A model for Concentration of proteins from dilute solutions in a continuous foam fractionation column is proposed. This model accounts for (1) kinetics of adsorption of proteins in the liquid pool as well as in the foam, (2) liquid drainage from thin films due to Plateau border suction and disjoining pressure, (3) gravity drainage of liquid from Plateau borders, and (4) bubble coalescence in the foam. Protein enrichment and recovery were found to increase as the liquid pool height increased, eventually attaining constant values (corresponding to adsorption equilibrium), thus demonstrating the strong dependence of protein separation on adsorption kinetics. Higher enrichments and lower recoveries were obtained for smaller gas velocities, larger bubble sizes, and higher feed flow rates. Enrichments as well as recoveries were higher at lower feed concentrations. Coalescence was found to lead to higher enrichments and lower recoveries, this dependence being stronger for larger inlet bubble sizes.