Studying beer dealcoholization by reverse osmosis

The production of low-alcohol beer (LAB) or alcohol-free beer (AFB) is important because of several reasons. In this research, pale lager beer samples were dealcoholized by reverse osmosis (RO) at a temperature of 15 ± 1 °C. Alfa Laval RO99 membrane with 0.05 m2 active surface was used for dealcoholization processes. Flux values were measured during the separations. Dynamic viscosity values and ethanol content of beer and permeate samples were measured. Initial flux values were determined by linear regression. Initial ethanol flux (JEtOH 0) values were calculated from initial flux values and ethanol content values. 2P type full factorial experimental design was applied, the two factors were the following: Transmembrane Pressure (TMP): 10, 20, 30 bar and Retentate Flow Rate (Q): 120, 180, 240 L hr-1 . JEtOH 0 was considered as a response of the full factorial experimental design. The effect sizes of the significant parameters were calculated. The global maximum of the objective function was found with self-developed Grid Search code. The best fitted linear function was as follows: JEtOH 0 = 80.871 + 41.094 × xTMP The effect size of the significant parameter was the following: TMP: 1.20. The optimal value of the factor amounted to TMP = 30 bar. The predicted JEtOH 0 under the above condition was 121.965 g m-2 hr-1 . The detailed method in this study can be implemented by breweries.