The present work analyses the hydrodynamic behaviour of a gas phase in a bubble column using different emulsions as liquid phase. The hydrodynamic behaviour was analysed on the basis of gas hold-up, bubble diameter and gas-liquid interfacial area; the different variables employed in this study [gas flow-rate (between 18 and 40 L h(-1)), as well as the organic phase nature, the organic phase concentration (between 0 and 1% (vol)) and the surfactant presence (between 0 and 0.1% (vol))] have been taken into account. The results obtained have been explained on the basis of the liquid phase physical properties and the special characteristics of the gas-liquid-liquid systems. (c) 2011 Elsevier B.V. All rights reserved.