The Andrussow process is the dominant industrial process for the production of hydrogen cyanide. It involves the reaction of methane, ammonia, and oxygen. The process is catalyzed by a platinum-rhodium alloy.
- 2 CH4 + 2 NH3 + 3 O2 → 2 HCN + 6 H2O
Hydrogen cyanide is highly valued for the production or acrylonitrile and adiponitrile, as well as alkali metal salts such as potassium cyanide.
Process details
This reaction is very exothermic. The change of enthalpy of this reaction is equal to -481.06 kJ. 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 minimized by only short exposures to the catalyst of the order of 0.0003 s.
Historical articles
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.
References
- ^ Gail, E.; Gos, S.; Kulzer, R.; Lorösch, J.; Rubo, A.; Sauer, M. "Cyano Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_159.pub2. ISBN 978-3527306732.
- Kondratenko, V.A.; Weinberg, G.; Pohl, M.-M.; Su, D.S. (2010). "Mechanistic aspects of the Andrussow process over Pt-Rh gauzes. Effect of gauze morphology and oxygen coverage on primary O2–NH3–CH4 interactions". Applied Catalysis A: General. 381 (1–2): 66–73. doi:10.1016/j.apcata.2010.03.046.
- Deák, Gyula (1980), Menné reakcie v organickej chémii, Bratislava: Vydavateľstvo technickej a ekonomickej literatúry, p. 14
- Pirie, J M (1958). "The Manufacture of Hydrocyanic Acid by the Andrussow Process" (PDF). Platinum Metals Rev. 2 (1): 7–11. doi:10.1595/003214058X21711. Archived from the original (PDF) on 31 January 2013. Retrieved 28 March 2014.
- 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.
- 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.