DE1066580B - Process for the production of cycloparaffins - Google Patents

Description

UTSCHES

PATENT OFFICE

kl. 12 ο 25

INTERNAT. KL. C 07 C

13 loo- H

B 45340 IVb / 12 ο

REGISTRATION DATE: JULY 16, 1957

NOTICE
THE REGISTRATION
AND ISSUE OF THE
INTERPRETATION RIFT:

OCTOBER 8, 1959

It is known that Cyclop ar affine by catalytic hydrogenation of cyclopolyolefins at elevated temperature to manufacture.

In this process, however, one obtains only when working in the liquid phase, e.g. B. in the trickle process and sump process, satisfactory yields when working under increased pressure. In addition, the presence of a solvent is usually required, from which the hydrogenation product has to be separated by distillation. ¹ Q

Another general drawback of the known process is the formation of isomeric by-products / can arise in unfavorable cases in amounts of 10 to 20 ° _0th These by-products cause particular difficulties when working up by distillation, since their boiling points differ only insufficiently from the boiling point of the main product.

It has now been found that cyclopolyolefins can be obtained in almost quantitative yield at elevated temperature in The presence of hydrogenation catalysts can hydrogenate to cycloparaffins if you use them as starting materials used cyclopolyolefins in vapor form with a large excess of hydrogen at normal pressure conducts over catalysts that are deposited on large-pore supports.

This process can be used to produce cyclopolyolefins of the cyclooctatetraene type or its higher homologues of the general formula C _2n H _2m , where η = 4 or a number greater than 4, e.g. B. mainly cyclooctatetraene itself and cyclodecapentaene or cyclododecahexaene, hydrogenate.

Noble metals, such as platinum or palladium, are suitable as catalysts for the hydrogenation. In general, a catalyst is used, the approximately 5 ° / ₀ containing such a noble metal. However, mixed catalysts can also be used. A particularly suitable mixed catalyst containing 15 ° / ₀ nickel, 5 ° / ₀ of copper and 1 ° / ₀ manganese. The use of inert, large-pored catalyst supports is important for the success of the hydrogenation. This is understood to mean carrier materials that have practically no micropores, but almost exclusively macropores. The pore diameter should not be smaller than 1000 Å = 0.1 μ. The inner surface is about 1 to 10 m ² / g. Such catalyst supports are for example

Italian pumice stone (grained)

inner surface 1.2 m ² / g

Micropore volume 0.012 cm ^s / g

Macropore volume 1.124 cm ³ / g

mean pore radius 20,000 Å = 2 μ

or diatomaceous earth

inner surface 5.58 m ² / g

Micropore volume 0.011 cm ³ / g

Method of manufacture
of cycloparaffins

Applicant:

Aniline & Soda Factory in Baden

Corporation,

Ludwigshafen / Rhine

Dr. Walter Reppe, Heidelberg,
Dr. Karl Baur and Dr. Walter Schweter,

Ludwigshafen / Rhine,
have been named as inventors

Macropore volume 1.836 cm ³ / g

mean pore radius 6,600 Å = 0.66 μ

Likewise, catalyst supports made from precipitated and muffled silica (mean pore radius = 15000Ä) and large-pore activated carbon can be used.
The use of these large-pore catalyst supports in the pressureless gas phase hydrogenation according to the invention, for example of cyclooctatetraene to cyclooctane, avoids the formation of bicyclo- [0,2,4] -octane by isomerization. In this way, in the hydrogenation of cyclooctatetraene, cyclooctane is obtained practically in quantitative yield. Another advantage of the process is that the hydrogenation can be carried out at normal pressure.

The hydrogenation is expediently carried out continuously at temperatures from 120 to 300 ° C., preferably at 150 to 170 ° C. Space-time yields of 1.5 to 2.0 kg / 1 catalyst space are achieved and day.

To carry out the process, the cyclopolyolefin to be hydrogenated, e.g. B. Cyclooctatetraene, after evaporation in its own evaporation room together with a multiple excess of hydrogen, e.g. B. with 10 to 50 times the amount of hydrogen, passed over the catalysts at normal pressure.

example 1

Into a reaction furnace with 3 1 content that is filled with a hydrogenation catalyst consisting of 5 ° / ₀ palladium on Italian pumice, hourly 120 to 140 g in a mixture with Cyclooctatetraendampf

909 637/418

Hydrogen initiated. The gas-steam mixture contains about 5 percent by volume of cyclooctatetraendampf. Through the apparatus is run at atmospheric pressure with a gas circulation pump of the hydrogen in a circle and at the same time maintaining the temperature at 150 to 160 ⁰ C constant. The hydrogen consumed, around 25 liters per hour, is continuously replenished.

The gas circulation goes through an evaporator in which the cyclooctatetraene evaporates continuously at 150 to 180 ° C. and is carried along by the hydrogen stream. After leaving the reaction furnace, the mixture of hydrogen and cyclooctane vapor is through a. Gas cooler passed and the condensed cyclooctane collected in a separator. The hydrogenation has that contains a solidification point of 8 ° to 10 ° C when using as starting material a cyclooctatetraene about 1 ° / ₀ styrene, 1 ° / ₀ 2% benzene and phenylbutadiene. In the distillation, which is carried out under normal pressure, the cyclooctane with a boiling point of 151 to 152 ° C. is obtained after a small forerun of ethylbenzene and benzene, while a small residue of phenylbutane remains in the flask.

The distilled cyclooctane has a freezing point of 14.0 to 14.6 ° C, the yield is almost quantitative.

Example 2

Carrying out the hydrogenation in the same manner as described in Example 1, but using a hydrogenation catalyst, the 15 ° / ₀ nickel, 5 ° / ₀ of copper and 1 ° / ₀ manganese on pumice granules contains, so will result in equally good results.

In the following a comparative test will be described with the same catalyst to large pore support material: In a reaction furnace of 50 mm diameter and a capacity of 2.8 1, with a hydrogenation catalyst consisting of 15 ° / ₀ nickel, 5 ° / ₀ of copper and 1 ° / ₀ manganese on Aluminiumoxydsträngen 2-3 mm in diameter filled, hourly from 120 to 130 g in a mixture with hydrogen Cyclooctatetraendampf: introduced (volume ratio 20: 1). Hydrogen is circulated through the apparatus at normal pressure and the reaction temperature is kept constant at 150 to 160.degree. The hydrogen consumed, around 25 liters per hour, is continuously replenished.

The gas circulation goes through an evaporator in which the cyclooctatetraene is continuously at 160 to 180 ° C evaporated and carried along by the hydrogen stream. After leaving the reaction oven, the Mixture of hydrogen and the reaction products passed through a gas cooler and condensable Trapped in a separator. The reaction mixture could not solidify with ice water to be brought. The ultra-red analysis then showed the following composition of the reaction product:

6th hours Cyclo
octane ethyl
benzene Bicyclo
- [0,2,4] -
oc tan Cyclo-
octen Ali
phat 12th hours 7th 7o 7o ⁰ O To 18th hours 75 6 to 8 1 -0.2 rest To 24 hours 72 6 to 8 2 0.5 rest To 30th hours 70 6 to 8 2 1 rest To 69 6 to 8 3 2 rest To 63 6 to 8 3 5 rest

The experiment was terminated after 30 hours. From the analysis it can be seen that the fine-pored Catalyst supports a large proportion of the cyclooctatetraene to aromatic, hydroaromatic and aliphatic Compounds isomerized.

Example 3

In a reaction vessel with a capacity of 11, containing a hydrogenation catalyst with a composition of 12%

"" Nickel, 3% copper and 2% manganese filled with kieselguhr V> iäjfc, about 40 g of vinylcyclooctatetraene are fed every hour

** inf mixture with hydrogen. The gas-steam mixture contains about 4 percent by volume of vaporous vinyl

'■ * cyclooctatetraen. The hydrogen is at normal pressure passed through the apparatus in a circuit and kept the reaction temperature at 160 to 180.degree. The hydrogen consumed, about 8 to 10 liters per hour, is continuously replaced. The circulating gas will passed through an evaporator in which vinylcyclooctatetraene evaporates continuously at 170 to 190 ° C and through which hydrogen is passed into the hydrogenation vessel. After the gas-vapor mixture emerges from the reactor it is passed through a gas cooler, and the condensed ethylcyclooctane is in collected in a separation vessel. In the distillation, which is carried out at normal pressure, ethylcyclooctane is obtained after a small initial run of 5% in total at 188 ° C. A small residue remains in the Pistons. Distillation gives a product of 98% purity.

Example 4

In the apparatus as described in Example 3, 50 g of a mixture per hour are obtained 60% cyclooctatetraene and 40% 1-phenylbutadiene (1,3) converted. Evaporation occurs at temperatures carried out from 160 to 180 ° C, while the reaction vessel is kept at a temperature of 160 to 170 ° C will. When the starting mixture is reacted with hydrogen, a mixture of cyclooctane and Phenylbutane, which can be easily separated after a few preliminary runs in the distillation at normal pressure. Man initially receives at 151 to 152 ° C cyclooctane and then after a slight intermediate run of about 8% des Total mixture of phenylbutane at 180 to 181 ° C.

The yield of cyclooctane is 85 to 90%, based on the cyclooctatetraene contained in the starting mixture, and the yield of phenylbutane 80 to 85%.

Example 5

80 to 100 g of cyclododecatriene (1,5,9) are put every hour together with hydrogen in a hydrogenation vessel of 2 liters Content introduced. The hydrogenation vessel is filled with a hydrogenation catalyst based on Italian Pumice stone contains 12% nickel, 2% copper and 0.8% manganese. The gas-steam mixture is 4 to 6 percent by volume Cyclododecatriendampf is saturated and is driven by the hydrogen at normal pressure by means of a pump circulated through the apparatus. The hydrogenation vessel is kept at a temperature of 240 to 250.degree kept constant and the hydrogen consumed, about 151 per hour, replenished. The gas cycle carries out an evaporator in which the cyclododecatriene evaporates continuously at 245 to 255 ° C and through the Hydrogen stream is passed into the hydrogenation vessel. The gas-steam mixture emerging from the hydrogenation vessel, which contains cyclododecane vapor is passed through a cooler in which the cyclododecane condenses will. The cyclododecane is then collected in a separator. The hydrogenation product has a

Melting point from 45 to 50 ° C and contains about 98 ° / ₀ cyclododecane. It contains only small amounts of starting materials.

Claims (2)

Patent claims: 1. Process for the preparation of cycloparaffins by vapor phase hydrogenation of cyclopolyolefins at elevated temperature and in the presence of hydrogenation catalysts, characterized in that that one cyclopolyolefins with 8 or more ring carbon atoms with a large excess of hydrogen at normal pressure passes over the catalysts, which are deposited on large-pore supports. 2. The method according to claim 1, characterized in that there is Italian pumice stone as a carrier used. Considered publications: German Patent Specifications Nos. 827 361, 857 493; British Patent No. 570,843; French Patent No. 1136 286; U.S. Patent No. 2,391,283; Dear. Ann. d. Chem., Vol. 567, 1950, pp. 1 to 43. © 909 637/418 9.59