Process for the separation of mixtures of substances

The process of separating a mixture which is in liquid state or solid state or liquid and solid state composed of a plurality of compounds at least one of which contains an organic group which comprises:

• a. contacting said mixture with a gas phase preferentially taking up said compound containing an organic group at the contacting conditions, said gas phase during said contacting being maintained under supercritical conditions of temperature and pressure such that the gas takes up at least a portion of said compound containing an organic group, the temperature being in a range in which the quantity of said compound containing an organic group taken up by said gas phase varies inversely with said temperature, and effecting said contacting in a manner so that this occurs, and so that there is a substantial gas component that is identifiable as a gaseous component, the critical temperature of said gas phase being in the range of 0.degree.-200.degree.C, the temperature of said gas phase during said contacting being within about 100.degree.C above the critical temperature,
• b. separating the gas phase in the form of said identifiable gaseous component loaded with said portion of the compound containing an organic group taken up during said contacting from any of the mixture not taken up by the gas phase while still maintaining supercritical conditions as aforesaid,
• c. thereafter separating at least part of the compound containing an organic group taken up, from the gas phase.