CN104588122B - Hydrocracking catalyst carrier and preparation method thereof - Google Patents

Abstract

The invention discloses a hydrocracking catalyst carrier and a preparation method thereof. The catalyst carrier comprises small-grain Y-type molecular sieve, alumina, and amorphous silica-alumina. According to the preparation method, the small-grain Y-type molecular sieve with high dealumination depth, good crystallinity maintenance and developed secondary pores is adopted as an acidic component, and cooperates with amorphous silica-alumina in the hydrocracking catalyst. According to the invention, the catalyst has better activity, better stability, higher target product selectivity and better product quality.

Description

A kind of carrier of hydrocracking catalyst and preparation method thereof

Technical field

The present invention relates to a kind of carrier of hydrocracking catalyst and preparation method thereof.

Background technology

With international refined products market, the demand of intermediate oil is continuously increased, in needing more to obtain from mink cell focus Between distillate, and one of important means of hydrocracking process exactly light materialization of heavy oil.Adapt to because this technique has raw material Property strong, good product quality, adjust flexible operation, midbarrel product yield is high, so that hydrogenation splits the features such as product structure is flexible The status of metallization processes becomes more and more important, particular for China be faced with present petroleum resources shortage, environmental requirement increasingly tight The problems such as lattice and oil product structure are not suitable with market, the application of hydrocracking technology will become raising petroleum product-quality, Reduce environmental pollution, the effective technology measure of increase market adaptability to changes, it has also become modernization refinery of paramount importance technique dress Put.Exactly these factors promote high selectivity to middle distillates hydrocracking technology and rapidly develop, and hydrocracking catalyst is The key of this technology.

Carrier is the important component part of catalyst, not only provides dispersion place for metal active constituent, simultaneously carrier basis Body also assists in reaction, works in coordination with and completes whole catalytic reaction, hydrocracking catalyst is a kind of pair of work(together with other active components Energy catalyst, it contains acidic components and hydrogenation component simultaneously.Hydrogenation activity is selected generally from b race and in the periodic table of elements Race's metal provides；And its acidic components is mainly provided by zeolite and inorganic oxide, major part is with aluminium oxide or no fixed Shape sial is carrier, is equipped with a certain amount of molecular sieve.And the key component playing cracking in such catalyst is usually y molecule Sieve, the quality of y molecular sieve performance, directly affect performance and the product quality of catalyst.

Y type molecular sieve is cracking active component the most universal in residual oil cracking field at present, and crystal grain is generally 1000nm about, its crystal grain is larger, and duct is relatively long, and diffusional resistance is big, and macromole is difficult to enter and is reacted inside duct, After reaction, product is also more difficult diffuses out, so the selectivity of its cracking activity and purpose product receives restriction.With conventional y type Molecular sieve is compared, and little crystal grain y type 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 more superior catalytic perfomance.Meanwhile, reduce y type zeolite crystal size acceptable Improve inner surface active sites utilization rate.In general, diffusion in molecular sieve endoporus duct for the reactant molecule is referred to as transgranular expansion Dissipate.Molecular sieve inner surface is made all to be used for catalyzed conversion it is necessary to make micropore diffusion speed be more than endoporus catalyzed conversion Speed.Shortening the evolving path is the best way.The effective way that micropore diffusion limits is overcome to be 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 grain nay molecular sieve and big crystal grain nay molecular sieve compare, and result shows, the former has higher to RFCC Active and preferable selectivity.

Little crystal grain nay molecular sieve is that do not possess acidity, needs to be modified processing, to meet the performance of Cracking catalyst Require.Cn1382632a discloses a kind of super stabilizing method of little crystal grain y type zeolite, and the method is gas to be dried with Silicon chloride. Body and little crystal grain nay zeolitic contact, obtain after washing, because the heat of its raw material itself and hydrothermal stability are just poor, simultaneously The method is to process molecular sieve by the way of gas phase dealumination complement silicon, and this makes the heat of product and hydrothermal stability worse, activity Low.Especially poor to heat stability and hydrothermal stability little crystal grain nay zeolite, the sial framing structure stability in zeolite Poor, modifying process easily causes the removing of framework aluminum, also some framework silicon, also with removing, causes portion simultaneously Skeleton is divided the phenomenon caved in occur so that the crystallization reservation degree of product is relatively low, the activity of zeolite is not high.

Cn200910188140.5 discloses a kind of hydrocracking catalyst and preparation method thereof.This catalyst includes being hydrogenated with Active metal component and the carrier of little crystal grain y molecular sieve, amorphous silica-alumina and aluminium oxide composition, wherein said little crystal grain y type divides Son sieve be using hydrothermal treatment consists after little crystal grain y type molecular sieve.Raw materials used little crystal grain nay molecular sieve is in cn101722023a Disclosed method preparation, i.e. sio₂/al₂o₃Mol ratio be 4.0～6.0, mean diameter in 100～700nm, after passing sequentially through Continuous modification is the mixed aqueous solution process of ammonium exchange, ammonium hexafluorosilicate dealumination complement silicon, hydrothermal treatment consists, aluminium salt and acid, obtains little crystalline substance Grain y molecular sieve.In the method, after needing first raw material to be processed with ammonium hexafluorosilicate dealumination complement silicon, then carry out the process such as hydrothermal treatment consists, The caving in of framing structure of molecular sieve so could be reduced, improve the crystallization reservation degree of molecular sieve, but the method is due to first with six After ammonium fluosilicate dealumination complement silicon is processed, due to there is sial isomorphous substitution, molecular sieve silica constructed of aluminium ratio is more complete, then carries out water Heat treatment, the secondary pore of formation is few, and secondary pore proportion is low, divides as catalyst molecule screen banks, and middle oil yield is low.

In preparation process, silicon and aluminum are easy to run off existing method little crystal grain nay type molecular sieve, and silicon utilization rate is low, and silicon, Reuniting, easily occurs in aluminum distributing inhomogeneity, and therefore still cannot to prepare silica alumina ratio high for existing method, and heat stability and hydro-thermal steady Qualitative and good little crystal grain nay type molecular sieve.Through successive modified it is impossible to obtain structural integrity, degree of crystallinity is high and has more The little crystal grain y type molecular sieve of secondary pore, as the cracking component of catalyst, middle oil yield is low.

Content of the invention

For weak point of the prior art, the invention provides a kind of good hydrocracking catalyst of catalytic performance carries Body and preparation method thereof.This carrier of hydrocracking catalyst using a kind of high silica alumina ratio, high-crystallinity, secondary pore many, greatly than table The little crystal grain y type molecular sieve of area as acidic components, be conducive to improve hydrocracking catalyst activity and middle distillates oil selectivity with And improve product property.

Carrier of hydrocracking catalyst of the present invention, including little crystal grain y molecular sieve, aluminium oxide and amorphous silica-alumina, wherein institute The little crystal grain y molecular sieve stated, its property is as follows: sio₂/a1₂o₃Mol ratio be 40～120, average grain diameter be 200～ 700nm, preferably 300～500nm, relative crystallinity more than 100%, preferably 100% ~ 120%, lattice constant 2.425～ 2.450nm, preferably 2.425～2.440, specific surface area is 850～1000m²/ g, pore volume is 0.40～0.60ml/g, 1.7～ Pore volume shared by the secondary pore of 10nm is more than the 50%, preferably 50% ~ 80%, more preferably 55% ~ 75% of total pore volume, na₂O content≤0.15wt%.

Carrier of hydrocracking catalyst property of the present invention is as follows: specific surface area is 450～650 m²/ g, pore volume is 0.5～ 0.80 ml/g, the pore volume of aperture 4 ~ 10nm accounts for the 55%～90% of total pore volume, preferably 65%～80%.

In described carrier of hydrocracking catalyst, on the basis of the weight of carrier, its composition includes: little crystal grain y type divides The content of son sieve is 5wt%～40wt%, preferably 10wt%～25wt%, and the content of amorphous silica-alumina is 20wt%～65wt%, It is preferably 30wt%～60wt%, the content of aluminium oxide is 10wt%～40 wt%, preferably 15wt%～30wt%.

The preparation method of carrier of hydrocracking catalyst of the present invention, comprising: by little crystal grain y type molecular sieve, amorphous silica-alumina With the binding agent mixing made with aluminium oxide, extruded moulding, then drying and roasting, make carrier.

Little crystal grain y molecular sieve described in catalyst carrier of the present invention, including following preparation process:

(1) preparation of little crystal grain nay type molecular sieve；

(2) little crystal grain nay type molecular sieve is prepared into na₂Little crystal grain nh of o content≤2.5wt%₄nay；

(3) little crystal grain nh is obtained to step (2)₄Nay molecular sieve carries out hydrothermal treatment consists；

(4) molecular sieve of step (3) gained carries out dealumination complement silicon with hexafluorosilicic acid aqueous ammonium, the molecular sieve obtaining and pair Product separates；

(5) molecular sieve obtaining step (4) is with containing nh₄ ⁺And h⁺Mixed solution process, be washed out and be dried, obtain To little crystal grain y type molecular sieve.

Little crystal grain nay molecular sieve described in step (1), its property is as follows: sio₂/al₂o₃Mol ratio is more than 6.0 and not Higher than 9.0, preferably 6.5～9.0, more preferably 7.0～8.0, average grain diameter is 200～700nm, preferably 300～ 500nm；Specific surface area is 800～1000 m²/ g, preferably 850～950 m²/ g, pore volume 0.30/～0.45ml/g, tie relatively Brilliant degree is 90%～130%, and cell parameter is 2.460～2.470nm, through relative crystallinity after 650 DEG C of in the air roastings 3 hours For more than 90%, generally 90%～110%, preferably 90% ~ 105%, through after 700 DEG C of water vapour hydrothermal treatment consists 2 hours relatively Degree of crystallinity is more than 90%, generally 90%～110%, preferably 90% ~ 105%.

The preparation method of little crystal grain nay type molecular sieve in step (1) in the inventive method, comprising:

I, preparation directed agents: silicon source, silicon source, alkali source and water are fed intake according to following proportioning: (6～30) na₂O:al₂o₃: (6 ～30) sio₂: (100～460) h₂O, after stirring, mixture is stirred at 0～20 DEG C ageing and is obtained for 0.5～24 hour Directed agents；

Ii, adopt 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 as 40wt%～75wt%, preferably 55 wt%～70wt%；Its preparation process includes:

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

The part sodium silicate solution adding step a to prepare in b, the sodium aluminate solution prepared to step a, then passes 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 ventilation stablize 10 ~ 30 minutes；

Iii, prepare silica-alumina gel

Press (0.5～6) na₂O:al₂o₃: (8～15) sio₂: (100～460) h₂Total molar ratio of o, at 0～40 DEG C Water, silicon source, directed agents and alkali source is added in the amorphous silica-alumina predecessor of step (2) gained under conditions of quick stirring, and Ph value is controlled to be 9.5 ~ 12.0, uniform stirring, obtain silica-alumina gel；Wherein directed agents addition accounts for the 1% of silica-alumina gel weight ～20%,

Iv, the reactant mixture of step iii gained are through two step dynamic crystallizations, then through filtering, wash, and are 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, silicon 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, 0～40 DEG C of controlling reaction temperature, preferably 10 ~ 30 DEG C, ph value 9.5～12.0, preferably ph value 10～ 11.

In step iv, the reactant mixture of gained carries out crystallization and adopts two step dynamic crystallizations, and the wherein first step enters Mobile state The condition of crystallization is as follows: at 50～90 DEG C, crystallization time is 0.5～18 hour to temperature control；Second step carries out dynamic crystallization Condition is as follows: at 80～140 DEG C, crystallization time is 3～10 hours to temperature control, after the completion of crystallization, then through filtering, washing, do Dry, prepared product.Two step dynamic crystallization conditions are preferably as follows: the first step: temperature control at 60～80 DEG C, crystallization time be 1～ 10 hours；Second step: at 80～120 DEG C, crystallization time is 5～10 hours to temperature control.

In step (3), the condition of described hydrothermal treatment consists is as follows: treatment temperature controls at 500～750 DEG C, preferably controls At 600～700 DEG C, pressure is 0.01～0.50mpa, preferably 0.05～0.30mpa, and process time is 1.0～4.0 hours.

In step (4), aqueous medium adds little crystal grain nh₄Nay molecular sieve (solid-liquid weight is than 1:4 ~ 1:8), stirring is simultaneously It is warmed up to 90～120 DEG C, is then added dropwise to hexafluorosilicic acid aqueous ammonium, constant temperature stirs 1～2 hour after completion of dropping, separate Molecular sieve and by-product, and filter, be dried.Concentration 10wt% of hexafluorosilicic acid aqueous ammonium ~ 40wt%, ammonium hexafluorosilicate addition For little crystal grain nh₄10wt% ~ the 50wt% of nay molecular sieve

In step (5), by the molecular sieve after hydrothermal treatment consists with acid and contain 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 hydrochloric acid, carbonic acid, nitric acid, in sulphuric acid One or more, containing nh₄ ⁺Salt be one or more of 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 be 70～120 DEG C, exchange serosity in molecular sieve Concentration be 0.1～0.5g/ml, swap time be 0.5～3.0 hour, exchange step may be repeated 1～4 time.Then remove Mother solution, washes with water, is dried.

Other operating procedures in the Modified Y Zeolites preparation method of the present invention, such as ammonium salt exchange can be normal using this area The operational approach of rule and condition, specific as follows: with nay molecular sieve as raw material, with solubility ammonium salt such as ammonium chloride, ammonium carbonate, nitre The aqueous solution of sour ammonium, ammonium sulfate, ammonium acetate, ammonium oxalate, ammonium citrate etc., the concentration of ammonium salt solution is 0.5～5.0mol/l.? 70～120 DEG C, at preferably 80～100 DEG C exchange 0.5～3.0 hour, y molecular sieve exchange serosity in concentration be 0.05～ 0.50g/ml, repeated exchanged l～5 time, filter off mother solution, washing, be dried.

Adhesive therefor of the present invention is made up of little porous aluminum oxide and mineral acid and/or organic acid.Aperture oxidation used Aluminum pore volume is 0.3～0.5 ml/g, and specific surface area is 200～400m²/g.

In catalyst carrier of the present invention, amorphous silica-alumina used can be prepared by coprecipitation or grafting copolymerization process, by document Prepared by middle conventional method.Sio in prepared amorphous silica-alumina₂Weight content be 20%～60%, preferably 25%～ 40%, the pore volume of amorphous silica-alumina is 0.6～1.1 ml/g, preferably 0.8～1.0 ml/g, and specific surface area is 300～500 m²/ g, preferably 350～500 m²/g.

Catalyst of the present invention can carry out molding according to actual needs, and shape can be cylindrical bars, Herba Trifolii Pratentis etc..Become in catalyst During type, shaping assistant can also be added, such as peptization acid, extrusion aid etc..Catalyst carrier of the present invention is using conventional method It is dried and roasting, specific as follows: through 80 ~ 150 DEG C of dryings 3 ~ 10 hours, in 500 ~ 600 DEG C of roastings 3 ~ 6 hours.

When catalyst carrier of the present invention is used for preparing hydrocracking catalyst, can be using conventional load side in prior art Method, preferably infusion process, can be saturation leaching, excessive leaching or complexation leaching, be catalyzed with the solution impregnation containing required active component Agent carrier, the carrier after dipping, after drying, roasting, is obtained final hydrocracking catalyst.

Carrier of hydrocracking catalyst of the present invention due to using little crystal grain y type molecular sieve as acidic components, this molecular sieve Have the characteristics that high silica alumina ratio, high-crystallinity, secondary pore be many, bigger serface, match with amorphous silica-alumina, be particularly suitable for making For middle oil type hydrocracking catalyst carrier.

In carrier of hydrocracking catalyst preparation method of the present invention, little crystal grain y molecular sieve used, its nay type molecular sieve The silica alumina ratio of raw material is higher, and degree of crystallinity is high, good stability, so in follow-up modification process, especially in dealumination complement silicon Just carry out hydrothermal treatment consists before, be so conducive to improving the ratio shared by secondary pore of molecular sieve, and special due to raw material Property makes molecular sieve remain in that good stability through hydrothermal treatment consists, is also beneficial to follow-up dealumination complement silicon, acid treatment Carry out, and do not affect the stability of final molecular sieve.The little crystal grain y type molecular sieve of the method preparation being provided with the present invention is obtaining Higher sio₂/a1₂o₃While mol ratio, the ratio shared by secondary pore is higher, and maintains the stability of y type molecular sieve, Molecular sieve has higher specific surface area and higher degree of crystallinity.The little crystal grain y type molecular sieve of the present invention, as Cracking Component, has Beneficial to the macromole improving in raw material diffusion rate in the catalyst, can preferably play molecular sieve as acid cracking center Performance, it is to avoid second pyrolysises, reduce carbon deposit, thus catalyst can be made to have good activity, middle distillates oil selectivity and excellent Product property.

In addition it is Cracking Component using small crystal grain molecular sieve in carrier of the present invention, there is bigger external surface area and more outer Active sites, are conducive to improving macromole hydrocarbon cracking capability, and can make by this molecular sieve is being hydrocracked of active component The activity increase of catalyst, can advantageously promote the performance of catalyst hydrogenation performance simultaneously.

Specific embodiment

In order to the present invention is better described, to further illustrate the present invention with reference to embodiment and comparative example.But this Bright scope is not limited solely to the scope of these embodiments.Analysis method of the present invention: specific surface area, pore volume adopt low temperature liquid nitrogen physics Absorption method, relative crystallinity and cell parameter adopt x optical diffraction method, and silica alumina ratio adopts chemical method, and the crystal grain of molecular sieve is big Measure by the way of little (scanning electron microscope) using sem.Wt% is mass fraction.

Embodiment 1

The present embodiment is preparing raw material little crystal grain nay type molecular sieve

The preparation of ny-1

(1) preparation of directed agents: take 8g sodium hydrate solid to be dissolved in 80g water, add sodium metaaluminate 2.5 g (al₂o₃ Content is 45wt%, na₂O content is 41wt%), then add 40g waterglass (sio₂Content is 28wt%, na₂O content is 8 Wt%), in 18 DEG C of stirring 4 hours prepared directed agents of ageing after mix homogeneously.

(2) preparation of amorphous silica-alumina predecessor

It is 100g a1 that solid sodium aluminate is configured to 0.3l concentration₂o₃/ l sodium aluminate working solution (a).By strong aqua ammonia plus Enter appropriate distilled water diluting and become about 10wt% weak ammonia (b).Take containing sio₂The sodium silicate solution of 28wt%, then it is dense to be diluted to 0.5l Spend for 140g sio₂/ l sodium silicate working solution (c).Take one 5 liters of steel retort, add 0.5 liter of distilled water in tank and stir Mix after being heated to 70 DEG C, open the valve having (a) and (b) and (c) Sulfur capacity device respectively simultaneously, control the flow of (a) and (c) with Make the neutralization reaction time at 40 minutes, and the flow of adjustment (b) rapidly makes the ph value of system be maintained at 7～8, and control system Temperature is at 60 DEG C about.After the completion of reacting aluminum sulfate, stop adding (b), the addition of (c) is 0.17l, the silicon-aluminum sol of generation After stablizing 20 minutes, continuously add (c) 0.33l, add in 10 minutes, start the ageing process of system, keep ph value 8.0, Temperature 60 C, aging 30 minutes.

(3) preparation of gel

1l h is added in the serosity obtained by step (2)₂o、140g sio₂/ l sodium silicate working solution 0.6l and step (1) directed agents 100g prepared, the ph value of gel is 11.5,15 DEG C of controlling reaction temperature, and uniform stirring 30 minutes staticizes 2.5 Hour.

(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, washing, dry nay zeolite product ny-1, property is listed in table l.

The preparation of ny-2

(1) preparation of directed agents: take 10 g sodium hydrate solids to be dissolved in 90g water, add sodium metaaluminate 3 g (al₂o₃ Content is 45wt%, na₂O content is 41wt%), then add 50g waterglass (sio₂Content is 28wt%, na₂O content is 8wt%), in 20 DEG C of stirring 4 hours prepared directed agents of ageing after mix homogeneously.

(2) preparation of amorphous silica-alumina predecessor

It is 80g a1 that Solid aluminum sulfate is configured to 0.5l concentration₂o₃/ l aluminum sulfate working solution (a).Strong aqua ammonia is added Appropriate distilled water diluting becomes about 10wt% weak ammonia (b).Take containing sio₂The sodium silicate solution of 28wt%, then it is diluted to 0.4l concentration For 150g sio₂/ l sodium silicate working solution (c).Take one 5 liters of steel retort, add 0.5 liter of distilled water in tank and stir After being heated to 70 DEG C, open the valve having (a) and (b) and (c) container respectively simultaneously, control the flow of (a) and (c) so that in With the response time at 40 minutes, and the flow of adjustment (b) rapidly makes the ph value of system be maintained at 7～8, and the temperature of control system At 60 DEG C about.After the completion of reacting aluminum sulfate, stop adding (b), the addition of (c) is 0.2l, and the silicon-aluminum sol of generation is stable After 20 minutes, continuously add (c) 0.2l, add in 10 minutes, start the ageing process of system, keep ph value 8.0, temperature 60 DEG C, aging 30 minutes.

(3) preparation of gel

1.2l h is added in the serosity obtained by step (2)₂o、150g sio₂/ l sodium silicate working solution 0.8l and step Suddenly directed agents 120g that prepared by (1), the ph value of gel is 12,30 DEG C of controlling reaction temperature, and uniform stirring 30 minutes staticizes 3 little When.

(4) crystallization

Gel obtained by step (2) is poured in stainless steel cauldron, stirs crystallization 6 hours at 80 DEG C, then heat up To 120 DEG C, stirring crystallization 5 hours, then filter, washing, dry nay zeolite product ny-2, property is listed in table l.

Embodiment 2

First ammonium exchange is carried out to raw material little crystal grain nay molecular sieve ny-1.Compound concentration is that 0.5mol/l ammonium nitrate is water-soluble 10 liters of liquid.Weigh 1000 grams of little crystal grain nay molecular sieve, be added in 10 liters of aqueous ammonium nitrate solutions preparing, speed of agitator is 300rpm, constant temperature stirring l hour at 90 DEG C, then filtering molecular sieve, and stay sample, analyze na₂O content；Repeat above-mentioned behaviour Make, na in molecular sieve₂O content reach 2.5wt%, obtain dried sample number into spectrum be nny-1.

Embodiment 3

First ammonium exchange is carried out to raw material little crystal grain nay molecular sieve ny-2.Compound concentration is that 0.8mol/l ammonium nitrate is water-soluble 10 liters of liquid.Weigh 1000 grams of little crystal grain nay molecular sieve, be added in 10 liters of aqueous ammonium nitrate solutions preparing, speed of agitator is 300rpm, constant temperature stirring l hour at 95 DEG C, then filtering molecular sieve, and stay sample, analyze na₂O content；Repeat above-mentioned behaviour Make, na in molecular sieve₂The content of o reaches 2.5wt%, and 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, with When maintain system water vapor pressure be 0.15mpa, process 2 hours, cooling, take out sample；Sample deionized water is pulled an oar, and Stirring under conditions of be brought rapidly up 95 DEG C, then with uniform speed in 2 hours Deca by 25 grams of ammonium hexafluorosilicate With the aqueous solution of 150m1 deionized water configuration, add rear slurry 2 hours of constant temperature under 95 DEG C of stirring conditions, stand 10 minutes, Through 3 washings, filter；Filter cake is contained nh with 500ml₄ ⁺And h⁺Concentration be respectively 0.6mol/l and 0.1mol/l mixing molten Liquid (ammonium chloride and hydrochloric acid) is processed, the non-framework aluminum in removing sample, and dealuminzation condition is to process 2 hours at 80 DEG C, and is gone with heat Ion water washing filter cake, stops washing, filter cake 120 DEG C of dryings 5 hours in an oven after 7 with the ph value of cleaning mixture, obtains Modified little crystal grain y-1, the physico-chemical property of y-1 is shown in Table 1.

Embodiment 5

Take 100 grams of nny-1 molecular sieves to be placed in heat-treatment furnace, control 400 DEG C/h of heating rate, 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 deionized water Making beating, and stirring under conditions of be brought rapidly up 90 DEG C, then with uniform speed in 2 hours Deca by 30 grams of hexafluoros Ammonium silicate and the aqueous solution of 150m1 deionized water configuration, add rear slurry 2 hours of constant temperature under 90 DEG C of stirring conditions, standing 10 minutes, through 3 washings, filter；Filter cake is contained nh with 400ml₄ ⁺And h⁺Concentration be respectively 0.8mol/l and 0.2mol/l Mixed solution (ammonium nitrate and nitric acid) process, the non-framework aluminum in removing sample, dealuminzation condition be process at 70 DEG C 3 little When, filter, and wash filter cake with hot deionized water, stop washing after 7 with the ph value of cleaning mixture, filter cake in an oven 120 DEG C drying 5 hours, obtains modified little crystal grain y-2, the physico-chemical property of y-2 is shown in Table 1.

Embodiment 6

Take 100 grams of nny-2 molecular sieves to be placed in heat-treatment furnace, control 400 DEG C/h of heating rate, temperature is risen to 700 DEG C, maintain the steam partial pressure 0.1mpa of system simultaneously, process 2 hours, cooling, take out sample；Sample deionized water is beaten Slurry, and stirring under conditions of be brought rapidly up 100 DEG C, then with uniform speed in 2 hours Deca by 20 grams of hexafluoros Ammonium silicate and the aqueous solution of 150m1 deionized water configuration, add rear slurry 2 hours of constant temperature under 100 DEG C of stirring conditions, standing 10 minutes, through 3 washings, filter；Filter cake is contained nh with 400ml₄ ⁺And h⁺Concentration be respectively 1.0mol/l and 0.2mol/l Mixed solution (ammonium chloride and hydrochloric acid) process, the non-framework aluminum in removing sample, dealuminzation condition be process at 75 DEG C 3 little When filter, and wash filter cake with hot deionized water, stop washing after 7 with the ph value of cleaning mixture, 120 DEG C in an oven of filter cake It is dried 6 hours, obtain modified little crystal grain y-3.The physico-chemical property of y-3 is shown in Table 1.

Embodiment 7

By 25 grams of y-1 molecular sieves (butt 90wt%), 106.5 grams of amorphous silica-aluminas (pore volume 0.9ml/g, than

Surface area 350m²/ g, butt 70wt%), (butt 20wt%, nitric acid is rubbed 120 grams of binding agents with little porous aluminum oxide You are than being 0.25) put into mixed grind in chaser, add water, be rolled into paste, extrusion, extrusion bar in 110 DEG C of dryings 4 hours, then In 550 DEG C of roastings 4 hours, obtain carrier tcat-1, property is shown in Table 2.

Embodiment 8

By 30 grams of y-2 molecular sieves (butt 90wt%), 100 grams of amorphous silica-aluminas (pore volume 0.9ml/g, than

Surface area 350m²/ g, butt 70wt%), (butt 20wt%, nitric acid is rubbed 120 grams of binding agents with little porous aluminum oxide You are than being 0.25) put into mixed grind in chaser, add water, be rolled into paste, extrusion, extrusion bar in 110 DEG C of dryings 4 hours, then In 550 DEG C of roastings 4 hours, obtain carrier tcat-2, property is shown in Table 2.

Embodiment 9

By 40 grams of y-3 molecular sieves (butt 90wt%), 90 grams of amorphous silica-aluminas (pore volume 0.9ml/g, specific surface areas 350m²/ G, butt 70wt%), 120 grams of binding agents (butt 20wt%, nitric acid is 0.25 with the mol ratio of little porous aluminum oxide) put into and roll Mixed grind in machine, adds water, and is rolled into paste, extrusion, extrusion bar, in 110 DEG C of dryings 4 hours, then in 550 DEG C of roastings 4 hours, obtains Carrier tcat-3.

The impregnation liquid room temperature immersion of carrier tungstenic and nickel 2 hours, 120 DEG C of dryings 4 hours, 500 DEG C of roastings 4 of temperature programming Hour, obtain catalyst cat-3, carrier and corresponding catalyst property are shown in Table 2.

Comparative example 1

1st, little crystal grain nay is prepared with reference to cn101722023a.

In this comparative example, feedstock property used 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, sequentially adds 59.4ml sulfur in the waterglass of 208ml Sour aluminum, the low sodium metaaluminate of 62.7ml and 42.2ml directed agents, then constant temperature constant speed stirring 1.5 hours, then by the conjunction obtaining Become liquid static aging 8 hours at the temperature disclosed above, obtain gel.

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

2nd, ammonium exchange is carried out to raw material little crystal grain nay molecular sieve, treatment conditions, with embodiment 2, obtain dried sample Numbering is cnny-1.

3rd, cnny-1 is carried out with subsequent treatment, processing mode and condition, with embodiment 4, obtain Reference Product cy-1.cy-1 Physico-chemical property be shown in Table 1.

4th, by 30 grams of cy-1 molecular sieves (butt 90wt%), 100 grams of amorphous silica-aluminas (pore volume 0.9ml/g, than

Surface area 350m²/ g, butt 70wt%), (butt 20wt%, nitric acid is rubbed 120 grams of binding agents with little porous aluminum oxide You are than being 0.25) put into mixed grind in chaser, add water, be rolled into paste, extrusion, extrusion bar in 110 DEG C of dryings 4 hours, then In 550 DEG C of roastings 4 hours, obtain carrier tccat-1.

The impregnation liquid room temperature immersion of carrier tungstenic and nickel 2 hours, 120 DEG C of dryings 4 hours, 500 DEG C of roastings 4 of temperature programming Hour, obtain catalyst ccat-1, carrier and corresponding catalyst property are shown in Table 2.

Comparative example 2

1st, little crystal 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.

14.21g water is positioned in beaker, controls temperature of liquid in beaker to be 60 DEG C, be simultaneously introduced under quick 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, in 60 DEG C of stirring crystallization 6 hours, then heat to 100 DEG C of static crystallizations 60 hours, then filter, washing, dry cny-2 molecular sieve.

2nd, ammonium exchange is carried out to raw material little crystal grain nay molecular sieve, treatment conditions, with embodiment 2, obtain dried sample Numbering is cnny-2.

3rd, cnny-2 is carried out with subsequent treatment, processing mode and condition, with embodiment 4, obtain Reference Product cy-2.cy-2 Physico-chemical property be shown in Table 2.

4th, by 30 grams of cy-2 molecular sieves (butt 90wt%), 100 grams of amorphous silica-aluminas (pore volume 0.9ml/g, specific surface areas 350m²/ g, butt 70wt%), 120 grams of binding agents (butt 20wt%, nitric acid is 0.25 with the mol ratio of little porous aluminum oxide) put Enter mixed grind in chaser, add water, be rolled into paste, extrusion, extrusion bar is in 110 DEG C of dryings 4 hours, then little in 550 DEG C of roastings 4 When, obtain carrier tccat-2, property is shown in Table 2.

Comparative example 3

1st, little crystal grain nay preparation.

(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 it is diluted to concentration for 100g sio₂/ l sodium silicate working solution.1l sodium aluminate working solution is taken to be placed in plastic cans In, it is subsequently adding 0.6l sodium silicate working solution, 20 DEG C of controlling reaction temperature, be passed through the co that concentration is 50v%₂Gas, when ph value Reach and when 10.0, stop logical co₂, then divulge information and stablize 20 minutes.

(3) preparation of gel is with embodiment 1.

(4) crystallization, with embodiment 1, obtains product cny-3, and product property is shown in Table 1.

2nd, ammonium exchange is carried out to raw material little crystal grain nay molecular sieve, treatment conditions, with embodiment 2, obtain dried sample Numbering is cnny-3.

3rd, cnny-3 is carried out with subsequent treatment, processing mode and condition, with embodiment 4, obtain Reference Product cy-3.cy-3 Physico-chemical property be shown in Table 2.

4th, by 40 grams of cy-3 molecular sieves (butt 90wt%), 90 grams of amorphous silica-aluminas (pore volume 0.9ml/g, specific surface areas 350m²/ g, butt 70wt%), 120 grams of binding agents (butt 20wt%, nitric acid is 0.25 with the mol ratio of little porous aluminum oxide) put Enter mixed grind in chaser, add water, be rolled into paste, extrusion, extrusion bar is in 110 DEG C of dryings 4 hours, then little in 550 DEG C of roastings 4 When, obtain carrier tccat-3, property is shown in Table 2.

Comparative example 4

1st, with the cnny-1 of comparative example 1 preparation as raw material, the method then adopting cn200910165116.x is modified, specifically As follows: to take 100 grams of cnny-1 100ml deionized water making beating, and be brought rapidly up 95 DEG C under conditions of stirring, then with equal Even speed Deca in 2 hours, by the aqueous solution of 25 grams of ammonium hexafluorosilicate and the configuration of 150m1 deionized water, adds rear slurry 2 hours of constant temperature under 95 DEG C of stirring conditions, stand 10 minutes, through 3 washings, filter, be dried；By sample after above-mentioned drying It is placed in heat-treatment furnace, controls the heating rate of 500 DEG C/h, temperature is risen to 600 DEG C, maintain the water vapor pressure of system simultaneously For 0.15mpa, process 2 hours, cooling, take out sample；Final sample contains al with 400ml³⁺And h⁺Concentration be respectively 1.0mol/ The mixed solution (aluminum nitrate and nitric acid) of l and 0.5mol/l removes the non-framework aluminum in sample, and dealuminzation condition is to process at 80 DEG C 2 hours, and wash filter cake with hot deionized water, washing, 120 DEG C in an oven of filter cake are stopped after 7 with the ph value of cleaning mixture It is dried 5 hours, obtain cy-4.The physico-chemical property of cy-4 is shown in Table 1.

2nd, by 40 grams of cy-4 molecular sieves (butt 90wt%), 90 grams of amorphous silica-aluminas (pore volume 0.9ml/g, specific surface areas 350m²/ g, butt 70wt%), 120 grams of binding agents (butt 20wt%, nitric acid is 0.25 with the mol ratio of little porous aluminum oxide) put Enter mixed grind in chaser, add water, be rolled into paste, extrusion, extrusion bar is in 110 DEG C of dryings 4 hours, then little in 550 DEG C of roastings 4 When, obtain carrier tccat-4.

The impregnation liquid room temperature immersion of carrier tungstenic and nickel 2 hours, 120 DEG C of dryings 4 hours, 500 DEG C of roastings 4 of temperature programming Hour, obtain catalyst ccat-4, carrier and corresponding catalyst property are shown in Table 2.

Comparative example 5

1st, little crystal grain nay is prepared with reference to cn92105661.3

Feedstock property used by nay 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: sequentially add the low sodium metaaluminate of 60ml aluminum sulfate, 60ml in the waterglass of 220ml, Then constant temperature constant speed stirs 0.5 hour, prepared silica-alumina gel.

(3) crystallization: under agitation, in 30 minutes, the gel in synthesis reactor is raised to 140 DEG C, constant temperature stirs 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 product cny-5, product property is shown in Table 1.

2nd, ammonium exchange is carried out to raw material little crystal grain nay molecular sieve cny-5, treatment conditions, with embodiment 2, obtain dried Sample number into spectrum is cnny-5.

3rd, cnny-5 is carried out with subsequent treatment, processing mode and condition, with embodiment 4, obtain Reference Product cy-5.cy-5 Physico-chemical property be shown in Table 1.

4th, by 30 grams of cy-5 molecular sieves (butt 90wt%), 100 grams of amorphous silica-aluminas (pore volume 0.9ml/g, specific surface areas 350m²/ g, butt 70wt%), 120 grams of binding agents (butt 20wt%, nitric acid is 0.25 with the mol ratio of little porous aluminum oxide) put Enter mixed grind in chaser, add water, be rolled into paste, extrusion, extrusion bar is in 110 DEG C of dryings 4 hours, then little in 550 DEG C of roastings 4 When, obtain carrier tccat-5, carrier and corresponding catalyst property are shown in Table 2.

Comparative example 6

1st, take 100gnny-1, adopt the method for cn200910165116.x modified the nny-1 of the present invention, specifically modified Method, with comparative example 4, obtains Reference Product cy-6.The physico-chemical property of cy-6 is shown in Table 1.

2nd, by 40 grams of cy-6 molecular sieves (butt 90wt%), 90 grams of amorphous silica-aluminas (pore volume 0.9ml/g, specific surface areas 350m²/ g, butt 70wt%), 120 grams of binding agents (butt 20wt%, nitric acid is 0.25 with the mol ratio of little porous aluminum oxide) put Enter mixed grind in chaser, add water, be rolled into paste, extrusion, extrusion bar is in 110 DEG C of dryings 4 hours, then little in 550 DEG C of roastings 4 When, obtain carrier tccat-6.

The impregnation liquid room temperature immersion of carrier tungstenic and nickel 2 hours, 120 DEG C of dryings 4 hours, 500 DEG C of roastings 4 of temperature programming Hour, obtain catalyst ccat-6, carrier and corresponding catalyst property are shown in Table 2.

The property of table 1 y type molecular sieve

Production code member	ny-1	ny-2	y-1	y-2	y-3	cy-1	cy-2	cy-3	cy-4	cy-5	cy-6
												Feed intake sio2/al2o3Mol ratio	9.1	10.1
sio2/al2o3Mol ratio	7.5	8.4	66	84	105	50	25	28	63	24	65
												Specific surface area, m2/g	916	898	950	990	1020	892	780	805	921	711	935
Pore volume, ml/g	0.39	0.38	0.53	0.58	0.62	0.33	0.32	0.34	0.48	0.30	0.51
												Secondary pore (1.7-10nm), %			62.1	66.4	71.1	37.1	27.5	35.2	42.1	25.2	46.0
External surface area, m2/g	191	182	2161	249	240	170	159	190	189	145	209
												Lattice constant, nm	2.461	2.462	2.436	2.432	2.430	2.441	2.450	2.443	2.436	2.449	2.436
Relative crystallinity, %	101	110	115	118	116	95	80	85	116	78	117
												Average crystallite size, nm	380	430	380	380	430	400	450	400	400	450	400

Table 2 carrier and the physico-chemical property of catalyst

Bearer number	tcat-1	tcat-2	tcat-3	tccat-1	tccat-2	tccat-3	tccat-4	tccat-5	tccat-6
										Little crystal grain y molecular sieve, wt%	18	22	29	29	29	22	22	29	22
Amorphous silica-alumina, wt%	62	58	51	51	51	58	58	51	58
										Aluminium oxide, wt%	20	20	20	20	20	20	20	20	20
Specific surface area, m2/g	493	500	516	435	418	420	460	382	478
										Pore volume, ml/g	0.59	0.60	0.62	0.50	0.46	0.44	0.53	0.42	0.55
Pore size distribution (4-10nm), %	64	65	72	45	43	40	50	38	52
										Catalyst is numbered			cat-2	ccat-1			ccat-4		ccat-6
Specific surface area, m2/g			425	318			346		395
										Pore volume, ml/g			0.56	0.44			0.47		0.50
Pore size distribution (4-10nm), %			67	42			47		49

The invention described above catalyst cat-3 and comparative example catalyst ccat-1, ccat-4, ccat-6 are carried out activity rating Test.Test is carried out on 200ml small hydrogenation device, and using one-stage serial technological process, raw materials used oil nature is shown in Table 3.Operating condition is as follows: hydrogen dividing potential drop 14.7mpa, hydrogen to oil volume ratio 1500:1, air speed 1.5h^{- 1}, control cracking zone nitrogen content 5 ～10 g/g.Catalyst Activating Test the results are shown in Table 4.

Table 3 raw material oil nature

Raw oil	Iranian vgo
		Density (20 DEG C), g/cm3	0.9025
Boiling range, DEG C	308～560
		Condensation point, DEG C	33
Acid number, mgkoh/g	0.53
		Carbon residue, wt%	0.2
S, wt%	1.5
		N, wt%	0.11
C, wt%	84.93
		H, wt%	12.52
Aromatic hydrocarbons, wt%	39.2
		Bmci value	41.5
Refractive power/nd 70	1.48570

Table 4 catalyst activity evaluation result

Catalyst is numbered	cat-3	ccat-1	ccat-4	ccat-6
					Reaction temperature, DEG C	378	383	382	381
< 370 DEG C of conversion ratios, wt%	65.0	64.8	64.5	65.2
					Middle distillates oil selectivity, %(132～370 DEG C)	86.9	81.1	83.5	84.5
Major product property
					Jet fuel (132 ~ 282 DEG C)
Freezing point, DEG C	< -60	< -60	< -60	< -60
					Aromatic hydrocarbons, wt%	3.3	4.2	4.0	3.9
Smoke point, mm	27	26	26	26
					Diesel oil (282 ~ 370 DEG C)
Cetane number	64	59	60	61
					Condensation point, DEG C	-7	-1	-3	-3

Be can be seen that by the evaluation result of table 4 catalyst, the catalyst prepared by the present invention, on the basis of greater activity, has There is good selectivity, product property is good.

Claims (29)

1. a kind of carrier of hydrocracking catalyst, including little crystal grain y molecular sieve, aluminium oxide and amorphous silica-alumina, wherein said Little crystal grain y molecular sieve, its property is as follows: sio₂/a1₂o₃Mol ratio is 40～120, and average grain diameter is 200～700nm, phase To degree of crystallinity more than 100%, lattice constant 2.425～2.450nm, specific surface area is 850～1000m²/ g, pore volume is 0.40 Pore volume shared by the secondary pore of～0.60ml/g, 1.7～10nm accounts for more than 50%, na of total pore volume₂O content≤0.15wt%.

2. according to the catalyst carrier described in claim 1 it is characterised in that the relative crystallization of described little crystal grain y type molecular sieve Spend for 100%～120%.

3. according to the catalyst carrier described in claim 1 it is characterised in that in described little crystal grain y type molecular sieve, 1.7～ Pore volume shared by the secondary pore of 10nm accounts for the 50%～80% of total pore volume.

4. according to the catalyst carrier described in claim 1 it is characterised in that in described little crystal grain y type molecular sieve, 1.7～ Pore volume shared by the secondary pore of 10nm accounts for the 55%～75% of total pore volume.

5. according to the catalyst carrier described in claim 1 it is characterised in that the lattice constant of described little crystal grain y type molecular sieve For 2.425～2.440.

6. according to the catalyst carrier described in claim 1 it is characterised in that described catalyst support properties are as follows: specific surface area It is 450～650m²/ g, pore volume is 0.5～0.80ml/g, and the pore volume of aperture 4～10nm accounts for the 55%～90% of total pore volume.

7. according to the catalyst carrier described in claim 1 it is characterised in that in described carrier of hydrocracking catalyst, to carry On the basis of the weight of body, its composition includes: the content of little crystal grain y type molecular sieve is 5wt%～40wt%, the content of amorphous silica-alumina For 20wt%～65wt%, the content of aluminium oxide is 10wt%～40wt%.

8. according to the catalyst carrier described in claim 1 it is characterised in that in described carrier of hydrocracking catalyst, to carry On the basis of the weight of body, the content of little crystal grain y type molecular sieve is 10wt%～25wt%, the content of amorphous silica-alumina be 30wt%～ 60wt%, the content of aluminium oxide is 15wt%～30wt%.

9. the preparation method of the arbitrary described catalyst carrier of claim 1～8, comprising: by little crystal grain y type molecular sieve, amorphous Sial and the binding agent mixing made with aluminium oxide, extruded moulding, then drying and roasting, make carrier.

10. in accordance with the method for claim 9 it is characterised in that the preparation method of described little crystal grain y type molecular sieve, comprising:

(1) preparation of little crystal grain nay type molecular sieve；

(2) little crystal grain nay type molecular sieve is prepared into na₂Little crystal grain nh of o content≤2.5wt%₄nay；

(3) little crystal grain nh is obtained to step (2)₄Nay molecular sieve carries out hydrothermal treatment consists；

(4) molecular sieve of step (3) gained carries out dealumination complement silicon with hexafluorosilicic acid aqueous ammonium, the molecular sieve obtaining and by-product Separate；

(5) molecular sieve obtaining step (4) is with containing nh₄ ⁺And h⁺Mixed solution process, be washed out and be dried, obtain little Crystal Particle Size Y Zeolites,

Little crystal grain nay molecular sieve wherein used by step (1), its property is as follows: sio₂/al₂o₃Mol ratio is not more than 6.0 and high In 9.0, average grain diameter is 200～700nm, specific surface 800～1000m²/ g, pore volume 0.30～0.45ml/g, tie relatively Brilliant degree is 90%～130%, and cell parameter is 2.460～2.470nm, through relative crystallinity after 650 DEG C of in the air roastings 3 hours For more than 90%, it is more than 90% through relative crystallinity after 700 DEG C of water vapour hydrothermal treatment consists 2 hours.

11. in accordance with the method for claim 10 it is characterised in that: the sio of little crystal grain nay molecular sieve used₂/al₂o₃Rub That ratio is 6.5～9.0.

12. in accordance with the method for claim 10 it is characterised in that: the sio of little crystal grain nay molecular sieve used₂/al₂o₃Rub That ratio is 7.0～8.0.

13. in accordance with the method for claim 10 it is characterised in that: the crystal grain of little crystal grain nay molecular sieve used is averagely straight Footpath is 300～500nm.

14. in accordance with the method for claim 10 it is characterised in that: little crystal grain nay molecular sieve used is through 650 DEG C of in the airs After roasting 3 hours, relative crystallinity is 90%～110%, through relative crystallinity after 700 DEG C of water vapour hydrothermal treatment consists 2 hours is 90%～110%.

15. in accordance with the method for claim 10 it is characterised in that: the preparation method of little crystal grain nay molecular sieve used, bag Include:

I, preparation directed agents: silicon source, silicon source, alkali source and water are fed intake according to following proportioning: (6～30) na₂O:al₂o₃: (6～ 30)sio₂: (100～460) h₂O, after stirring, mixture is stirred at 0～20 DEG C ageing 0.5～24 hour and is obtained and lead To agent；

Ii, adopt 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 as 40wt%～75wt%；Its preparation process includes:

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

The part sodium silicate solution adding step a to prepare in b, the sodium aluminate solution prepared to step a, then passes 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 and always leads to Enter amount 60%～100% when, add remainder sodium silicate solution, wherein in step b, remainder sodium silicate solution is with dioxy SiClx meter accounts for step b and adds 5wt%～85wt% in terms of silicon dioxide for the sodium silicate solution total amount；

C, at the control temperature and ph value of step b, said mixture ventilation 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 Than, 0～40 DEG C quick stir under conditions of to the amorphous silica-alumina predecessor of step ii gained in add water, silicon source, guiding Agent and alkali source, and control ph value for 9.5～12.0, uniform stirring, obtain silica-alumina gel；Wherein directed agents addition accounts for sial and coagulates The 1%～20% of glue weight,

Iv, the reactant mixture of step iii gained are through two step dynamic crystallizations, then through filtering, wash, and are dried, obtain little crystal grain nay The condition that molecular sieve, the wherein first step carry out dynamic crystallization is as follows: at 50～90 DEG C, crystallization time is 0.5～18 to temperature control Hour；The condition that second step carries out dynamic crystallization is as follows: at 80～140 DEG C, crystallization time is 3～10 hours to temperature control.

16. in accordance with the method for claim 15 it is characterised in that in step ii, amorphous silica-alumina predecessor, with amorphous On the basis of the weight of the butt of sial predecessor, content that silicon is counted with silicon dioxide as 55wt%～70wt%.

17. in accordance with the method for claim 15 it is characterised in that: step b controlling reaction temperature be 15～35 DEG C.

18. in accordance with the method for claim 15 it is characterised in that: in step b, as the co being passed through₂Gas flow accounts for total intake 80%～100% when, add remainder sodium silicate solution.

19. in accordance with the method for claim 15 it is characterised in that: in step b, remainder sodium silicate solution is with titanium dioxide Silicon meter accounts for step b and adds 30wt%～70wt% in terms of silicon dioxide for the sodium silicate solution total amount.

20. in accordance with the method for claim 15 it is characterised in that in step i and iii, silicon source, alkali source are respectively selected from silicic acid Sodium and sodium hydroxide, in step i, silicon source is selected from sodium metaaluminate.

21. in accordance with the method for claim 15 it is characterised in that in step iii, 10～30 DEG C of controlling reaction temperature, ph value 10～11.

22. in accordance with the method for claim 15 it is characterised in that step iv adopts two step dynamic crystallizations, the wherein first stepping The condition of Mobile state crystallization is as follows: at 60～80 DEG C, crystallization time is 1～10 hour to temperature control；It is brilliant that second step enters Mobile state The condition changed is as follows: at 80～120 DEG C, crystallization time is 5～10 hours to temperature control.

23. in accordance with the method for claim 10 it is characterised in that in step (3), 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 process time is 1.0～4.0 hours.

24. in accordance with the method for claim 10 it is characterised in that in step (3), 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 process time is 1.0～4.0 hours.

25. in accordance with the method for claim 10 it is characterised in that in step (4), compare 1:4 by solid-liquid weight in aqueous medium ～1:8 adds little crystal grain nh₄Nay molecular sieve, stirs and is warmed up to 90～120 DEG C, is then added dropwise to hexafluorosilicic acid aqueous ammonium, Constant temperature stirring after completion of dropping, separates molecular sieve and by-product, and filters, is dried, and wherein hexafluorosilicic acid aqueous ammonium is dense Degree 10wt%～40wt%, ammonium hexafluorosilicate addition is little crystal grain nh₄10wt%～the 50wt% of nay molecular sieve.

26. in accordance with the method for claim 10 it is characterised in that in step (5), by the molecular sieve after hydrothermal treatment consists and acid With containing nh₄ ⁺Salt composition mixed solution contact, exchange molecular sieve in na⁺With removing molecular sieve in part non-framework aluminum, Acid therein is one or more of hydrochloric acid, carbonic acid, nitric acid, sulphuric acid, containing nh₄ ⁺Salt be in the ammonium salt containing above acid group one Plant or multiple；H in mixed solution⁺Concentration be 0.05～0.6mol/l, nh₄ ⁺Concentration be 0.5～3.0mol/l, exchange temperature For 70～120 DEG C, the concentration exchanging molecular sieve in serosity is 0.1～0.5g/ml, and swap time is 0.5～3.0 hour, exchanges Step repeats 1～4 time.

27. in accordance with the method for claim 10 it is characterised in that: step (2) adopt ammonium salt exchange method, process is such as Under: with nay molecular sieve as raw material, exchanged 0.5～3.0 hour at 70～120 DEG C with the aqueous solution of solubility ammonium salt, molecular sieve Concentration in exchanging serosity is 0.05～0.50g/ml, repeated exchanged l～5 time, filters off mother solution, washing, is dried；Ammonium salt is chlorine Change one or more of ammonium, ammonium carbonate, ammonium nitrate, ammonium sulfate, ammonium acetate, ammonium oxalate, ammonium citrate, the concentration of ammonium salt solution For 0.5～5.0mol/l.

28. in accordance with the method for claim 9 it is characterised in that: sio in described amorphous silica-alumina₂Weight content be 20%～60%, the pore volume of amorphous silica-alumina is 0.6～1.1ml/g, and specific surface area is 300～500m²/g.

29. in accordance with the method for claim 9 it is characterised in that: the drying of carrier and roasting condition are as follows: through 80～150 DEG C drying 3～10 hours, in 500～600 DEG C of roastings 3～6 hours.