NZ202185A

NZ202185A - Zircono-and/or hafno-aluminosilicates having a pentasil structure,their preparation and use as olefin producing catalysts

Info

Publication number: NZ202185A
Application number: NZ202185A
Authority: NZ
Inventors: H Baltes; H Litterer; E I Leupold; F Wunder
Original assignee: Hoechst Ag
Priority date: 1981-10-17
Filing date: 1982-10-15
Publication date: 1985-10-11
Also published as: AU550136B2; EP0077523B1; AU8940082A; EP0077523A3; DE3263914D1; EP0077523A2; CA1196903A

Description

New Zealand Paient Spedficaiion for Paient Number £02185 202185 HO DRAWINGS Pr iority Date(s): 2. s"-& -&a Complete Specification Filed: Class: •Sf? .'.TT-A'./M,. P.f.i.f.?. .

Publication Date: . P.O. Journal, No: N.Z. No.

NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION "Zirconium-and/or hafnium-containing zeolites, process for their manufacture, and their use." We, HOECHST AKTIENGESELLSCHAFT, a corporation organized under the laws of the Federal Republic of Germany,of D-6230 Frankfurt/Main 80, Federal Republic of Germany, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the ;method by which it is to be performed,to be particularly described in and by the following statement:- I r 202185 mq*! m/r K # 15 # Zeolites are crystalline aluminosilicates, in which due tc a three-dimensional linkage of SiO^ and AIO^ tetrahedra regular structures with cavities and pores are formed. In hydrated state, these pores and cavities are filled with water, which, on the other hand, can be easily removed without influencing the crystalline structure, or replaced by other molecules. The negative charges of the AlC^ tetrahedra are balanced by cations, which can be replaced by other ions of positive charge. These properties allow the use of the zeolites as ion exchangers, adsorbents and catalysts (D.W. Breck: Zeolite Molecular Sieves, 197*0 .

Zeolites of the X, Y, mordenite, erionite or offre-tite type, for example, are of considerable interest in the industrial practice as catalysts for hydrocarbon conversion reactions such as cracking, hydrocracking or isomerization. Zeolites of the pentasil type (for example Zeolite ZSM-5) become increasingly important as catalysts for the conversion of methanol to hydrocarbons.

Because of the numerous application possibilities as catalysts, there is great interest in novel zeolites having specific catalytical properties.

Very interesting zeolites are for example obtained by incorporating other elements instead of aluminum and/or silicon into the zeolite frame. Thus, zeolites of the pentasil series are known which contain boron, iron, arsenic, antimony, vanadium, chromium, or gallium in tetrahedral position.

Furthermore, titanosilicates (U.S. Patent No. 3,329,481) and zirconosilicates (U.S. Patent No. 3,329,480) have been described; where, hwoever, a pentasil structure can be safely excluded according to the X-ray diffraction diagram and the chemical composition.

Subject of the invention are zircono- and/or hafno-iminosilicates having a pentasil structure. 1 1 JUL 1985^ 202185 jaaftAwr n?n.i i: By pentasils, there are to be understood those defined by Ko-kotailo and Meier ("Pentasil family of high silica crystalline materials" in: Special Publication No. 33 of the Chemical Society, London 1980). The pentasil family comprises for 5 example the synthetic zeolites ZSM-5 (US Patent No. 3,702,886), ZSM-8 (British Patent No. 1,334,243), ZSM-11 (US Patent No. 3,709,979) and ZSM-23 (US Patent No. 4,076,842).

Subject of the invention are especially zircono- and/or hafno -aluminosilicates having a ZSM-5 structure, 10 preferably those having the following composition, expressed as molar ratio of oxides: Si02 :(Up to 0.15) a12°3 : (°-002 - 1-°) M02> especially Si02 : (Up to 0.1) M?°3 : (0*01 ~ °-^ M°2 > M being zirconium and/or hafnium.

The zirconium and/or hafnium-containing zeolites can be prepared according to the same methods and with the use of 20 the same organic compounds as described for the synthesis of the zirconium- or hafnium-free zeolite ZSM-5, for example with the use of alkylammonium compounds (U.S. Patent No. 3,702,886) alkylamines (U.S. Patent No. 4,151,189) alkyldiamines alkylamines in the presence of alkylation agents (Published European Patent Application No.11362), aminoalcohols (British Patent No.2,023,562) alcohols (U.S. Patents Nos. 4, 199,556, 4,175,114, Published European Patent Application No.42225) ethers (European Patent Application No.51741). *5 Preferably, alkylammonium compounds, alkyl diamines or alkylamines are used in the presence of alkylation agents. Especially preferred alkylammonium compounds are tetrapro- * # 202185 - 4 - Hfi? "Vr iiTil pylammonium compounds, for example the hydroxide or one of the halides. A particularly suitable alkyldiamine is hexa-methylene diamine.

For the synthesis of the zeolites of the invention, 5 one or more compounds from the cited classes are mixed with zirconium and/or hafnium compounds, silicon and sodium compounds , water, and aluminum compounds and the mixture is heated in a closed vessel.

^Before heating the mixture, preferably, seed crystals of a pentasil are furthermore added. In the case where tetrapropylammonium compounds are used, the starting compounds are generally used in the following ratio, expressed as molar ratio of oxides: Si02 : (Up to 0.2) A1,,03 : (0.01 - 1.0) M02 : (0.01 - 0.5) Na20 : (0.02 - 1.0) R20 : (5 - 100) H20, preferably in a ratio of Si02 : (Up to 0.1) A1203 : (0.01 - 0.4) MC>2 : (0.02 - 0.3) Na20 : (0.03 - 0.6) R20 : (10 - 40) H20, M being zirconium and/or hafnium, and R being tetrapropyl-ammonium.

As silicon, aluminum, zirconium, hafnium or sodium compounds, there are used for example silica gel, sodium silicate, alu-25 ininum hydroxide, aluminum sulfate, sodium aluminate, aluminum halides, aluminum metahydroxide, zirconium halides, zirconium sulfate, zirconyl chloride, hafnium halides hafnium sulfate, sodium hydroxide, sodium sulfate, sodium halides. Other compounds of the four cited elements are also 30 suitable for the manufacture of the zeolites according to the invention.

The mixture of the compounds chosen and water is generally heated for 18 to 360, preferably 24 to 240, hours at a temperature of from 100 to 200°C, peferably 130 to 35 170°C, in a closed vessel.

The zeolites which are formed are isolated in usual manner, for example by filtration, washed and dried. They can be converted according to known methods to catalytically "5" 20218 5* : active forms, for example by calcination-and/or ion exchange (D.W. Breck, Zeolite Molecular Sieves, 1374).

After conversion to the catalytical'ly active form, the zeolites of the invention display high selectivity and a 5 considerably reduced deposition of coke in the conversion of methanol to lower olefins. This reaction is carried out, for example, at temperatures between 350 and 430°C using methanol with a water content of 0 to 80 % by weight or* raw methanol.

The following Examples illustrate the invention with out limiting it in its scope. All X-ray diffraction data as indicated were obtained by means of a computer-controlled powder diffractometer D-500 of the Siemens company. The radiation was the K-^K doublet of copper.

Example 1 1.66 g of sodium aluminate (54 weight % Al^O^, 41 weight % Na^O) and 1.48 g of sodium hydroxide are dissolved in 20 g of 20 weight % aqueous tetrapropylammonium 20 hydroxide solution (solution A). A further solution (solution B) is obtained by dissolving 62 g of 40 weight % colloidal silica gel in 230 g of 20 weight % aqueous tetrapropylammonium hydroxide solution and concentrating this solution to a total 220 g in a rotation evaporator. The solu-25 tions A and B are mixed, and 3-78 g of zirconyl chloride ZrOCl^ 8H20 are added to this mixture with thorough stirring. The suspension obtaiend is homogenized and heated for 120 hours at 160°C in a closed vessel. The product formed is filtered off, washed with water and dried at 30 120°C. 27-3 g of zircono-aluminosilicate according to the invention is obtained.

An X-ray diffraction analysis shows a well crystallized product having a ZSM-5 structure. According to a chemical analysis of the product calcined for 16 hours at 35 540°C, it has the following composition, expressed as molar ratio of oxides: ol02 : 0.035 Zr02 . 0.026 A1203 : 0.023 Na20. - 6 n o j Koe-e^=g=-g-rfr-K Example 2 0.77 g of sodium hydroxide are dissolved in 5 g of 20 weight % aqueous tetrapropylaramonium hydroxide solution (solution A). A second solution (solution B) is prepared by 5 dissolving 12.4 g of 40 weight % colloidal silica gel in 45 g of 20 weight % tetrapropylammonium hydroxide solution, and concentrating this solution to a total 45 g in a rotation evaporator. Solutions A and B are mixed. 1.88 g of zirconyl chloride ZrOCl2 * 8 H^O in 5 ml of H20, and 0.1 g of 10 seed crystals (product 1) are added with thorough stirring to this mixture. The suspension formed is homogenized and heated for 160 hours at 150°C in a closed vessel. The product obtained is filtered off, washed with water and dried at 120°C. 4.2 g of zirconosilicate of the invention 15 are obtained. According to X-ray diffraction analysis, the product has a ZSM-5 structure. The chemical analysis of the ■ product calcined for 16 hours at 540°C yields the following composition: Si02 : 0.210 ZrOg : 0.121 Na20 Example 3 The zircono-aluminosilicate having a ZSM-5 structure prepared according to Example 1 (calcined form) is exchan-25 ged with ammonium nitrate solution, and together with a binder (Boehmit) extruded (zeolit^e content 65 weight %), and calcined again as indicated in Example 1. 520 ml/h of 33 weight % aqueous methanol are dosed at a temperature of 350°C under normal pressure to a verti-30 cally positioned, electrically heated tube reactor having a lenght of 1 m and packed with 250 ml of this catalyst. The reaction mixture which forms is cooled, and after separation of the condensable portions the gaseous phase is analyzed. The C2~C^ olefin selectivity is 65 %, and the se-35 lectivity to hydrocarbons having more than 4 carbon atoms is 14 ?. 2,02 nos-a I/fsth-"-g- Comparative Example Operations are as in Example 3; however, instead of the zircono-aluminosilicate a commercial aluminosilicate catalyst having a ZSM-5 structure is used.

The C2~^4 olefin selectivity is 56 %r and the selectivity to hydrocarbons having more than 4 carbon atoms is 23 %. 202185

Claims

WHAT WE CLAIM IS: : '

1. Zircono- and/or haf no-aluminosilicates having a pentasil structure.

2. Zircono- and/or hafno--aluminosilicates 5 having a ZSM-5 structure.

3. Zircono- and/or hafno-aluminosilicates as claimed in Claim 1 or 2, having the following composition, expressed as molar ratio of oxides: 10 Si02 :(Up to 0.15) A1203 : (0.002 - 1.0) M02,. M being zirconium and/or hafnium. 15

4. Zircono- and/or hafno-aluminosilicates as claimed in one of Claims 1 to 3, having the following composition, expressed as molar ratio of oxides: 20 Si02 : (Up to 0.1) A1203 : (0.01 - 0.4) M02, M being zirconium and/or hafnium.

5. A process for the manufacture of zircono- and/or hafno -aluminosilicates as claimed in one of 25 Claims 1 to 4, which comprises mixing zirconium and/or hafnium, silicon and sodium compounds, water, as well as aluminum compounds with one or more organic compounds selected from the group consisting of alkylam-monium compounds, alkylamines, alkyldiamines, aminoal-30 cohols, alcohols and ethers, and heating this mixture in a closed vessel.

6. The process as claimed in Claim 5, which comprises using alkylammoniura compounds as organic compounds. Vs" ~3.TtjU985 10 " ;■ 2021 ss - 9 - ,;i»r cvr r;T^»K

7. The process as claimed in Claim 5, which, comprises using tetrapropylammonium compounds as organic compounds.

8. The process as claimed in Claim 5, which comprises using alkylamines in the presence of alkylating agents as organic compounds.

9. The process as claimed in Claim 5, which comprises using alkyldiamines as organic compounds.

10. The process as claimed in one of Claims 5 to 9, which comprises adding seed crystals of a pentasil to the mixture before heating. 15

11. A process for the manufacture of zircono- and/or hafno- aluminosilicates as claimed in one of Claims 1 to 4, which comprises preparing a mixture of zirconium and/or hafnium compounds, silicon, sodium and tetrapropylammonium compounds , water, as well as- alu-20 minum compounds, vihich has the following composition, expressed as molar ratio of oxides: Si02 : (Up to 0.2) A1203 : (0.01 - 1.0) M02 : (0.01 - 0.5) Na20 : (0.02 - 1.0) R20 : (5 - 100) H20, 25 M being zirconium and/or hafnium, and R being tetrapropylammonium, and heating this mixture in a closed vessel.

12. The process as claimed in Claim 11, wherein the mixture 30 to be heated has. the following composition, expressed as molar ratio of oxides: Si02 : (Up to 0.1) A1203 : (0.01 - 0.4) M02 : 35 (0.02 - 0.3) Na20 : (0.03 - 0.6) R20 : (10 - 40) H20, M being zirconium and/or hafnium, and R being tetrapropylammonium .

13. Use of zircono- and/or hafno-aluminosilicates s/X- 40 as claimed in one of Claims 1 to 4 as catalysts>■^or % the manufacture of C -C., olefins from methanol. j! -n] ^ •}■ A xox |* 5" - 10 -

14. Zircono- and/or hafno aluminosilicates according to claim 1 or claim 2 substantially as herein described. HOECHST AKTIENGESELLSCHAFT By Their Attorneys HENRY HUGHES LIMITED