Beer dealcoholization using non-porous membrane distillation

• Non-porous membrane distillation method is applied for beer dealcoholization.
• The other nutritive and flavoring components in beer are retained.
• The increase of feed pressure and vacuum pressure can improve membrane flux.
• Membrane selectivity is decreased with the increase of vacuum pressure.
• A long run operation can reduce the alcohol content from 5%-vol. to 2.45%-vol.

In this present work, performance of non-porous membrane distillation method is investigated during beer dealcoholization process. A thin-film composite polyamide membrane is used as membrane module while a commercial beer product with 5%-volume ethanol is used as feed. The results indicate that non-porous membrane distillation can be used to dealcoholize beer without losing the other nutrients and flavoring components such as maltose and glycerol. The increase of feed pressure and vacuum pressure can improve membrane flux due to higher permeability. However, membrane selectivity is decreased with the increase of vacuum pressure. The membrane flux and ethanol concentration in permeate are 0.15–0.76 L/m2 h and 3.66–4.64%-vol., respectively. Meanwhile, there are no specific sequences on the maltose concentration in the effect of operating conditions. The slight loss of maltose in the dealcoholized beer can be attributed to adsorption phenomena in membrane surface thus membrane flushing may be conducted to recover it. The glycerol behavior in dealcoholization process is similar to maltose. Some glycerol compounds are found in the permeate stream but all of them are less than 0.005%-vol. At 3000 mbar feed pressure and 580 mbar vacuum pressure, the flux of membrane is 0.69 L/m2 h with 3.70%-vol. and 4.60%-vol. of ethanol concentration in dealcoholized beer and permeates side respectively, no maltose and only 0.001%-vol. glycerol in permeate side. A long run operation for beer dealcoholization using these operating conditions can reduce the alcohol content from 5%-vol. to 2.45%-vol. in 6 h.