Foam Fractionation - History

History

Whilst protein skimmers have been common place in aquaria for many years, it was not until the 1960s that a concerted effort was made by Robert Lemlich of the University of Cincinnati to characterise of model adsorptive bubble separation processes, of which foam fractionation is one example. Until the mid-2000s, there was very little further development of foam fractionation or attempts to understand the underlying physics of the process. Many workers were satisfied with empirical descriptions of specific systems rather than attempt a mechanistic model of the process, and it is possibly for this reason that the adoption of the technology has been slow despite its enormous potential.

Foam fractionation is closely related to the allied process of froth flotation in which hydrophobic particles attach to the surface of bubbles which rise to form a pneumatic (i.e. rising) foam. In this way, relatively hydrophobic particles can be separated from relatively hydrophilic particles. Froth flotation is typically used to separate coal particles from ash or particles of valuable minerals from gangue material. It was research into the froth phase of froth flotation conducted at the University of Newcastle, Australia, specifically into the prediction of liquid fraction and liquid flux in a pneumatic foam, that enabled a preliminary mechanistic description of foam fractionation. The synergies between foam fractionation and froth flotation have been explored in a 2009 special issue of the Asia Pacific Journal of Chemical Engineering.