Birkeland–Eyde process – Wikipedia
From Wikipedia, the free encyclopedia
The Birkeland–Eyde process was one of the competing industrial processes in the beginning of nitrogen-based fertilizer production. It is a multi-step nitrogen fixation reaction that uses electrical arcs to react atmospheric nitrogen (N2) with oxygen (O2), ultimately producing nitric acid (HNO3) with water.[1] The resultant nitric acid was then used as a source of nitrate (NO3−) in the reaction
[2] based on a method used by Henry Cavendish in 1784.[3][4] A factory based on the process was built in Rjukan and Notodden in Norway, combined with the building of large hydroelectric power facilities.[5][6]
The Birkeland–Eyde process is relatively inefficient in terms of energy consumption. Therefore, in the 1910s and 1920s, it was gradually replaced in Norway by a combination of the Haber process and the Ostwald process. The Haber process produces ammonia (NH3) from molecular nitrogen (N2) and hydrogen (H2), the latter usually but not necessarily produced by steam reforming methane (CH4) gas in current practice. The ammonia from the Haber process is then converted into nitric acid (HNO3) in the Ostwald process.[7]
The process[edit]
An electrical arc was formed between two coaxial water-cooled copper tube electrodes powered by a high voltage alternating current of 5 kV at 50 Hz. A strong static magnetic field generated by a nearby electromagnet spreads the arc into a thin disc by the Lorentz force. This setup is based on an experiment by Julius Plücker who in 1861 showed how to create a disc of sparks by placing the ends of a U-shaped electromagnet around a spark gap so that the gap between them was perpendicular to the gap between the electrodes, and which was later replicated similarly by Walther Nernst and others.[8][9] The plasma temperature in the disc was in excess of 3000 °C. Air was blown through this arc, causing some of the nitrogen to react with oxygen forming nitric oxide. By carefully controlling the energy of the arc and the velocity of the air stream, yields of up to approximately 4–5% nitric oxide were obtained at 3000 °C and less at lower temperatures.[10][11] The process is extremely energy intensive. Birkeland used a nearby hydroelectric power station for the electricity as this process demanded about 15 MWh per ton of nitric acid, yielding approximately 60 g per kWh. The same reaction is carried out by lightning, providing a natural source for converting atmospheric nitrogen to soluble nitrates.[12]
References[edit]
- ^ Remsen, I.; Renoup, H. (1906). “The Oxidation of Atmospheric Nitrogen with Reference to the Manufacture of Nitrates and Nitric Acid” (PDF). American Chemical Journal. 35: 358–367. Retrieved 1 February 2019.
- ^ Eyde, Sam (1909). “The Manufacture of Nitrates from the Atmosphere by the Electric Arc—Birkeland-Eyde Process”. Journal of the Royal Society of Arts. 57 (2949): 568–576. JSTOR 41338647.
- ^ Cavendish, Henry (1785). “Experiments on air”. Philosophical Transactions of the Royal Society of London. 75: 372–384.
- ^ Aaron John Ihde (1984). The development of modern chemistry. Courier Dover Publications. p. 678. ISBN 0-486-64235-6.
- ^ G. J. Leigh (2004). The world’s greatest fix: a history of nitrogen and agriculture. Oxford University Press US. pp. 134–139. ISBN 0-19-516582-9.
- ^ Birkeland, Kr. (1906). “On the oxidation of atmospheric nitrogen in electric arcs”. Transactions of the Faraday Society. 2 (December): 98. doi:10.1039/tf9060200098. ISSN 0014-7672.
- ^ Trevor Illtyd Williams; Thomas Kingston Derry (1982). A short history of twentieth-century technology c. 1900-c. 1950. Oxford University Press. pp. 134–135. ISBN 0-19-858159-9.
- ^ Plücker (1861). “Ueber die Einwirkung des Magnets auf die elektrische Entladung” [On the effect of the magnet on the electric discharge]. Annalen der Physik und Chemie (in German). 113: 249–280. From p. 255: ” … die Curven, welche dieselbe durchziehen, soweit die Schätzung des Auges reicht, genau die Form von Kreisbogen an[nehmen], die sämmtlich auf der die beiden Spitzen des Entladers verbindenden geraden Linie, als gemeinschaftlicher, senkrecht stehen.” ( … the curves which [the luminous discharges] traverse, assume — as far as the eye can judge — exactly the form of circular arcs, all of which stand perpendicular to the same straight line that joins the two points of the electrodes.)
- ^ Worden, Edward Chauncey (1921). Technology of Cellulose Esters. Vol. 1:2. D. Van Nostrand Company. p. 870.
- ^ Mellor, J. W. (1918). Modern Inorganic Chemistry. Longmans, Green and Co. p. 509.
- ^ Martin, Geoffrey; Barbour, William (1915). Industrial Nitrogen Compounds and Explosives. Crosby Lockwood and Son. p. 21.
- ^ Karl Fisher; William E. Newton (2002). G. J. Leigh (ed.). Nitrogen fixation at the millennium. Elsevier. pp. 2–3. ISBN 0-444-50965-8.
- ^ Webb, H. W. (1923). Absorption of Nitrous Gases. Edward Arnold & Co. p. 20.
- ^ Douglas Erwin (2002). Industrial Chemical Process Design. McGraw-Hill. p. 613. ISBN 0-07-137621-6.
- ^ Knox, Joseph (1914). The Fixation of Atmospheric Nitrogen. D. Van Nostrand Company. pp. 45-50.
Recent Comments