摘要 |
An oxido-reduction process for nitrogen oxides contained in a gas stream also containing oxygen, in a countercurrent gas-liquid contact device. In this process, (a) for values of the ratio NO/NO2 greater than 1, in that section of the gas-liquid device where the NOx content in the gas stream is less than about 6000 vpm, the ratio K, which is the ratio of the liquid retention volume in m3 to the flow rate of the gas stream in Nm3/hour, is increased so that the NOx are preferentially absorbed according to the reaction: NO+NO2+H2O->2HNO2 (liquid phase); and (b) oxidation is then induced, to reduce the value of the ratio NO/NO2 and to restore the conditions of stage (a). In practice, the operating point describes a curve A0A2B1A3B2A4, as shown in FIG. 1. |