CN101555023B

CN101555023B - Preparation method of SAPO-34 molecular sieve

Info

Publication number: CN101555023B
Application number: CN2009100829184A
Authority: CN
Inventors: 薛云鹏; 李飞; 朱伟平; 李艺
Original assignee: China Shenhua Coal to Liquid Chemical Co Ltd; Shenhua Group Corp Ltd
Current assignee: China Shenhua Coal to Liquid Chemical Co Ltd; Shenhua Group Corp Ltd
Priority date: 2009-04-22
Filing date: 2009-04-22
Publication date: 2011-05-11
Anticipated expiration: 2029-04-22
Also published as: CN101555023A

Abstract

The invention discloses a method for synthesizing an SAPO-34 molecular sieve with a supplementary crystallization method. The method includes the following steps of: 1) mixing a template agent and de-ionized water and then adding the raw powder of the mixture of an SAPO-5 sieve and an SAPO-34 molecular sieve to the mixed liquid, and stirring uniformly; 2) filling the uniformly stirred mixed solution in a crystallization kettle, then sealing and heating to crystallization temperature and crystallizing at the crystallization temperature; and 3) after the centrifugal separation, filtration and washing of the crystallized mixture, heating and drying a solid sample and finally obtaining the pure SAPO-34 molecular sieve. The method can improve the rate of certified products of the prepared SAPO-34 molecular sieve, recover and treat the prepared unqualified mischcrystal products and also easily recover the template agent simultaneously.

Description

A kind of preparation method of SAPO-34 molecular sieve

Technical field

The present invention relates to a kind of preparation method of SAPO-34 molecular sieve, be specifically related to the method that a kind of mixture that will contain SAPO-5 and SAPO-34 is made pure SAPO-34 molecular sieve.

Background technology

Novel silicon aluminium phosphate series molecular sieve (US4440871, US4499327)-SAPO-n molecular sieve that U.S. combinating carbide company (UCC) researched and developed out in 1984, be be template with the organic amine, be aluminium source, phosphorus source and silicon source with hydrated aluminum oxide, phosphoric acid, silicon sol respectively, at first obtain having the organic amine/aluminum phosphate/silicon complex body of micropore phase, remove by roasting then that template (organic amine) obtains by hydrothermal crystallization method.SAPO-34 is wherein a kind of, and its similar chabazite has the three dimensional intersection duct, and the aperture is about 0.38nm, belongs to isometric system.Because it has suitable proton acidity, suitable pore passage structure, bigger specific surface area, absorption property and thermostability and hydrothermal stability etc. preferably preferably, makes it present catalytic activity and selectivity preferably in as the methanol to olefins reaction catalyzer.

Because the skeleton structure of SAPO molecular sieve is by SiO ₂, PO ₂ ⁺And AlO ₂ ^-3 kinds of tetrahedrons interconnect by certain way and form, and template consumption difference, the template action that is subjected to when they interconnect are also just different, thereby their orders of connecting and being orientated also with different, finally can produce the crystalline phase of different types of structure.Mention template agent and can produce purified SAPO-34 molecular sieve within the specific limits in many pieces of articles of research SAPO-34 synthetic, what then make in another scope is SAPO-5 or SAPO-5 and SAPO-34 mixture.As the people such as Li Tianwen of sky, Lu group at " effect of template in molecular sieve is synthetic " delivered on " chemical intermediate ", Et ₃N/P ₂O ₅Consumption ratio be 1.68～2.08 o'clock, pH value is 6.00～7.04, has the SAPO-5 molecular sieve and generates; And Et ₃N/P ₂O ₅Consumption ratio be 2.55～4.30 o'clock, pH value is 8.10～13.60, just can generate pure SAPO-34 molecular sieve.So, under the situation such as, template less when the template consumption lost, mixing of materials is inhomogeneous, all may generate the mixture of SAPO-34 and SAPO-5 molecular sieve in crystallization process.If can make product by crystal formation conversion is that the mixture of SAPO-34 and SAPO-5 molecular sieve is converted into pure SAPO-34 molecular sieve, just can improve the percentage of A-class goods of SAPO-34 molecular sieve on the one hand, on the other hand, by reclaiming the defective SAPO-34 molecular sieve of doping SAPO-5 molecular sieve, reduced preparation cost.

Therefore, it is necessary seeking the method that a kind of new mixture that can make SAPO-34 and SAPO-5 molecular sieve changes into pure SAPO-34 molecular sieve at last.

Summary of the invention

At above technical problem, the present inventor finds by adopting additional crystallization method can realize that SAPO-34 and SAPO-5 molecular sieve mixture transform to the SAPO-34 molecular sieve.

Therefore, the invention provides the method for the synthetic SAPO-34 molecular sieve of a kind of additional crystallization method, described method comprises the steps:

1) template and deionized water are mixed, to wherein adding SAPO-5 and the former powder of SAPO-34 molecular sieve mixture, stir then;

2) homogeneous mixture solotion of step 1) gained is packed in the crystallizing kettle, the airtight crystallization temperature that is heated to carries out crystallization under the crystallization temperature;

3) mixture after the crystallization is carried out centrifugation, filtration, washing, solid sample obtains the SAPO-34 molecular sieve by heat drying.

The usage quantity of template and deionized water in the inventive method step 1), those skilled in the art can and determine the usage quantity of template and deionized water at concrete SAPO-5 and SAPO-34 mixture in conjunction with this area routine techniques general knowledge.

The present invention replenishes the crystallization legal system and is equipped with in the method for SAPO-34 molecular sieve, described template can be the template of this area routine, the present invention includes but is not limited to tetraethyl ammonium hydroxide, triethylamine, diethylamine, morpholine, aniline, Isopropylamine, di-n-propylamine or they mixture arbitrarily.

Among the preparation method of the present invention, the mixing in the described step 1), whipping temp are 15-80 ℃, and preferred mixing, whipping temp are 25-60 ℃; Mixing, churning time are 1-10 hour, and preferred mixing, churning time are 2-8 hour.

Among the preparation method of the present invention, described step 2) crystallization temperature in is 150-250 ℃, and preferred crystallization temperature is 180-220 ℃; Described crystallization time is 10-120 hour, and preferred crystallization time is 24-110 hour.

Preparation method of the present invention can make the SAPO-34 that contains SAPO-5 impurity be transformed into pure SAPO-34 molecular sieve, and washing, to filter the SAPO-34 molecular sieve simple; And the upper strata crystallization liquid after crystallization of the present invention finishes is a transparent liquid, is the mixed solution of template and water, can be easier to reclaim unreacted template.

The present invention has realized the crystal formation conversion by replenishing the crystallization method, make the SAPO-34 catalyzer that originally cancels because of doping SAPO-5 molecular sieve, conversion by crystal formation, change into purified SAPO-34 molecular sieve, and the SAPO-34 molecular sieve of degree of crystallinity and ordinary method preparation is approximate, therefore, reduced consumption because of the waste product material of doping SAPO-5.

The inventive method has improved the percentage of A-class goods of preparation SAPO-34 molecular sieve, has recycled the underproof mixed crystal product of preparation, simultaneously the easy recycling of template.

Description of drawings

Fig. 1: be the process flow sheet of comparative example 1-2;

Fig. 2: be the process flow sheet of embodiment 1-2;

Fig. 3: be X-ray diffraction (XRD) figure of comparative example 1-2, embodiment 1-2 product.

Embodiment

The present invention is further illustrated now to pass through following comparative example and embodiment, but the present invention is not limited to this.

The comparative example 1

85% phosphoric acid of 15.38g, the pseudo-boehmite of 10.98g, the triethylamine of 6.75g, the deionized water of 61.94g, the 40% silicon sol operation as shown in Figure 1 of 6.04g are prepared, and wherein crystallization temperature is 200 ℃, and crystallization time is 48 hours; Each component mol ratio is in the resulting mixing solutions: 1.0Et ₃N: 0.6SiO ₂: 1.0Al ₂O ₃: 1.0P ₂O ₅: 60H ₂O; Last product A.

The comparative example 2

The deionized water operation as shown in Figure 1 of 40% silicon sol of 85% phosphoric acid with 15.38, the pseudo-boehmite of 10.96g, 6.00g, the triethylamine of 10.14g, 62.06g is prepared, and wherein crystallization temperature is 200 ℃, and crystallization time is 48 hours; Each component mol ratio is in the resulting mixing solutions: 1.5Et ₃N: 0.6SiO ₂: 1.0Al ₂O ₃: 1.0P ₂O ₅: 60H ₂O; Last product B.

Embodiment 1

From Comparative Examples 1, get the SAPO-34 of 4.01g and the mixture of SAPO-5, add the triethylamine of 45.01g, the deionized water of 45.28g, undertaken by operation as shown in Figure 2; Crystallization condition: temperature: 200 ℃, the time: 72 hours; Last products C.

Embodiment 2

Get the SAPO-34 of 4.00g and the mixture of SAPO-5 from Comparative Examples 2, the triethylamine of adding 16.83g, the deionized water operation as shown in Figure 5 of 60.03g are carried out; Crystallization condition: temperature: 200 ℃, the time: 96 hours; Last product D.

Claims

1. the method for the synthetic SAPO-34 molecular sieve of additional crystallization method is characterized in that described method comprises the steps:

1) template and deionized water are mixed, in mixed solution, add SAPO-5 and the former powder of SAPO-34 molecular sieve mixture then, stir;

2) homogeneous mixture solotion is packed into crystallizing kettle, the airtight crystallization temperature that is heated to carries out crystallization under crystallization temperature;

3) mixture after the crystallization is carried out centrifugation, filtration, washing after, solid sample obtains the SAPO-34 molecular sieve by heat drying;

Wherein, the resulting SAPO-34 molecular sieve of step 3) is purified SAPO-34 molecular sieve;

Described template is tetraethyl ammonium hydroxide, triethylamine, diethylamine, morpholine, aniline, Isopropylamine, di-n-propylamine or they mixture arbitrarily.

2. method according to claim 1 is characterized in that, comprises described mixing in the step 1), stirs to carry out under 15-80 ℃.

3. method according to claim 2 is characterized in that, the described mixing in the step 1), is stirred under 25-60 ℃ and carries out.

4. method according to claim 1 is characterized in that, the time that also comprises described mixing, stirring in the step 1) is 1-10 hour.

5. method according to claim 4 is characterized in that, the time of mixing described in the step 1), stirring is 2-8 hour.

6. molecular sieve according to claim 1 is characterized in that, described step 2) in crystallization temperature be 150-250 ℃.

7. molecular sieve according to claim 6 is characterized in that, described step 2) in crystallization temperature be 180-220 ℃.

8. molecular sieve according to claim 1 is characterized in that, described step 2) in comprise that also crystallization time is 10-120 hour.

9. molecular sieve according to claim 8 is characterized in that, described step 2) in crystallization time be 24-110 hour.