Mass transfer characteristics during NH3/H2O bubble absorption with surfactants

The objectives of this paper are to study the mass transfer performance during NH3 bubble absorption with chemical surfactant, to find the dominant effect between Marangoni effect and barrier effect and to suggest the optimal design conditions for the small sized absorption system with high performance. Mass transfer performance was evaluated by visualizing the disappearance length and residence time of ammonia bubbles. Three kinds of high alcohols were considered as the surfactants, i.e. 2-Ethyl-1-Hexanol, n-Octanol, and n-Decanol. The surfactant concentration ranged from 0 ppm to 2000 ppm for each surfactant. The results showed that the surfactants in the fluid increase the disappearance length and residence time of ammonia bubbles. It was found that the surfactant made the rising velocity of the bubbles higher and enhances the absorption performance. It was concluded that the Marangoni effect of surfactants was more dominant than barrier effect for this experiment conditions.