DE1202254B - Process for the preparation of a catalyst for the addition of water to olefins - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

BOIj

German class: 12 g - * ffit // ■ //%.

Number: 1202254

File number: J 20561IV a / 12 g

Filing date: September 19, 1961

Opening day: October 7, 1965

Process for the preparation of a catalyst for the addition of water to olefins

Applicant:

Imperial Chemical Industries Ltd., London

Representative:

Dr.-Ing. H. Fincke, Dipl.-Ing. H. Bohr and Dipl.-Ing. S. Staeger, Patent Attorneys, Munich 5, Müllerstr. 31

Named as inventor:

George Walter Bridger,

John Walton Marshall,

Norton-on-Tees, Durham (UK)

Claimed priority:

Great Britain of 23 September 1960 (32 738),

of February 14, 1961 (5445), of September 11, 1961

According to the invention there is provided a method for producing a catalyst for water attachment proposed to olefins, which is characterized in that one tungsten oxide or a Tungsten-containing compound, which can easily be converted into tungsten oxide, with one related to the entire mixture small amount, preferably 1 to 5 percent by weight, of finely divided polytetrafluoroethylene mixes and then shapes the mixture into pieces.

A “catalyst” is a substance which, when it comes into contact with one or more reaction substances, causes a chemical reaction to take place more quickly leaves as without his presence. Under a compound containing wolf, which is easily converted into tungsten oxide can be transferred, a substance is to be understood that through one or more further treatments, such as B. heating, dehydration or contact with another reaction partner, yourself converts to tungsten oxide. In the case of the compound containing tungsten, which is easily converted into tungsten oxide can be converted, it can be, for example, a hydrated oxide or a carbonate or act an ammonium salt, such as. B. tungstic acid or ammonium tungstate. The use

generation of tungstic acid H ₂ WO ₄ is, however,

preferred. ~

In the preparation of the catalyst you can in

Individuals proceed in such a way that the tungsten oxide is used, but apparently work or tungsten-30, which can be converted into tungsten oxide, only as a diluent.

containing compound in powdered form with poly- As polytetrafluoroethylene is preferably used

tetrafluoroethylene mixes, puts the mixture in an extruder and cuts the strands into pellets. The polytetrafluoroethylene can be used in the form of an aqueous dispersion, but is especially used in large-scale production, preferably in powder form. Using a powdered polymer, water can be added while mixing. The usage

a pelletizing lubricant is usually known. At the temperature of the crystalline unnecessary. If necessary, the melting point of the crystalline areas of the can also be used like catalysts customary carriers eingear- amorphous polymer. Melting of the polymer occurs be worked on. at this temperature, however, not one, but that

The proportion of polymer required in the catalyst gives its structure so far that one Polytetrafluoroethylene depends on the type and amount 45 sintering is possible. Through this heat treatment of the components that are used in addition to the tungsten oxide in the manufacture of the catalyst is the mechain the catalyst may be included. It becomes niche strength of the shaped catalyst pieces however, it is preferred that the polytetrafluoroethylene increase. In the case of polytetrafluoroethylene, the appropriate one is in an amount of 1 to 5 percent by weight, based on temperature for this heat treatment at no-up the total mass of the catalyst, is present. 50 to 330 ° C.

Quantities of 2 to 3 percent by weight are preferred- The catalyst can be used to increase or modify

admitted. Larger amounts of polytetrafluoroethylene can adorn its catalytic effectiveness yet another

509 690/458

wise highly polymerized products, which have a molecular weight between 500,000 and 5,000,000.

In the preparation of the catalyst according to the invention, it can undergo a heat treatment be subjected to a temperature at which the polymer undergoes a phase change. These Phase change is known as the »crystalline melting point«

be subjected to further treatment. The further treatment of the catalyst consists in one Reduction treatment before using the catalyst. This reduction treatment can, for example be made by the fact that the catalyst of the action of hydrogen or Carbon monoxide or an aliphatic alcohol with a maximum of 4 carbon atoms. she should be operated so far that the tungsten

the usual catalyst.

Example 2

30 minutes at room temperature in a conical mixing vessel dry with 250 g of powdered polytetrafluoroethylene mixed, and then at one print

then allowed to cool to room temperature in still air.

When using this catalyst to promote water attachment to propylene for recovery of isopropanol in a converter at 250 ° C, at pressure and using a weight ratio from water to propylene of 4.6: 1 and a space velocity of 41 / hour. per liter of catalyst-filled Space was the transformation like that

oxide WO ₃ into a lower oxide of tungsten with io which, when using a conventional tungsten oxide of approximate composition WO _{25, is} converted into a catalyst without polytetrafluoroethylene content. This reduction can also be found in reaction; however, after prolonged use, mixing would take place. found in this reaction that the degree of phy-

The catalysts according to the invention show physical destruction of the pellets, as has several advantages over known catalysts. 15 shows the proportion of dust in the example according to the invention, they are mechanically stronger and, compared to the physical product, was considerably less resistant than in the case of the pellets.
without a content of polytetrafluoroethylene, namely
both with short-term use and with
prolonged use. These advantages are particularly 20 10 kg of finely powdered tungstic acid (which is important if the catalyzed reaction went in the presence of a sieve with 0.152 mm mesh size) were a liquid phase and especially in the presence
of water takes place.

The compositions of matter are believed to have the advantages found because 25 out of about 1575 kg / cm ² pelletizes. The resulting polymer forms a basic structure, which in the case of pellets were broken by using them, for example in a pellet, to pass the particles of the catalyst through a plate with 2.38 mm holes through table material and other given vibrating sieves . The mass was bound together if any materials were present. then under 11025 to 15 750 kg / cm ² pressure to

As examples of pellets used in this process, 4.76 x 4.76 mm. The pellets Barren olefins may be mentioned ethylene, propylene and were then filled in 2.54 cm high flat Butenes and higher olefins, for example pentenes, shells in a gas-fired oven under gradually-hexenes, Octene, Heptene, Nonene. licher even temperature increase during

The catalyst is particularly suitable for the 6 hours heated to 300 to 330 ° C, 2 hours of water attachment to propylene, kept at temperatures 35 at 300 ° C and then in still air to in the range of 200 to 300 ° C and pressures in the Be - let it cool down to room temperature,
rich from 200 to 300 at. This catalyst was used to promote

The operation of a process for water-water attachment to propylene for the purpose of extraction addition to other olefins requires something different from isopropanol in a converter at 250 ° C, Temperature and / or pressure conditions than the 40 250 at pressure and use of a weight ratio for the water attachment for propylene ratio of water to propylene such as 4.6: 1 and were recommended to achieve optimal alcohol yields at a space velocity of 101 / hr. per liter to reach. catalyst-filled space used. The conversion

Heterogeneously catalyzed reactions in liquid development was that when using a usual Wolf phase can be obtained by this process over a long period of time, but showed the same ramoxide catalyst Periods of uninterrupted physical activity after prolonged use in this reaction Comminution of the catalyst are carried out, the catalyst according to the invention the usual so that the process leads to considerable savings in terms of strength of operating costs. put by the percentage of dust only 1%

The invention is represented by the following Examples 50 compared with 2.0 to 3.0% in the conventional explained in more detail: Catalyst with the same service life.

example 1

5 kg of finely powdered tungstic acid (which passed through a sieve of 0.152 mm mesh size) were mixed with 125 g of polytetrafluoroethylene in the form of an aqueous dispersion containing 18% (w / v) of polytetrafluoroethylene in a Hobart mixer for 30 minutes at room temperature . The product obtained was a granular solid. It was pressed through a sieve with a mesh size of 1.41 mm and air-dried at 105 ° C. for 2 hours. Then it was pelletized into cylinders (3.18-3.18 mm) using a pressure of 15.75 t / cm ^2. The pellets were then heated in shallow dishes in a gas-fired oven while increasing the temperature uniformly for 6 hours up to 330 ° C and then for 2 hours at 330 ° C and

Claims (5)

Patent claims: 1. A process for the preparation of a catalyst for the addition of water to olefins, thereby characterized in that tungsten oxide or a compound containing tungsten, which can easily be converted into tungsten oxide, with a small amount in relation to the total mixture, preferably 1 to 5 percent by weight, finely divided polytetrafluoroethylene and then the mixture is shaped into pieces. 2. The method according to claim 1, characterized in that there is an amount of 2 to 3 percent by weight of polytetrafluoroethylene, based on the total amount of the catalyst, is used. 3. The method according to any one of the preceding claims, characterized in that a Polytetrafluoroethylene is used, which has a molecular weight between 500,000 and 5,000,000 owns. 4. The method according to any one of the preceding claims, characterized in that the Catalyst mixture is subjected to a temperature at which a phase change of the Polytetrafluoroethylene takes place. 5. The method according to any one of the preceding claims, characterized in that the Catalyst mixture of a partial reduction treatment with carbon monoxide, hydrogen or an aliphatic alcohol having not more than 4 carbon atoms.