Todd Rausch, M.G. Newell Corporation, Greensboro, NC, U.S.A.
Coauthor(s): Mimi Cartee,
M.G. Newell Corporation,
In typical brewing systems, conventional dispersive techniques must first disperse small bubbles of gas into a moving liquid and then cause those bubbles to be absorbed into the liquid by using pressure, temperature, and time. With hollow fiber membranes, CO2 or N2 is instantaneously transported into solution by absorption at a molecular level through a hydrophobic hollow fiber membrane. Since the membrane is hydrophobic, it acts as an inert support that allows direct contact between the gas and the liquid phase without dispersion. By creating a pressure differential between the gas and the liquid, the gas will pass through the membrane and into the liquid. This design provides a fast equilibrium of the system and a very efficient transfer of gas to liquid due to the high surface area/volume ratio. Membranes can be used to remove oxygen or carbon dioxide or to add carbon dioxide or nitrogen. Between batches, the membrane can be cleaned using conventional CIP methods. This paper will provide a layman’s view of the membrane’s operation as well as answer questions about the suitability of the system for beer.