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US 2026/0258218 A1Published application
Process for the depolymerization of a polystyrene feedstock by pyrolysis
AssigneeCompagnie Generale Des Etablissements Michelin
InventorsLISE MAISONNEUVE, FLORENT MATHIEU
Life of this patent
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Abstract
A process for depolymerizing a polystyrene feedstock comprises at least two pyrolysis sections, in which the hydrogen partial pressure and/or the residence time of the gas phase are controlled in the pyrolysis section in step d).
Claims15
-14. (canceled)
A process for depolymerizing a polystyrene feedstock, comprising at least the following steps:
- (a) a step of preparing the polystyrene feedstock so as to bring about melting of plastic compounds;
- (b) a step of performing a first pyrolysis of the feedstock resulting from step (a) involving a pyrolysis section and producing at least a first gaseous pyrolysis stream and a first liquid pyrolysis stream;
- (c) a separating step supplied at least by the first gaseous pyrolysis stream from step (b) and a second gaseous pyrolysis stream from step (d) and producing at least a stream rich in light compounds, a stream rich in oligomers, and a stream rich in aromatics;
- (d) a step of performing a second pyrolysis involving a pyrolysis section supplied at least by the stream rich in oligomers from step (c) and producing at least the second gaseous pyrolysis stream and a second liquid pyrolysis stream;
- and
- (e) a step of separating the stream rich in aromatics from step (c) into at least a stream comprising predominantly ethylbenzene, a stream comprising predominantly styrene and a stream of heavy compounds,
- wherein a hydrogen partial pressure and a residence time of gas phase are controlled in the pyrolysis section in step (d).
4 more elements
Dependencies are inferred from the claim text.