CO2 recovery plants are specially designed to recover CO2 from the fermentation processes at breweries. Through appropriate scrubbing, filtration and separation technology the recovered CO2 is purified to comply with the highest quality requirements in the market. Using state of the art structured packing material in the water scrubber reduces the water consumption to 0.25 kg water/kg CO2 which equals up to 75 % reduction compared with traditional plants.
After passing the stage of scumming at the scum collector, the gaseous CO2 enters the wash column to remove alcohols and sugar-containing aerosols.
The gas is then compressed in two stages to approx. 15-18 bar(g) by the CO2 compressor.
The compressed gas is then fed to an activated carbon filter, which removes residues of alcohols, as well as odorous and aromatic hydrocarbon impurities contained in CO2. Regeneration is carried out automatically, either by steam or by pumping hot air, followed by cooling and pressure set-up, by supplying purge gas from CO2 condenser.
Prior to liquefaction, the gas is dried to a dewpoint of approx. - 60 °C in the dehydrator. Regeneration of the latter is done automatically by electrical heating and use of dry purge gas from the CO2 condenser.
Traces of acetaldehyde are also removed in the dehydrator.
The process of removal of non-condensable ballast gases from CO2 is carried out in a distillation unit. Gaseous CO2 is condensed at the temperature of approx. - 27 /- 23 °C in a CO2 condenser, where the non-condensed gases are purged off. Liquid purified CO2 is led to the storage tank.
A refrigeration unit, controlled by the CO2 pressure in the CO2 condenser, supplies therefrigeration capacity required for liquefaction. The liquid CO2 is stored under a pressure of approx. 15-18 bar(g) and a corresponding temperature of approx. - 27 /- 23 °C.
During a non CO2 production period, the refrigeration unit is able to operate independently of the rest of the CO2 plant in order to maintain the correct CO2 storage tank temperature/pressure.
The CO2 produced has a minimum purity of 99.998% (v/v) at oxygen residual content < 5 ppm and fulfills quality standards for brewing industry.