Carbon dioxide as choice solvent for extraction of basic compounds
7 Apr 2000
According to recent studies by the Supercritical Technology Research Group at VTT Chemical Technology, weakly basic compounds such as pyridine can be extracted effectively from aqueous solutions using dense carbon dioxide as a solvent. New experiments carried out in a bench scale, counter-current, continuous extraction column show that the solvent power of carbon dioxide at 40 degrees C and 10MPa is comparable to the solvent power of xylene when pyridine is extracted from an aqueous solution.
Conventional extraction processes use organic, liquid solvents such as benzene, which carbon dioxide could replace as an effective solvent. Carbon dioxide is also non-toxic, non-flammable and is the second least expensive solvent after water.
