| 摘要 |
<p>The concentration of nitric oxide in a gas mixture is decreased, at least to a level at which any NO still remaining is not deleterious in use, by mixing ClO2 with the gas mixture to oxidize NO to NO2. The gas mixture may be town gas, producer gas, coke oven gas, coal gas, "convert gas," or flue gas. The ClO2 may be prepared by passing Cl2, preferably diluted with a carrier gas, e.g. N2, through an aqueous solution of sodium chlorite. The gas mixture may be scrubbed with water under pressure before contact with ClO2 to remove CO2. After such contact, the gas mixture may be scrubbed with an aqueous alkaline solution (of pH greater than 7), eg. aqueous NaOH, or an aqueous alkaline reducing solution of sodium sulphite, or sodium thiosulphate, to remove NO2, Cl2, and chlorine compounds.</p> |
