DE674751C - Process for the production of higher alcohols - Google Patents

Description

Process for the preparation of higher alcohols It is known that when Passing ethyl alcohol over dehydrating or dehydrating catalysts condensation products are obtained at high temperatures, among which see also higher alcohols such as butyl alcohol are found. It is also known to eat when Passing methyl alcohol together with hydrogen and carbon oxide over catalysts at high temperatures and pressures in the mixture obtained; Alcohols are present are. In these reactions, however, arise at the same time as a result of secondary reactions also unwanted products, such as ethyl acetate, ketones, Kohlznivasserst @ offt--, esters etc.

It is also already known to combine methyl alcohol with ethyl alcohol and to conduct hydrogen over catalysts, but practically hardly any higher Form alcohols.

It has now been found .that when passing over ethyl alcohol in the mixture with methyl alcohol in a vaporous state over catalysts that are the same Composition as in patent 594,6; z exhibit at high temperatures and at normal pressure or moderately increased pressure up to about 30 atm. together with hydrogen a conversion of the two lower alcohols into higher alcohols also takes place. These Reaction allows the nature of the @ formed higher alcohols to this extent affect than as a result of the participation of methanol, in addition to butyl alcohol and other alcohols with an even carbon number also those with an odd carbon number, such as propyl alcohol, amyl alcohol, can be used.

So that no unwanted by-products and decomposition products are obtained are, the activators are in the contact mass in relatively small amounts to be used in relation to the main component of the catalyst, the magnesium oxide. The upper limit for the amount of activators is about i o 0; o of the total m, -: ng @ en of the contact. It is also advantageous to add substances to the contact that not catalytic per se, but such. B. the oxides or hydroxides of aluminum or, other earth metals, titanium, thorium, have a stabilizing effect and so the Favorably influence the service life of the contact.

It is advisable to use hydrogen in such amounts that there are 1j to 3 mol of hydrogen for every 1 mol of alcohol. Larger excess hydrogen can also be used. Methyl alcohol and ethyl alcohol can be mixed with one another in any ratio. If you work under normal pressure, the reaction mixture, which consists essentially of higher alcohols, contains almost no esters, ketones and other non-toxic substances. By changing the # # r1! Äl-ice. the quantities of both alcohols.! ' `` v d Composition of the reaction device. influence. If you apply a higher Dru_a @ _ as atmospheric pressure; ä.n, the Umwanet, @, long of the alcohols more completely with a single pass over the catalyst. If you increase the pressure. further, you can limit the amount of hydrogen in the reaction mixture without. that relatively more aldehydes are formed as by-products; Surprisingly, the formation of the by-products is even reduced. The most favorable reaction temperatures are generally higher when working under pressure than when working under atmospheric pressure, generally above 30 °.

Example i A mixture of the oxides of magnesium, aluminum and copper in a ratio of 89: 8: 3 is used as the catalyst. The catalyst was prepared by stirring 3009 i 50% aluminum hydroxide paste with 400 cc of water and thoroughly mixing it in a paint mill, then kneading a mixture of 40 g of magnesium oxide and 12 g of copper oxide with the aluminum hydroxide milk and then kneading the whole Sheets were dried at 12 to 140 ° and then brought to a size of 3 to 5 mm. The catalyst was located in an electrically heated aluminum tube 30 mm in diameter and in length. 500 cc were filled with the catalyst. A mixture of 0.38 mol of methanol, 0.25 mol of ethanol and 0.75 mol of hydrogen was sent through the tube per hour. The temperature was 260 ° at ordinary pressure.

During a 10-hour test were used: 120 g of methanol, 115 g of ethanol and 1881 of hydrogen. This gave 216 g of condensate, D, 20 0.861o. The work-up of the condensate gave 12 g of acetaldehyde, 15 g of butyraldehyde, 49 g of methanol, 63 g of ethanol, 8 g of n-propanol, 10 g of isobut, i; nol, 16 g of n-butanol, 14 g of 2-ethylpropanol-1.5 g hexanols and 10 g higher alcohols (heptyl, octyl alcohol). Thus, from the alcohol mixture used, 2359, 112g were recovered and converted accordingly x23 g or 52.40; 0. . . #. # Were from the converted alcohol mixture @ 3, t behave in percent by weight: @, A 9Zoetaldehyde g, 8, butyraldehyde 12.2, n-Pro- tpanol 6.5, isobutanol 8.1, n-liutanol 13, o, methylethylcarbine carbinol 10.7, exanols 4.0, higher alcohols 8.1.

Example 2 Via the contact listed in example i, also 50o ccm, but in a steel tube, but of the same dimensions, were 2.2 per hour Mol of methanol and 1.5 M o1 ethanol and 1.5 M: ol H, passed. The temperature was 35o ° at 3o atm. Overpressure.

During a 10-hour test, 702 g of methanol, 690 g of ethanol and 3751 g of hydrogen were used with 50 ° cc of contact precipitation. 32 og condensate of D @, O 0.836 ° was obtained. Fractionation gave i 5 g of acetaldehyde, 38 g of butyraldehyde, 160 g of methanol, 4709 ethanol, 579 n-propaiiol, 1049 isobutanol, 37 g of n-butanol, 95- methylethylcarbincarbin0l, 54 g of hexanols and 104 g of higher alcohols (heptyl, octyl). 63o g of the alcohol mixture used were recovered, so 762 g are converted. The following were obtained in percent by weight from the reacted mixture: Acetaldehyde d 2, o, butyraldehyde 5, i, u-propyl 7.6, is, obutyl 14.2,, n-butyl 4.9, methylethylcarbine carbinol 12.4, hexane oil 7, 1 and higher alcohols 14.2.

Claims (1)

PATENT CLAIM: Process for the production of higher alcohols from one Mixture of methyl alcohol and ethyl alcohol at high temperatures and possibly under pressure in the presence of catalysts and hydrogen, characterized in that the alcohol-hydrogen mixture at Zoo to 35o ° about a substantially consisting of magnesium oxide, with small amounts of one or more catalytic more effective metal oxides or metals added to the catalyst at ordinary pressure or moderately elevated pressures to about 30 atm. directs.