| 摘要 |
<p>1348153 Purification of halogens; nitrosyl chloride PULLMAN Inc 22 Oct 1971 [16 Feb 1971] 49186/71 Heading C1A Purifying a halogen stream containing hydrogen halide, water, nitroxyl halide, the concentration of water being not more than 1À5 weight per cent by contact with silica or silica-containing particles having a surface area of at least 50 m.<SP>2</SP>/g. and maintaining a mole ratio of between 1 : 2 and 1 : 100 nitroxyl halide to hydrogen halide to convert the nitroxyl halide to nitrosyl halide at a temperature between 0‹ and 450‹ F. under a pressure of up to 50 atmospheres, separating the nitrogen containing compounds and recovering purified halogen. The contacting with silica is carried out in the presence of a hydrogen halide containing the halogen corresponding to the halogen product. The halogen stream may be one from the oxidation of an inorganic halide such as hydrogen halide or an alkali metal halide (KCl), the oxidizing agent being oxygen or air promoted with a nitrogen-oxygen containing compound such as NO 2 , NO, nitroxyl halide, nitrosyl halide, nitric acid or mixtures thereof. If desired, nitroxyl halide or nitric acid may be used in the absence of air or oxygen. Any excess water (above 1À5%) should be removed by a conventional drying agent, e.g. concentrated H 2 SO 4 , CaCl 2 or SiO 2 before passing the gases to the high surface silica. The silica or molecular sieve may be in the form of a fixed or fluidized bed. The nitrogen compounds in the product are removed, e.g. in an inert still. When chlorine is the halogen concerned, the gaseous product contains nitrosyl chloride.</p> |
