Chemistry:Andrussow process

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Late 1930: Experimental plant for the production of hydrogen cyanide with the Andrussow process in Herne, Germany, operated by Leonid Andrussow.
Diagram from 1931 showing the Andrussow process

The Andrussow process is the dominant industrial process for the production of hydrogen cyanide.[1] It involves the reaction of methane, ammonia, and oxygen. A catalyst, typically platinum, is required.[2][3]

2 CH4 + 2 NH3 + 3 O2 → 2 HCN + 6 H2O

The process is based on a reaction that was discovered by Leonid Andrussow in 1927. In the following years he developed the process that is named after him. HCN is also produced in the BMA process.

Process details

This reaction is very exothermic. The change of enthalpy of this reaction is equal to -481.06 kJ.[4] The heat provided by the main reaction serves as a catalyst for other side reactions.

CH4 + H2O → CO + 3 H2
2 CH4 + 3 O2 → 2 CO + 4 H2O
4 NH3 + 3 O2 → 2 N2 + 6 H2O

These side reactions can be reduced by only short exposures to the catalyst of the order of 0.0003s.[5]

References

  1. Gail, E.; Gos, S.; Kulzer, R.; Lorösch, J.; Rubo, A.; Sauer, M.. "Ullmann's Encyclopedia of Industrial Chemistry". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_159.pub2. 
  2. Leonid Andrussow (1927). "Über die schnell verlaufenden katalytischen Prozesse in strömenden Gasen und die Ammoniak-Oxydation (V)". Berichte der Deutschen Chemischen Gesellschaft 60 (8): 2005–2018. doi:10.1002/cber.19270600857. 
  3. L. Andrussow (1935). "Über die katalytische Oxydation von Ammoniak-Methan-Gemischen zu Blausäure (The catalytic oxidation of ammonia-methane-mixtures to hydrogen cyanide)". Angewandte Chemie 48 (37): 593–595. doi:10.1002/ange.19350483702. 
  4. Deák, Gyula (1980), Menné reakcie v organickej chémii, Bratislava: Vydavateľstvo technickej a ekonomickej literatúry, p. 14 
  5. Pirie, J M (1958). "The Manufacture of Hydrocyanic Acid by the Andrussow Process". Platinum Metals Rev. 2 (1): 7–11. http://www.platinummetalsreview.com/pdf/pmr-v2-i1-007-011.pdf. Retrieved 28 March 2014.