An empirical model of absorption of nitric oxide with ammoniacal cobalt (II) solutions in a Spray Tower.

• The overall mass transfer coefficient was obtained for NO absorption. • Liquid flow rate had minor effect on the absorption process. • Increase of temperature reduced the NO absorption efficiency. • An empirical model for the prediction of NO absorption efficiency was proposed. An empirical model was developed for the prediction of the absorption efficiency of nitric oxide (NO) into ammoniacal cobalt (II) solution in terms of gas flow rate, liquid flow rate, and temperature. The model parameters were determined experimentally using a spraying tower with initial absorbent solution pH of 10.0–10.2 for temperatures in the range of 281.15–323.15 K. The reactions between Co2+ complexes and NO were found to be in the fast pseudo-first-order reaction regime. The correlation between the overall mass transfer coefficient and the gas and liquid flow rates was determined for NO absorption. The liquid flow rate (0.225 to 0.730 L/min) had negligible effect on the NO absorption efficiency for the conditions with excessive Co2+ complexes in the solution due to the fast reaction rates. Temperature showed detrimental effects on the NO absorption for conditions in this study. [ABSTRACT FROM AUTHOR]