DE1643754A - - Google Patents

Description

A poorly crystalline aluminum oxide, which had a surface area of 250 m ² / g, a micropore volume (300 Å) of 0.37 ml / g and an average micropore diameter of 50 Å, was heated in air at 580 ° C. for 2 hours and then one subjected to the same treatment in nitrogen.

The aluminum oxide was converted into a catalyst suitable for the co-reaction of olefins, which contained 10 percent by weight MoO ₃ , as follows: The dry aluminum oxide was impregnated with an aqueous solution of ammonium molybdate containing the theoretical amount of molybdenum, dried at 110 ° C and 24 Whirled in a stream of air at 580 ° C for hours. The catalyst was also treated with nitrogen at 580 ° C. for 1 hour before use.

The catalyst was then tested for its suitability for the coreaction of isobutene and 2-butene. The reaction conditions and test results are given in the table below.

example 1

An aqueous solution of 0.25N NaHCO ₃ was circulated continuously over the aluminum oxide mentioned in Example 1 for 25 hours at room temperature. The solid was filtered off and dried at 110 ° C. The alumina was then activated and treated in the manner described in Example 1 to give a catalyst _{containing 10 percent by weight MoO 3} and 0.25 percent by weight sodium ions.

The catalyst was tested for its suitability for the coreaction of isobutene and butene-2.

Input material *

Temperature, ° C ...
Pressure, atmospheres
Space velocity,
V / V / h based
on gas state) ..

Products, percent by weight

C ₃ H ₆

C ₄ H ₈ -I

C ₄ H ₈ -2

1-C ₄ H ₈

nC ₅ H ₁₀

iC ₅ H ₁₀

Comparative experiment

1
190

2400

track
1.5
4.5
75.6
0.4
1.9
track
15.9

example
1 2

2
200

400

0.2

10.1

2.2

23.7

52.2

1.8

9.8

0.0

210
1

2000

track

62.4

17.1

10.5

* Feed 1: 16.7% isobutene, 83.3% by weight butene-2.

Feed 2: 30.0% isobutene, 70.0% by weight butene-2.
** Mainly Q oligomers.

Example 2

The experiment described in Example 2 was repeated with the difference that an O, 5N calcium acetate solution instead of solving

0.2Sn-NaHCO _{3 was} used to obtain a catalyst containing 1.15% by weight of calcium ions.

The results of the experiment described in the comparative experiment show that MoO ₃ on untreated aluminum oxide causes the polymerization of isobutene to the exclusion of the co-reaction of the olefins. Under the conditions chosen in Example 1, the person skilled in the art would have to expect that the polymerization would be even more favored, but the results show that the pretreatment of the catalytic aluminum oxide with sodium ions completely prevented the polymerization and made a considerable coreaction possible. The results of the experiment described in Example 2 show that the pretreatment of the aluminum oxide with calcium ions also prevented the polymerization of isobutene, albeit to a lesser extent.

Claims (2)

1 2 not previously possible to convert mixtures of olefins, patent claims: which contain an easily polymerizable olefin, over a disproportionation catalyst, 1. Process for catalytic disproportionate without substantial polymerization of the feedstock of acyclic olefinic hydrocarbon 5 material takes place. substances in the presence of a molybdenum oxide and It has now been found that a small human optionally cobalt oxide on aluminum oxide, alkali metal or alkaline earth metal ions of modified catalyst catalyst, where the aluminum oxide carrier sator, the molybdenum oxide on aluminum oxide as well or the molybdenum oxide and, if appropriate, cobalt oxide and optionally also cobalt oxide, are used for baltoxide on alumina-containing cata- io disproportionation of olefin mixtures which lysator by adding a small amount of an easily polymerizable olefin, without Alkali or alkaline earth metal ions were modified so that the easily polymerizable olefin was substantially den is characterized in that the periphery is polymerized. one monoolefins of the general formula The invention is a process for KfR ") C = CR CR) ¹⁵ catalytic disproportionation of acyclic olefinic hydrocarbons in the presence of a where R to R _{3 are} hydrogen atoms or alkyl molybdenum oxide and optionally cobalt oxide or aryl radicals, in a mixture with slightly aluminum oxide catalyst, the aluminum-polymerizable tertiary olefins with the group of oxide carriers or molybdenum oxide and given I ao if containing cobalt oxide on aluminum oxide \ 'Catalyst by adding a small amount of / \ Alkali or alkaline earth metal ions have been modified \ _ _ / is characterized by the fact that one mono- / ~~ \ olefine of the general formula / j R (R ₁ ) C = CR ₂ (R ₃ ) or secondary olefins with the group Y ^or j ⁿ »■ J» ⁸ . ^R | Hydrogen atoms or alkyl or Mean aryl radicals, in a mixture with slightly polymeric / sizable tertiary olefins with the group Ar - CH = c (, ^XX c where Ar is an aromatic radical, / \ . implements. . \ £ _ q / 2. The method according to claim 1, characterized in that 35
draws that with isobutene-containing starting mixtures, in particular with a mixture
is worked from essentially butene-2 and isobutene. or secondary olefins with the group Ar-CH = C ' Subject of Belgian patent specification 672 589 in which Ar is an aromatic radical, converts, is a process for the production of olefins * which contains 45 commercially available alumina is characterized in that one starting usually sodium ions in a small amount mixture of two dissimilar acyclic olefins, for example about 0.03 percent by weight, the the formulas come from the manufacturing process. The inventor However, R (R ₁ ) C = C (R ₂ ) R ₃ or R ₄ (R ₅ ) C = C (R ₆ ) R _{7 is} based on the statement that 50 selective catalysts can be obtained, have, in which the substituents R for hydrogen if the aluminum oxide serving as a carrier or atoms or alkyl or aryl radicals, where the one composed of molybdenum oxide on aluminum oxide but not more than two catalyst from the groupings alkali or alkaline earth metal ions R (R ₃ ) Cc R ₃ (R ₂ ) Cc: R ₄ (R ₅ ) Cc or R ₇ (R ₆ ) Cc are added beyond the amount that comes from the are the same, remains in the presence of an olefin disproportionate 55 manufacturing process. It will conversion catalyst converts. assumed that the alkali or alkaline earth metal A disproportionation catalyst is a catalyst deposited on the surface of the support sator, which is an olefin in a mixture of olefins that are. have higher and lower carbon numbers than the component The proportions of the various oxides can gangsolefin, able to transform. Vary from the British 6o, but contain the catalysts in the Patent specification 1056 980 it is already known, the general 0.5 to 30 percent by weight MoO ₃ , 0 to Disproportionation of olefins in the presence of a 20 percent by weight CoO and 50 to 99 percent by weight by small amounts of alkali or alkaline earth ions, percent Al ₂ O ₃ . Catalysts, the oxides of molyb modified molybdenum oxide-aluminum oxide catalysis, cobalt and aluminum are included in the sators to carry out, which is also commercially available cobalt oxide 65. Materials are representative may contain. of this type, the 2.5 to 5 percent by weight CoO and Certain olefins, e.g. B. isobutene, polymerize 12.5 to 25 percent by weight MoO ₃ contain. Special known to be very easy. For this reason, it is more suitable to use a catalyst that is 3.8% by weight Percent CoO and 13.8 percent by weight MoO ₃ . These mixed oxide catalysts are referred to below as the base catalyst. The optimal content of metal ions depends on the choice of metal ion. Catalysts that one too contain a small amount of the metal ion, while partially retaining their polymerization activity Catalysts which contain too large an amount of metal ions have a lower catalytic effect carry out the co-reaction of the olefins. Sodium, potassium and calcium ions are preferred as alkali or alkaline earth metal ions. In these cases the catalyst should be 0.02 to 5.0 percent by weight, preferably 0.1 to 1.0 percent by weight contain added metal ion. The incorporation of the alkali or alkaline earth metal ions into the base catalyst for the purpose of Invention can be carried out by known methods, e.g. B. by treating the base catalyst with an aqueous solution of an alkali salt, such as sodium carbonate, sodium bicarbonate or sodium acetate, Separation of the solid catalyst from the liquid medium and subsequent drying. Before being used for the reaction, the catalysts are activated by subjecting them to a thermal treatment either in a flowing inert gas, such as nitrogen, carbon dioxide or helium, or preferably in a flowing air or flowing oxygen and a final treatment in an inert gas. The catalysts are preferably heated in air to a temperature in the range from 300 to 900 ^° C. for 1 minute to 20 hours and then under similar conditions in an inert gas. Isobutene is preferred as the readily polymerizable olefin. A very suitable input material for the process is a mixture which consists essentially of butene-2 and isobutene, since the reaction products, namely propylene and 2-methylbutene-2, are very popular olefins. The uses for propylene are so well known that it is not necessary to go into more detail about them, and Dehydrogenation of 2-methylbutene-2 gives isoprene. The method can be used continuously of the catalyst can be carried out as a fixed bed, fluidized bed or moving bed. The conditions under which the olefins react can vary with the composition of the feed and the products desired. The reaction temperatures can lie between 80 and 500 ⁰ C, which temperatures are preferably in the range of 90 to 24O ⁰ C. The reaction pressures can range from 0 to 140 atmospheres. In a continuous process, the reaction times can be between 0.01 seconds and 120 minutes vary. They are preferably 0.1 second to 10 minutes. In a batch process, there are weight ratios of olefin to catalyst in the range from 1000: 1 to 1: 1 in question. The process can optionally be carried out in the presence of an inert diluent, e.g. B. a paraffinic or cycloparaffinic hydrocarbon. The invention is illustrated by the following examples. The experiment described below was not carried out according to the invention and is for comparison only. Comparative experiment