DE1014257B - Process for the production of an aluminum oxide carrier containing ªÃ-aluminum oxide for solid catalysts for the conversion of hydrocarbons - Google Patents

Description

GERMAN

PATENT OFFICE

INTERNATIONAL KL.

C 10g; BOIj

St 9212 IVc / 23 b REGISTRATION DATE: DECEMBER 22, 1954

NOTICE
THE REGISTRATION
AND ISSUE OF THE
EXPLORATION PAPER: AUGUST 22, 19 S 7

The invention relates to the preparation of improved solid catalyst for conversion of hydrocarbons, especially the improved production of ^ -aluminum oxide, an excellent one effective support for catalysts, especially for platinum-containing hydroforming catalysts.

Recent developments in petroleum refining have dealt with methods of conversion low-boiling feeds, especially those feeds whose boiling range is in the middle and higher The boiling range of the raw gasoline is in products with an improved octane number. A considerable success on this one Area has been achieved using the process known as hydroforming.

It has been found that platinum on an alumina support is a particularly useful catalyst for represents this procedure. For example, a commonly used catalyst consists of 0.001 to 2.0% by weight Platinum and the rest from the clay carrier or the clay base.

A form of alumina particularly suitable for use as a carrier material has already been produced by reacting metallic aluminum with a water-insoluble, anhydrous alcohol, hydrolyzing the aluminum alcoholate, separating the hydrous aluminum oxide from the alcohol and extracting the aluminum oxide from its aqueous slurry. The hydrolysis temperature used is in the range from 21 to 93 ° and produces an effective catalyst support. It turns out, however, that the aluminum oxide produced in this way contains only about 30 ° / ₀ μ-aluminum oxide, while the remainder is in the y-form. Experiments have now shown that the activity of the catalyst and the maintenance of the activity are improved with increasing iy-aluminum oxide content of the support. This improvement is achieved without the selectivity with respect to the hydrocarbons having 5 or more carbon atoms being impaired. The aim is therefore to obtain aluminum oxide carriers which predominantly, ie at least 80 percent by weight, or essentially consist of ^ -aluminum oxide.

It has now been found that 77-aluminum oxide can be produced in quantitative yields, if desired to 100%, if the hydrolysis of the aluminum alcoholate with water with regard to the amount of water used, the hydrolysis temperature and the time of aging, ie the time during which the hydrous aluminum oxide is left in the aqueous slurry before dewatering, controls together. By regulating all of these factors together, alumina with the above? 7 content can be obtained. The ^ -Aluminum oxide can then with other catalyst components according to the method of production
of a η -aluminum oxide containing

Alumina support
for solid catalysts

for the conversion
of hydrocarbons

Applicant:

Esso Research and Engineering Company, Elizabeth, N.J. (V.St.A.)

Representative:

Dr. W. Beil and A. Hoeppener, lawyers,
Frankfurt / M.-Höchst, Antoniterstr. 36

Claimed priority:
V. St. V. America dated December 31, 1954 and January 5, 1954

methods known in the art can be mixed.

Metallic aluminum is first converted to aluminum alcoholate with an alcohol. With this one In the process, the alcohol must be essentially anhydrous. Alcohols used in this process can are ethyl, propyl, isopropyl, n-butyl alcohol, secondary butyl alcohol, isobutyl alcohol, pentanol-1, Pentanol-2,3-methyl-butanol-l, 2-methyl-butanol-3, pentanol-3, Hexanol-1, Hexanol-2, Hexanol-3, the various Methylpentanols, the various dimethylbutanols, the various heptyl alcohols, the various Octyl alcohols, etc., including those higher alcohols which are liquid at the process temperature are. Instead of a single alcohol, alcohol mixtures, such as. B. mixed amyl alcohols are used will. Mixtures of alcohols of different molecular weights can also be used.

In general, it is preferred to use _{alcohols immiscible with H 2} O, ie alcohols with 5 or more carbon atoms, since this facilitates the recovery of the alcohol in anhydrous form for reuse in the production of aluminum alcoholate. When using a water-insoluble alcohol, the

709 658/359

To facilitate the separation of the alcohol from the water, a hydrocarbon, e.g. B. a petroleum distillate with the boiling range 90 to 260 ° or higher, preferably with a narrow boiling range in which the boiling range of the alcohol used is to be added to the alcohol. Instead of a hydrocarbon fraction, you can also certain hydrocarbons, e.g. B. heptane, octane, toluene, xylene, etc. can be used. Although the Hydrocarbon addition is not essential to the process, the use of the hydrocarbon has as a Thinner has the following advantages:

1. The diluent promotes the control of the reaction between alcohol and metallic aluminum, since the reaction releases a large amount of heat, which is better distributed by the diluent;

2. the hydrocarbon serves as a solvent for the solid aluminum alcoholate, and

3. the diluent consisting of hydrocarbons is after hydrolysis in the separation and Recovery of the alcohol from the slurry is of great use.

The metallic aluminum is in the form of chips, granules, turnings, ingots or the like, preferably in Presence of a hydrocarbon diluent and in the presence of a suitable one Catalyst, such as of mercury chloride or other mercury salts, iodine, aluminum halides or the like., reacted with the alcohol. The alcoholate is formed according to the following equation:

6 ROH + 2 Al > 2 Al (OR) ₃ +3 H ₂ (1)

The hydrogen escapes from the reaction mixture in a gaseous state.

The aluminum alcoholate is then mixed with a large excess of water, i.e. with good stirring. H. with 1 to 10 times the volume of the alcoholate, hydrolyzed at low temperatures of 0 to 21 °. The slurry of crystalline aluminum oxide is left in the aqueous layer for about 10 to 40 hours at the Aging ambient temperature. In general, working in the upper temperature range also requires the Use of the upper range of aging times and water-alcoholate ratios.

The alcoholate-aluminum oxide solution is slowly dissolved in water (e.g. 4 liters of alcoholate per hour with stirring to 81 water). However, if the hydrolysis temperature falls, the rate of addition can be within the above-mentioned limits can be increased. Usually the alcoholate is added to the water. Will conversely, if the water is slowly added to the alcoholate, amorphous aluminum oxide is formed.

When using water-insoluble alcohols, the alcohol regenerated by the hydrolysis forms together with the hydrocarbon diluent one of the slurry of hydrous alumina separate and distinct layer and is easily obtained by simply decanting or the like and removed.

If a water-soluble alcohol is used to convert the aluminum into the alcoholate, this works alcohol, which is re-formed by hydrolysis of the alcoholate, is dissolved in water and can be obtained by distillation will. The alcohol obtained must then be dehydrated in a known manner before it is used again Implementation with metallic aluminum is used.

The alumina slurry in which the alumina is present as /? - trihydrate, is then preferably first dried at about 90 to 120 ° in order to remove the water, containing the aluminum oxide. ^ -Aluminum oxide is removed by further drainage of the (β-aluminum oxide trihydrates (bayerite) in general made in the presence of lutt. This conversion has been found to be essentially quantitative takes place when the activation temperature is in the range from 200 to 680 °, preferably 230 to 590 °. The above mentioned Conversion of /? - trihydrate into ^ -aluminium oxide can also be used to determine the amount of r; -form produced by activation of the hydrolysis product to indicate in aluminum oxide.

ίο The calcination or activation can also be done after adding the catalytically active component take place. The calcination takes place in the same temperature range carried out, as explained in more detail below. In the same way, it can be dehydrating or active The catalyst component can be added to the support either before or after it has been dried.

The invention is illustrated by the following examples, which illustrate the preparation and advantages of the invention Catalyst carrier concern, better understandable.

Example I.

Same samples of aluminum amylate were made at different temperatures using the same Water-alcoholate ratio, namely 2: 1, hydrolyzed. The same aging time and temperature, namely 40 hours at room temperature, applied. The amount of β-trihydrate obtained is in the table below as a function of temperature specified.

Temperature, ⁰ C / J-trihydrate, weight percent 1.7
26.7
65.5 100
78
28

Since, as explained above, the conversion of the jß-trihydrate into the η-Έοττα takes place quantitatively, this shows the importance of hydrolysis at low temperature.

Example II

Same samples of aluminum amylate were used for the same Temperature, namely at 1.6 °, hydrolyzed using the same water-alcoholate ratio, wherein the aging time was varied to determine the effect of these variables. The alcohol was slow added to distilled water with stirring. The mixture was then allowed to cool to room temperature and stand. After standing, the alcohol layer was decanted off. The remaining part of the mixture was stripped to remove any remaining alcohol in the aqueous layer. Then became the precipitate dried at 120 ° and examined with X-rays. The results are in the following Table specified:

Aging time, hours

15th
40

45

75

100

This example shows the importance of aging time in the production of ^ -aluminium oxide.

Example III

Same samples of aluminum amylate were hydrolyzed and under controlled at the same temperature Conditions aged. The effect of the hydrolysis

The amount of water used is shown in the table below.

Vol. Water / vol. Alcoholate

2: 1
7: 1

/ 3-trihydrate,%

78

100

η content of
Aluminum-
oxyds No acid
treatment Relative
activity acid
treated
catalyst Relative
activity 5
70
90 91
92.5
94.5 100
120
160 96
97
98 195
225
275

a controlled hydroforming process. The results shown below show the inevitable connection between the effectiveness of the catalyst and the amount of γ-aluminum oxide.

0.6% Pt dry mix catalyst

This example shows the importance of using an excess of water in hydrolysis. That /? - Trihydrate is converted into the?; - form by heating to 590 ° converted.

Example IV

There were catalysts made of 0.6 percent by weight platinum on aluminum oxide, the different Quantities;? - contained aluminum oxide (the remainder consisted made of j / -aluminium oxide).

These catalysts were used in the hydroforming of unprocessed coastal petrol (petroleum extracted from the Gulf of Mexico with a relatively high naphthene and low paraffin content) with an octane rating of 50 and a boiling range of 90 to 165 °. Process conditions: 14 kg / cm ² overpressure, temperature: 480 °, ratio of hydrogen to hydrocarbon 6: 1; furthermore, 4 kg of oil per hour per kg of catalyst were used in the reaction zone. The results of hydroforming and the harmful effects of heat aging on the catalysts are shown graphically in the drawing.

Another good method for making the? 7 form of alumina is as follows:

Example V

The effect of the γ-aluminum oxide content is also evident after the acid treatment and during the production of catalysts using the dry mix technique. Catalysts were produced which contained 0.6 percent by weight of platinum on aluminum oxide with varying amounts of γ-aluminum oxide (the remainder consisted of γ-aluminum oxide). These catalysts were used in the hydroforming of an unprocessed coastal raw gasoline (raw gasoline obtained in the Gulf of Mexico with a relatively high naphthene and low paraffin content) with an octane number of 50 and a boiling range of 90 to 165 °. The process conditions were: 14 kg / cm ² overpressure, bath temperature 490 ° and 89.15 m ³ H ₂ per hl of feed material. The results are shown in the table below:

Effect of the η- aluminum oxide content
G ₃₊ == octane number (Research Clear)

Example Vl

The increased activity achieved by using? 7-alumina is shown in this example further explained. Dry mix catalysts were mixed with alumina in varying amounts ?? - contained aluminum oxide and the catalysts in

Impregnated Thinner
Aluminum oxide G ₅₊ -
Octane number
(Research
Clear) 1 part 6% Pt
100% η
1 part 6% Pt
100% Y ₇ 4.5 parts 4 ⁰ I ₀ η +
4.5 parts 40% η
4.5 parts 40% η +
4.5 parts 80% ί / 89.5
90.4

50

55

60 catalysts with the inventive carrier from ^ -Aluminiumoxyd are suitable for use in hydroforming, hydrogenation, hydrocracking, cracking, and other oxidizing those skilled known reactions. These catalysts are particularly useful for the production of aromatic hydrocarbons from naphthenes and for the dehydrogenative cyclization of paraffins and olefins.

The process of the invention is useful in making pill, powder, pelletized, extruded Catalysts etc. applicable. It can be impregnated, mixed precipitated or dry mixed Catalysts are used.

The special names of the crystal modifications of aluminum oxide and aluminum oxide hydrates, which are generally recognized in the literature today and used in the present case are in detail in a work by H. C. Stumpf and employee of the "Aluminum Company of America" in "Industrial and Engineering Chemistry .., Vol. 42, p. 1398, Juü 1950, described.

Claims (2)

Patent claims: 1. A process for the production of an aluminum oxide-containing aluminum oxide support for solid catalysts for the conversion of hydrocarbons by hydrolysis of aluminum alcoholates with water and subsequent drying of the alumina obtained, characterized in that the aluminum alcoholate at temperatures between 0 and 21 ° with 1 to 10 Parts by volume of water are hydrolyzed to 1 part by volume of alcoholate by allowing the aluminum oxide precipitate obtained as an aqueous sludge of hydrous alumina to age for about 10 to 40 hours until the content of /; - alumina is at least 80%, then the sludge to remove the aqueous medium and dries to obtain the aluminum oxide and the aluminum oxide is heated to 200 to 675 ° for further dehydration. 2. The method according to claim 1, characterized in that amylates are used as aluminum alcoholate takes these amylates at 1.6 ° in water, the amount of which is 2 parts by volume to 1 part by volume of amylate is, the precipitation is allowed to age for 40 hours at ambient temperature and in the final dehydration maintains a temperature of 590 °. Considered publications:
German patent specifications No. 820 893, 801 395. 1 sheet of drawings © 709 658/359 8.57