A special case of extraction is the removal of water from a substrate. Or to put it more simply Drying. In this case we don’t extract the valuable compound, but the least valuable compound. The removal of water is normally done using heat; in spray dryers, ovens, sun etc. Opposite to a normal extraction, water has the highest concentration in the substrate and it is also not very soluble in carbon dioxide. However, the most performed application by FeyeCon is the extraction of water: CO2 drying. Although counter-intuitive, extracting water with CO2 is an excellent way of drying and preserving food products. Our CTO G.W. Hofland developed a process for this in 2002. During the drying with Co2 the surface tensions is lowered, the voids are filled with CO2 and temperatures remain constant due to the high heat capacity of the CO2. In short the process yields to a superior product in many aspects:
