Degussa Aktiengesellschaft

Other

Carl Voigt

Peter K Kleinschmit

Reinhard Manner

Gerd Schreyer

Hans Strack

Friedrich Bittner

Peter Albers

Hans Schaefer

Wolf D Pfeifer

Eberhard Walter

Michael Witzel

Lothar Schmidt

Gerhard Sperka

Wolf-Dieter Pfeifer

As a result of a special form of the surface coating of Al.sub.2 O.sub.3 catalysts using additional amounts of aluminum ions and very slight amounts of platinum ions, Al.sub.2 O.sub.3 was able to be used as catalyst for continuous operation (150 days and longer) in the preparation of hydrogen cyanide from hydrocarbons and ammonia, preferably in the BMA method.

Method of preparing hydrogen cyanide

There is obtained an increase in the throughput in the known BMA furnace or a BMA furnace chamber without changing the construction and dimensions already present by changing the lower part of the cooling head into a short tubular heat exchanger while maintaining the necessary temperature profile for the process by arranging the ceramic tubes in the furnace chamber in closer or less close fashion and/or by using ceramic tubes having different inner and outer geometries and/or structure.

Process and apparatus for the production of hydrogen cyanide

The previously carried out internal coating of contact tubes not only required very much manual labor and was very time consuming, but it was also unsatisfactory in regard to adhesion of the contact liquid to the surface and homogenity of the catalyst. By the simultaneous action of heat on the liquid interface in the tubes during the lowering of the liquid level as well as by a specially suited apparatus for this purpose which operates according to the principle of communicating tubes there is provided the possibility of a good adhesion to the surface as well as the formation of a homogeneous layer at very little operating expense.

Apparatus for the internal coating of contact tubes

Process for the internal coating of contact tubes

In order to be independent of the situation in regard to methane and natural gas and at the same time to obtain a heating gas there is employed in the hydrocyanic acid-methane-ammonia process (the BMA process) in place of methane an alkanol or alkanediol having 2-4 carbon atoms, preferably ethyl alcohol, and this is reacted with ammonia in a C:N ratio of 0.8:1 to 2:1. Optionally additional hydrogen can be present.

Process for the production of hydrogen cyanide

Hydrogen cyanide in hydrogen cyanide containing gas is transformed into ammonia by a special iridium catalyst in the presence of at least the equivalent amount of hydrogen for the change. The ammonia is analyzed to provide a measure of the hydrogen cyanide in the hydrogen cyanide containing gas.

Process for the analytical determination of hydrogen cyanide in gases

By introducing the reaction gas mixture of hydrocarbons and ammonia at increased velocity through an inlet tube with one or more openings in a customary reaction tube in the hydrocyanic acid-methane-ammonia (BMA) process the yield of HCN is increased considerably.

For the reduction of the ammonia content in the product gas of the hydrocyanic acid-methane-ammonia (BMA) process and accordingly to increase the yield the reaction gas mixture of this process is brought into contact with zeolite and the ammonia thereafter desorbed from the zeolite preferably again employed in the reaction step. If the desorption is carried out with a flushing gas such as the hydrocarbon used in the reaction then this mixture can be directly supplied again to the BMA reactor. Through this procedure the amount of ammonia previously lost to the process can again be made useful in the process itself.

The known hydrocyanic acid-methane-ammonia (BMA) process for the production of hydrogen cyanide can now be carried out with liquified gases namely through the presence of additional hydrogen at the beginning of the reaction. The atomic ratio of carbon to nitrogen and hydrogen is from 1:1:7.1 to 1:1.33:13. As additional hydrogen there is the portion of hydrogen present coming out of the reaction 'hydrocarbon+NH.sub.3 '. Otherwise the reaction conditions are the same as in the known BMA process.

Hydrogen cyanide in hydrogen cyanide containing gas is transformed into ammonia by a special iridium catalyst in the presence of at least the equivalent amount of hydrogen for the change.

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Rodenbach, Germany

Carl Voigt