DE1062376B - Catalysts for the dehydrogenation and dehydrocyclization of non-aromatic hydrocarbons - Google Patents

Description

The invention relates to new catalysts for the dehydrogenation and dehydrocyclization of non-aromatic hydrocarbons.

The catalysts of the invention which can be used for these processes contain chromium oxide a carrier material, preferably aluminum oxide, and are characterized by the fact that they also have a contain a small amount of germanium in bound form. The germanium is preferably in the form of an oxide before. If appropriate, the catalysts can also contain small amounts of other activating agents, for example Contain alkali metals, preferably potassium, which can also be present as oxides. The parts of the catalysts, based on the total catalyst stable at 150 ° C., are preferably in the following proportions:

Chromium oxide 5 to 25 per cent

Germanium Oxide O ₁ Ibis 5%

Alumina remainder

The catalysts can be in any suitable manner, for example by impregnation or joint Precipitation. Since the chromium trioxide and many chromium salts that are converted into Let the oxide transfer, are water-soluble, the carrier material can be in a simple form with a solution of the chromium compounds are impregnated, dried and then calcined. But it is the same possible to precipitate the aluminum oxide hydrate and a chromium compound together from a solution and to dry and calcine the resulting gel.

Water-soluble germanium compounds that can be converted into the oxide by calcination, can be added to the catalysts in the same way. However, they are germanium dioxide and most of the germanium compounds that can be converted into the oxide by calcination, insoluble in water. Such germanium compounds can be dissolved in a solvent other than water and this solution can then be used to impregnate the carrier material. Such a procedure will however remain of relatively limited importance for technical use, because large amounts of the relatively expensive solvents are required.

A particularly suitable method for catalyst production is a variant in the technology of common precipitation, in which germanium dioxide or suitable germanium compounds in a solution of an aluminum salt are suspended and the aluminum oxide hydrate then mixed with the suspended germanium compound is precipitated.

Catalysts for dehydrogenation
and dehydrocyclization of non-aromatic hydrocarbons

"

Applicant:
The British Petroleum Company Limited,

London

Representative: Dr.-Ing. A. ν. Kreisler, Dr.-Ing. Κ. Schönwald, Dipl.-Chem. Dr. phil. H. Siebeneicher
and Dr.-Ing. Th. Meyer, patent attorney _r

Cologne 1, Deichmannhaus

Claimed priority:
Great Britain 7 December 1956

John Arthur Edgar Moy and John Leather,
Sunbury-on-Thames, Middlesex (Great Britain),
have been named as inventors

Another particularly suitable method is the so-called "wet-gel" method, in which a germanium compound is intimately mixed with the previously formed aluminum oxide hydrate gel. In both The resulting gel is then dried and calcined.

The specified processes are for the preparation of granular catalysts or those in the form of Spheres as well as suitable for the production of fluidized bed catalysts. Granular catalysts can be prepared by carefully controlling gel drying while using catalyst beads can be obtained by drying the gel into fine particles and then shaping it into spheres. Catalysts are produced in the form of very fine particles that are later used in the flowing state are to be, so is with the "wet-gel" process or with the precipitation of the aluminum oxide hydrate in the presence of the suspended germanium compounds to ensure that a intimate mixture of gel and germanium compound occurs, so that the individual catalyst particles a have uniform composition.

When used, the catalysts can be used as a fixed bed, fluidized bed or as a fluidized bed

909 579/395

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catalysts are used. The fluidized bed or fluidized bed processes are in use of catalysts is preferred because this form of catalyst is different from the carbonaceous deposits easily regenerated by burning it in a stream of oxygen-containing gas.

Another possibility for the production of catalysts consists in the joint grinding of dry Aluminum oxide and a germanium compound to form a finely divided mixture, which then is spherically deformed and calcined. Granular catalysts and catalysts for fluidized bed processes however, cannot be made in this way.

The germanium compound of the catalyst can be before, together with or after the chromium compound be admitted.

Calcining should be carried out at temperatures below the temperature in which aluminum oxide is converted into its α-form to an undesirable extent. A suitable calcination temperature is about 550 ° C

The catalysts of the invention are particularly for use in a dehydrogenation and dehydrocyclization process suitable, as is the subject of patent application B 47026 IVc / 23 b. They are characterized by their superior effectiveness the dehydrogenation and dehydrocyclization as well as with regard to the yield of the reaction product obtained.

For the methods of using the catalysts prepared according to the invention, see No protection is claimed in the present invention.

2,376

example 1

1326 g of aluminum nitrate (Al (NO ₃ ) ₃ · 9 H ₂ O) are dissolved in 1500 ml of distilled water and 2 g of germanium dioxide are suspended in the solution. 675 ecm of ammonia (specific gravity 0.880) are added and the precipitate is filtered, washed with distilled water, dried at 50.degree. C. and roasted at 550.degree. The catalyst is then impregnated with a solution of 50 g of chromium trioxide in 90 ecm of distilled water, dried and roasted at 550 ° C. for 2 hours.

The new effects of the catalysts according to the invention are shown in Examples 2 and 3 below explained.

Example 2

A platinum catalyst containing by hydroforming a gasoline fraction over a bound halogen The reformate made on an alumina support is available in light and heavy Fractions separated. The light fraction has a final boiling point of 108 ° C and a research octane number (without addition) of 76.1. This fraction is treated further under the following conditions:

Pressure normal pressure

Space flow velocity. 0.2 V / V / hour

Recirculated gas volume -

Duration of the procedure 5 hours

Reaction temperature 475 to 530 ° C

The results are shown in Table 1 below.

Table 1

catalyst Reaction
temperature
⁰ C Butane free
yield
Weight percent s product
Research
Octane number
(without addition) Austr
Fljeß-
speed
m ³ / m ³ ittsgas
H ₂ content
Volume
percent 1. 10% Cr ₂ O ₄ AAl ₂ O ₃ + 1 Vo Ce ₂ O ₃
+ 1% K ₂ O
2. 1% Ce ₂ O ₃ + 1% K ₂ O
3. 1% Ce ₂ O ₃ + 1% GeO ₂
4. IVo Ce ₂ 0 ₃ + 1% GeO ₂ 475
530
475
530 82
62
78
53 93.7
102.2
95.2
104.2 157
319
225
382 87
81
73
62

Example 3

A straight run, low boiling point gasoline with an ASTM boiling range of 42.5 to 112 ° C and one Research Octane Number (no addition) of 61.2 is treated under the following conditions.

Pressure normal pressure

Room flow velocity .. 0.2 V / V / hour.

Recirculated gas volume -

Duration of the procedure 5 hours

Experiments are carried out at different temperatures with the catalyst of Example 2, the IOVo contains chromium oxide on an aluminum oxide carrier activated with 1 Vo germanium dioxide. The results are shown in Table 2 below.

Table 2

Butane-free s product Exit gas Reaction temperature yield Research octane number Flow rate H ₂ content ⁰ C Weight percent (without addition) m ³ / m ³ Volume percentage 475 77 83.1 213 77.5 500 72 90.1 258 81.8. 525 62.6 93.9 352 78.7 550 45.9 99.1 440 77.0

Claims (3)

Patent claims: 1. catalysts for the dehydrogenation and dehydrocyclization of non-aromatic hydrocarbons, containing chromium oxide on a carrier material of preferably aluminum oxide, characterized in that it additionally contain small amounts of germanium. 2. Catalysts according to claim 1, characterized in that they contain 5 to 25% chromium oxide and Contains 0.1 to 5% germanium (as oxide). 3. Catalysts according to Claims 1 and 2, characterized in that they also have a low Amount of alkali metal, especially potassium. © 909 579/395 7.59