Along with the understanding that the NaY molecular sieve is acted on is goed deep into, it is found that small crystal grain NaY molecular sieve has catalytic performance preferably in catalytic cracking process.EP0,204,236 (1986) have reported the cracking catalyst that made by small crystal grain NaY molecular sieve and big crystal NaY molecular sieve relatively, and heavy oil fluid catalytic cracking is had higher activity and selectivity preferably.
Corma thinks to have high SiO
2/ Al
2O
3NaY molecular sieve than, little crystal grain can improve gasoline octane rating, have preferably water, thermostability (ACS Symp Ser., 375, Chap, 2,1988, P.17).
Synthetic method report about small crystal grain NaY molecular sieve is more, concludes to get up to mainly contain:
1, improve the basicity of NaY when synthetic, add directed agents (US3,755,538).As the synthetic total proportioning of NaY is 6.5Na
2O: Al
2O
3: 16SiO
2: 280H
2O, mole consist of 16Na
2O: Al
2O
3: 15SiO
2: 320H
2The directed agents add-on of O is 20% (with total Al in the system
2O
3The mole number meter).Crystal grain diameter with this method synthetic NaY molecular sieve is 0.06 micron, and lattice constant is 24.66 nanometers.
2, by control directed agents digestion time, factors such as temperature are improved crystal seed, preparation small crystal grain NaY molecular sieve (CKR8601-488B).
3, add dispersion medium.As add methyl alcohol, ethanol, dimethyl sulfoxide (DMSO), and the left and right sugar etc. that revolves can make the X.Y one type small crystal grain molecular sieve that crystal grain diameter is the 0.01-0.1 micron (US3,516,786 as dispersion medium; EP0.041,338).
4, by improving processing condition, become glue as low temperature, stir for a long time at a high speed, modes such as micro-wave energy heating make small-grain Y-type, X-type, and ZSM-5 equimolecular sieve (GB1,223,592; US4,587,115; US4,778,666).
Adopting the common feature of the little brilliant NaY molecular sieve of above several method synthetic is the SiO of product
2/ AL
2O
3Than low, only be suitable for synthetic X-type molecular sieve and SiO
2/ Al
2O
3Y-shaped molecular sieve than≤5.
Prepare high SiO
2/ Al
2O
3The report of the NaY molecular sieve of ratio is more, as adopting the crystallization guiding technique, replaces the work of more expensive silicon sol synthesizing high-silicon Y-shaped molecular sieve more and more to cause people's attention with the water glass of cheapness.Industrialized at present high SiO
2/ Al
2O
3Ratio-NaY molecular sieve mainly is that employing water glass, sodium metaaluminate, sodium hydroxide and Tai-Ace S 150 are (US4,166,099 that raw material makes; CN85102733A; " refining of petroleum " 11-12 phase, P22-25,1978), but also be only limited to crystal grain diameter) 0.30 micron NaY molecular sieve.
EP0.204,455 have reported a kind of directed agents technology of preparing that can improve molecular sieve catalyst intensity, promptly join by the sodium silicate solution with significant quantity and generate a kind of as clear as crystal improvement directed agents solution in the conventional directed agents.The long service life of this improvement directed agents is used this directed agents to carry out the carclazyte microspherical catalyst that in-situ crystallization makes and is had advantages of high strength, but in this patent and the grain size of the not mentioned synthetic NaY of institute molecular sieve.
The purpose of this invention is to provide a kind of by adopting the method that the directed agents technology prepares small crystal grain NaY molecular sieve of improving.This method both can synthesize SiO
2/ Al
2O
3Small crystal grain NaY molecular sieve than≤5 can synthesize Si again
2/ Al
2O
3Small crystal grain NaY molecular sieve than>5.
The preparation process of the said small crystal grain NaY molecular sieve of the present invention is as follows:
1, prepare conventional directed agents: with modulus be 0.5-3.5, preferably 1.0-3.3 concentration is the heavy % of 20-65, the sodium silicate solution of the heavy % of 25-60 preferably, severe give birth to than for the high alkali deflection aluminium acid sodium solution of 10-12 and deionized water 0-45 ℃, preferably 5-40 ℃ mix stirring 0.5-2 hour, then 15-60 ℃, preferably left standstill aging 6-30 hour at 20-40 ℃, make transmittance<30%, mole consists of (13-36) Na
2O: Al
2O
3: (12-21) SiO
2: (250-800) H
2O, preferably (15-19) Na
2O: Al
2O
3: (14-19) SiO
2: (300-380) H
2The conventional directed agents of O;
2, preparation improves directed agents: the sodium silicate solution that specification is identical with step 1 is pressed 5-80 volume %, preferably the amount of 10-70 volume % joins in the conventional directed agents that step 1 makes, at room temperature placed 0.5-2 hour, and made transmittance>75%, mole consists of (12-180) Na
2O: Al
2O
3: (17-210) SiO
2: (160-3100) H
2O, (16-150) Na preferably
2O: Al
2O
3: (20-180) SiO
2: (250-2500) H
2The improvement directed agents solution of O;
3, sodium silicate solution that specification is identical with step 1, improvement directed agents solution, Al that step 2 makes
2O
3Content is the alum liquor of 0.085-0.095 grams per milliliter and causticity than synthetic according to the NaY hydro-thermal that the preparation method of conventional NaY molecular sieve carries out different ingredients for the low alkali aluminium acid sodium solution of 1.0-3.0, and the add-on of wherein improving directed agents is 0.5-25%, preferably 1.0-20% is (with total Al in the system
2O
3The mole number meter), stirred 0.5-2 hour, be warming up to 95-100 ℃, crystallization 5-35 hour, filter, dry, the NaY zeolite product that makes little crystal grain.
The said employing of the present invention improves directed agents technology synthetic NaY molecular sieve and relatively has the short characteristics of the little crystallization time of crystal grain with adopting conventional directed agents synthetic NaY molecular sieve.
The said sodium silicate solution that joins in the conventional directed agents among the present invention if modulus reduces, just makes the life-span of improving directed agents prolong, and crystallization time shortens, and the crystal grain of NaY zeolite product diminishes.
Said improvement directed agents of the present invention and conventional directed agents relatively have active high, long service life, anti-95 ℃ of characteristics such as left and right sides high temperature.
To improve directed agents and conventional directed agents mix be used in the NaY hydro-thermal synthetic in, the grain size of gained NaY molecular sieve is between using two kinds of directed agents respectively between the grain size of synthetic NaY molecular sieves.
Adopt its SiO of synthetic small crystal grain NaY molecular sieve of the present invention
2/ Al
2O
3Than both can≤5.0, also can>5.0.And the latter also is characteristics of the present invention.
The following examples are described further the present invention.
Example one
The preparation of sodium aluminate solution: with sodium hydroxide (medication purchasing supply station, Wenzhou, Zhejiang, chemical pure) is dissolved in the deionized water, evenly add aluminium hydrate powder (Shandong Aluminum Plant then, technical pure), 120 ℃ of reactions 5 hours, treat below the as clear as crystal postcooling to 60 of solution ℃, can be mixed with different causticities than (Na according to the test needs
2O/Al
2O
3Mol ratio) sodium aluminate solution.
With 158 milliliters of sodium silicate solution (moduluses 3.28, proportion 1.261, concentration 27.3 heavy %, the water glass plant, Tianjin) (causticity is than=11.76 with 109 milliliters of high alkali deflection aluminium acid sodium solution, proportion 1.343) and 12 ml deionized water mix to stir 1 hour at 35 ℃, leave standstill at 35 ℃ then and made mole in aging 6 hours and consist of 16Na
2O: Al
2O
3: 15SiO
2: 320H
2O, the conventional directed agents of transmittance<30%.
158 milliliters of specification sodium silicate solutions same as described above are joined in the conventional directed agents by 36.2 volume % amount, and after 1.5 hours, making transmittance is 90% 30 ℃ of placements, and mole consists of 20.6Na
2O: Al
2O
3: 30SiO
2: 495H
2The improvement directed agents solution that O is as clear as crystal uses after room temperature is placed 24 hours.
According to mol ratio is 3.84Na
2O: Al
2O
3: 12SiO
2: 220H
2The NaY hydro-thermal synthesizing formula of O, with 316 milliliters of sodium silicate solutions that specification is same as described above, (add-on of improving directed agents is with total Al in the system for 437 milliliters of above-mentioned improvement directed agents solution that make
2O
3Mole number counts 20%), 204 milliliters of Al
2O
3Content is that (causticity is than 2.45 for the alum liquor (Xian Xingta chemical plant, Kingsoft, Shanghai, chemical pure) of 0.0856 grams per milliliter (proportion=1.262) and 12 milliliters of low alkali aluminium acid sodium solutions, proportion=1.239) mix stirring 1 hour, be warming up to 97 ℃ then, crystallization 26 hours, filtration, drying obtain SiO
2/ Al
2O
3Than being 5.8, the small crystal grain NaY molecular sieve product, analytical results sees Table 1.
In the table 1:
1, x-ray diffraction method is measured the lattice constant of NaY molecular sieve.
Product SiO
2/ Al
2O
3Ratio and crystalline substance bag constant a
0The pass be:
2, the mensuration of outer specific surface data adopts the t-pLot method, and t value scope is the 0.6-0.8 nanometer, and crystal grain diameter D (micron) with the pass of outer specific surface Sex is:
Wherein ρ is a NaY molecular sieve ideal granule degree, is 1.92 gram per centimeters
3, Sex is an outer specific surface (rice
2/ gram)
3, crystallization time: finish till back 2 hours since 97 ℃ of crystallization to crystallization.
Example 2
Except the add-on of improving directed agents is (with total Al in the system 5.0%
2O
3The mole number meter), other experimental procedure is with example 1, crystallization 34 hours, and the analytical results of products obtained therefrom sees Table 1.
Example 3
Except conventional directed agents digestion time changed into 20 hours by 6 hours, improve the add-on of directed agents, and other experimental procedure is with example 2, product analysis the results are shown in Table 1.
Comparative Examples 1
Except replace improving directed agents with conventional directed agents, other preparation process is with example 2, and the add-on of conventional directed agents is 5.0% (with total Al in the system
2O
3The mole number meter), the analytical results of products obtained therefrom sees Table 1.
From the analytical results of example 1-3 and Comparative Examples 1 as can be seen: the NaY molecular sieve that the present invention makes and the NaY molecular sieve that adopts conventional directed agents to make relatively, it is little to have crystal grain, the short characteristics of crystallization time, the SiO of products obtained therefrom
2/ Al
2O
3Ratio can be up to 5.8.As example 2 and Comparative Examples 1SiO
2/ Al
2O
3Than identical (5.8), the directed agents add-on all is 5.0% (with Al in the system
2O
3The mole number meter), but the former crystal grain has only 0.16 micron, and the latter but is 0.78 micron; The former is 34 hours for a crystallization time, and the latter is 55 hours (latter's crystallization 34 hours, crystallization are trace).
Table 1
Example 4
The proportioning of directed agents, raw material and preparation method be with example 1, and the add-on of improving directed agents is 5% (with total Al in the system
2O
3The mole number meter), the proportioning of synthetic NaY molecular sieve is 3.0Na
2O: Al
2O
3: 9.4SiO
2: 180H
2O, crystallization 24 hours, other experimental procedure are with example 1, and the analytical results of product sees Table 2, and stereoscan photograph is seen Fig. 1.
Comparative Examples 2
Except replace improving directed agents with conventional directed agents, other preparation process is with example 4, and the add-on of conventional directed agents is 5.0% (with total Al in the system
2O
3The mole number meter), the analytical results of product sees Table 2, and stereoscan photograph is seen Fig. 2.
By table 2 and Fig. 1, Fig. 2 as can be seen: the NaY molecular sieve that the present invention makes is with to adopt conventional directed agents synthetic NaY molecular sieve relatively to have crystal grain little, the characteristics that crystallization time is short.As example 4 and Comparative Examples 2, SiO
2/ Al
2O
3Than all is 5.4, example 4 is the NaY molecular sieves that make by the present invention, its crystal grain diameter is 0.22 micron, crystallization time is 24 hours, and Comparative Examples 2 is NaY molecular sieves of making of directed agents routinely, its crystal grain diameter is 0.63 micron, and crystallization time reaches 32 hours (latter's crystallization 24 hours, crystallization are trace).
Table 2
Example 5
Conventional directed agents and improve the directed agents preparation method with example 2 is just improved the directed agents add-on and is 1.0% (with total Al in the system
2O
3The mole number meter), the proportioning of synthetic NaY molecular sieve is 3.6Na
2O: Al
2O
3: 9.8SiO
2: 202H
2O, crystallization 14 hours, the products obtained therefrom analytical results is: SiO
2/ Al
2O
3Than 4.9; 0.15 micron of crystal grain diameter.
Example 6-9
The proportioning of directed agents, raw material and preparation method be with example 1, and the add-on of improving directed agents is 20% (with total Al in the system
2O
3The mole number meter), improve directed agents and be followed successively by 1 hour by example number storage period, 4 hours, 15 hours, 52 hours.
The proportioning of synthetic NaY molecular sieve is 3.6Na
2O: Al
2O
3: 9.8SiO
2: 200H
2O, crystallization 16 hours, other step are with example 1, and the analytical results of product sees Table 3.
Comparative Examples 3
Except replace improving directed agents with conventional directed agents, the proportioning of directed agents, raw material and preparation method be with example 1, and the add-on of conventional directed agents is 20% (with total Al in the system
2O
3The mole number meter), the proportioning of synthetic NaY molecular sieve, raw material and preparation method are with example 6, and the analytical results of product sees Table 3.
From the analytical results of example 6-9 and Comparative Examples 3 as can be seen: the improvement directed agents according to example 1 preparation was placed about 50 hours, and the crystal grain of gained NaY molecular sieve is still little than the crystal grain according to the NaY molecular sieve of conventional directed agents preparation.
Table 3
Example 10
Conventional directed agents proportioning, raw material and preparation method are with example 1, the specification that joins the sodium silicate solution in the conventional directed agents is with example 1, just add-on is 12.5 volume %, adds the back and places 20 hours, obtains as clear as crystal improvement directed agents solution, its transmittance is 85%, the proportioning of synthetic NaY molecular sieve, raw material and preparation method are with example 2, and 34 hours products obtained therefrom analytical resultss of crystallization see Table 4.
Comparative Examples 4
Except replace improving directed agents with conventional directed agents, other preparation process is with example 2, and the add-on of conventional directed agents is 5.0% (with total Al in the system
2O
3The mole number meter), crystallization 32 hours, the analytical results of products obtained therefrom sees Table 4.
As can be seen from Table 4: when crystallization time is 34 hours, the SiO of example 2 and example 10 products
2/ Al
2O
3Than and the grain size basically identical, and Comparative Examples 4 is in the same time, the crystallization of product is a trace, has only the crystallization could crystallization after 55 hours, its crystal grain diameter is 0.78 micron, shown in Comparative Examples 1.
Table 4
Annotate ※: Comparative Examples 4 is in 34 hours, and the crystallization of product is a trace.
Example 11
50 milliliters of the sodium silicate solutions that raw material specification and example 1 is identical, 27 milliliters of high alkali deflection aluminium acid sodium solution, 3 milliliters of mixing of deionized water, stirring at normal temperature 1 hour left standstill in 45 ℃ of water-baths aging 12 hours then, and making transmittance is 28%, and mole consists of 17.6Na
2O: Al
2O
3: 19SiO
2: 369H
2The conventional directed agents of O.
With modulus is that 2.0 concentration are 40.1 heavy %, proportion is that 80 milliliters of 1.473 sodium silicate solutions (account for add back cumulative volume 50%) join in the above-mentioned conventional directed agents, obtain transmittance after 1 hour and be 86% as clear as crystal improvement directed agents solution, place after 10 days and use, this moment, transmittance was 91%, and mole consists of 40.4Na
2O: Al
2O
3: 64.7SiO
2: 710H
2O.
The proportioning raw materials preparation method of synthetic NaY molecular sieve is with example 6, and the add-on of improving directed agents is 5.0% (with total Al in the system
2O
3The mole number meter), crystallization time is 12 hours, and the analytical results of products obtained therefrom sees Table 5.
Example 12
The modulus of sodium silicate solution is 1.0, and concentration is 40.6 heavy %, and proportion is 1.549, and add-on is 120 milliliters (account for add back cumulative volume 60%), places 15 days, and obtaining transmittance is 92%, mole consists of 72.3Na
2O: Al
2O
3: 73.7SiO
2: 903H
2The as clear as crystal improvement directed agents solution of O.In addition, other preparation process is with example 11, crystallization 10 hours, and the analytical results of products obtained therefrom sees Table 5.
From the analytical results of the NaY zeolite product of example 9,11,12 gained as can be seen: the modulus that joins the sodium silicate solution the conventional directed agents reduces, and improves directed agents and prolongs work-ing life, and crystallization time shortens, and the crystal grain of product diminishes.
Table 5
Annotate: the modulus of ※ sodium silicate solution=SiO2/Na2O mol ratio
Example 13
The improvement directed agents that example 2 is made be heated to 95 ℃ 30 minutes, reduce to normal temperature then and use, other technical recipe and preparation method are with example 4, the analytical results of products obtained therefrom sees Table 6.From the product analysis result of example 13 as can be seen: improve directed agents through 95 ℃ handle 30 minutes after, still can keep the directed agents activity, the performance of product is suitable with example 4.
Example 14
NaY synthesizing formula and preparation method be with example 4, and the conventional directed agents that will make according to example 4 and improve directed agents and add respectively, the add-on of mixing directed agents are 5.0% (with total Al in the system
2O
3The mole number meter), wherein two kinds of directed agents respectively account for 2.0% and 3.0%, the analytical results of product sees Table 6, from the analytical results of example 14 products as can be seen: with conventional directed agents and improve directed agents mixed its grain size of NaY molecular sieve between distinguishing with two kinds of directed agents between the synthetic NaY zeolite crystal sizes.
Table 6
Annotate: mix directed agents and mean conventional directed agents and improve the directed agents that the directed agents mixing is used.
Example 15
The preparation method of conventional directed agents and improvement directed agents is with example 1, and the synthesizing formula of NaY molecular sieve is 4.4Na
2O: Al
2O
3: 10SiO
2: 182H
2O, the add-on of improving directed agents is 5.% (with total Al in the system
2O
3The mole number meter), crystallization 6 hours, the analytical results of products obtained therefrom sees Table 7.
Example 16
The preparation method of conventional directed agents and improvement directed agents is with example 1, and the synthesizing formula of NaY molecular sieve is 3.0NaO
2: Al
2O
3: 6.5SiO
2: 170H
2O, the add-on of improving directed agents is 5.0% (with total Al in the system
2O
3The mole number meter), crystallization 10 hours, the analytical results of products obtained therefrom sees Table 7.
As can be seen from Table 7, the present invention can synthesize SiO
2/ Al
2O
3Than≤5, small crystal grain NaY molecular sieve.
Table 7