Especially of interest for the food and pharmaceutical industries
is multistage gas extraction in countercurrent columns. This
process is identical, in concept, to liquid–liquid extraction (solvent
extraction), and it has been considered since the middle of the
1970s as an alternative separation technique for the extraction
and fractionation of liquid mixtures. Potential applications in the chemical industry are deacidification and deodorization of
vegetable oils, separation and enriching of flavors, fat-soluble
vitamins, organic compounds of aqueous solutions, purification of
synthetic chemicals, and others