CO2 Recovery in Beer 

Beer and other carbonated beverages contain CO2. Usually, breweries have to purchase the CO2 which they use for manufacturing. During beer production, a large amount of CO2 is generated during alcoholic fermentation. Centec offers plants to recover this CO2 so that it can be used for the manufacturing process. We offer CO2 recovery plants for a wide range of capacities. They pay for themselves quickly and offer the brewery an enormous savings potential.

The Principle

CO2 raw gas from fermentation is fed into the plant. Before entering the plant, a foam probe is used to check whether the raw gas contains fermentation foam. If necessary, this foam is discharged into the atmosphere via the foam flap. Between the foam flap and the gas scrubber, the raw gas flows into a gas balloon. The balloon serves as a reservoir and equalizing tank in the event of fluctuating gas levels. This maintains a constant low overpressure in the feed line up to the fermentation tanks. The system is automatically switched on or off by the filling level of the gas balloon. The foam-free gas is purified from water-soluble substances in a gas scrubber column with fresh water in counter-flow. The CO2 is compressed in two stages with an oil-free dry[1]running compressor and cooled after each stage with the intercoolers and freed from condensate water via the separators. The outlet temperature of the compressed CO2 gas is monitored by means of a temperature sensor. If the temperature exceeds 50°C, the CO2 compressor is stopped. To remove odorous substances, the pre-cleaned and com[1]pressed CO2 is passed over a bed of activated carbon. Drying to a dew point below the liquefaction temperature of the compressed gas takes place in dryers specially designed for the treatment of fermentation gas. As in the case of purification, the two alternately operated apparatuses ensure continuous operation with regeneration of the loaded silica gel. Due to its wide range of pore sizes, the desiccant used (special silica gel) has the property of adsorbing not only moisture but also other fermentation by-products. Regeneration of the respective dryer is also carried out with dry inert gas. Liquefaction of the compressed carbon dioxide takes place in a shell-and-tube heat exchanger at a temperature of approx. – 27 °C.

The non-condensable inert gases (O2, N2, etc.) are removed from the system via automatic venting, depending on the process pressure. The liquid CO2 then flows into the insulated storage tank and is now available for consumption. The storage tank is dimensioned in such a way that at the planned plant capacity, the production of at least 70 h (normal weekend) can be stored. The refrigeration required to liquefy the pure CO2 is generated by an NH3 refrigeration system with an evaporation temperature of – 32°C. This plant works in dependence of the pressure sensor in the storage tank and switches it on or off. The CO2 extraction from the storage tank and the evaporator are dimensioned in such a way that, beyond the nominal capacity, short-term peak capacities are possible. Withdrawal is controlled fully automatically via the CO2 gas temperature after evaporation.

Typical Technical Data
Capacity 150 kg/h; 300 kg/h; 500 kg/h; 1.000 kg/h; 1.500 kg/h (others on request)
Options Aerosol scrubber; foam trap; stripper system to reduce O2 content to < 5ppm; glycol-heated CO2 evaporator for energy recovery; CO2 cylinder filling unit

About ProDetec

ProDetec was established in 2003 and is a quality ISO9001 company with an extensive client base throughout Australia and New Zealand. ProDetec is focused on client satisfaction and process efficiency. We have in-house and on-site service & commissioning capabilities and a team of qualified engineers.