Transport of soluble surfactant on and within a foam film in the context of a foam fractionation process

• Foam fractionation with reflux is modelled for a soluble surfactant Reflux induces Marangoni-driven transfer from Plateau border to film Two isotherms (global and local Henry) relate on within foam Surfactant slowed by solubility Henry isotherm Film drainage reduces recovery but improves enrichment This study models transport during process. Marangoni flow drives onto the film, also concentration assumed be uniform across thin film. Adsorption are used couple mass equations, so as determine evolution of total amount (surface plus bulk) at any location. considered both in absence presence drainage. It observed that having slows down compared cases assuming insoluble surfactant. because cases, surfactants diffuse bulk even whilst being transferred surface. Furthermore, it quasisteady state typically occurs after long time, such become comparable.