Silicon carbide (SiC) membranes in œnology: a laboratory-scale study
Résumé
Unfiltered wine is a turbid medium that is not generally accepted by the consumer. Therefore, one or several filtration steps are required before bottling. Silicon carbide (SiC) membranes desirable parameters (porosity, tortuosity fluxes) allow filtering several different types of loaded matrices like wine or residue sediment. An in-depth filtration study was carried out on white and red wines to evaluate membrane efficiency and to optimise their cleaning procedure. Retention rates were studied as a function of wine type, filtration mode, and volumetric concentration factor. Compared to ceramic membranes, SiC membrane permeate fluxes are higher, up to a factor of 10 for red wine. For white wines, equivalent permeate fluxes could be obtained with dead-end filtration. Moreover, SiC membranes appear to be effective in obtaining a clear and brilliant wine and do not modify the concentration of the compounds of interest in wine. Finally, an optimised cleaning protocol has been identified and shown to restore a sufficient permeability to the SiC membranes.