NZ204154A

NZ204154A - Titanium-containing zeolites,their preparation and use

Info

Publication number: NZ204154A
Application number: NZ204154A
Authority: NZ
Inventors: H Baltes; H Litterer; E I Leupold; F Wunder
Original assignee: Hoechst Ag
Priority date: 1982-05-08
Filing date: 1983-05-06
Publication date: 1985-10-11
Also published as: CA1195675A; ZA833240B; JPS58204818A; DE3217324A1; AU1434483A; EP0094024A1

Description

New Zealand Paient Spedficaiion for Paient Number £04154 Priority Date(s): .. ~*r>. / _r Complete Specification Filed: v. ..... Class: . .<£*? /?.?.'» . fe'.'.Tra !/?#. i ..C.<?.7/Z-A/Z(t Publication Date: ... .JS.1.P.QT. 19855...

P.O. Journal, No: . A2.Ik NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION "TITANIUM-CONTAINING ZEOLITES, A PROCESS FOR THEIR PREPARATION, 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:- 204154 MB DRAWINGS r ~6M4*I983- N-Z. No.

Zeolites are/ in particular, crystalline alumino-silicates in which ordered structures containing cavities and pores are formed as a result of three-dimensional linking of SiO^ and AIO4 tetrahedra. In the hydrated 5 state, these pores and cavities are filled with water.

This can be removed or replaced by other molecules, with-out the crystal structure being affected. The negative charges on the AlO^ tetrahedra are compensated by cations. These can, if desired, be exchanged for other cat-10 ions. The properties described make it possible to use the zeolites as ion exchangers, adsorbents and catalysts (D.W. Breck: Zeolite Molecular Sieves, 1974).

Zeolites of the X, Y, mordenite, erionite and offretite types, for example, are of considerable indus-15 trial interest as catalysts for transformation reactions of hydrocarbons, such as cracking, hydrocracking or iso-merization. Zeolites of the pentasil type (e.g. zeolite ZSM-5) are becoming increasingly important as catalysts for converting methanol to hydrocarbons. 20 Because of the very large number of possible uses as catalysts, there is considerable interest in novel zeolites having specific catalytic properties.

For example, very interesting zeolites are obtained if, instead of aluminum and/or silicon, other 25 elements are incorporated into the zeolite frameworks.

Thus, other zeolites of the pentasil series which contain / <2.<3£15~4 boron, iron, arsenic, antimony, vanadium, chromium or gallium in tetrahedral sites have been disclosed. Titanosilicates (U.S. Patent 3,329,481) and zirconosilicates (U.S. Patent 3,329,480) having a zeolite structure have also been disclosed.

Furthermore, boron-containing zeolites, gallium-containing and/or indium-containing zeolites, titanium-containing zeolites and zirconium-containing and/or hafnium-containing zeolites have already been described The invention relates to titanium-containing zeolites which a) in addition to sodium, potassium and choline, contain the elements silicon, aluminum and titanium in the following ratio, expressed as molar ratios of oxides: (Si(>2 + TiOg) : (0.02 - 0.30) AI2O3 and b) exhibit the characteristic signals, listed in Table 1 in the X-ray diffraction diagram: 204154 Tab L e 1 Interplanar spacings Relative intensity o dCAD I/I0 11.4 _+ 0.3 strong to very strong 9.2 +_ 0.2 weak f 7.6 +_ 0.2 weak to medium 6.6 +_ 0.1 medium to strong .7 +_ 0.1 weak to medium 5.35 0.1 weak 4.56 0.1 medium to strong 4.32 0.1 st rong 4.16 _+ 0.1 weak 3.81 +_ 0.1 medium to strong 3.75 _+ 0.1 strong to very strong 3.59 +_ 0.1 strong to very strong 3.30^0.1 medi um 3.15 + 0.1 medium 2.86 _+ 0.1 strong to very strong 2.80 + 0.1 weak to medium 20 In this table, Iq denotes the intensity of the strongest signal.

The following values apply to the intensity data in Table 1: Relative intensity 100 I/I0 very strong 80 - ■ 100 strong 50 - - 80 medi um - ■ 50 weak 0 - - 20 The ratio of silicon to titanium, expressed as * J 5* molar ratios of the oxides, is in general as follows SiO~ Si02 + Ti02 preferably sio2 Si02 + Ti02 = 0,4 - 0,99/ = 0,7 - 0,99/ The novel zeolites according to the invention possess a structure similar to that of the T (U.S. Patent 2,950,952) or ZSM-34 1 zeolites, but differ from these in composition in particular as a result of the titanium content.

The titanium-containing zeolites according to the invention differ in structure from the titanosilicates according to U.S. Patent 3,329,481»r The zeolites according to the invention can be 15 prepared by mixing titanium compounds with aluminum compounds, silicon compounds, sodium compounds, potassium compounds, choline compounds and water, and heating the mixture in a closed vessel. It is also possible to add seed crystals to this mixture before it is heated. 20 The starting compounds are employed in general in the following ratio, expressed as molar ratios of the oxides: (Si02 + Ti02) : (0.02 - 0.30)Al203 : (0.05 - 0.70)Na20 : (0.02 - 0.30)K20 : (0.02 - 0.5)R20 : (10 - 90)H20, 25 preferably in the ratio (Si02 + Ti02) : (0.02 - 0.18)Al203 : (0.10 - 0.60)Na20 : (0.04 - 0.20)K o0 : (0.10 - 0.40)Ro0 : (10 - 40)H90' 041 54 - 6 - £, wherein R is choline.

The ratio of silicon to titanium in the mixture of the starting compounds, expressed as molar ratios of the oxides, is in general as follows: Si0o — = 0,4 - 0,99, Si02 + Ti02 preferably SiO 2 = 0,6 - 0199, Si02 + Ti02 Examples of compounds which can be employed are: silica gel, potassium silicate, sodium silicate, aluminum 10 hydroxide, aluminum sulfate, sodium aluminate, potassium aluminate, aluminum halides, aluminum met ahydroxide, titanium halides, titanium sulfate, titanium oxide sulfate, sodium titanate, potassium titanate, titanium dioxide, sodium hydroxide, sodium sulfate, sodium halides, potas-15 sium hydroxide, potassium sulfate, potassium halides, choline hydroxide and choline chloride. However, other silicon, aluminum, titanium, potassium, sodium and choline compounds are also suitable for the preparation of the zeolites according to the invention.

A mixture of the particular selected compounds with water is heated in general for 48 to 2,000 hours, preferably 48 to 1,000 hours, at a temperature between 80 and 160°C, preferably between 90 and 150°C, in a closed vessel.

The zeolites formed are isolated in a customary manner,, for example by filtration, and are washed and dried. They can be converted to the catalytically active % 154 •forms by known methods, e.g. by calcination and/or ion exchange (D.W. Breck, Zeolite Molecular Sieves, 1974).

After they have been converted to the catalytic-ally active forms, the zeolites according to the invention 5 are distinguished in particular by high selectivity and by a low level of coking in the conversion of methanol to lower olefines. It is surprising that it is at all possible to obtain zeolites having the characteristics according to the invention with the aid of the stated 10 method.

The examples which follow are intended to illustrate the invention, but are not intended to restrict it in any way. All X-ray diffraction data given have been recorded using a computer-controlled D-500 powder dif-15 fTactometer from Siemens. Copper K% radiation was used. Example 1 1.5 g of sodium aluminate (54% by weight of AI2O3 and 41% by weight of Na20), 7.7 g of sodium hydroxide, 1.6 g of potassium hydroxide and 12.7 g of choline chloride 20 are dissolved in 43 g of water. First 4.1 g of titanium tetrachloride and then 29.4 g of 40% strength by weight colloidal silica gel are introduced into this solution, while stirring thoroughly. The resulting mixture is homogenized, and heated for 8 days at 150°C in a closed ves-25 sel. The product formed is filtered off, washed with water and dried at 120°C.

The product contains silicon, aluminum and titanium in the following amounts, expressed as molar ratios of oxi des: iL 041 Si02 : 0.064 Al203 : 0.175 Ti02 The result of the X-ray diffraction analysis is reproduced in Table 2.

Table 2 Relative intensity InterpLanar spacings dCAU 100 I/I0 11.45 100 9.16 3 7.56 14 6.62 41 6.33 15 5.74 18 .34 3 4.56 42 4.33 51 4.14 6 3.80 44 3.76 89 3.58 74 3.31 35 3.16 32 2.92 8 2.86 83 2.80 5 2.67 9 2.48 7 Example 2 .0 g of sodium aluminate, 19.5 g of sodium hydroxide, 4.4 g of potassium hydroxide and 42 g of choline ,ji 4^ 4- I chloride are dissolved in 135 g of water. First 102 g of 40% strength by weight colloidal silica gel and then 6.8 g of titanium tetrachloride are introduced into this solution, while stirring thoroughly. The resulting mixture 5 is heated for 30 days at 105°C in a closed vessel. The product formed is filtered off, washed with water and dri ed at 120°C.

The product contains silicon, aluminum and titanium in the following amounts, expressed as molar ratios 10 ofoxides: Si02 : 0.072 Al203 : 0.103 Ti02.

Claims

WHAT WE CLAIM IS:

1. A titanium-containing zeolite which a) in addition to sodium, potassium and choline, contains the elements silicon, aluminum and titanium in the following ratio, expressed as molar ratios of oxides: (Si02 +■ Ti02) : (0.02 - 0.30)Al203 and b) exhibits the following characteristic signals in the X-ray diffraction diagram: InterpLanar spacings Relative intensity dCAD I /10 11.4 _+ 0.3 strong to very strong 9.2 + 0.2 weak 7.6 _+ 0.2 weak to medium 6.6 _+ 0.1 medium to strong 5.7 0.1 weak to medium 5.35 ^ 0.1 weak 4.56 _+ 0.1 medium to strong 4.32+^0.1 strong 4.16 _+ 0.1 weak 3.81 _+ 0.1 medium to strong 3.75 +_ 0.1 strong to very strong 3.59 + 0.1 strong to very strong 3.30+^0.1 medi um 3.15 +_ 0.1 medium 2.86 0.1 strong to very strong

2.80 +_ 0.1 weak to medium where Ig denotes the intensity of the strongest signal. 2. A titanium-containing zeolite as claimed in claim . 'V 3 Jm - 11 - 1, wherein the ratio of silicon to titanium, expressed as molar ratios of the oxides, is as follows: Sl°2 = 0,4 - 0,99, Si02 + Ti02

3. A titanium-containing zeolite as claimed in claim 1, wherein the ratio of silicon to titanium, expressed as molar ratios of the oxides, is as follows: Si0o ± = 0.7 - 0,99, Si02 + Ti02

4. A process for the preparation of a titanium-containing zeolite as claimed in any one of claims 1 to 3, wherein a mixture of a silicon compound, a titanium compound, an aluminum compound, a sodium compound, a potassium compound, a choline compound and water is prepared, which has the following composition, expressed as molar ratios of the oxides: (Si02 + Ti02) : (0.02 - 0.30)Al203 : (0.05 - 0.70)Na20 : (0.02 - 0.30)K20 : (0.02 - 0.5)R20 : (10-90)H20, where R is choline, and this mixture is heated in a closed vessel.

5. A process as claimed in claim 4 , wherein the mixture to be heated has the following composition, expressed as molar ratios of the oxides: (Si02 + Ti02) : (0.02 - 0.18)Al203 : (0.10 - 0.60)Na20 : (0.04 - 0.20)K20 : (0.10 - 0.40)R20 : (10 - 40)H20, where R is choline.

6. A process as claimed in claim 4 or 5, wherein the ratio of silicon to titanium in the mixture of the starting compounds, expressed as molar ratios of the oxides, 20^15"4 - 12 - is as follows: . . Si00 ± = 0/4 - 0,99, Si02 + Ti02

7. A process as claimed in claim A or 5, wherein the ratio of silicon to titanium in the mixture of the starting compounds, expressed as molar ratios of the oxides, is as follows: SiO~ ± = 0,6 - 0,99, Si02 + Ti02

8. Use of a titanium-containing zeolite as claimed in any one of claims 1 to 3 as a catalyst in the preparation of C2~ to C^-olefines from methanol. HOECHST AKTIENGESELLSCHAFT By Their Attorneys HENRY HUGHES LIMITED