Andrussow process
{{Short description|Process for industrial production of hydrogen cyanide}}
File:1931.01.31 23 Andrussow Pilot Plant diagramm Herne Germany.jpg
The Andrussow process is the dominant industrial process for the production of hydrogen cyanide.{{ Ullmann |last1=Gail|first1=E.|last2=Gos|first2=S.|last3=Kulzer|first3=R.|last4=Lorösch |first4=J.|last5=Rubo|first5=A.|last6=Sauer|first6=M. | title = Cyano Compounds, Inorganic | doi = 10.1002/14356007.a08_159.pub2 }} It involves the reaction of methane, ammonia, and oxygen. The process is catalyzed by a platinum-rhodium alloy.{{cite journal |doi=10.1016/j.apcata.2010.03.046 |title=Mechanistic aspects of the Andrussow process over Pt-Rh gauzes. Effect of gauze morphology and oxygen coverage on primary O2–NH3–CH4 interactions |date=2010 |last1=Kondratenko |first1=V.A. |last2=Weinberg |first2=G. |last3=Pohl |first3=M.-M. |last4=Su |first4=D.S. |journal=Applied Catalysis A: General |volume=381 |issue=1–2 |pages=66–73 |bibcode=2010AppCA.381...66K }}
: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.{{Citation | first=Gyula | last=Deák | title=Menné reakcie v organickej chémii|year = 1980|publisher=Vydavateľstvo technickej a ekonomickej literatúry| location = Bratislava| page = 14}} 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.{{cite journal|last=Pirie|first=J M|title=The Manufacture of Hydrocyanic Acid by the Andrussow Process|journal=Platinum Metals Rev.|year=1958|volume=2|issue=1|pages=7–11|doi=10.1595/003214058X21711 |url=http://www.platinummetalsreview.com/pdf/pmr-v2-i1-007-011.pdf|access-date=28 March 2014|archive-date=31 January 2013|archive-url=https://web.archive.org/web/20130131122838/http://www.platinummetalsreview.com/pdf/pmr-v2-i1-007-011.pdf|url-status=dead}}
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.{{cite journal
| title = Über die schnell verlaufenden katalytischen Prozesse in strömenden Gasen und die Ammoniak-Oxydation (V)
| author = Leonid Andrussow
| journal = Berichte der Deutschen Chemischen Gesellschaft
| volume = 60
| issue = 8
| pages = 2005–2018
| year = 1927
| doi = 10.1002/cber.19270600857 }}{{cite journal
| title = Über die katalytische Oxydation von Ammoniak-Methan-Gemischen zu Blausäure (The catalytic oxidation of ammonia-methane-mixtures to hydrogen cyanide)
| author = L. Andrussow
| journal = Angewandte Chemie
| volume = 48
| issue = 37
| pages = 593–595
| year = 1935
| doi = 10.1002/ange.19350483702 }}
References
{{Reflist}}
{{Organic reactions}}
{{DEFAULTSORT:Andrussow Oxidation}}