Raschig process
The Raschig process is a chemical process for the production of hydroxylamine, developed by German chemist Friedrich Raschig. The main step in this process, patented by Raschig in 1887, is the reduction of nitrite with bisulfite towards hydroxylamine disulfonate, which is hydrolysed to hydroxylammonium sulfate.[1] Most of the hydroxylamine produced is used in the manufacture of caprolactam, the precursor to the polymer Nylon 6.[2]
The commercially used Raschig process consists of the following steps:[2]
- ammonium carbonate solution is prepared by reacting ammonia, carbon dioxide and water
- an alkaline solution of ammonium nitrite is formed by reacting ammonium carbonate solution with nitrogen oxides
- ammonium nitrite is converted to hydroxylamine disulfonate with sulfur dioxide
- hydroxylamine disulfonate is hydrolysed to hydroxylammonium sulfate
See also
- the Raschig–Hooker process, producing phenol from chlorobenzene
- the Olin Raschig process, producing hydrazine from sodium hypochlorite and ammonia
References
- ↑ DE patent 41987, Friedrich Raschig, "Verfahren zur Darstellung der hydroxylamindisulfonsauren Alkalisalze und von Hydroxylamin aus letzteren.", issued 1887-01-22
- 1 2 Ritz, Josef; Fuchs, Hugo; Perryman, Howard G. (2000). "Hydroxylamine". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a13_527.
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