DE1218424B - Process for the production of secondary alcohols - Google Patents

Description

Process for the preparation of secondary alcohols is the subject of Invention is a process for the production of secondary alcohols by catalytic Hydrogenation of unsaturated ketones at elevated temperature, which is characterized is that the hydrogenation takes place in the presence of a copper deposited on a support - Nickel catalyst is carried out.

According to one embodiment of the invention, the vapor is the unsaturated aliphatic ketone initially with hydrogen in the presence of a carrier deposited copper catalyst brought into contact, and the vaporized product is then used to complete the reaction with hydrogen in the presence of a implemented on a support arranged copper-nickel catalyst.

The invention can be carried out, for example, by a Mixture of hydrogen and the vapor of the unsaturated ketone in a reaction vessel over the copper-nickel catalyst arranged on a support at elevated temperature is sent away. If initially only a copper catalyst supported on a carrier is to be used, the mixture of hydrogen and the vapor of the unsaturated Ketones passed over said copper catalyst in a first reaction vessel and then the vaporized product along with more hydrogen on top of one Supported copper-nickel catalyst sent away in a second reaction vessel will. However, the invention can also be carried out in a single reaction vessel in which the two catalysts are in separate zones of the reaction vessel arranged and the reactants then first over the copper catalyst and then be sent over the copper-nickel catalyst.

The copper-nickel catalyst is preferably on a silica (Infusor earth), like kieselguhr, superimposed on it. The catalyst thus constructed contains expediently a total of 25 to 90 and preferably 45 to 70 percent by weight of copper and nickel, based on the total weight of copper, nickel and carrier. The ratio of copper to nickel in the catalyst is preferably by weight 5: 1 to 20: 1.

If a copper catalyst is used first, this is preferred deposited on a silica such as diatomaceous earth. The catalyst thus obtained contains expediently 25 to 90 percent by weight copper, calculated on the total weight of copper and carrier. The supported copper catalyst can optionally also any of the known ones Modifiers of copper hydrogenation catalysts contain, such as zinc, magnesium, chromium, iron or compounds or Mixtures of these metals or a phosphate, tungstate, chromate, dichromate, molybdate, Silicate or metaborate.

The inventive method is preferably carried out in a reaction vessel carried out, which is heated to a temperature in the range of 130 to 300 "C from the outside will. If two reaction vessels are used, each reaction vessel is preferably used externally, heated to a temperature in the range of 130 to 300 "C.

At the higher temperatures the reaction equilibrium is changed, and there will be increased yields of the corresponding saturated ketone at the expense the yield of the secondary alkanol obtained. At the lower temperatures the production of the secondary alcohol is favored. The reaction can be at about atmospheric pressure or also carried out at elevated pressures will.

The higher pressures favor the production of the secondary alkanol.

Suitable unsaturated aliphatic ketones used in the present invention Processes that can be used as starting products are, for example, those with 4 to 9 carbon atoms in the molecule.

From the German Auslegeschrift 1 027 654 it is known in one Hydrogenation process using palladium catalysts α, ß-unsaturated Convert ketones into saturated aliphatic ketones.

In this process, the corresponding falls in small quantities Carbinol, but its extraction is not worthwhile.

From British patent specification 362 457 it is already known for the production of saturated ketones under a pressure of 20 to 30 atmospheres to work. The reaction described should have such a low reaction rate at normal pressure have that a technical process cannot be carried out. In addition, should Undesired by-products are formed under such conditions.

In the German Auslegeschrift 1 103 926 the hydrogenation of unsaturated ketones to saturated ketones using catalysts mentioned. Metals, for example, are mentioned as suitable catalysts.

However, the evidence does not suggest that this procedure can be used can also apply, especially when using a copper-nickel catalyst, to hydrogenate the unsaturated ketones to the secondary alcohols. In contrast succeeds in the method according to the invention using on a carrier superimposed copper-nickel catalyst, the saturated used as starting material Ketone to be completely converted into the carbinol lead, taking this procedure already can be carried out at atmospheric pressure.

Example 1 A vertical reaction tube 3.75 in diameter cm was charged with a catalyst containing 45 weight percent copper, 5 weight percent Nickel and 50 percent by weight of kieselguhr contained.

The volume of the catalyst used was 150 cm3. The reaction tube was placed in an oil bath, the temperature of which could be controlled.

A reaction mixture was passed through the reaction tube, the hydrogen and ethylideneacetone in a ratio of 6 moles of hydrogen per 1 mole Contained ethylidene acetone. The organic component of the feed contained 400% Ethylidene acetone, 601o methyl propyl ketone, 1501o mesityl oxide, 10 01o acetone, 1501o Water and small amounts of other organic matter.

The catalyst charges were made with hydrogen and that with nitrogen had been diluted, preactivated at a bath temperature of 170 ° C. The results of three test series are summarized in Table 1.

For comparison with this example, similar tests were carried out, using the same charge a copper catalyst placed on diatomaceous earth was used. The results of these tests are also summarized in Table 1. In this table, ÄA means ethylidene acetone, MPK means methyl propyl ketone, MPC means methyl propyl carbinol and HC hydrocarbon by-products.

The products were determined by standard methods including UV spectrometry and gas-liquid chromatography.

Table 1 Molar ratios Bath liquid MPK MPC% % ÄA Catalyst temperature supply in the product in the product molar loss in the raw product to KW ° C cm³ / hour in feed in feed (1) 62 0.02 0.22 0.78 0.2 130 45: 5: 50 ° / 0 (2) 100 0.02 0.34 0.66 0.2 Cu: Ni: diatomaceous earth 130 (3) 100 0.02 0.35 0.65 0.0 140 Comparative tests (1) 60 0.04 0.36 0.61 2.5 140 50: 5001o (2) 80 0.08 0.42 0.55 2.5 Cu: diatomaceous earth 140 (3) 120 0.40 0.52 0.46 2.0 140 Example 2 A batch was prepared by partially hydrogenating a crude ethylidene acetone of about the composition set forth in the example above using a copper-diatomaceous earth catalyst. The feed contained 20Io ethylidene acetone and the following substances: methyl propyl ketone .............. 25.5% methylpropylcarbinol ............ 29% isopropanol ..... ................ 7% acetone ........................ 6% water .... .................... 11% methyl isobutyl ketone ............. 10.5% methyl isobutyl carbinol ......... .. 7.5% The other components consisted of small amounts of unspecified organic substances.

The feed was then fed to a reactor, one like manufactured in Example 1 and activated catalyst in an amount of 30 cm3 contained. The copper-nickel-diatomite and copper-diatomite catalysts were again checked for comparison, and the results obtained are in the table 2 compiled.

Table 2 Analysis of the products Bath liquid hydrogen molar ratio olo temperature supply supply MPK MPC Molar loss catalyst % in the product in the product ° C cm³ / hour l / h in feed in feed 45: 5: 50% (1) 20 8 0.03 0.19 0.80 0.5 140 Copper: Nickel: Kieselguhr (2) 40 16 0.04 0.30 0.60 0.8 140 Comparative experiments 50: 500 / o (1) 20 8 0.15 0.41 0.57 1.0 140 Copper: diatomaceous earth (2) 40 16 0.30 0.47 0.51 0.9 140 Claims: 1. Process for the preparation of secondary alcohols by catalytic hydrogenation of unsaturated ketones at elevated temperature, characterized in that the hydrogenation is carried out in the presence of a copper-nickel catalyst supported on a support.

Claims (1)

2. The method according to claim 1, characterized in that as a catalyst support a silica such as diatomaceous earth is used. 3. The method according to claim 1 and 2, characterized in that the Catalyst contains a total of 45 to 70 percent by weight copper and nickel, calculated on the total weight of copper, nickel and carrier. 4. The method according to claim 1 to 3, characterized in that the Contains catalyst copper and nickel in a ratio of 5: 1 to 20: 1. 5. The method according to claim 1 to 4, characterized in that the Catalyst zinc, magnesium, chromium, iron or a mixture or compounds of these Metals or a phosphate, tungstate, chromate, dichromate, molybdate, silicate metaborate contains as a modifier. 6. The method according to claim 1 to 5, characterized in that a Starting material is used, which is first pre-hydrogenated over a copper catalyst has been subjected. Publications considered: German Auslegeschriften No. 1,033,926, 1,027,654; British Patent No. 362,457; U.S. Patent No. 2,760,994; French Patent No. 1,165,584; Chemie et Industrie, 80 (1958), Pp. 240 to 247.