DE1238451B - Process for the production of 1,2-dichloroethane by oxychlorination of ethylene - Google Patents

Description

U IN D US K UF UB JLJL K GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C07c

German class: 12 ο -2/01

Number: 1238 451

File number: D 35731IV b / 12 ο

Filing date: March 23, 1961

Opened on: April 13, 1967

The present invention relates to a process for preparing 1,2-dichloroethane by oxychlorination of ethylene, which is characterized in that, in a fluidized bed of a copper chloride catalyst supported on a carrier of active alumina, at temperatures up to 280 ⁰ C. works, and that a conversion space is used for the implementation mentioned, which has the shape of an inverted truncated cone whose cone angle is between 5 and 15 ° and whose ratio of the lower to the upper diameter is 1: 2 to 1: 3, the upper other The end of the truncated cone is seated on a cylindrical part, the height of which is one fifth that of the truncated cone, and the catalyst fills about three quarters of the conversion space when at rest.

The catalyst layer fills the conical reaction space that widens from bottom to top about three-quarters in a calm, non-whirling state, and completely in a whirling state. Achieved here the catalyst layer does not have the cylindrical part, which is used to calm the gas flow and to avoid it serves to discharge parts of the catalyst in the event of gas surges.

The drawing shows schematically the design of such a reactor.

At the conical part 1 closes the cylindrical Part 2, the height of which is only a fifth of the height of the conical part 1. That The ratio of the lower diameter 3 to the upper diameter 4 of the conical part is approximately 1: 2.3.

A great uniformity of the vortex state is achieved with a small temperature gradient connected is. 1,2-Dichloroethane is obtained with a purity of over 99% and a high Yield.

Due to the uniform temperatures obtained over the entire height of the fluidized bed, the The reaction temperature is significantly lower than the lowest reaction temperatures known to date. Due to the design of the reactor according to the invention, the maximum deviation is the The temperature within the reaction zone is only 2 ° C. As a result, the oxychlorination reaction takes place without any side reaction, d. H. There is no noticeable combustion of ethylene, nor are more highly chlorinated ones Hydrocarbons as ethylene dichloride. With the high purity of the ethylene dichloride obtained the costs of a distillative separation of the organic crude product and all with it are eliminated associated procedural complications.

Process for the production of 1,2-dichloroethane
by oxychlorination of ethylene

Applicant:

Dynamit Nobel Aktiengesellschaft, Troisdorf

Named as inventor:
Dipl.-Ing. Harald von Metnitz,
Ranzel over Troisdorf;
Dr. Walter Krings, Aachen

example

a) Preparation of the catalyst
(not subject of the invention)

Y-alumina with a grain size of 0.10 to 0.50 mm is dissolved in a dilute methanolic solution of copper chloride submerged. The solution contains 0.38 kg

CuCl ₂ · 2 H ₂ O

in 2 l of methanol. After the excess solution has been filtered off with suction, the catalyst is dried. The ready-to-use The catalyst contains 6.3% copper and weighs 0.60 kg per liter.

b) Carrying out the reaction

An amount of air sufficient to swirl the grains is fed into the reactor. The catalyst is heated to the start-up temperature of the reaction of 160 to 180 ^° C. by heating the reactor wall. Once this temperature has been reached, a gas mixture of the following composition is fed into the reactor:

125 Nl / hour ethylene (Nl = normal liter),
250 Nl / hour hydrogen chloride gas,
360 Nl / hour of air (20% O ₂ excess over the stoichiometrically correct amount of oxygen). Reaction temperature: 240 ° C.

The gases leaving the reactor are first in one with water, then in one with cooling brine freed of condensable components from the -35 ° C cooled condenser.

Both condensates are summarized in the following information.

709 549/426

a) gas phase

The gas phase was investigated partly by gas chromatography and partly by gas volumetrically and contained in addition the nitrogen some oxygen, ethylene, traces of carbon dioxide and 9.2 percent by volume Ethylene dichloride. That is 31 Nl / hour or 137 g ethylene dichloride per hour.

b) condensate

Ethylene dichloride 389 g / hour

Aqueous hydrochloric acid (18.2% (HCl). 117 g / hour

125 Nl / hour of technically pure ethylene of 98% purity would have to form 541 g / hour of ethylene dichloride at 100% conversion. Actually emerged
526 g / hour ethylene dichloride. The conversion of ethylene to ethylene dichloride is therefore 97.2%

The liquid organic crude product distills practically 100% at the theoretical boiling point of ethylene dichloride at 83.5 ° C. Gas chromatographic analysis shows traces of impurities just above the detectability limit, i.e. in the order of a tenth percent by weight of the organic raw product. The product has a purity of at least 99.5%

Claims (1)

Claim: Process for the production of 1,2-dichloroethane by oxychlorination of ethylene, thereby characterized in that in a fluidized bed of a copper chloride catalyst, which is applied to a carrier made of active alumina, operates at temperatures up to 280 ° C, and that for the said Implementation an implementation space is used that has the shape of an inverted truncated cone has, whose cone angle is between 5 and 15 ° and whose ratio of the lower to upper diameter is 1: 2 to 1: 3, with the upper further end of the truncated cone on a cylindrical part, the height of which is one fifth that of the truncated cone, and the At rest, the catalyst fills about three quarters of the conversion space. 1 sheet of drawings 709 549/426 4. 67 © Bundesdruckerei Berlin