Extraction
Origin
- Natural volcanic CO2 sources
- Combustion of fossil fuels
- Hydrogen production in refineries
- Synthesis gas production of ammonia
- Synthesis of ethylene oxide
- Alcoholic fermentation (bio-alcohol and beer)
- Per kg alcohol 0.96 kg CO2
- approx. 1.5 - 2.0 kg per 100 litres of beer
- Breathing (a person breathes out 20 litres per hour - but the concentration is only approx. 4 %)
- Air (natural content approx. 0.03 % by volume)
Sources
In areas of volcanic origin. The CO2 is either collected on the surface or, in the case of known deposits, tapped by drilling, which is normally around 1000 metres deep, but in some cases can reach depths of 2000 to 4000 metres.
The purity is usually 99 - 99.9% CO2 by volume.
Combustion
Today, so-called process CO2 provides the main share of CO2 production for industrial needs. Before it can be utilised, a complex purification process is usually necessary in which undesirable components are removed by means of chemical and physical separation steps.Unfortunately, the CO2 produced in power stations from the combustion of coal and oil cannot be utilised economically today, as it only occurs in a concentration of 10 - 20 %.
Fermentation
The resulting CO2 is collected from the closed fermentation vats and then purified. Fermentation carbon dioxide contains sulphur and organic impurities, which have to be removed at great expense. The CO2 obtained in this way is almost exclusively reused in the brewery sector; its share of technical requirements is very small.
Air
In contrast to other gases, the low proportion of CO2 in the air has not yet been of any significance for industrial requirements.