by the method that synthesized gel rubber and two sections of alternating temperature dynamic crystallizations combine, the method is the method system using optimum synthesis condition Standby fine grain NaY type molecular sieve, its silica alumina ratio is the most relatively low, and its heat stability and hydrothermal stability await carrying further High.

At present, existing method fine grain NaY type molecular sieve is in preparation process, and silicon and aluminum are easy to run off, and silicon utilization rate is low, and And silicon, aluminum distributing inhomogeneity, easily occur reuniting, it is high that the most existing method still cannot prepare silica alumina ratio, and heat stability and The fine grain NaY type molecular sieve that hydrothermal stability is the best.

Small crystal grain NaY molecular sieve is not possess acidity, needs to be modified processing, to meet the performance of Cracking catalyst Requirement.CNl382632A discloses a kind of super stabilizing method of small-grain Y-type zeolite, and the method is with the dry gas of Silicon chloride. Body and fine grain NaY zeolitic contact, obtain after washing, owing to heat and the hydrothermal stability of its raw material self are the most poor, simultaneously This inventive method is that the mode using gas phase dealumination complement silicon processes molecular sieve, and this makes the heat of product and hydrothermal stability worse, Activity is low.Especially to the fine grain NaY zeolite that heat stability and hydrothermal stability are poor, itself sial framing structure steady Qualitative the most poor, modifying process easily causes the removing of framework aluminum, the most also some framework silicon is also with removing, Easily causing the phenomenon that caving in occurs in part skeleton so that the crystallization reservation degree of product is relatively low, the activity of molecular sieve is with stable Property is the highest.

CN200910165116.X discloses a kind of small crystal grain Y-shaped molecular sieve and preparation method thereof.Handled by the method Raw material small crystal grain NaY molecular sieve is prepared by the method disclosed in CN101722023A, i.e. SiO₂/Al₂O₃Mol ratio be 4.0～ 6.0, mean diameter, 100～700nm, passes sequentially through at successive modified i.e. ammonium exchange, ammonium hexafluorosilicate dealumination complement silicon, hydro-thermal The mixed aqueous solution of reason, aluminium salt and acid processes, and obtains small-grain Y molecular sieve.In the method, need first to raw material ammonium hexafluorosilicate After dealumination complement silicon processes, then carrying out hydrothermal treatment consists etc. and process, so could reduce the caving in of framing structure of molecular sieve, raising divides The crystallization reservation degree of son sieve, but after the method is owing to first processing with ammonium hexafluorosilicate dealumination complement silicon, owing to occurring the sial isomorphous to take In generation, molecular sieve silica constructed of aluminium ratio is more complete, then carries out hydrothermal treatment consists, and the secondary pore of formation is few, and secondary pore proportion is low.

At present, owing to the hydrothermal stability of small crystal grain NaY molecular sieve is poor, structural instability, through successive modified, it is impossible to Obtaining structural integrity, degree of crystallinity is high and has the small crystal grain Y-shaped molecular sieve of more secondary pore.

Summary of the invention

In order to overcome weak point of the prior art, the invention provides a kind of small crystal grain Y-shaped molecular sieve and preparation thereof Method.This small crystal grain Y-shaped molecular sieve has that high silica alumina ratio, high-crystallinity, secondary pore be many, the feature of bigger serface.The method Preparation flow is simple, and preparation cost is low.

The small crystal grain Y-shaped molecular sieve of the present invention, character is as follows: SiO₂/ A1₂O₃Mol ratio 10 less than 40, preferably Being 15 ~ 38, average grain diameter is 200～700nm, preferably 300～500nm, and relative crystallinity, more than 100%, is preferably 100% ~ 120%, lattice constant 2.430～2.450nm, specific surface area is 850～1000m²/ g, pore volume is 0.50～0.80mL/ G, the pore volume shared by the secondary pore of 1.7～10nm accounts for more than the 50% of total pore volume, preferably 50% ~ 65%, Na₂O content≤ 0.15wt%.

The preparation method of the small crystal grain Y-shaped molecular sieve of the present invention, including:

(1) preparation of fine grain NaY type molecular sieve；

(2) by fine grain NaY with containing alkaline solution treatment；

(3) the fine grain NaY type molecular sieve that step (2) obtains is prepared as Na₂The little crystal grain of O content≤2.5wt% NH₄NaY；

(4) step (3) is obtained little crystal grain NH₄NaY molecular sieve carries out hydrothermal treatment consists；

(5) molecular sieve step (4) obtained is with containing NH₄ ⁺And H⁺Mixed solution process, scrubbed and dry, obtain Small crystal grain Y-shaped molecular sieve；

The wherein preparation method of fine grain NaY type molecular sieve in step (1), including:

I, preparation directed agents: silicon source, aluminum source, alkali source and water are fed intake according to following proportioning: (6～30) Na₂O:Al₂O₃: (6 ～30) SiO₂: (100～460) H₂O, after stirring, stirs mixture ageing at 0～20 DEG C and prepares for 0.5～24 hour Directed agents；

II, use preparing amorphous silicon alumnium using carbonization predecessor, with the weight of the butt of amorphous silica-alumina predecessor as base Standard, the content that silicon is counted with silicon dioxide is as 40wt%～75wt%, preferably 55 wt%～70wt%；Its preparation process includes:

A, respectively preparation sodium aluminate solution and sodium silicate solution；

B, the part sodium silicate solution that addition step a is prepared in the sodium aluminate solution of step a preparation, then pass to CO₂ Gas, controlling reaction temperature is 10 ~ 40 DEG C, preferably 15～35 DEG C, and the pH value controlling cemented into bundles is 8 ~ 11；Wherein when being passed through CO₂Gas flow accounts for the 60% ~ 100% of total intake, when preferably 80% ~ 100%, adds remainder sodium silicate solution, wherein In step b, remainder sodium silicate solution accounts for step b addition sodium silicate solution total amount in terms of silicon dioxide in terms of silicon dioxide 5wt% ~ 85wt%, preferably 30wt% ~ 70wt%；

C, at the control temperature and pH value of step b, said mixture ventilate stablize 10 ~ 30 minutes；

III, prepare silica-alumina gel

By (0.5～6) Na₂O:Al₂O₃: (8～15) SiO₂: (100～460) H₂Total molar ratio of O, at 0～40 DEG C In the amorphous silica-alumina predecessor of step (2) gained, quickly add water, silicon source, directed agents and alkali source under conditions of stirring, and Control ph is 9.5 ~ 12.0, and uniform stirring obtains silica-alumina gel；Wherein directed agents addition accounts for the 1% of silica-alumina gel weight ～20%,

IV, step III gained reactant mixture through two step dynamic crystallizations, then through filter, washing, be dried, obtain little crystalline substance Grain NaY molecular sieve.

In the present invention, in step I and III, silicon source, alkali source are respectively selected from sodium silicate and sodium hydroxide.In step I, aluminum source Selected from sodium metaaluminate.

In step II, the concentration of the sodium aluminate solution used by step a is preferably 15～55g Al₂O₃/ l, sodium silicate solution Concentration be 50～150 gSiO₂/ l, CO used by step b₂The concentration of gas is 30v% ~ 60v%.

In step III, control reaction temperature 0～40 DEG C, preferably 10 ~ 30 DEG C, pH value 9.5～12.0, preferable ph 10～ 11。

In step IV, the reactant mixture of gained carries out crystallization and uses two step dynamic crystallizations, and wherein the first step is carried out dynamically The condition of crystallization is as follows: temperature controls at 50～90 DEG C, and crystallization time is 0.5～18 hour；Second step carries out dynamic crystallization Condition is as follows: temperature controls at 80～140 DEG C, and crystallization time is 3～10 hours, after crystallization completes, then through filtering, washing, dry Dry, prepare product.Two step dynamic crystallization conditions are preferably as follows: the first step: temperature controls at 60～80 DEG C, crystallization time be 1～ 10 hours；Second step: temperature controls at 80～120 DEG C, and crystallization time is 5～10 hours.

Small crystal grain NaY molecular sieve prepared by said method, its character is as follows: SiO₂/Al₂O₃Mol ratio is 6.0 ~ 9.0, excellent Select 6.5～9.0, more preferably 7.0～8.0, average grain diameter is 200～700nm, preferably 300～500nm；Compare table Area is 800～1000 m²/ g, preferably 850～950 m²/ g, pore volume 0.30/～0.45mL/g, relative crystallinity is 90% ～130%, cell parameter is 2.460～2.470nm, after roasting in 650 DEG C of air 3 hours relative crystallinity be 90% with On, generally 90%～110%, preferably 90% ~ 105%, after 700 DEG C of water vapour hydrothermal treatment consists 2 hours, relative crystallinity is More than 90%, generally 90%～110%, preferably 90% ~ 105%.In step (2), by the water of small crystal grain NaY molecular sieve Yu alkali Solution making beating mix homogeneously, and maintain stir process 1～4h under the temperature conditions of 60～120 DEG C, filter, wash.Wherein used The mixture that alkali is NaOH, KOH or NaOH and KOH.The concentration of the aqueous solution of alkali is generally 0.1～3 mol/L, divides in serosity The concentration of son sieve is 0.05～1.0g/mL.

In step (4), the condition of described hydrothermal treatment consists is as follows: treatment temperature controls, at 500～750 DEG C, preferably to control At 600～700 DEG C, pressure is 0.01～0.50MPa, preferably 0.05～0.30MPa, and the process time is 1.0～4.0 hours.

In step (5), by the molecular sieve after hydrothermal treatment consists and acid with containing NH₄ ⁺Salt composition mixed solution contact, exchange Na in molecular sieve⁺With the part non-framework aluminum in removing molecular sieve, acid therein can be in hydrochloric acid, carbonic acid, nitric acid, sulphuric acid One or more, containing NH₄ ⁺Salt be one or more in the ammonium salt containing above acid group；H in mixed solution⁺Concentration be 0.05～0.6mol/L, NH₄ ⁺Concentration be 0.5～3.0mol/L, exchange temperature is 70～120 DEG C, exchange serosity Middle molecule sieve Concentration be 0.1～0.5g/mL, swap time is 0.5～3.0 hour, and exchange step may be repeated 1～4 time.Then remove Mother solution, washes with water, is dried.

Other operating procedure in the modified Y molecular sieve preparation method of the present invention, as ammonium salt exchange can use this area normal The operational approach of rule and condition.Step (3) uses the method for ammonium salt exchange, specific as follows: with NaY molecular sieve as raw material, and using can The aqueous solution of undissolved ammonium salt, at 70～120 DEG C, exchanges 0.5～3.0 hour at preferably 80～100 DEG C, and Y molecular sieve is at exchange slurry Concentration in liquid is 0.05～0.50g/mL, repeated exchanged l～5 times, filters off mother solution, washing, is dried.Ammonium salt such as ammonium chloride, carbon One or more in acid ammonium, ammonium nitrate, ammonium sulfate, ammonium acetate, ammonium oxalate, ammonium citrate etc., the concentration of ammonium salt solution is 0.5 ～5.0mol/L.

Small crystal grain Y-shaped molecular sieve of the present invention has that high silica alumina ratio, high-crystallinity, secondary pore be many, the feature of bigger serface, It is especially suitable as the acidic components of light oil type hydrogen cracking catalyst.

The preparation method that the present invention provides has the advantage that the silica alumina ratio of the NaY type Molecular sieve raw material due to the present invention Higher, degree of crystallinity is high, good stability, so in follow-up modification process, the not crystal structure of saboteur's sieve, and not shadow Ring the stability of final molecular sieve.Molecular sieve of the present invention has carried out alkali process before ammonium exchanges, and matches with hydrothermal treatment consists afterwards Close, i.e. reached preferable dealumination depth, the most preferably maintained molecular sieve structure, create substantial amounts of secondary pore simultaneously, make Obtain modified molecular screen product and there is good serviceability.

The small-grain Y molecular sieve of the present invention is particularly well-suited to the acidic components of light oil type hydrogen cracking catalyst, Gao Bibiao Face and flourishing secondary pore not only improve the accessibility of catalyst active center, and the diffusion of beneficially product, Holding charcoal ability also to greatly enhance, secondary pore is many, then reduce the occurrence probability of excessive fragmentation and second pyrolysis, improves product choosing Selecting property, thus catalyst can be made to have good activity, heavy naphtha selectivity and the product property of excellence.

Accompanying drawing explanation

Fig. 1 is the SEM electromicroscopic photograph of embodiment 1 gained NY-1；

Fig. 2 is the XRD diffraction pattern of embodiment 1 gained NY-1.

Detailed description of the invention

In order to the present invention is better described, further illustrate the present invention below in conjunction with embodiment and comparative example.But this Bright scope is not limited solely to the scope of these embodiments.The present invention analyzes method: specific surface area, pore volume use low temperature liquid nitrogen physics Absorption method, relative crystallinity and cell parameter use x-ray diffraction method, and silica alumina ratio uses chemical method, and the crystal grain of molecular sieve is big The mode of little employing SEM (scanning electron microscope) measures, and sodium content uses plasma emission spectrometry.

Embodiment 1

The present embodiment is to prepare raw material small crystal grain NaY molecular sieve

The preparation of NY-1

(1) preparation of directed agents: take 10 g sodium hydrate solids and be dissolved in 80g water, adds sodium metaaluminate 2g (Al₂O₃Contain Amount is 45wt%, Na₂O content is 41wt%), then add 36g waterglass (SiO₂Content is 28wt%, Na₂O content is 8 Wt%), 15 DEG C of stirring 4 hours prepared directed agents of ageing after mix homogeneously.

(2) preparation of amorphous silica-alumina predecessor

It is 40gAl that solid sodium aluminate is configured to concentration₂O₃/ L sodium aluminate working solution, takes containing SiO₂The silicic acid of 28wt% Sodium solution, then to be diluted to concentration be 100g SiO₂/ L sodium silicate working solution.Take 1L sodium aluminate working solution and be placed in plastic cans In, it is subsequently adding 0.2L sodium silicate working solution, controls reaction temperature 20 DEG C, be passed through the CO that concentration is 50v%₂Gas, works as pH value Reach to stop when 10.0 logical CO₂, add 0.4L sodium silicate working solution, then ventilate and stablize 20 minutes.

(3) preparation of gel

Serosity obtained by step (2) adds 100g SiO₂Prepared by/L sodium silicate working solution 1.5L and step (1) Directed agents 120g, the pH value of gel is 12, control reaction temperature 20 DEG C, uniform stirring 30 minutes, staticize 2 hours.

(4) crystallization

Gel obtained by step (2) is poured in stainless steel cauldron, stirs crystallization 4 hours at 70 DEG C, then heat up To 100 DEG C, stirring crystallization 8 hours, then filter, wash, be dried to obtain NaY molecular sieve product NY-1, product property is shown in Table 1.

The preparation of NY-2

(1) preparation of directed agents: take 8 g sodium hydrate solids and be dissolved in 80g water, adds sodium metaaluminate 2.5 g (Al₂O₃ Content is 45wt%, Na₂O content is 41wt%).Then 40g waterglass (SiO is added₂Content is 28wt%, Na₂O content is 8 Wt%), 18 DEG C of stirring 4 hours prepared directed agents of ageing after mix homogeneously.

(2) preparation of amorphous silica-alumina predecessor

It is 30gAl that solid sodium aluminate is configured to concentration₂O₃/ L sodium aluminate working solution, takes containing SiO₂The silicic acid of 28wt% Sodium solution, then to be diluted to concentration be 70g SiO₂/ L sodium silicate working solution.Take 1L sodium aluminate working solution to be placed in plastic cans, It is subsequently adding 0.4L sodium silicate working solution, controls reaction temperature 18 DEG C, be passed through the CO that concentration is 50v%₂Gas, when pH value reaches To stopping logical CO when 10.2₂, add 0.6L sodium silicate working solution, then ventilate and stablize 20 minutes.

(3) preparation of gel

Serosity obtained by step (2) adds 70g SiO₂Prepared by/L sodium silicate working solution 1.5L and step (1) Directed agents 100g, the pH value of gel is 11.5, control reaction temperature 15 DEG C, uniform stirring 30 minutes, staticize 2.5 hours.

(4) crystallization

Gel obtained by step (2) is poured in stainless steel cauldron, stirs crystallization 5 hours at 75 DEG C, then heat up To 110 DEG C, stirring crystallization 7 hours, then filter, wash, be dried to obtain NaY molecular sieve product NY-2, product property is shown in Table 1.

Embodiment 2

First raw material small crystal grain NaY molecular sieve is carried out alkali process, be 1 mol/L's by 1000 grams of NY-1 Yu 5L concentration NaOH solution making beating mix homogeneously, and maintains stir process 2h under the temperature conditions of 80 DEG C, filter, be washed to solution close in Property；Being contacted by the 0.5mol/L aqueous ammonium nitrate solution of filter cake and 10 liters, speed of agitator is 300rpm, constant temperature stirring at 90 DEG C L hour, then filtering molecular sieve, and stay sample, analyze Na₂O content；Repeat aforesaid operations, until Na in molecular sieve₂O content Reaching 2.5wt%, obtaining dried sample number into spectrum is NNY-1.

Embodiment 3

First raw material small crystal grain NaY molecular sieve is carried out alkali process, be 0.8 mol/L's by 1000 grams of NY-2 Yu 5L concentration KOH solution making beating mix homogeneously, and maintain stir process 2h under the temperature conditions of 80 DEG C, filter, be washed to solution close to neutral； Being contacted by the 0.5mol/L aqueous ammonium nitrate solution of filter cake and 10 liters, speed of agitator is 300rpm, and at 95 DEG C, constant temperature stirring l is little Time, then filtering molecular sieve, and stay sample, analyze Na₂O content；Repeat aforesaid operations, until Na in molecular sieve₂The content of O reaches To 2.5wt%, obtaining dried sample number into spectrum is NNY-2.

Embodiment 4

Take 100 grams of NNY-1 to be placed in heat-treatment furnace, control the heating rate of 500 DEG C/h, temperature is risen to 600 DEG C, simultaneously The water vapor pressure of maintenance system is 0.15MPa, processes 2 hours, cooling, takes out sample；By sample with 500mL containing NH₄ ⁺And H⁺ Concentration be respectively 0.6mol/L and 0.1mol/L mixed solution (ammonium chloride and hydrochloric acid) process, removing sample in non-bone Frame aluminum, dealuminzation condition is to process 2 hours at 80 DEG C, and washs filter cake with hot deionized water, stops with the pH value of cleaning mixture after 7 Only washing, filter cake 120 DEG C dry 5 hours in an oven, obtain the small crystal grain Y-shaped molecular sieve product A of the present invention, the thing of product A Change character and be shown in Table 2.

Embodiment 5

Take 100 grams of NNY-1 to be placed in heat-treatment furnace, control the heating rate of 400 DEG C/h, temperature is risen to 650 DEG C, Maintain the steam partial pressure 0.08MPa of system simultaneously, process 2 hours, cooling, take out sample；By sample with 400mL containing NH₄ ⁺And H⁺Concentration be respectively 0.8mol/L and 0.2mol/L mixed solution (ammonium nitrate and nitric acid) process, removing sample in non-bone Frame aluminum, dealuminzation condition is to process 3 hours at 70 DEG C, filters, and washs filter cake with hot deionized water, connects with the pH value of cleaning mixture Stop washing, filter cake 120 DEG C dry 5 hours in an oven after nearly 7, obtain the small crystal grain Y-shaped molecular sieve product B of the present invention, produce The physico-chemical property of product B is shown in Table 2.

Embodiment 6

Take 100 grams of NNY-2 to be placed in hydrothermal treatment consists stove, control the heating rate of 400 DEG C/h, temperature is risen to 700 DEG C, maintain the steam partial pressure 0.1MPa of system simultaneously, process 2 hours, cooling, take out sample；By sample with 400mL containing NH₄ ⁺ And H⁺Concentration be respectively 1.0mol/L and 0.2mol/L mixed solution (ammonium chloride and hydrochloric acid) process, removing sample in Non-framework aluminum, dealuminzation condition is to process 3 hours to filter at 75 DEG C, and washs filter cake with hot deionized water, with the pH of cleaning mixture It is worth after 7 and stops washing, filter cake 120 DEG C dry 6 hours in an oven, obtain the small crystal grain Y-shaped molecular sieve product of the present invention C, the physico-chemical property of products C is shown in Table 2.

Comparative example 1

1, fine grain NaY is prepared with reference to CN101722023A

Feedstock property used in this comparative example is as follows: low alkali sodium metaaluminate: Na₂O content 120g/L, Al₂O₃Content 40g/L；Waterglass: SiO₂Content 250g/L；Aluminum sulfate: Al₂O₃Content 90g/L.

(1) preparation of directed agents: the preparation of directed agents is with NY-1 in embodiment 1.

(2) preparation of gel: temperature is 8 DEG C, under stirring condition, be sequentially added into 59.4mL sulfur in the waterglass of 208mL Acid aluminum, the low sodium metaaluminate of 62.7mL and 42.2mL directed agents, then constant temperature constant speed stirs 1.5 hours, the conjunction that then will obtain Become liquid the most static aging 8 hours, obtain gel.

(3) crystallization: under agitation, was raised to 50 DEG C by the gel in synthesis reactor in 20 minutes, constant temperature stirring crystallization 7 Hour；After low temperature crystallized end, in 20 minutes, the temperature in synthesis reactor being brought up to 120 DEG C, then constant temperature stirs 6 hours. Through filtering, washing and be dried, obtaining product little crystal grain CNY-l, product property is shown in Table 1.

2, raw material small crystal grain NaY molecular sieve CNY-1 being carried out ammonium exchange, treatment conditions, with embodiment 2, obtain dried Sample number into spectrum is CNNY-1.

3, CNNY-1 is carried out subsequent treatment, processing mode and condition with embodiment 4, obtain Reference Product CA.The thing of CA Change character and be shown in Table 2.

Comparative example 2

1, fine grain NaY is prepared with reference to CN1785807A

The preparation of directed agents: the preparation of directed agents is with NY-1 in embodiment 1.

Being positioned in beaker by 14.21g water, in control beaker, temperature of liquid is 60 DEG C, is quickly simultaneously introduced under stirring The A1 of 12.79g50wt%₂(SO₄)₃) solution and 31.91g waterglass.After stirring, add above-mentioned directed agents 1.90g, gel PH value be 12.5, after stirring, be loaded in stainless steel cauldron, 60 DEG C of stirring crystallization 6 hours, then heat to 100 DEG C of static crystallizations 60 hours, then filter, wash, are dried and to obtain CNY-2 zeolite product, and product property is shown in Table 1.

2, raw material small crystal grain NaY molecular sieve CNY-1 being carried out ammonium exchange, treatment conditions, with embodiment 2, obtain dried Sample number into spectrum is CNNY-2.

3, CNNY-2 is carried out subsequent treatment, processing mode and condition with embodiment 4, obtain Reference Product CB.The thing of CB Change character and be shown in Table 2.

Comparative example 3

1, fine grain NaY is prepared with reference to CN92105661.3

In this comparative example, the feedstock property used by NaY is as follows: low alkali sodium metaaluminate: Na₂O content 120g/L, Al₂O₃Content 40g/L；Waterglass: SiO₂Content 250g/L；Aluminum sulfate: Al₂O₃Content 90g/L.

(1) preparation of directed agents: the preparation of directed agents is with NY-1 in embodiment 1.

(2) preparation of gel: be sequentially added into the low sodium metaaluminate of 60mL aluminum sulfate, 60mL in the waterglass of 220mL, so Rear constant temperature constant speed stirs 0.5 hour, prepares silica-alumina gel.

(3) crystallization: under agitation, was raised to 140 DEG C by the gel in synthesis reactor in 30 minutes, constant temperature stirring crystallization 2 hours；Add 35mL directed agents, mixing and stirring, then continue crystallization 15 hours at 100 DEG C, through filtering, washing and do Dry, obtain products C NY-3, product property is shown in Table 1.

2, raw material small crystal grain NaY molecular sieve CNY-3 being carried out ammonium exchange, treatment conditions, with embodiment 2, obtain dried Sample number into spectrum is CNNY-3.

3, CNNY-3 is carried out subsequent treatment, processing mode and condition with embodiment 4, obtain Reference Product CC.The thing of CC Change character and be shown in Table 2.

Comparative example 4

1, prepared by fine grain NaY

(1) preparation of directed agents: the preparation of directed agents is with NY-1 in embodiment 1.

(2) preparation of amorphous silica-alumina predecessor.

It is 40gAl that solid sodium aluminate is configured to concentration₂O₃/ L sodium aluminate working solution, takes containing SiO₂The silicic acid of 28wt% Sodium solution, then to be diluted to concentration be 100g SiO₂/ L sodium silicate working solution.Take 1L sodium aluminate working solution and be placed in plastic cans In, it is subsequently adding 0.6L sodium silicate working solution, controls reaction temperature 20 DEG C, be passed through the CO that concentration is 50v%₂Gas, works as pH value Reach to stop when 10.0 logical CO₂, then ventilate and stablize 20 minutes.

(3) preparation of gel is with embodiment 1.

(4) crystallization is with embodiment 1, obtains products C NY-4, and product property is shown in Table 1.

2, raw material small crystal grain NaY molecular sieve CNY-4 being carried out ammonium exchange, treatment conditions, with embodiment 2, obtain dried Sample number into spectrum is CNNY-4.

3, CNNY-4 is carried out subsequent treatment, processing mode and condition with embodiment 4, obtain Reference Product CD.The thing of CD Change character and be shown in Table 2.

Comparative example 5

With the CNNY-1 of comparative example 1 preparation as raw material, the method then using CN200910165116.X is modified, the most such as Under: take 100 grams of CNNY-1 100mL deionized water making beating, and be brought rapidly up 95 DEG C, then with uniformly under conditions of stirring Speed in 2 hours, drip the aqueous solution configured by 25 grams of ammonium hexafluorosilicate and 150m1 deionized water, add rear slurry and exist Constant temperature 2 hours under 95 DEG C of stirring conditions, stands 10 minutes, through washing for 3 times, filter, being dried；Above-mentioned dried sample is put In heat-treatment furnace, controlling the heating rate of 500 DEG C/h, temperature rises to 600 DEG C, the water vapor pressure simultaneously maintaining system is 0.15MPa, processes 2 hours, cooling, takes out sample；Final sample 400mL contains Al³⁺And H⁺Concentration be respectively 1.0mol/L Removing the non-framework aluminum in sample with the mixed solution (aluminum nitrate and nitric acid) of 0.5mol/L, dealuminzation condition is to process 2 at 80 DEG C Hour, and wash filter cake with hot deionized water, with the pH value of cleaning mixture close to stop after 7 washing, filter cake in an oven 120 DEG C do Dry 5 hours, obtain Reference Product CE.The physico-chemical property of CE is shown in Table 2.

Comparative example 6

Take 100gNNY-1, modified to the method for the NNY-1 employing CN200910165116.X of the present invention, concrete modification side Method, with comparative example 5, obtains Reference Product CF.The physico-chemical property of CF is shown in Table 2.

The character of table 1 small crystal grain NaY molecular sieve

In table 1, * roasting condition: roasting 3 hours in 650 DEG C of air；The condition of * hydrothermal treatment consists: 700 DEG C of steam treatment 2 hours.

The character of table 2 finished product small crystal grain Y-shaped molecular sieve

Claims (14)

1. a preparation method for small crystal grain Y-shaped molecular sieve, including:

(1) preparation of fine grain NaY type molecular sieve；

(2) by fine grain NaY with containing alkaline solution treatment；

(3) the fine grain NaY type molecular sieve that step (2) obtains is prepared as Na₂The little crystal grain NH of O content≤2.5wt%₄NaY；

(4) step (3) is obtained little crystal grain NH₄NaY molecular sieve carries out hydrothermal treatment consists；

(5) molecular sieve step (4) obtained is with containing NH₄ ⁺And H⁺Mixed solution process, scrubbed and dry, obtain little crystalline substance Grain Y type molecular sieve；

The wherein preparation method of the small crystal grain NaY molecular sieve used by step (1), including:

I, preparation directed agents: silicon source, aluminum source, alkali source and water are fed intake according to following proportioning: (6～30) Na₂O:Al₂O₃: (6～ 30)SiO₂: (100～460) H₂O, after stirring, stirs mixture to be aged 0.5～24 hour to prepare at 0～20 DEG C and leads To agent；

II, employing preparing amorphous silicon alumnium using carbonization predecessor, on the basis of the weight of the butt of amorphous silica-alumina predecessor, silicon The content counted with silicon dioxide is as 40wt%～75wt%；Its preparation process includes:

A, respectively preparation sodium aluminate solution and sodium silicate solution；

B, the part sodium silicate solution that addition step a is prepared in the sodium aluminate solution of step a preparation, then pass to CO₂Gas, Controlling reaction temperature is 10～40 DEG C, and the pH value controlling cemented into bundles is 8～11；Wherein as the CO being passed through₂Gas flow accounts for total logical When entering the 60%～100% of amount, add remainder sodium silicate solution, wherein in step b remainder sodium silicate solution with dioxy SiClx meter accounts for step b and adds the sodium silicate solution total amount 5wt%～85wt% in terms of silicon dioxide；

C, at the control temperature and pH value of step b, said mixture ventilate stablize 10～30 minutes；

III, prepare silica-alumina gel: by (0.5～6) Na₂O:Al₂O₃: (8～15) SiO₂: (100～460) H₂O always feeds intake mole Ratio, adds water, silicon source, guiding under conditions of 0～40 DEG C of quick stirring in the amorphous silica-alumina predecessor of step II gained Agent and alkali source, and control ph is 9.5～12.0, uniform stirring, obtains silica-alumina gel；Wherein directed agents addition account for sial coagulate The 1%～20% of glue weight,

IV, step III gained reactant mixture through two step dynamic crystallizations, then through filter, washing, be dried, obtain fine grain NaY Molecular sieve.

The most in accordance with the method for claim 1, it is characterised in that in step II, amorphous silica-alumina predecessor, with amorphous silicon On the basis of the weight of the butt of aluminum predecessor, silicon content in terms of silicon dioxide is 55 wt%～70wt%.

The most in accordance with the method for claim 1, it is characterised in that: it is 15～35 DEG C that step b controls reaction temperature.

The most in accordance with the method for claim 1, it is characterised in that: in step b, as the CO being passed through₂Gas flow accounts for total intake When 80%～100%, add remainder sodium silicate solution.

The most in accordance with the method for claim 1, it is characterised in that: in step b, remainder sodium silicate solution is with silicon dioxide Meter accounts for step b and adds the sodium silicate solution total amount 30wt%～70wt% in terms of silicon dioxide.

The most in accordance with the method for claim 1, it is characterised in that in step I and III, silicon source, alkali source are respectively selected from sodium silicate And sodium hydroxide, in step I, aluminum source is selected from sodium metaaluminate.

The most in accordance with the method for claim 1, it is characterised in that in step III, control reaction temperature 10～30 DEG C, pH value 10 ～11.

The most in accordance with the method for claim 1, it is characterised in that step IV uses two step dynamic crystallizations, and wherein the first step is carried out The condition of dynamic crystallization is as follows: temperature controls at 50～90 DEG C, and crystallization time is 0.5～18 hour；Second step carries out dynamic crystalline substance The condition changed is as follows: temperature controls at 80～140 DEG C, and crystallization time is 3～10 hours.

The most in accordance with the method for claim 1, it is characterised in that step IV uses two step dynamic crystallizations, and wherein the first step is carried out The condition of dynamic crystallization is as follows: temperature controls at 60～80 DEG C, and crystallization time is 1～10 hour；Second step carries out dynamic crystallization Condition as follows: temperature controls at 80～120 DEG C, and crystallization time is 5～10 hours.

The most in accordance with the method for claim 1, it is characterised in that in step (2), by the water of small crystal grain NaY molecular sieve Yu alkali Solution making beating mix homogeneously, and maintain stir process 1～4h under the temperature conditions of 60～120 DEG C；Alkali wherein used be NaOH, The mixture of KOH or NaOH and KOH；The concentration of the aqueous solution of alkali is 0.1～3 mol/L, and the concentration of serosity Middle molecule sieve is 0.05～1.0g/mL.

11. in accordance with the method for claim 1, it is characterised in that in step (4), the condition of described hydrothermal treatment consists is as follows: Treatment temperature controls at 500～750 DEG C, and pressure is 0.01～0.50MPa, and the process time is 1.0～4.0 hours.

12. in accordance with the method for claim 1, it is characterised in that in step (4), the condition of described hydrothermal treatment consists is as follows: Treatment temperature controls at 600～700 DEG C, and pressure is 0.05～0.30MPa, and the process time is 1.0～4.0 hours.

13. in accordance with the method for claim 1, it is characterised in that in step (5), by the molecular sieve after hydrothermal treatment consists with acid and Containing NH₄ ⁺Salt composition mixed solution contact, acid therein is one or more in hydrochloric acid, carbonic acid, nitric acid, sulphuric acid, containing NH₄ ⁺Salt be one or more in the ammonium salt containing above acid group；H in mixed solution⁺Concentration be 0.05～0.6mol/L, NH₄ ⁺ Concentration be 0.5～3.0mol/L, exchange temperature is 70～120 DEG C, exchange serosity Middle molecule sieve concentration be 0.1～0.5g/ ML, swap time is 0.5～3.0 hour, and exchange step repeats 1～4 time.

14. in accordance with the method for claim 1, it is characterised in that: step (3) uses the method for ammonium salt exchange, and process is as follows: With NaY molecular sieve as raw material, exchanging 0.5～3.0 hour at 70～120 DEG C with the aqueous solution of solubility ammonium salt, molecular sieve exists Concentration in exchange serosity is 0.05～0.50g/mL, repeated exchanged l～5 times, filters off mother solution, washing, is dried；Ammonium salt is chlorination One or more in ammonium, ammonium carbonate, ammonium nitrate, ammonium sulfate, ammonium acetate, ammonium oxalate, ammonium citrate, the concentration of ammonium salt solution is 0.5～5.0mol/L.