Pechiney-Ugine-Kuhlmann process
The Pechiney-Ugine-Kuhlmann process is a process for the industrial production of hydrazine through the oxidation of ammonia with hydrogen peroxide. It was developed in the early 1970s by Produits Chimiques Ugine Kuhlmann,[1][2] the chemicals division of Pechiney-Ugine-Kuhlmann, and is now operated by Arkema at its Lannemezan plant in southern France.
Process chemistry
The original Pechiney-Ugine-Kuhlmann process produced acetone azine from acetone (2 eq.), ammonia (2 eq.) and hydrogen peroxide (1 eq.).[1] The first step is the formation of acetone imine, Me2C=NH; this is then oxidized by hydrogen peroxide through a complex mechanism to give 3,3-dimethyloxaziridine, which reacts with a further molecule of ammonia to produce acetone hydrazone. The hydrazone then condenses with a further molecule of acetone to produce the azine. The acetone azine product is distilled out of the reaction mixture as its azeotrope with water (n(H2O)/n(azine) ≈ 6).[2] Later developments of the process replace the acetone with butanone (methyl ethyl ketone): the basic chemistry remains the same, but the butanone azine is immiscible in the reaction mixture, and can be separated by decantation.[3][4] Typical process conditions are 50 °C and atmospheric pressure, with a feed mix of H2O2:ketone:NH3 in a molar ratio of about 1:2:4.[3] A similar process based on the production of benzophenone azine from benzophenone has also been described,[5] but never industrially implemented.
The hydrolysis of the azine is acid-catalyzed, hence the need to isolate the azine from the initial ammonia-containing reaction mixture. It is also endothermic,[6] and so requires an increase in temperature (and pressure) to shift the equilibrium in favour of the desired products: ketone (which is recycled) and hydrazine hydrate.[2] The reaction is carried out by simple distillation of the azeotrope: typical conditions are a pressure of 8 bar and temperatures of 130 °C at the base of the column and 179 °C at the top of the column. The hydrazine hydrate (30–45% aqueous solution) is run off from the base of the column, while the acetone is distilled off from the top of the column and recycled.[2]
Lannemezan plant
The Lannemezan plant, on the outskirts of the town of Lannemezan in the Hautes-Pyrénées départment of southern France, is the world's largest hydrazine hydrate plant,[7] producing 17,000 tonnes of hydrazine products per year.[8] It was founded in 1917 by the Poudrerie Nationale to produce calcium cyanamide, and was privatized in 1921 as the Société des Produits Azotés (SPA). The first hydrazine hydrate plant, based on the Raschig process, was installed by the SPA in 1962. The plant was overhauled in 1980 to install the new Pechiney-Ugine-Kuhlmann process.[8]
References
- ↑ 1.0 1.1 Schirmann, Jean-Pierre; Combroux, Jean; Delavarenne, Serge Yvon (Produits Chimiques Ugine Kuhlmann) Method for preparing azines and hydrazones. US Patent 3972878, issued 3 August 1976. Schirmann, Jean-Pierre; Tellier, Pierre; Mathais, Henri, et al. (Produits Chimiques Ugine Kuhlmann) Process for the preparation of hydrazine compounds. US Patent 3978049, issued 31 August 1976.
- ↑ 2.0 2.1 2.2 2.3 Schirmann, Jean-Pierre; Combroux, Jean; Delavarenne, Serge Y. (Atochem) Preparation of a concentrated aqueous solution of hydrazine hydrate. US Patent 4724133, issued 9 February 1988.
- ↑ 3.0 3.1 Maxwell, Gary R. Synthetic nitrogen products: a practical guide to the products and processes; Springer, 2004; pp 342–44. ISBN 0306482258.
- ↑ Cotton, F. Albert; Wilkinson, Geoffrey Advanced Inorganic Chemistry, 5th ed.; Wiley-Interscience: New York, 1988; pp 317–18. ISBN 0-471-84997-9.
- ↑ Hayashi, Hiromu; Kainoh, Akihiko; Katayama, Masayoshi; Kawasaki, Kengo; Okazaki, Tatsuya Hydrazine Production from Ammonia via Azine. Ind. Eng. Chem. Prod. Res. Dev. 1976, 15 (4), 299–303. DOI: 10.1021/i360060a016.
- ↑ Gilbert, E. C. Studies on Hydrazine. The Hydrolysis of Dimethylketazine and the Equilibrium between Hydrazine and Acetone. J. Am. Chem. Soc. 1929, 51 (11), 3394–3409. DOI: 10.1021/ja01386a032.
- ↑ Arkema consolidates its Hydrazine Hydrate and Derivatives activity at its Lannemezan industrial facility; Arkema, 2008-09-30, <http://www.arkema.com/sites/group/en/press/pr_detail.page?p_filepath=/templatedata/Content/Press_Release/data/en/2008/080930_arkema_consolidates_its_hydrazine_hydrate_and_derivatives_activity_at_its_lannemezan_indus.xml>.
- ↑ 8.0 8.1 Site industriel de Lannemezan; Arkema, <http://www.arkema.com/pdf/FR/corporate/SITE_LANNEMEZAN.pdf>. (accessed 2 July 2010).
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