DE1063592B - Process for the production of methyl isobutyl ketone and diisobutyl ketone - Google Patents

Description

C O 7 C * 5/37 OH

GERMAN

REGISTRATION DAY; FEBRUARY 25, 1954

NOTICE THE REGISTRATION AND ISSUE OF THE EDITORIAL! 20th AU G U ST 1 9 5 9

It is known that methyl isobutyl ketone is im technical scale on the intermediate stages of acetone, diacetone alcohol and mesityl oxide from isopropanol produced, isopropanol is converted into acetone by dehydration:

H ₃ C CHOH CH ₃

H ₃ C -CO CH ₃ + H ₂

Then the acetone is condensed to diacetone alcohol by means of alkali:

H ₃ C OH

2H, C-CO-CH,

X-CH ₂ CO-CH,

In a third stage, the dehydration to mesityl oxide takes place:

H ₃ C.

H ₃ C ⁷
H ₃ C.

OH
: C -CH, -CO CH,

>, C-CH-CO-CH ₃ + H ₂ O

H ₃ C ⁷

The unsaturated ketone mesityl oxide is finally converted into the saturated by a hydrogenation catalyst Converted methyl isobutyl ketone:

H ₃ C
H ₃ C _s

> ·
H ₃ C

= CHCO-CH ₃ + H ₈

^ CH-CHs-CO-CH ₃

It is also possible to combine methyl isobutyl ketone with a metallic copper and magnesium oxide Contact that can be obtained from copper oxide and magnesite with the addition of hydrogen from acetone at 180 to 300 ° C.

Furthermore, a method has become known, ketones such as acetone, methyl isobutyl ketone, diisibutyl ketone or mesityl oxide, from secondary alcohols at higher temperatures up to 500 ° C at various Establish mixed contacts, for example from chromium, zinc, copper, magnesium and cadmium; however has this known process has the disadvantage that indefinable oils are formed as a by-product, which the Make the catalyst unusable after a relatively short time.

Method of manufacture

of methyl isobutyl ketone

and diisobutyl ketone

Applicant:

Knapsack-Griesheim Aktiengesellschaft,
Knapsack near Cologne

Dr. Wolfgang Opitz, Knapsack near Cologne,

and Werner Urbanski, Cologne-Bickendorf,

have been named as inventors

It has also already been proposed to use higher alcohols and the aldehydes corresponding to them or to produce ketones from lower alcohols at a mixed contact in one operation. The one with this one known method used catalyst consists of two components, one of which is a component hydrating and dehydrating and the other has a dehydrating effect. This catalyst possesses the property, not just the carbon double bond of the unsaturated aldehyde or ketone formed, but also to hydrogenate the carbonyl bond, so that a mixture of aldehydes and alcohols or ketones and alcohols is formed.

Since methyl isobutyl ketone and diisobutyl ketone have excellent solvent properties, among other things for plastics and polymers, the object of the present invention was to provide them Manufacture substances without disruptive by-products and in one step if possible.

This was achieved through the action of a mixed contact consisting of three components isopropanol. Dehydration, condensation, dehydration and hydrogenation are known Way effected at ordinary pressure and elevated temperature at the same time. The contact has the property primarily to hydrogenate the carbon double bond and not the carbonyl bond, so that it avoids the formation of corresponding alcohols and only the ketones are produced. This mixed contact consists of a mixture of copper oxide, magnesium oxide and pumice powder. The oxides are in one Ratio of preferably CuO: MgO such as 3: 2 is used.

The method of the invention is characterized in that a known Mff

Mixable contact that can be produced and regenerated, expedient in the form of compacts, the CuO, MgO and pumice dust in a ratio of about 5: 3: 2.

Particularly advantageous to use a mixed catalyst has been found, which is about 48.4% CuO, 34.6 ⁰ Zo MgO and 17 ° / o pumice dust contains. The pumice dust used in turn consists preferably of about 20.1% aluminum oxide, 55.5% silica and 12% alkali oxide. The copper oxide fulfills the task of dehydrogenation and hydrogenation; Magnesium oxide, as an alkaline component, causes not only its ability to store and split off hydrogen, but also condensation and, in combination with the pumice powder, has a dehydrating property.

The mixed contact can be achieved by mixing the oxides or by precipitating them together from the respective Salts are obtained.

The contact mixture is expediently made using an approximately 0.5% solution of methyl cellulose in water moistened and pressed into shapes. The methyl cellulose solution serves as a binding agent to give the pressed part abrasion resistance. Since they are glowing burns, it gives the contact a large porosity. The pressed moldings are 24 hours dried at 100 ° C for a long time and then baked at 600 ° C for 2 hours. The mixed contact can also tabletted or on a carrier, e.g. B. pumice, are applied.

The contact is activated by treatment with steam at 400 to 500 ° C and subsequent reduction with hydrogen at 200 to 300 ° C.

The starting material used for converting isopropanol to methyl isobutyl ketone and diisobutyl ketone is as high a percentage of isopropanol as possible, since the dehydrating effect of the contact and consequently the formation of methyl isobutyl ketone and diisobutyl ketone is reduced with increasing water content. A long dwell time on the contact is advantageous for the formation of the two substances. The most favorable is a contact load of isopropanol of one tenth to one eighth of the contact volume. The optimum reaction temperature is between 250 and 300 ° C. 94 to 97% of the isopropanol used is converted, namely, in addition to methyl isobutyl ketone and diisobutyl ketone, acetone and small amounts of higher-boiling fractions are obtained. At the beginning of the reaction, the formation of methyl isobutyl ketone and diisobutyl ketone is particularly preferred. It is suppressed with increasing operating time with a simultaneous increase in acetone formation. The formation of diisobutyl ketone also shifts in favor of methyl isobutyl ketone with increasing operating time.

After the contact has been regenerated, the same process is repeated, so that depending on the point in time the regeneration acetone, methyl isobutyl ketone and diisobutyl ketone in the desired proportions can be produced.

The contact is regenerated by means of air, Water vapor and hydrogen. First, contact at 200 to 250 ° C with air, if necessary with the addition of nitrogen, slowly oxidized, then post-oxidized at 400 to 500 ° C and with Treated water vapor at 400 to 500 ° C. This is followed by the reduction with steam at 200 to 300 ° C.

The inventive. Process enables an economically and technically advantageous production of methyl isobutyl ketone and diisobutyl ketone due to the long life and high turnover of the used Catalyst.

35

example

2.1 l of the contact described above, which consists of 48.4% CuO, 34.6% MgO and There was 17% pumice dust, in the form of pellets with a grain size of 3 to 6 mm in diameter.

99% isopropanol was used as the starting material.

Operating
duration temperature sales Yield in mol% (based on converted isopropanol) Diisobutyl ketone acetone all in all after
hours ⁰ C W-iditsprozcnt methyl
isobutyl ketone 65.8 9.0 94.4 16 250 ■ 98.0 19.6 14.9 50.5 95.5 72 250 94.0 30.1 11.5 51.1 97.6 136 260 95.0 35.0 7.4 62.2 98.7 312 260 94.0 29.1 4.4 68.1 99.0 952 270 93.8 26.5

After "984 hours of operation, the average I 93.9 I 29.2 | 10.4 | 58.5

98.1

Claims (6)

Patent claims: 1. Process for the production of methyl isobutyl ketone and diisobutyl ketone by action a mixed contact on isopropanol at normal pressure and temperatures of 250 to 300 ° C, characterized in that a mixed contact which can be produced and regenerated by methods known per se, expediently in the form of Compacts, is used which contains CuO, MgO and pumice dust in a ratio of about 5: 3: 2. 2. The method according to claim 1, characterized in that the mixed contact is about 48.4% CuO-34.6% Contains MgO and 17% pumice dust. 3. The method according to claim 1 and 2, characterized in that the to be used in the Mixed contact contained pumice dust from about 20.1% aluminum oxide, 55.5% silica and 12% alkali oxide. 4. The method according to claim 1 to 3, characterized in that a catalyst is used made with methylcellulose solution as a binder. 5 6 5. The method according to claim 1 to 4, characterized by pre-oxidation at 200 to 250 ° C, then below characterized in that the catalyst by loading post-oxidation at 400 to 500 ° C, further below act with steam at elevated temperature steam treatment at 400 to 500 ° C and door, preferably at 400 to 500 ° C, and finally with reduction with hydrogen subsequent reduction with hydrogen at 200 to 300 ° C is regenerated. is activated up to 300 ° C. 6. The method according to claim 1 to 4, characterized characterized in that the catalyst is activated by means of air. or air and nitrogen initially under slow German patent specification No. 627 676. © 909 «OS / 427 8. 59