DE1061768B - Process for the dehydration of alcohols - Google Patents

Description

C 07C 45/37 OH

GERMAN

R19146 IVb / 12 ο

REGISTRATION DAY; JUNE 27, 1956

NOTICE THE REGISTRATION AND ISSUE DEB EDITORIAL: JULY 23, 1959

Subject of patent application R18234IVb / 12o is a process for the dehydrogenation of alcohols in the presence of copper, metals of subgroup VIII of the Periodic Table and Dehy-S containing alkaline alkali metal compounds dration catalysts, which is characterized in that the dehydrogenation at 200 to 300 ° C with a catalyst is carried out which consists of copper and nickel in a weight ratio of 2: 1 to 1: 2 and 1: 30%, preferably 3 to 20%, based on the weight of the mixture of copper and nickel, of alkaline-reacting alkali metal compound Consists of diatomite. It is advantageous to add the catalyst at room temperature in batches To precipitate metal nitrate solution to the precipitant, which already contains the kieselguhr, then briefly boil, wash, add the alkali metal compound and dry. Before commissioning the catalyst is still 15 to 300 minutes, preferably 50 to 150 minutes, at 150 to 500 ° C, preferably 250 to 350 ° C., with 100 to 5000, in particular 500 to 2000 cbm of hydrogen per cubic meter Reduce catalyst mass and hour. This catalyst converts alcohols at the low level Temperature from 200 to 300 ° C and the high load of 3 to 6 1 alcohol (liquid) per liter of catalyst mass and hour by dehydrogenation into the corresponding carbonyl compounds practically without Side reactions around. The hydrogen produced in the dehydrogenation does not contain any olefins.

It has now been found that the life sdatter of the patent application R 18234 IVb / 12o used Catalyst can be increased significantly if the catalyst before its reduction with Hydrogen for more than 30 minutes, preferably more than 60 minutes, at 250 to 600 ° C, preferably 350 up to 450 ° C, with the passage of inert and / or oxidizing gases, preferably oxidizing gases, z. B. air and / or oxygen is annealed. By this measure according to the invention, only a small Requires equipment expenditure, the life of the dehydrogenation catalyst is more than doubled.

The method according to the invention is explained in more detail using the following example:

50 parts by weight copper and 50 parts by weight ^ icJsgL. in the form of a 5% nitrate solution are added in batches at room temperature to a 5% soda solution containing 100 parts of diatomite. When the precipitation is complete, the p _n value is about 8 to 9. The catalyst sludge is briefly boiled, filtered off, washed six times with ten times the amount of hot water, based on copper and nickel, impregnated with 10 parts by weight of potassium carbonate and added

Method of dehydration
of alcohols

Addition to patent application R 18234 FVb / 12 ο (Laying out guide 1 055 520)

Applicant:

Rheinpreussen Aktiengesellschaft

for mining and chemistry,

Homberg (Ndrh.)

Dipl.-Chem. Dr. Robert Langheim, Homberg (Ndrh.),
has been named as the inventor

100 ° C dried. 801 of the granular catalyst are placed in an upright tubular furnace that is heated with flue gases. The inner diameter of the individual tubes is 20 mm. The catalyst is heated at 400 ° C. for 200 minutes while passing about 40 cbm of air through it per hour. There is ^a decrease in volume of about 12%. This missing 12 percent by volume of catalyst mass is supplemented with the same catalyst, which was tempered under the same conditions in a second furnace. The catalyst is then reduced at 300 ° C. for 1 hour while 50 cbm of hydrogen are passed through. Then the temperature is lowered to about 230 ° C, and there are 270 to 2801, calculated as liquid sck. Butyl alcohol, in vapor form per hour passed over the catalyst. A conversion of 88 to 92 ⁰ Zo is achieved. This conversion can be kept at 240 to 250 ° C. for 800 to 1000 hours. Then the temperature must be slowly increased to 290 ° C. up to the 1500th to 1600th hour.

Since it is not favorable to carry out the dehydrogenation above 300 ° C. on the catalyst according to the invention carry out, he is now according to the method of patent application R 18234 IVb / 12o by treatment regenerated with air at 100 ° C.

Claims (1)

Claim: Process for the dehydrogenation of alcohols according to patent application R18234 TV b / 12 o, thereby characterized in that dehydrogenation is carried out with a catalyst, which prior to the reduction with hydrogen more than 30 minutes, preferably more than 60 minutes, at 250 to 600 ° C, preferably 350 up to 450 ° C, with the passage of inert and / or oxidizing gases, preferably air and jijoder Oxygen, has been annealed. © 909 578/444 7. 59