The Alfa Laval Beer DeAL system is a standardized cross-flow membrane filtration system which is specifically designed for the brewing industry. This plug-in unit is a self-contained and fully automated modular system for dealcoholization of beer and production of similar low-alcohol products. The Alfa Laval Beer DeAL system is available in four standard sizes with capacities between 300 and 1000 hl/day of dealcoholized beer
Design and operation
The Alfa Laval Beer DeAL system is supplied as a skid-mounted plant for reverse osmosis with pre-assembled components and prefabricated piping. The hearth of the system is the loop section containing between 12 and 42 Alfa Laval housings installed with up to 168 spiral membranes.
The design and the operation of the Alfa Laval Beer DeAL system is based on more than 20 years of experience by Alfa Laval with the beer dealcoholization process. This system has been developed specifically for making low-alcohol beer or other similar low-alcohol products in a practical and cost-effective way.
Whilst any process temperature in the range of 1-30°C can be chosen, the temperature normally used is 7-8°C to minimize any negative effects on the dealcoholized beer, such as loss of aroma. Using membrane filtration the beer is not exposed to the effects of heat and does not undergo a phase change, as is normally the case when evaporation is applied.
The same plant can handle all types of beer, including wheat beers and dark beers. The process is the same for all these types. The same process can also be used to produce beers with different levels of alcohol content in the same plant.
The system is fully automated, which means that the volume of the charge, the alcohol content of the original beer and the desired alcohol content in the dealcoholized beer can simply be entered into the programme of the control system. The Alfa Laval Beer DeAL system then works automatically, including the necessary CIP and disinfection procedures after treatment.
- processing at low temperature minimizes unfavourable aroma effects on the dealcoholized beer
- no oxygen pick-up in the beer as the beer is treated at 30-35 bar pressure
- all beer types can be handled in the same plant
- beers with different alcohol levels can be processed in the same plant
- modular design that is easy to extend
- four standard sizes with up to 168 spiral membranes in 3 loops
- self-contained, fully automated plug-in system, ready for operation
- low operating and spiral membrane replacement cost
- main components are manufactured by Alfa Laval
- all piping and equipment in contact with the product or cleaning liquids are of sanitary-level design. AISI 316L stainless steel parts
How it works
The membranes separate the feed beer into two streams. The permeate stream, consisting of water and alcohol, passes through the membranes whereas the retentate stream, consisting of concentrated proteins, colours and flavours, does not and can therefore be led back to the beer tank.
The original beer from the beer tank is pumped to the dealcoholization unit. Two feed pumps then bring the pressure of the beer up to 30 bar. At this point, the beer is introduced into the first loop where the beer is circulated over the membranes in loop 1 by a pump. The retentate from the first loop continues to the second loop and is recirculated over the membranes in loop 2.
The retentate from loop 2 is returned to the beer tank via a pressure release valve. The permeate (water + alcohol having passed through the membranes) from all loops is collected and led to a drain or stored in tanks with a view to recovering the alcohol.
The beer is made to flow parallel to the membrane surface which keeps the membranes clean (cross flow). Due to the static pressure of 30-35 bar on the membranes the small molecules, such as water and alcohol, are pressed through the membranes whereas the larger molecules, such as flavours, colour and protein, are unable to pass. These compounds therefore remain in the retentate.
Pre-concentration - step 1
This step reduces the volume of the feed beer. After passing through the membrane modules, the feed beer is recycled over the batch tank. The permeate is removed, while the retentate goes back into the beer tank until the desired reduction in volume has been achieved.
Diafiltration - step 2
This step involves washing out the alcohol using diafiltration. It is similar in principle to the pre-concentration step, but diafiltration water is now added. The volume used is the same as that of the permeate leaving the installation, thus keeping the level in the beer tank constant. The diafiltratin step reduces the alcohol content to the desired value for the final low-alcohol beer.
Alcohol adjustment - step 3
After diafiltration, the beer can be adjusted still further by adding water into the batch tank in order to achieve the desired final alcohol content and to fine-tune the taste. The amount of water added is normally the same as the amount of permeate in step. 1
Post-treatment - step 4
The dealcoholized beer can be given its special characteristics by adjusting CO2 levels or by using hop extract or other flavour enhancers.
Membrane technology from Alfa Laval
Membrane filtration complements the range of other separation technologies offered by Alfa Laval. This ensures that we are always in a position to provide you with the ideal solution for your particular process. By using membrane filtration alone or in combination with our range of centrifuges, decanters or evaporators.