| 摘要 |
<p>1275140 Separating NO from N 2 O L'AIR LIQUIDE SOC ANON POUR L'ETUDE ET L'EXPLOITATION DES PROCEDES GEORGES CLAUDE 24 Dec 1969 [27 Dec 1968] 62950/69 Heading B1L [Also in Division Cl] NO contained as impurity in gas streams comprising predominantly N 2 O is removed by contacting the gas stream under non-oxidising conditions and generally at ambient temperature with a molecular sieve, suitably a mordenite charged with an elemental transition metal, e.g. Cu, Co, Ni or, preferably Fe. Thus, a gas stream from the thermal decomposition of NH 4 NO 3 and containing NO, NO 2 , N 2 O 4 , NH 3 and H 2 O in addition to N 2 O is suitably first washed with water and/or NaOH solution and then passed through a guard bed of a zeolite, such as an acid mordenite, before entering the metal-charged bed where residual NO is removed. The beds are regenerated by vacuum or by elution with a reducing and/or inert non-oxidising gas, and if desired at elevated temperature. Periodically, any decrease in bed activity resulting from metal oxidation may be overcome by a reduction step. A twocolumn dual-bed process is described in which one column is on stream while the other is being regenerated (see Fig. 2, not shown).</p> |
