摘要 |
In a process and apparatus for maintaining the efficiency of ammonia oxidation in a nitric acid plant, the ammonia content of the reactant mixture and the nitrogen oxide content of the reaction product are determined by spectrometry, any nitric oxide in the sample of reaction product first being converted to nitrogen dioxide at elevated temperature and pressure. The apparatus comprises delay means for ensuring conversion of the sample of reaction product before analysis. Analysis may be by UV or IR spectrophotometry or by mass spectrography. |