Supercritical Carbon Dioxide Extraction of Benzoic Acid, Caffeine, and Thiophene from Liquid Phases Based on PEG-400 and PEG-1500

A supercritical fluid extraction method is used to isolate benzoic acid, caffeine, and thiophene from liquid phases based on the water soluble polymers PEG-400 and PEG-1500. The degree of extraction of the considered compounds is constructed as a function of temperature and pressure, i.e., the parameters determining the behavior of the supercritical fluid. The degree of extraction of benzoic acid, caffeine, and thiophene within a single extraction cycle is found to be 43, 48.5, and 84%, respectively.