Germany hydrogen cyanide

Two synthesis processes account for most of the hydrogen cyanide produced. The dominant commercial process for direct production of hydrogen cyanide is based on classic technology (23—32) involving the reaction of ammonia, methane (natural gas), and air over a platinum catalyst it is called the Andmssow process. The second process involves the reaction of ammonia and methane and is called the BlausAure-Methan-Ammoniak (BMA) process (30,33—35) it was developed by Degussa in Germany. Hydrogen cyanide is also obtained as a by-product in the manufacture of acrylonitrile (qv) by the ammoxidation of propjiene (Sohio process). 

Plants for the production of sodium cyanide from Andmssow process or from acrylonitrile synthesis by-product hydrogen cyanide are operating in the United States, Italy, Japan, the UK, and AustraUa. In Germany, sodium cyanide is produced from BMA hydrogen cyanide, and in AustraUa one plant uses Fluohmic process hydrogen cyanide. 

Huthmacher, K. Krill, S. Reactions with Hydrogen Cyanide (Hydrocyanation). In Applied Homogeneous Catalysis with Organometallic Compounds Cornils, B., Herrmann, W. A., Eds. VCH Weinheim, Germany, 1996 pp 465-486. 

ACH (1) [Acetone cyanhydrin] A process for making methyl methacrylate via this intermediate. Acetone reacts with hydrogen cyanide to yield the cyanhydrin. This is then converted to methacrylamide, using concentrated sulfuric acid. Methanolysis of this yields methyl methacrylate. Developed by Rohm GmbH Chemische Fabrik, Germany, and ICI, UK used in 11 countries in 1990. 

The product gases are freed from ammonia by scmbbing with sulfuric acid and the hydrogen cyanide is then absorbed in water or diethanolamine. Invented in 1930 by L. Andmssov at IG Farbenindustrie, Germany. 

F-S [Ferrous sulfate] A process for removing ammonia, hydrogen sulfide, and hydrogen cyanide from coke-oven gas by scrubbing with aqueous ferrous sulfate solution obtained from steel pickling. A complex series of reactions in various parts of the absorption tower yield ammonium sulfate crystals and hydrogen sulfide (for conversion to sulfur or sulfuric acid) as the end products. Developed in Germany by F. J. Collin A.G. 

Knapsack A process for making acrylonitrile from lactonitrile, itself made from acetaldehyde and hydrogen cyanide. Operated in Germany from 1958. Not industrially significant today for the production of acrylonitrile, although part of the process is still used for making lactic acid in Japan. 

Acrylonitrile was first produced in Germany and the United States on an industrial scale in the early 1940s. These processes were based on the catalytic dehydration of ethylene cyanohydrin. Ethylene cyanohydrin was produced from ethylene oxide and aqueous hydrocyanic acid at 60°C in the presence of a basic catalyst. The intermediate was then dehydrated in the liquid phase at 200°C in the presence of magnesium carbonate and alkaline or alkaline earth salts of fonnic acid. A second commercial route to acrylonitrile was the catalytic addition of hydrogen cyanide to acetylene. The last commercial plants using these process technologies were shut down in 1970 (Langvardt, 1985 Brazdil, 1991). 

Economic Aspects. Dimethyl and dieihyl malonaies are produced via the carbon monoxide process at Hiils (Germany i. Juzen (Japan), and Korean Fertilizers iS. Korea) they arc produced via ihe hydrogen cyanide process ai L.ouza (Switzerland) and Tateyama (Japan). Total capacity is estimated to be aboul 12,000 t/yr. Furthermore, producers are also reported in the People s Republic of China mid in Romania. 

In 1893, the French chemist Moreau described two routes for the synthesis of acrylonitrile that were based on the dehydration of either acrylamide or ethylene cyanohydrin [10]. There was very little interest in acrylonitrile until 1937 when synthetic rubber based on acrylonitrile-butadiene copolymers was first developed in Germany. A process based on the addition of hydrogen cyanide to acetylene was developed at that time and in the 1950s, the acrylic fiber industry provided the stimulus for further process developments. Today acrylonitrile is made commercially by one of three possible methods (a) from propylene, (b) from acetylene and hydrogen cyanide, and (c) from acetaldehyde and hydrogen cyanide. 

The acetylene process was developed in Germany in the early 1940s to supply the synthetic rubber industry [19]. Acetylene is reacted with hydrogen cyanide in an aqueous medium in the presence of catalytic amounts of cuprous chloride. The reaction is maintained at 80 90°C at a pressure of 1-2 atm. The reaction is highly exothermic forming a gaseous reactor effluent. This crude product is water-scrubbed and the pure acrylonitrile product is recovered from the resultant 1-3% aqueous solution by fractional distillation. The major drawbacks of this process are the large number of by-products formed by hydration, the loss of catalyst activity from hydrolysis reactions, and the buildup of ammonium chloride and tars. 

Hazardous Product. The synthesis of hydrogen cyanide (HCN) is an example of a fast, high-temperature process that generates a hazardous gas. Researchers at the Institut fiir Microtechnik Mainz, Germany, aimed to develop a portable on-site, on-demand HCN-generating unit [1]. The Andrussow process was selected for generating HCN on the microscale. The reaction can be written as... 

In 1885, Heinrich Kiliani (Freiburg, Germany) discovered that an aldose can be converted to the epimeric aldonic adds having one additional carbon through the addition of hydrogen cyanide and subsequent hydrolysis of the epimeric cyanohydrins. Fischer later extended this method by showing that aldonolactones obtained from the aldonic acids can be reduced to aldoses. Today, this method for lengthening the carbon chain of an aldose is called the Kiliani-Fischer synthesis. 

However, despite Haber s clear loyalty to his country, his Jewish ancestry was at odds with the rising tide of anti-semitism in Nazi Germany, making his presence in the country undesirable to the authorities. In 1933, he was forced to leave Germany, and he died of heart problems in Switzerland in 1934. Ironically and as a final tragic twist in this complex story, Zykion B, a development from the hydrogen cyanide (HCN) insecticide... 

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