Method and facility for treating human or animal tissue by dynamically circulating an additive-containing supercritical fluid

A method for treating a tissue of human or animal origin by extracting organic matter residues in order to purify and/or decontaminate said tissue, the method using carbon dioxide in supercritical state and a reactor provided with an inlet and an outlet, the method comprising:

• arranging the tissue within an internal volume of the reactor;
• pressurizing the reactor, by inserting carbon dioxide in the supercritical state into the internal volume via the inlet, such that the carbon dioxide in the supercritical state reaches an area of contact with the tissue and exits the reactor via the outlet;
• adding at least one chemical additive for purification and/or decontamination into a flow of liquid or supercritical carbon dioxide being circulated so as to reach the area of contact, in order to create a circulation of a treatment flow within the internal volume which combines the carbon dioxide in the supercritical state as a solvent and the at least one chemical additive as a co-solvent;
• and
• while maintaining said pressurization, causing said treatment flow to circulate, outside of the area of contact, in a loop that is in communication with the inlet, thereby creating a recirculation which contributes to making the treatment flow dynamic and to purifying and/or decontaminating the tissue,
• wherein the carbon dioxide circulating in a loop successively transitions to a gaseous state, downstream of a pressure-regulating valve, then to a liquid state by being cooled.