SAPO-34 zeolite having diglycolamine as templating agent and synthesis method for the zeolite

Abstract

The present invention provides a SAPO-34 molecular sieve, whose chemical composition in the anhydrous state is expressed as: mDGA.(Si.sub.xAl.sub.yP.sub.z)O.sub.2; wherein DGA is diglycolamine, distributing in the cages and pores of said molecular sieve; m is the molar number of the template agent diglycolamine per one mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, and m is from 0.03 to 0.25; x, y, z respectively represents the molar number of Si, Al, P, and x is from 0.01 to 0.30, and y is from 0.40 to 0.60, and z is from 0.25 to 0.49, and x+y+z=1. Said SAPO-34 molecular sieve can be used as an acid-catalyzed reaction catalyst, such as a methanol to olefins reaction catalyst. The present invention also concerns the application of said SAPO-34 molecular sieve in adsorption separation of CH.sub.4 and CO.sub.2.

Claims

1. A SAPO-34 molecular sieve whose chemical composition in the anhydrous state is expressed as:
mDGA.(Si.sub.xAl.sub.yP.sub.z)O.sub.2; wherein, DGA is diglycolamine; m is the molar number of diglycolamine per one mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, and m is from 0.03 to 0.25; x, y, z respectively represents the molar number of Si, Al, P, and x is from 0.01 to 0.30, and y is from 0.40 to 0.60, and z is from 0.25 to 0.49, and x+y+z=1.

2. A SAPO-34 molecular sieve according to claim 1, wherein the X-ray diffraction spectrogram of said SAPO-34 molecular sieve includes the diffraction peaks at following peak positions: TABLE-US-00006 No. 2 1 9.4445 2 15.942 3 17.7583 4 22.9708 5 29.428.

3. A method for preparing said SAPO-34 molecular sieve according to claim 1, including the steps as follows: (a) deionized water, a silicon source, an aluminum source, a phosphorus source and DGA are mixed according to a certain ratio, and an initial gel mixture with following molar ratio is obtained: SiO.sub.2/Al.sub.2O.sub.3 is from 0.05 to 2.5; P.sub.2O.sub.5/Al.sub.2O.sub.3 is from 0.5 to 1.5; H.sub.2O/Al.sub.2O.sub.3 is from 5 to 200; DGA/Al.sub.2O.sub.3 is from 2.5 to 30, DGA is diglycolamine; (b) the initial gel mixture obtained in said step (a) is transferred into an autoclave, then sealed and heated to crystallization temperature range from 150 C. to 220 C., crystallized for crystallization time range from 5 h to 72 h under the autogenous pressure; (c) after finishing the crystallization, the solid product is separated, washed to neutral using deionized water and dried to obtain said SAPO-34 molecular sieve.

4. A method according to claim 3, wherein in the initial gel mixture obtained in said step (a), the silicon source is one or more selected from silica sol, active silica, orthosilicate esters and metakaolin; the aluminum source is one or more selected from aluminum salts, activated alumina, aluminum alkoxide and metakaolin; the phosphorus source is one or more selected from phosphoric acid, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, organophosphorous compounds and phosphorus oxides.

5. A method according to claim 3, wherein in said step (b), the crystallization is carried out statically or dynamically.

6. A method according to claim 3, wherein in the initial gel mixture obtained in said step (a), the molar ratio of organic amine DGA to Al.sub.2O.sub.3 SDA/Al.sub.2O.sub.3 is from 5.5 to 16.

7. A catalyst for acid-catalyzed reaction, which is obtained by calcining at least one of said SAPO-34 molecular sieves according to claim 1, at a temperature from 400 to 700 C. in air.

8. A catalyst for oxygenates to olefins reaction, which is obtained by calcining at least one of said SAPO-34 molecular sieves according to claim 1, at a temperature from 400 to 700 C. in air.

9. A material used for adsorption separation of CH.sub.4/CO.sub.2, which is obtained by calcining at least one of said SAPO-34 molecular sieves according to claim 1, at a temperature from 400 to 700 C. in air.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a scanning electron microscope image of the sample prepared in Example 1 (SEM).

SPECIFIC EMBODIMENTS OF THE INVENTION

(2) The elemental analysis was determined using Magix 2424 X-ray fluorescence spectrometer (XRF) produced by Philips.

(3) The X-ray powder diffraction analysis (XRD) was determined using X'Pert PRO X-ray diffractometer produced by PANalytical, with Cu K radiation (=0.15418 nm), operated at 40 KV and 100 mA.

(4) The SEM morphology analysis was determined using KYKY-AMRAY-1000B scanning electron microscope produced by Scientific Instruments Factory of Chinese Academy of Sciences.

(5) Carbon-13 nuclear magnetic resonance analysis (.sup.13C MAS NMR) was determined using Infinity plus 400WB Solid-state nuclear magnetic resonance spectrometer produced by Varian, with a BBO MAS probe operating at a magnetic field strength of 9.4 T.

(6) CHN elemental analysis was determined using German Vario EL Cube elemental analyzer.

(7) The present invention will be described in details by Examples, but the present invention is not limited to these Examples.

Examples 1

(8) The amount of ingredients, the crystallization condition and the sample elemental composition are shown in Table 1. The synthesis process was as follows: 14 g of pseudoboehmite (with Al.sub.2O.sub.3 mass percent of 72.5%) and 79.2 g of deionized water were mixed homogeneously, and then 5.96 g of silica sol (with SiO.sub.2 mass percent of 30.24%) was added and stirred to smooth, and then 23.06 g of phosphoric acid (with H.sub.3PO.sub.4 mass percent of 85%) was added by droplets. 31.5 g dialycolamine (abbreviated as DGA, with mass percent of 99%) were added into the mixture, stirring to smooth to obtain the initial gel mixture. The initial gel mixture was transferred into a stainless steel autoclave. The molar ratio of the compositions in the initial gel mixture was 3.0DGA:0.30SiO.sub.2:1Al.sub.2O.sub.3:1P.sub.2O.sub.5:50H.sub.2O.

(9) The autoclave was put into a stove and temperature programmed heated to 200 C. dynamically crystallized for 48 h. After finishing the crystallization, the solid product was centrifugal separated, washed and dried at 100 C. in air to obtain the raw powder sample. The raw powder sample was detected with XRD and XRD data were shown in Table 2, indicating that the raw powder sample prepared had the structural characteristics as same as SAPO-34 molecular sieve.

(10) The CHN elemental analysis of the raw powder sample obtained in Example 1 was detected, and the chemical compositions of the racy powder sample were obtained by normalization of the CHN elemental analysis results and the inorganic elemental analysis results detected by XRF.

(11) TABLE-US-00002 TABLE 1 The list of amount of ingredients and crystallization conditions of the molecular sieves* Aluminum Phosphorus Silicon source and source and source and Crystal- Molar molar amount molar amount molar amount lization Crystal- amount of Al.sub.2O.sub.3 of P.sub.2O.sub.5 of SiO.sub.2 Temper- lization Chemical Example of DGA thereof thereof thereof H.sub.2O ature Time Composition 1 0.3 mol pseudoboehmite phosphoric silica sol 5.0 mol 200 C. 48 h 0.19DGA 0.10 mol acid 0.03 mol (Si.sub.0.13Al.sub.0.49P.sub.0.38)O.sub.2 0.10 mol 2 0.59 mol aluminium phosphoric silica sol 1.6 mol 180 C. 48 h 0.12DGA isopropoxide acid 0.005 mol (Si.sub.0.01Al.sub.0.50P.sub.0.49)O.sub.2 0.1 mol 0.10 mol 3 0.25 mol aluminium phosphoric silica sol 0.5 mol 200 C. 24 h 0.10DGA isopropoxide acid 0.15 mol (Si.sub.0.30Al.sub.0.45P.sub.0.25)O.sub.2 0.1 mol 0.10 mol 4 0.38 mol -alumina phosphoric silica sol 8.3 mol 200 C. 24 h 0.08DGA 0.1 mol acid 0.10 mol (Si.sub.0.25Al.sub.0.41P.sub.0.34)O.sub.2 0.10 mol 5 0.5 mol aluminum phosphoric active silica 2.6 mol 190 C. 48 h 0.25DGA sulfate acid 0.25 mol (Si.sub.0.28Al.sub.0.46P.sub.0.26)O.sub.2 0.1 mol 0.05 mol 6 0.3 mol aluminium phosphoric ethyl 1.2 mol 200 C. 24 h 0.22DGA chloride acid orthosilicate (Si.sub.0.20Al.sub.0.35P.sub.0.45)O.sub.2 0.1 mol 0.15 mol 0.08 mol 7 1.0 mol pseudoboehmite phosphoric silica sol 5.1 mol 200 C. 24 h 0.21DGA 0.1 mol acid 0.04 mol (Si.sub.0.10Al.sub.0.49P.sub.0.41)O.sub.2 0.09 mol 8 0.8 mol aluminium phosphoric silica sol 10 mol 200 C. 24 h 0.17DGA isopropoxide acid 0.01 mol (Si.sub.0.06Al.sub.0.60P.sub.0.34)O.sub.2 0.1 mol 0.15 mol 9 0.26 mol pseudoboehmite ammonium silica sol 6. 6 mol 220 C. 5 h 0.16DGA 0.1 mol dihydrogen 0.06 mol (Si.sub.0.14Al.sub.0.47P.sub.0.39)O.sub.2 phosphate 0.10 mol 10 1.5 mol pseudoboehmite diammonium active silica 2.2 mol 200 C. 24 h 0.18DGA 0.1 mol hydrogen 0.06 mol (Si.sub.0.11Al.sub.0.49P.sub.0.40)O.sub.2 phosphate 0.10 mol 11 2.0 mol aluminum diammonium silica sol 8.8 mol 200 C. 18 h 0.15DGA sulfate hydrogen 0.07 mol (Si.sub.0.16Al.sub.0.47P.sub.0.37)O.sub.2 0.1 mol phosphate 0.15 mol 12 0.3 mol pseudoboehmite diammonium silica sol 6.5 mol 180 C. 24 h 0.12DGA 0.1 mol hydrogen 0.12 mol (Si.sub.0.25Al.sub.0.40P.sub.0.35)O.sub.2 phosphate 0.12 mol 13 0.4 mol pseudoboehmite phosphoric active silica 12 mol 210 C. 18 h 0.19DGA 0.1 mol anhydride 0.03 mol (Si.sub.0.15Al.sub.0.49P.sub.0.36)O.sub.2 0.13 mol 14 0.39 mol pseudoboehmite phosphoric silica sol 4.5 mol 190 C. 12 h 0.19DGA 0.1 mol acid 0.03 mol (Si.sub.0.15Al.sub.0.49P.sub.0.36)O.sub.2 0.10 mol 15 0.39 mol aluminium phosphoric tetramethyl 6.5 mol 150 C. 72 h 0.22DGA isopropoxide acid orthosilicate (Si.sub.0.15Al.sub.0.46P.sub.0.39)O.sub.2 0.1 mol 0.10 mol 0.03 mol 16 0.30 mol pseudoboehmite trimethyl silica sol 6.5 mol 210 C. 15 h 0.17DGA 0.1 mol phosphine 0.03 mol (Si.sub.0.13Al.sub.0.48P.sub.0.37)O.sub.2 0.10 mol 17 0.35 mol pseudoboehmite triethyl silica sol 6.5 mol 170 C. 60 h 0.19DGA 0.1 mol phosphine 0.03 mol (Si.sub.0.13Al.sub.0.48P.sub.0.39)O.sub.2 0.10 mol 18 0.8 mol pseudoboehmite phosphoric silica sol 3.0 mol 200 C. 24 h 0.20DGA 0.1 mol acid 0.20 mol (Si.sub.0.26Al.sub.0.44P.sub.0.30)O.sub.2 0.10 mol 19 3.00 mol pseudoboehmite phosphoric silica sol 20 mol 200 C. 24 h 0.21DGA 0.1 mol acid 0.03 mol (Si.sub.0.15Al.sub.0.50P.sub.0.35)O.sub.2 0.10 mol

(12) TABLE-US-00003 TABLE 2 XRD result of the sample obtained in Example 1 No. 20 d() 100 I/I 1 9.4445 9.36452 66.76 2 12.7935 6.91968 15.26 3 13.9312 6.35701 6.2 4 15.942 5.55943 43.18 5 17.7583 4.99471 21.85 6 18.9695 4.67843 2.26 7 20.5083 4.33075 100 8 20.9495 4.24053 4.27 9 21.9655 4.04662 16.19 10 22.2848 3.98936 8.18 11 24.9225 3.57281 70.93 12 25.7931 3.45415 22.85 13 27.5092 3.24245 6.1 14 28.1221 3.17316 4.82 15 29.428 3.03525 3.39 16 30.4672 2.93405 42.98 17 31.0098 2.88394 25.27 18 32.2329 2.77725 1.71 19 33.4612 2.67805 4.49 20 34.3373 2.61171 7.7 21 35.9729 2.49663 6.8 22 39.5319 2.27967 3.7 23 43.2766 2.0907 3.73 24 47.4623 1.91563 4.54 25 49.3238 1.84761 2.58 26 50.6098 1.80364 6.32 27 53.0197 1.7272 4.94 28 55.2438 1.66281 2.49 29 58.1695 1.58595 0.83 30 59.3794 1.5565 1.83

Examples 2 to 19

(13) The amount of ingredients and the crystallization conditions were shown in Table 1, and the synthesis processes were the same as Example 1.

(14) The samples were detected with XRD. XRD data of samples were similar to Table 2, which showed that each corresponding peak had the same peak position and the 10% difference of peak intensity, indicating the samples prepared had the structural characteristics as same as SAPO-34 molecular sieve.

(15) The elemental analysis results of the samples were shown in Table 1.

(16) The raw powder samples obtained in Examples 1 to 10 were detected with .sup.13C MAS NMR analysis respectively, comparing the results with the .sup.13C MAS NMR standard spectrum of diglycolamine, only the resonance peak of diglycolamine was observed.

Example 20

(17) The sample obtained in Example 1 was calcined at 550 C. for 4 hours in air, then pressed, crushed and sieved to 20-40 mesh. 5.0 g of the sample was added into a batch reactor loaded 30 mL of ethanol to carry out an ethanol dehydration reaction evaluation. The reaction was carried out at 150 C. under stirring. The result showed that ethanol conversion reached 92% and the selectivity for ether in products was 92%.

Example 21

(18) The sample obtained in Example 1 was calcined at 550 C. for 4 hours in air, then pressed, crushed and sieved to 20-40 mesh. 1.0 g, of the sample was weighted and loaded into a fixed bed reactor to carry out a methanol to olefins reaction evaluation. The sample was activated at 550 C. for 1 hour in nitrogen gas and reduced to 450 C. to perform a reaction. Methanol was carried by nitrogen gas with a flow rate of 40 ml/min and the Weight Hour Space Velocity of the methanol was 4.0 h.sup.. The reaction products were analyzed by an on-line gas chromatograph (Varian3800. HD detector, capillary column was PoraPLOT Q-HT). The result was shown in Table 3.

(19) TABLE-US-00004 TABLE 3 The reaction result of methanol to olefins on the sample Life Selective (mass %) * Sample (min) CH.sub.4 C.sub.2H.sub.4 C.sub.2H.sub.6 C.sub.3H.sub.6 C.sub.3H.sub.8 C.sub.4.sup.+ C.sub.5.sup.+ C.sub.2H.sub.4 + C.sub.3H.sub.6 Example 1 126 1.38 43.14 0.55 37.60 1.03 12.17 4.13 80.74

Example 22

(20) The sample obtained in Example 10 was calcined at 550 C. for 4 hours in air. The adsorption isotherms or CO.sub.2 and CH.sub.4 were detected using Micrometrics ASAP 2020. Before being detected, the sample was degassed at 350 C. for 4 hour under vacuum conditions. The adsorption isotherms were detected at the temperature or 25 C. and the pressure or 101 kpa.

(21) TABLE-US-00005 TABLE 4 The adsorption separation result of CO.sub.2/CH.sub.4 on the sample Adsorption Capacity (mmol/g) Sample CO.sub.2 CH.sub.4 CO.sub.2/CH.sub.4 Example 10 3.82 0.20 19.1