The goals of the present investigation are to study and to model pale lager beer dealcoholization
via reverse osmosis (RO). Samples were dealcoholized at a temperature of 15 ± 1 °C.
An Alfa Laval RO99 membrane with a 0.05 m2 surface was used. The flux values were
measured during the separations. The ethanol content, extract content, bitterness,
color, pH, turbidity, and dynamic viscosity of beer and permeate samples were measured.
The initial flux values were determined using linear regression. The initial ethanol
flux (JEtOH 0) values were calculated from the initial flux values and the ethanol
content values. A 2P full factorial experimental design was applied, and the factors
were as follows: transmembrane pressure (TMP): 10, 20, 30 bar; retentate flow rate
(Q): 120, 180, 240 L/h; JEtOH 0 was considered as the response. The effect sizes of
the significant parameters were calculated. The global maximum of the objective function
was found using a self-developed Grid Search code. The changes in the analytical parameters
were appropriate. The TMP had a significant effect, while the Q had no significant
effect on the JEtOH 0. The effect size of the TMP was 1.20. The optimal value of the
factor amounted to TMP = 30 bar. The predicted JEtOH 0 under the above conditions
was 121.965 g/m2 h.
