Advances in separation technology for the brewer: ceramic crossflow microfiltration of rough beer.

Burrell, K., Gill, C., McKechnie, M. and Murray, J.

Abstract
The development of membrane technology for the filtration of beer, which theoretically offers considerable advantages over other filtration techniques but in practice is subject to various problems which limit its performance and cost effectiveness, is reviewed. Laboratory and pilot scale trials of a new type of ceramic cross flow filter module are described. Produced by the Ceramem Corporation, the module consists of an extruded cylindrical monolithic support body of extremely porous material, through which parallel channels, 1.9 mm square in cross section, run 1 mm apart. The walls of the channels are lined with a hydrophilic membrane with a highly asymmetric pore structure, formed by sintering ceramic particles onto the channel walls in a process which enables the pore size to be controlled with great accuracy. The trial modules had pore sizes of 0.5, 1.0 or 1.3 microns. The effects of transmembrane differential pressure, cross flow velocity, beer brand characteristics, beer suspended solids content and pore size on filter performance and filtrate quality were evaluated. The 0.5 micron membrane produced very bright, almost sterile filtrates, while the larger pore sizes led to higher haze levels in the filtered beer. No significant loss of essential beer constituents was observed. However, it was found that the quantity and size distribution of the suspended particles in the rough beer interacted with pore size to produce complex effects on filter performance. As these Ceramem modules are much cheaper than most ceramic filter membranes, the economic aspects of cross flow filtration are also made more attractive.
Keywords : beer ceramic cross flow filtration membrane performance