Brum's supercritical extraction breakthroughs
15 Jan 2000
Since the early 1970s researchers at Birmingham have been investigating supercritical fluid behaviour, particularly with respect to extraction and separation.
The use of liquid CO2 is a preferable alternative to organic solvents; it causes little damage to the extracts and has low environmental impact.
Current projects include the extraction of valuable components from plant material and algae and the generation of realistic extraction rate models. Researchers are also generating fine and uniform powders with this technology.
Other work includes the extraction of intracellular metabolites from fermentation broths, an investigation of the influence of water on extraction rates and equilibria and a project on the solubility determinations for a variety of components in compressed CO2.
Water is often present in the material being extracted and if 'wet' industrial CO2 is used it will be also present in the solvent.
Group leader Mike King says: 'Small quantities of water can have a profound affect and our work includes the study of phase equilibria in the CO2-water system.'
Birmingham holds an EPSRC CASE studentship for work on powders and a BBSRC award for research into metabolites.
Under King, the researchers have published papers on the evaluation of supercritical extraction costs. Adsorption from supercritical streams has also been studied and a book has been published on the use of supercritical and marginally sub-critical solvents for extracting natural products.
