Method for extraction and transformation by hydrolysis of phtalates contained in pvc plastics

Process for recovering phthalic acid and a reusable target PVC plastic from a PVC feedstock containing at least one phthalate, including the following steps:

• a) a solid-liquid extraction of said PVC feedstock in the form of particles (1) by placing said particles of the PVC feedstock in contact with at least one organic solvent (7) for extracting said phthalate, to produce a liquid phase enriched in said phthalate and a first solid phase comprising PVC plastic depleted in said phthalate;
• b) a chemical conversion of said phthalate extracted in step a) to phthalic acid of formula C6H4 (COOH)2 by hydrolysis using water to produce an aqueous phase comprising said phthalic acid;
• c) a solid-liquid extraction between said first solid phase and said liquid phase enriched in said phthalate or said aqueous phase comprising said phthalic acid to produce at least one solid stream comprising the PVC plastic depleted in said phthalate (8) in order to recover said target PVC plastic;
• d) a phase change of the phthalic acid from the dissolved state in said aqueous phase to a solid state to produce a mixed stream comprising an aqueous liquid phase depleted in phthalic acid and a second solid phase enriched in phthalic acid (5, 19, 22);
• e) a solid-liquid separation between the phthalic acid in the solid state from step d) and the aqueous liquid phase of said mixed stream to produce a solid stream of phthalic acid (6) and a liquid effluent (11, 14, 20) comprising residual water from step b).