| 摘要 |
Nitric oxides can be absorbed from gas mixtures containing nitric oxides (NO and NO2) and oxygen by absorption with aqueous solutions. According to the invention, the absorption is effected in bubble columns, superficial velocities of 2 to 30 cm/second being maintained. It is advantageous to connect several bubble columns in series such that the gas and absorption liquid pass in counter-current to one another. In this embodiment, considerably less counter-current stages are required to achieve a high degree of absorption of NOx than in the case of conventional processes. At superficial velocities of 10 to 30 cm/second, large bubbles of gas can rapidly form from the gas introduced and can interact with the absorption liquid only with difficulty. In this case, gas distributor devices are incorporated in the bubble column. Since NO2 is more readily absorbed than NO, it is advantageous to connect flow reactors, in which NO2 is formed from NO and O2, upstream of the bubble columns.
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