Abstract: A direct contact densified fluid-based thermodynamic treatment system uses the fluid to effect heat transfer as the working fluid in a separate yet linked treatment system. During certain phases of operation of a densified fluid-based treatment process wherein it is necessary to distill the fluid to maintain the purity of the densified fluid heat is imparted to the densified fluid raising it above the boiling point for the associated pressure within a vessel. A densified fluid-based refrigeration/thermodynamic system removes heat during the condensing cycle of a working densified fluid treatment system and use the removed heat for distillation of the same working fluid in the distillation vessel. The process does not require an external heating or cooling system, and thus can be entirely supported by a single machine using the same densified fluid during its operational phase.