CN104588078B - Hydrocracking catalyst and preparation method thereof - Google Patents

Abstract

The invention discloses a hydrocracking catalyst and a preparation method thereof. The catalyst comprises a hydrogenation active metal component and a carrier prepared from a small grain Y type molecular sieve, amorphous silicon aluminum and alumina. According to the preparation method, the small grain Y type molecular sieve with the characteristics of great dealumination depth, good crystallinity retentivity and well-developed secondary pores is used as an acid component and cooperates with the amorphous silicon aluminum and the hydrogenation active metal component to form the hydrocracking catalyst. The hydrocracking catalyst has the advantages of better activity and stability, higher product selectivity and superior product quality.

Description

A kind of hydrocracking catalyst and preparation method thereof

Technical field

The present invention relates to a kind of hydrocracking catalyst and preparation method thereof, more specifically a kind of to contain small-grain Y-type Middle oil type hydrocracking catalyst of molecular sieve and preparation method thereof.

Background technology

As international refined products market is continuously increased to the demand of intermediate oil, 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.As there is the technique raw material to adapt to Property strong, good product quality, adjust flexible operation, midbarrel product yield is high, the features such as product structure is flexible so that hydrogenation splits The status of chemical industry skill becomes more and more important, particular for China be faced with present petroleum resources shortage, environmental requirement it is 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, increase the effective technology measure of market adaptability to changes, it has also become the of paramount importance technique dress in modernization refinery Put.Exactly these factors promote high selectivity to middle distillates hydrocracking technology and rapidly develop, and hydrocracking catalyst is The key of the technology.

Carrier is the important component part of catalyst, not only provides dispersion place for metal active constituent, while carrier sheet Body also assists in reaction, cooperates with and complete whole catalytic reaction together with other active components, and hydrocracking catalyst is a kind of pair of work( Energy catalyst, it contains acidic components and hydrogenation component simultaneously.Hydrogenation activity is selected generally from VI B races in the periodic table of elements and VIII race's metal is provided；And its acidic components is mainly provided by zeolite and inorganic oxide, major part is with aluminium oxide or without fixed Shape sial is carrier, is equipped with a certain amount of molecular sieve.And the key component that cracking is played in such catalyst is usually Y molecules Sieve, the quality of Y molecular sieve performance directly affect the performance and product quality of catalyst.

Y type molecular sieve is at present universal in residual oil cracking field cracking active component, and crystal grain is generally 1000nm or so, its crystal grain are larger, and duct is relatively long, and diffusional resistance is big, and macromole is difficult to be reacted into 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 types 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 with more superior catalytic perfomance.Meanwhile, reducing Y type molecular sieve crystallite dimension can be with Improve inner surface active sites utilization rate.In general, diffusion of the reactant molecule in molecular sieve endoporus duct 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.It is the best way to shorten the evolving path.The effective way that micropore diffusion is limited is overcome to be to reduce zeolite crystal Size.This can not only increase the external surface area of zeolite crystal, and while shorten diffusion length.EP0204236 is to little Crystal NaY molecular sieve and big crystal grain NaY molecular sieve are compared, and are as a result shown, the former has higher to RFCC Active and preferable selectivity.

Small crystal grain NaY molecular sieve is that do not possess acidity, and needs are modified process, to meet the performance of Cracking catalyst Require.CN1382632A discloses a kind of super stabilizing method of small-grain Y-type zeolite, and the method is to be dried gas with Silicon chloride. Body and fine grain NaY zeolitic contact, obtain after washing, due to the heat and hydrothermal stability of its raw material itself it is just poor, while The method is by the way of gas phase dealumination complement silicon to process molecular sieve, and this causes the heat and hydrothermal stability of product worse, activity It is low.Especially poor to heat stability and hydrothermal stability fine grain NaY zeolite, the sial framing structure stability in zeolite It is poor, the removing of framework aluminum is easily caused in modifying process, while also some framework silicon causes portion also with removing Skeleton is divided the phenomenon caved in occur so that the crystallization reservation degree of product is relatively low, and the activity of zeolite is not high.

CN200910188140.5 discloses a kind of hydrocracking catalyst and preparation method thereof.The catalyst includes hydrogenation The carrier of active metal component and small-grain Y molecular sieve, amorphous silica-alumina and aluminium oxide composition, wherein the small-grain Y-type point Son sieve be using hydrothermal treatment consists after small crystal grain Y-shaped molecular sieve.During raw materials used small crystal grain NaY molecular sieve is CN101722023A Prepared by disclosed method, i.e. SiO₂/Al₂O₃Mol ratio be 4.0～6.0, mean diameter in 100～700nm, after passing sequentially through The mixed aqueous solution of continuous modified i.e. ammonium exchange, ammonium hexafluorosilicate dealumination complement silicon, hydrothermal treatment consists, aluminium salt and acid is processed, and obtains little crystalline substance Grain Y molecular sieve.In the method, after needing first raw material is processed with ammonium hexafluorosilicate dealumination complement silicon, then the process such as hydrothermal treatment consists is carried out, The framing structure that molecular sieve could so be reduced is caved in, and improves the crystallization reservation degree of molecular sieve, but the method due to first with six After the process of ammonium fluosilicate dealumination complement silicon, due to there is sial isomorphous substitution, molecular sieve silica constructed of aluminium is than more complete, then enters water-filling Heat treatment, the secondary pore of formation are few, and secondary pore proportion is low, and used as catalyst molecule screen banks point, middle oil yield is low.

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

The content of the invention

For weak point of the prior art, the invention provides a kind of good hydrocracking catalyst of catalytic performance and Its preparation method.The hydrocracking catalyst is using there is provided a kind of high silica alumina ratio, high-crystallinity, secondary pore be more, Large ratio surface Long-pending small crystal grain Y-shaped molecular sieve has higher activity as acidic components, prepared hydrocracking catalyst, and middle grease separation is selected Property and excellent product property.

Hydrocracking catalyst of the present invention, including hydrogenation active metals component and by small-grain Y molecular sieve, aluminium oxide and nothing The carrier of amorphous silicon-alumina composition, wherein described small-grain Y molecular sieve, 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%, 2.425～2.450nm of lattice constant, preferably 2.425～2.440, specific surface area are 850～1000m²/ g, pore volume is Pore volume shared by the secondary pore of 0.40～0.60mL/g, 1.7～10nm is more than the 50%, preferably 50% ~ 80% of total pore volume, enters One step is preferably 55% ~ 75%, Na₂O content≤0.15wt%.

Hydrocracking catalyst property of the present invention is as follows：Specific surface area is 300～500 m²/ g, pore volume is 0.35～ 0.60mL/g.The pore volume of 4 ~ 10nm of aperture accounts for the 55%～90% of total pore volume, and preferably 65%～80%.

The hydrocracking catalyst of the present invention, described hydrogenation active metals are the metal of vib and/or the VIIIth race, Vib metals are preferably molybdenum and/or tungsten, and the metal of the VIIIth race is preferably cobalt and/or nickel.On the basis of the weight of catalyst, Vib metals（In terms of oxide）Content be 10wt%～30wt% and group VIII metal（In terms of oxide）Content be 4wt%～10wt%, the content of carrier is 61 wt%～86 wt%.

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

The preparation method of hydrocracking catalyst of the present invention, comprises the steps：

By small-grain Y molecular sieve, amorphous silica-alumina and with binding agent mechanical mixture, molding, Ran Hougan made by aluminium oxide Dry and roasting, makes catalyst carrier；Hydrogenation active metals component, drying and roasting are loaded in the catalyst carrier of gained, Make catalyst；

Wherein described small-grain Y molecular sieve, including following preparation process：

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

(2) fine grain NaY type molecular sieve is prepared into 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 obtained by step (3) carries out dealumination complement silicon with hexafluorosilicic acid aqueous ammonium, the molecular sieve for obtaining and pair Product is separated；

(5) molecular sieve for obtaining step (4) is with containing NH₄ ⁺And H⁺Mixed solution process, be washed out and be dried, obtain To small crystal grain Y-shaped molecular sieve.

Step（1）Described in small crystal grain NaY molecular sieve, 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 be 200～700nm, preferably 300～ 500nm；Specific surface area is 800～1000 m²/ g, preferably 850～950 m²/ g, 0.30/～0.45mL/g of pore volume are relative to tie Brilliant degree is 90%～130%, and cell parameter is 2.460～2.470nm, the relative crystallinity Jing after roasting in 650 DEG C of air 3 hours It is for more than 90%, generally 90%～110%, preferably 90% ~ 105%, relative Jing after 700 DEG C of water vapour hydrothermal treatment consists 2 hours Degree of crystallinity is more than 90%, generally 90%～110%, preferably 90% ~ 105%.

In the inventive method in step (1) fine grain NaY type molecular sieve preparation method, including：

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) H₂Mixture, after stirring, at 0～20 DEG C is stirred ageing and is obtained for 0.5～24 hour by O Directed agents；

II, using preparing amorphous silicon alumnium using carbonization predecessor, the weight with the butt of amorphous silica-alumina predecessor is 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 for adding step a to prepare in b, the sodium aluminate solution prepared to step a, then passes to CO₂ Gas, controlling reaction temperature are 10 ~ 40 DEG C, and preferably 15～35 DEG C, the pH value for 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

By (0.5～6) Na₂O：Al₂O₃：(8～15) SiO₂：(100～460) H₂Total molar ratio of O, at 0～40 DEG C To step under conditions of quick stirring（2）Water, silicon source, directed agents and alkali source are added in the amorphous silica-alumina predecessor of gained, 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%,

Two step dynamic crystallizations of reactant mixture Jing obtained by IV, step III, then Jing filtrations, washing, 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, preferable ph 10～ 11。

In step IV, the reactant mixture of gained carries out crystallization using 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, and after the completion of crystallization, then Jing is filtered, washs, done It is dry, product is obtained.Two step dynamic crystallization conditions are preferably as follows：The first step：Temperature control at 60～80 DEG C, crystallization time is 1～ 10 hours；Second step：At 80～120 DEG C, crystallization time is 5～10 hours to temperature control.

Step（3）In, the condition of described hydrothermal treatment consists is as follows：Treatment temperature is controlled at 500～750 DEG C, preferred to control At 600～700 DEG C, pressure is 0.01～0.50MPa, and preferably 0.05～0.30MPa, process time are 1.0～4.0 hours.

Step（4）In, little crystal grain NH is added in aqueous medium₄NaY molecular sieve（Solid-liquid weight compares 1：4~1：8）, stirring is simultaneously 90～120 DEG C are warmed up to, hexafluorosilicic acid aqueous ammonium is then added dropwise to, constant temperature is stirred 1～2 hour after completion of dropping, separated 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 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 hydrochloric acid, carbonic acid, nitric acid, in 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 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 molecular sieve preparation method of the present invention, such as ammonium salt are exchanged can be normal using this area The operational approach and condition of rule, it is 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, and washing is dried.

Detailed process prepared by carrier of hydrocracking catalyst of the present invention is：By small crystal grain Y-shaped molecular sieve, amorphous silicon aluminium Mix with binding agent, extruded moulding, be then dried 3～10 hours and at 500 DEG C～600 DEG C at a temperature of 80 DEG C～150 DEG C Roasting 3～6 hours, is prepared into carrier.

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 It is prepared by middle conventional method.SiO in obtained amorphous silica-alumina₂Weight content be 20%～60%, preferably 25%～ 40%, the pore volume of amorphous silica-alumina is 0.6～1.1 mL/g, and preferably 0.8～1.0 mL/g, specific surface area are 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..Catalyst into During type, shaping assistant, such as peptization acid, extrusion aid etc. can also be added.Catalyst carrier of the present invention is using conventional method It is dried and roasting, it is specific as follows：80 ~ 150 DEG C of Jing dryings 3 ~ 10 hours, in 500 ~ 600 DEG C of roastings 3 ~ 6 hours.

The load of catalyst activity metal of the present invention, can adopt conventional carrying method in prior art, preferred infusion process, Can be saturation leaching, excessive leaching or complexation leaching, i.e., with the solution impregnated catalyst carrier containing required active component, after dipping Carrier is dried l～12 hour at 100 DEG C～150 DEG C, then in 450 DEG C～550 DEG C roastings 3～6 hours, final catalysis is obtained Agent.

Hydrocracking catalyst of the present invention is used for hydrocracking process, is suitable for treatment of heavy hydrocarbon material, it is adaptable to this law Heavy charge scope it is very wide, they include vacuum gas oil (VGO), and coker gas oil, deasphalted oil, thermal cracking gas oil, catalysis split Change the various hydrocarbon-type oils such as gas oil, catalytic cracking recycle oil, can also be used in mixed way, raw material usually contains 300～600 DEG C of boiling point Hydro carbons, nitrogen content can be in 50～2500 g/ g.

The hydrocracking catalyst of the present invention is particularly well-suited to single hop once by, in method for hydrogen cracking, operating condition is such as Under：350～420 DEG C of reaction temperature, more preferably 360～390 DEG C, 6～20MPa of hydrogen dividing potential drop, more preferably 9～15MPa, hydrogen oil volume Than 500～2000:1, more preferably 800～1500：1,0.5～1.8 h of volume space velocity during liquid^-1, more preferably 0.8～1.5h^-1。

Hydrocracking catalyst of the present invention is as using small crystal grain Y-shaped molecular sieve, used as acidic components, the molecular sieve has High silica alumina ratio, high-crystallinity, secondary pore are more, bigger serface the characteristics of, with amorphous silica-alumina and hydrogenation active metals component It is engaged, is particularly suitable as middle oil type hydrocracking catalyst.

As, in method for preparing catalyst of the present invention, the silica alumina ratio of its NaY type Molecular sieve raw material is higher, degree of crystallinity is high, surely It is qualitative good, so in follow-up modification process, especially just carrying out hydrothermal treatment consists before dealumination complement silicon, being so conducive to The ratio shared by the secondary pore of molecular sieve is improved, and as the particularity of raw material makes molecular sieve still protect through hydrothermal treatment consists Good stability is held, follow-up dealumination complement silicon, the carrying out of acid treatment is also beneficial to, and is not affected stablizing for final molecular sieve Property.Higher SiO is being obtained with small crystal grain Y-shaped molecular sieve prepared by the method that the present invention is provided₂/A1₂O₃While mol ratio, Ratio shared by secondary pore is higher, and maintains the stability of Y type molecular sieve, molecular sieve have higher specific surface area and Higher degree of crystallinity.The present invention is conducive to the macromole improved in raw material to exist using small crystal grain Y-shaped molecular sieve as Cracking Component Diffusion rate in catalyst, can preferably play molecular sieve as the performance at acid cracking center, with amorphous silica-alumina and Hydrogenation active metals component is engaged, and energy hydrocracking catalyst has more preferable activity, stability, higher middle distillates oil selectivity More excellent product quality.

Specific embodiment

In order to the present invention is better described, the present invention is further illustrated 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-ray diffraction method, silica alumina ratio to adopt chemical method, and the crystal grain of molecular sieve is big It is little to be determined by the way of SEM (scanning electron microscope).Wt% is mass fraction.

Embodiment 1

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

The preparation of NY-1

（1）The preparation of directed agents：Take 8g sodium hydrate solids to be dissolved in 80g water, add 2.5 g (Al of sodium metaaluminate₂O₃ 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）The preparation of amorphous silica-alumina predecessor

Solid sodium aluminate is configured to into 0.3L concentration for 100g A1₂O₃ / L sodium aluminate working solutions（a）.By strong aqua ammonia plus Enter appropriate distilled water diluting into about 10wt% weak ammonia（b）.Take containing SiO₂The sodium silicate solution of 28wt%, then to be diluted to 0.5L dense Spend for 140g SiO₂/ L sodium silicate working solutions（c）.One 5 liters of steel retort is taken, 0.5 liter of distilled water is added in tank and is stirred Mix after being heated to 70 DEG C, while open having respectively（a）、（b）With（c）The valve of Sulfur capacity device, control（a）With（c）Flow with The neutralization reaction time is made at 40 minutes, and is adjusted rapidly（b）Flow make the pH value of system be maintained at 7～8, and control system Temperature is at 60 DEG C or so.After the completion of reacting aluminum sulfate, stop adding（b）,（c）Addition be 0.17L, the silicon-aluminum sol of generation After stablizing 20 minutes, continuously add（c）0.33L, added in 10 minutes, started the ageing process of system, kept pH value 8.0, Temperature 60 C, aging 30 minutes.

（3）The preparation of gel

In step（2）1L H are added in resulting serosity₂O、140g SiO₂/ L sodium silicate working solution 0.6L and step （1）Directed agents 100g of preparation, the pH value of gel is 11.5, and 15 DEG C of controlling reaction temperature, uniform stirring 30 minutes staticize 2.5 Hour.

（4）Crystallization

By step（2）Resulting gel is poured in stainless steel cauldron, is stirred crystallization 5 hours at 75 DEG C, is then heated up To 110 DEG C, stirring crystallization 7 hours, then filter, washing, dry NaY molecular sieve product NY-1, property is listed in table l.

The preparation of NY-2

（1）The preparation of directed agents：Take 10 g sodium hydrate solids to be dissolved in 90g water, add 3 g (Al of sodium metaaluminate₂O₃ 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）The preparation of amorphous silica-alumina predecessor

Solid aluminum sulfate is configured to into 0.5L concentration for 80g A1₂O₃ / L aluminum sulfate working solutions（a）.Strong aqua ammonia is added Appropriate distilled water diluting is into 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 solutions（c）.One 5 liters of steel retort is taken, 0.5 liter of distilled water is added in tank and is stirred After being heated to 70 DEG C, while open having respectively（a）、（b）With（c）The valve of container, control（a）With（c）Flow so that in With the response time at 40 minutes, and adjust rapidly（b）Flow make the pH value of system be maintained at 7～8, and the temperature of control system At 60 DEG C or so.After the completion of reacting aluminum sulfate, stop adding（b）,（c）Addition be 0.2L, the silicon-aluminum sol of generation is stable After 20 minutes, continuously add（c）0.2L, added in 10 minutes, started the ageing process of system, kept pH value 8.0, temperature 60 DEG C, aging 30 minutes.

（3）The preparation of gel

In step（2）1.2L H are added in resulting serosity₂O、150g SiO₂/ L sodium silicate working solution 0.8L and step Suddenly（1）Directed agents 120g of preparation, the pH value of gel is 12, and 30 DEG C of controlling reaction temperature, uniform stirring 30 minutes staticize 3 little When.

（4）Crystallization

By step（2）Resulting gel is poured in stainless steel cauldron, is stirred crystallization 6 hours at 80 DEG C, is then heated up To 120 DEG C, stirring crystallization 5 hours, then filter, washing, dry NaY molecular sieve product NY-2, property is listed in table l.

Embodiment 2

Ammonium exchange is carried out to raw material small crystal grain NaY molecular sieve NY-1 first.Compound concentration is that 0.5mol/L ammonium nitrates are water-soluble 10 liters of liquid.1000 grams of small crystal grain NaY molecular sieve is weighed, is added in 10 liters of aqueous ammonium nitrate solutions for preparing, speed of agitator is 300rpm, at 90 DEG C, constant temperature stirs l hours, then filtering molecular sieve, and stays sample, analyzes Na₂O content；The above-mentioned behaviour of repetition Make, the Na in molecular sieve₂O content reaches 2.5wt%, obtains dried sample number into spectrum for NNY-1.

Embodiment 3

Ammonium exchange is carried out to raw material small crystal grain NaY molecular sieve NY-2 first.Compound concentration is that 0.8mol/L ammonium nitrates are water-soluble 10 liters of liquid.1000 grams of small crystal grain NaY molecular sieve is weighed, is added in 10 liters of aqueous ammonium nitrate solutions for preparing, speed of agitator is 300rpm, at 95 DEG C, constant temperature stirs l hours, then filtering molecular sieve, and stays sample, analyzes Na₂O content；The above-mentioned behaviour of repetition Make, the Na in molecular sieve₂The content of O reaches 2.5wt%, obtains dried sample number into spectrum for NNY-2.

Embodiment 4

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, while the steam partial pressure 0.08MPa of the system of maintenance, is processed 2 hours, sample is taken out in cooling；By sample deionized water Beating, and is brought rapidly up 90 DEG C under conditions of stirring, then with uniform speed in 2 hours Deca by 30 grams of hexafluoros Ammonium silicate and the aqueous solution of 150m1 deionized waters configuration, add rear slurry 2 hours of constant temperature under 90 DEG C of stirring conditions, stand 10 minutes, through 3 washings, filter；Filter cake is contained into NH with 400mL₄ ⁺And H⁺Concentration be respectively 0.8mol/L and 0.2mol/L Mixed solution (ammonium nitrate and nitric acid) process, remove the non-framework aluminum in sample, dealuminzation condition is to process 3 little at 70 DEG C When, filter, and wash filter cake with hot deionized water, stop washing after 7 being close to the pH value of cleaning mixture, filter cake in an oven 120 DEG C drying 5 hours, obtains modified small-grain Y -2.The physico-chemical property of Y-2 is shown in Table 1.

Embodiment 5

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, while the steam partial pressure 0.1MPa of the system of maintenance, is processed 2 hours, sample is taken out in cooling；Sample deionized water is beaten Slurry, and is brought rapidly up 100 DEG C under conditions of stirring, then with uniform speed in 2 hours Deca by 20 grams of hexafluoros Ammonium silicate and the aqueous solution of 150m1 deionized waters configuration, add rear slurry 2 hours of constant temperature under 100 DEG C of stirring conditions, stand 10 minutes, through 3 washings, filter；Filter cake is contained into NH with 400mL₄ ⁺And H⁺Concentration be respectively 1.0mol/L and 0.2mol/L Mixed solution (ammonium chloride and hydrochloric acid) process, remove the non-framework aluminum in sample, dealuminzation condition is to process 3 little at 75 DEG C When filter, and wash filter cake with hot deionized water, stops washing after being close to 7 with the pH value of cleaning mixture, 120 DEG C in an oven of filter cake It is dried 6 hours, obtains modified small-grain Y -2.The physico-chemical property of Y-2 is shown in Table 1.

Embodiment 6

By 30 grams of Y-1 molecular sieves (butt 90wt%), 100 grams of amorphous silicon aluminiums (pore volume 0.9ml/g, than

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

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, catalyst CAT-1 is obtained, carrier and corresponding catalyst property are shown in Table 2.

Embodiment 7

By 40 grams of Y-1 molecular sieves (butt 90wt%), 90 grams of amorphous silicon aluminiums (pore volume 0.9ml/g, than

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

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, catalyst CAT-2 is obtained, carrier and corresponding catalyst property are shown in Table 2.

Comparative example 1

1st, fine grain NaY is prepared with reference to CN101722023A.

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

3rd, subsequent treatment is carried out to CNNY-1, processing mode and condition obtain Reference Product CY-1 with embodiment 4.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 silicon aluminiums (pore volume 0.9ml/g, than

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

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, catalyst CCAT-1 is obtained, carrier and corresponding catalyst property are shown in Table 2.

Comparative example 2

1st, fine grain NaY is prepared with reference to CN1785807A.

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

3rd, subsequent treatment is carried out to CNNY-2, processing mode and condition obtain Reference Product CY-2 with embodiment 4.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 silicon aluminiums (pore volume 0.9ml/g, specific surface areas 350m²/ g, butt 70wt%), (butt 20wt%, 0.25) mol ratio of nitric acid and little porous aluminum oxide to put for 120 grams of binding agents Enter mixed grind in chaser, add water, be rolled into paste, extrusion, extrusion bar are in 110 DEG C of dryings 4 hours, then little in 550 DEG C of roastings 4 When, obtain carrier TCCAT-2.

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, catalyst CCAT-2 is obtained, carrier and corresponding catalyst property are shown in Table 2.

Comparative example 3

1st, prepared by fine grain NaY

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

（2）The preparation of amorphous silica-alumina predecessor.

2）The preparation of amorphous silica-alumina predecessor.

Solid sodium aluminate is configured to into concentration for 40gAl₂O₃/ L sodium aluminate working solutions, take containing SiO₂The silicic acid of 28wt% Sodium solution, then concentration is diluted to for 100g SiO₂/ L sodium silicate working solutions.Take 1L sodium aluminate working solutions and be placed in plastic cans In, 0.6L sodium silicate working solutions are subsequently adding, 20 DEG C of controlling reaction temperature is passed through the CO that concentration is 50v%₂Gas, works as pH value Stop logical CO when reaching 10.0₂, then divulge information and stablize 20 minutes.

（3）The preparation of gel is with embodiment 1.

（4）Crystallization obtains products C NY-3 with embodiment 1, and product property is shown in Table 1.

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

3rd, subsequent treatment is carried out to CNNY-3, processing mode and condition obtain Reference Product CY-3 with embodiment 4.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 silicon aluminiums (pore volume 0.9ml/g, than

Surface area 350m²/ g, butt 70wt%), (butt 20wt%'s 120 grams of binding agents, nitric acid are rubbed with little porous aluminum oxide You than 0.25) to be put into mixed grind in chaser, adding water, being rolled into paste, extrusion, extrusion bar in 110 DEG C of dryings 4 hours, then In 550 DEG C of roastings 4 hours, carrier TCCAT-3 is obtained.

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, catalyst CCAT-3 is obtained, carrier and corresponding catalyst property are shown in Table 2.

Comparative example 4

1st, the preparation of CNNY-4 is with comparative example 1.Then it is modified using the method for CN200910165116.X, it is specific as follows： 100 grams of CNNY-4 100mL deionized waters beating are taken, and 95 DEG C are brought rapidly up under conditions of stirring, then with uniform The speed aqueous solution that Deca is configured by 25 grams of ammonium hexafluorosilicates and 150m1 deionized waters in 2 hours, adds rear slurry 95 2 hours of constant temperature under DEG C stirring condition, stand 10 minutes, through 3 washings, filter, be dried；Sample after above-mentioned drying is placed in The heating rate of 500 DEG C/h in heat-treatment furnace, is controlled, temperature is risen to into 600 DEG C, while the water vapor pressure of the system of maintenance is 0.15MPa, is processed 2 hours, and sample is taken out in cooling；Final sample contains Al with 400mL³⁺And H⁺Concentration be respectively 1.0mol/L With the non-framework aluminum in mixed solution (aluminum nitrate and nitric acid) the removing sample of 0.5mol/L, dealuminzation condition is to process 2 at 80 DEG C Hour, and filter cake is washed with hot deionized water, stop washing, filter cake do for 120 DEG C in an oven after 7 being close to the pH value of cleaning mixture Dry 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 silicon aluminiums (pore volume 0.9ml/g, specific surface areas 350m²/ g, butt 70wt%), (butt 20wt%, 0.25) mol ratio of nitric acid and little porous aluminum oxide to put for 120 grams of binding agents Enter mixed grind in chaser, add water, be rolled into paste, extrusion, extrusion bar are 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, catalyst CCAT-4 is obtained, carrier and corresponding catalyst property are shown in Table 2.

Comparative example 5

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

Feedstock property in this comparative example 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：The low sodium metaaluminate of 60mL aluminum sulfate, 60mL is sequentially added in the waterglass of 220mL, Then constant temperature constant speed is stirred 0.5 hour, and silica-alumina gel is obtained.

(3) crystallization：Under agitation, the gel in synthesis reactor is raised to into 140 DEG C in 30 minutes, constant temperature stirring crystallization 2 hours；35mL directed agents, mixing and stirring are added then to continue crystallization 15 hours at 100 DEG C, Jing is filtered, washed and dry It is dry, products C NY-5 is obtained, product property is shown in Table 1.

2nd, ammonium exchange is carried out to raw material small crystal grain NaY molecular sieve CNY-3, treatment conditions obtain dried with embodiment 2 Sample number into spectrum is CNNY-5.

3rd, subsequent treatment is carried out to CNNY-5, processing mode and condition obtain Reference Product CY-5 with embodiment 4.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%), (butt 20wt%, 0.25) mol ratio of nitric acid and little porous aluminum oxide to put for 120 grams of binding agents Enter mixed grind in chaser, add water, be rolled into paste, extrusion, extrusion bar are in 110 DEG C of dryings 4 hours, then little in 550 DEG C of roastings 4 When, obtain carrier TCCAT-5.

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, catalyst CCAT-5 is obtained, carrier and corresponding catalyst property are shown in Table 2.

Comparative example 6

1st, 100gNNY-1 is taken, the NNY-1 of the present invention is modified using the method for CN200910165116.X, it is concrete modified Method obtains Reference Product CY-6 with comparative example 4.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%), (butt 20wt%, 0.25) mol ratio of nitric acid and little porous aluminum oxide to put for 120 grams of binding agents Enter mixed grind in chaser, add water, be rolled into paste, extrusion, extrusion bar are 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, catalyst CCAT-6 is obtained, carrier and corresponding catalyst property are shown in Table 2.

The property of 1 Y type molecular sieve of table

Production code member	NY-1	NY-2	Y-1	Y-2	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	83	105	50	25	28	63	24	65
											Specific surface area, m2/g	916	898	960	980	892	780	805	921	711	935
Pore volume, mL/g	0.39	0.38	0.57	0.59	0.33	0.32	0.34	0.48	0.30	0.51
											Secondary pore（1.7-10nm）, %			68.4	72.2	37.1	27.5	35.2	42.1	25.2	46.0
External surface area, m2/g	191	182	246	235	170	159	190	189	145	209
											Lattice constant, nm	2.461	2.462	2.432	2.430	2.441	2.450	2.443	2.436	2.449	2.436
Relative crystallinity, %	101	110	118	116	95	80	85	116	78	117
											Average crystallite size, nm	380	430	380	430	400	450	400	400	450	400

2 carrier of table and the physico-chemical property of catalyst agent

Bearer number	TCAT-1	TCAT-2	TCCAT-1	TCCAT-2	TCCAT-3	TCCAT-4	TCCAT-5	TCCAT-6
									Y molecular sieve, wt%	22	29	29	29	22	22	29	22
Amorphous silicon aluminium, wt%	58	51	51	51	58	58	51	58
									Aluminium oxide, wt%	20	20	20	20	20	20	20	20
Specific surface area, m2/g	500	516	435	418	420	460	382	478
									Pore volume, ml/g	0.60	0.62	0.50	0.46	0.44	0.53	0.42	0.55
Pore size distribution（4-10nm）, %	65	72	45	43	40	50	38	52
									Catalyst is numbered	CAT-1	CAT-2	CCAT-1	CCAT-2	CCAT-3	CCAT-3	CCAT-5	CCAT-6
Specific surface area, m2/g	400	425	318	302	298	346	274	395
									Pore volume, ml/g	0.52	0.56	0.44	0.42	0.41	0.47	0.38	0.50
Pore size distribution（4-10nm）, %	62	67	42	41	37	47	38	49

By the invention described above catalyst CAT-1, CAT-2 and comparative example catalyst CCAT-1, CCAT-2, CCAT-3 and CCAT-4 carries out active evaluation test.Test is carried out on 200ml small hydrogenation devices, using one-stage serial technique stream Journey, raw materials used oil nature are 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}, 5～10 g/g of control cracking zone nitrogen content.Catalyst Activating Test the results are shown in Table 4.

3 raw material oil nature of table

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 values	41.5
Refractive power/nD 70	1.48570

4 catalyst activity evaluation result of table

Catalyst is numbered	CAT-1	CAT-2	CCAT-1	CCAT-2	CCAT-3	CCAT-4	CCAT-5	CCAT-6
									Reaction temperature, DEG C	380	378	383	384	386	382	387	381
<370 DEG C of conversion ratios, wt%	64.8	65.0	64.8	64.9	64.9	64.5	64.8	65.2
									Middle distillates oil selectivity, %（132～370 DEG C）	86.5	86.9	81.1	81.2	81.5	83.5	80.6	84.5
Major product property
									Jet fuel（132~282℃）
Freezing point, DEG C	<- 60	<- 60	<- 60	<- 60	<- 60	<- 60	-58	<- 60
									Aromatic hydrocarbons, wt%	3.6	3.3	4.2	4.9	5.1	4.0	5.4	3.9
Smoke point, mm	28	27	26	25	26	26	24	26
									Diesel oil（282~370℃）
Cetane number	63	64	59	58	57	60	55	61
									Condensation point, DEG C	-5	-7	-1	0	0	-3	2	-3

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

Claims (32)

1. a kind of hydrocracking catalyst, including hydrogenation active metals component and with small-grain Y molecular sieve, amorphous silica-alumina and oxygen Change the carrier of aluminum composition, wherein described small-grain Y molecular sieve, its property is as follows：SiO₂/A1₂O₃Mol ratio is 40～120, brilliant Grain average diameter be 200～700nm, relative crystallinity more than 100%, 2.425～2.450nm of lattice constant, specific surface area For 850～1000m²/ g, pore volume are 0.40～0.60mL/g, and the pore volume shared by the secondary pore of 1.7～10nm accounts for total pore volume More than 50%, Na₂O content≤0.15wt%.

2. according to the catalyst described in claim 1, it is characterised in that the relative crystallinity of described small crystal grain Y-shaped molecular sieve is 100%~120%。

3. according to the catalyst described in claim 1, it is characterised in that in described small crystal grain Y-shaped molecular sieve, 1.7～10nm's Pore volume shared by secondary pore accounts for the 50% ~ 80% of total pore volume.

4. according to the catalyst described in claim 1, it is characterised in that in described small crystal grain Y-shaped molecular sieve, 1.7～10nm's Pore volume shared by secondary pore accounts for the 55% ~ 75% of total pore volume.

5. according to the catalyst described in claim 1, it is characterised in that the lattice constant of described small crystal grain Y-shaped molecular sieve is 2.425～2.440.

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

7. according to the catalyst described in claim 1, it is characterised in that in described carrier of hydrocracking catalyst, with carrier On the basis of weight, its composition includes：The content of small crystal grain Y-shaped molecular sieve is 5wt%～40wt%, and the content of amorphous silica-alumina is 20wt%～65wt%, the content of aluminium oxide is 10wt%～40wt%.

8. according to the catalyst described in claim 1, it is characterised in that in described carrier of hydrocracking catalyst, with carrier On the basis of weight, its composition includes：The content of small crystal grain Y-shaped molecular sieve is 10wt%～25wt%, and the content of amorphous silica-alumina is 30wt%～60wt%, the content of aluminium oxide is 15wt%～30wt%.

9. according to the catalyst described in claim 1, it is characterised in that described hydrogenation active metals are vib and/or the The metal of VIII race, vib metals are molybdenum and/or tungsten, and the metal of the VIIIth race is cobalt and/or nickel.

10. according to the catalyst described in claim 9, it is characterised in that on the basis of the weight of catalyst, vib metals The content counted with oxide as 10wt%～content counted with oxide of 30wt% and group VIII metal as 4wt%～10wt%, carrier Content be 61wt%～86wt%.

11. according to the catalyst described in claim 1, it is characterised in that described hydrocracking catalyst property is as follows：Compare table Area is 300～500 m²/ g, pore volume is 0.35～0.60mL/g, the pore volume of 4 ~ 10nm of aperture account for total pore volume 55%～ 90%.

The preparation method of the arbitrary catalyst of 12. claim 1 ~ 11, including：By small-grain Y molecular sieve, amorphous silica-alumina and With binding agent mechanical mixture, molding made by aluminium oxide, then it is dried and roasting, makes catalyst carrier；The catalyst of gained Supported on carriers hydrogenation active metals component, drying and roasting, make catalyst.

13. in accordance with the method for claim 12, it is characterised in that the preparation method of the small crystal grain Y-shaped molecular sieve, including：

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

(2) fine grain NaY type molecular sieve is prepared into 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 obtained by step (3) carries out dealumination complement silicon with hexafluorosilicic acid aqueous ammonium, the molecular sieve for obtaining and by-product Separate；

(5) molecular sieve for obtaining step (4) is with containing NH₄ ⁺And H⁺Mixed solution process, be washed out and be dried, obtain little Grain Y-molecular sieve,

Small crystal grain NaY molecular sieve wherein described in step (1), its property are as follows：SiO₂/Al₂O₃Mol ratio is not more than 6.0 and high In 9.0, average grain diameter is 200～700nm, 800～1000 m of specific surface²/ g, 0.30～0.45mL/g of pore volume are relative to tie Brilliant degree is 90%～130%, and cell parameter is 2.460～2.470nm, the relative crystallinity Jing after roasting in 650 DEG C of air 3 hours For more than 90%, Jing after 700 DEG C of water vapour hydrothermal treatment consists 2 hours, relative crystallinity is more than 90%.

14. in accordance with the method for claim 12, it is characterised in that：The SiO of described small crystal grain NaY molecular sieve₂/Al₂O₃Rub You are than being 6.5～9.0.

15. in accordance with the method for claim 12, it is characterised in that：The SiO of described small crystal grain NaY molecular sieve₂/Al₂O₃Rub You are than being 7.0～8.0.

16. in accordance with the method for claim 12, it is characterised in that：The crystal grain of described small crystal grain NaY molecular sieve is averagely straight Footpath is 300～500nm.

17. in accordance with the method for claim 12, it is characterised in that：In described 650 DEG C of air of small crystal grain NaY molecular sieve Jing After roasting 3 hours, relative crystallinity is 90%～110%, and Jing after 700 DEG C of water vapour hydrothermal treatment consists 2 hours, relative crystallinity is 90%～110%.

18. in accordance with the method for claim 12, it is characterised in that：The preparation method of described small crystal grain NaY molecular sieve, 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 at 0～20 DEG C is stirred to be aged to be obtained for 0.5～24 hour and is led To agent；

II, using preparing amorphous silicon alumnium using carbonization predecessor, on the basis of the weight of the butt of amorphous silica-alumina predecessor, The content that silicon is 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 for 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 for controlling cemented into bundles is 8 ~ 11；Wherein as the CO being passed through₂Gas flow is accounted for and is always passed through Amount 60% ~ 100% when, add remainder sodium silicate solution, wherein in step b, remainder sodium silicate solution is with silicon dioxide Meter accounts for step b and adds 5wt% ~ 85wt% of the sodium silicate solution total amount in terms of silicon dioxide；

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's always feeds intake mole Than, 0～40 DEG C it is quick stir under conditions of water, silicon source, guiding are added in the amorphous silica-alumina predecessor obtained by step II Agent and alkali source, and control ph is 9.5 ~ 12.0, uniform stirring obtains silica-alumina gel；Wherein directed agents addition accounts for sial and coagulates The 1%～20% of glue weight,

Two step dynamic crystallizations of reactant mixture Jing obtained by IV, step III, then Jing filtrations, washing, are dried, obtain little crystal grain NaY molecular sieve；Wherein the first step carry out dynamic crystallization condition it is as follows：Temperature control at 50～90 DEG C, crystallization time is 0.5～ 18 hours；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.

19. in accordance with the method for claim 18, 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, the content that silicon is counted with silicon dioxide is as 55 wt%～70wt%.

20. in accordance with the method for claim 18, it is characterised in that：Step b controlling reaction temperature is 15～35 DEG C.

21. in accordance with the method for claim 18, 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.

22. in accordance with the method for claim 18, 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% of the sodium silicate solution total amount in terms of silicon dioxide.

23. in accordance with the method for claim 18, it is characterised in that in step I and III, and silicon source, alkali source are respectively selected from silicic acid Sodium and sodium hydroxide, in step I, silicon source is selected from sodium metaaluminate.

24. in accordance with the method for claim 18, it is characterised in that in step III, 10 ~ 30 DEG C of controlling reaction temperature, pH value 10～11.

25. in accordance with the method for claim 18, it is characterised in that step IV adopts two step dynamic crystallizations, wherein the 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 of change is as follows：At 80～120 DEG C, crystallization time is 5～10 hours to temperature control.

26. in accordance with the method for claim 13, it is characterised in that step（3）In, the condition of described hydrothermal treatment consists is as follows： At 500～750 DEG C, pressure is 0.01～0.50MPa, and process time is 1.0～4.0 hours for treatment temperature control.

27. in accordance with the method for claim 13, it is characterised in that step（3）In, the condition of described hydrothermal treatment consists is as follows： At 600～700 DEG C, pressure is 0.05～0.30MPa, and process time is 1.0～4.0 hours for treatment temperature control.

28. in accordance with the method for claim 13, it is characterised in that step（4）In, compare 1 by solid-liquid weight in aqueous medium： 4~1：8 add 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, The 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 are little crystal grain NH₄10wt% ~ the 50wt% of NaY molecular sieve.

29. in accordance with the method for claim 13, 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 be hydrochloric acid, carbonic acid, nitric acid, one or more in sulphuric acid, containing NH₄ ⁺Salt be in the ammonium salt containing above acid group one Plant or various；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 for exchanging molecular sieve in serosity is 0.1～0.5g/mL, and swap time is 0.5～3.0 hour, is exchanged Step repeats 1～4 time.

30. in accordance with the method for claim 13, it is characterised in that：Step（2）The method exchanged using ammonium salt, 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 serosity is exchanged is 0.05～0.50g/mL, and repeated exchanged l～5 time filter off mother solution, wash, are dried；Ammonium salt is chlorine Change one or more in 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.

31. in accordance with the method for claim 13, it is characterised in that：SiO in described amorphous silica-alumina₂Weight content be 20%～60%, the pore volume of amorphous silica-alumina is 0.6～1.1 mL/g, and specific surface area is 300～500 m²/g。

32. in accordance with the method for claim 12, it is characterised in that：The drying of carrier and roasting condition are as follows：Jing 80 ~ 150 DEG C drying 3 ~ 10 hours, in 500 ~ 600 DEG C of roastings 3 ~ 6 hours, the drying of catalyst and roasting condition were as follows：100 DEG C～150 DEG C L～12 hour are dried, then in 450 DEG C～550 DEG C roastings 3～6 hours.