Back to results
US 12,492,295 B2Granted
Apparatus and method for depolymerization of polymers
AssigneeGr3N SA
InventorMaurizio Crippa
Life of this patent
Estimating the term…
Abstract
An apparatus for depolymerization of polymers, in particular polyesters, polyamides, polyurethanes and polycarbonates, comprises a microwave depolymerization reactor having a reaction chamber; a microwave generation and transport system to send microwaves into the reaction chamber and comprising a microwave generator and a guide device housed in the reaction chamber to convey and distribute microwaves in the reaction chamber; a mixing device, rotating around the axis in the reaction chamber and configured so as to dynamically distribute inside the reaction chamber a mixture of liquids and solids contained in the reaction chamber; and a pressurization system configured to vary the pressure within the reaction chamber.
Claims25
An apparatus for depolymerization of polymers selected from polyesters, polyamides, polyurethanes, and polycarbonates, comprising:
- a microwave depolymerization reactor, having a reactor vessel extending along and around a longitudinal axis and delimiting an internal reaction chamber in which a depolymerization reaction of the polymer to be treated with a liquid reacting composition takes place;
- a microwave generation and transport system for sending microwaves into the reaction chamber and comprising a microwave generator, located outside the vessel, and a guide device associated with the generator and housed in the reaction chamber to convey and distribute along and around the axis and in the reaction chamber the microwaves generated by the generator;
- a mixing device, housed in the reaction chamber and rotating around the axis and configured to keep stirred a mixture of liquids and solids contained in the reaction chamber, dynamically distributing said mixture inside the reaction chamber both along the axis and radially with respect to the axis and so as to ensure constant uniform mixing of the liquid and solid components contained in the reaction chamber and to guarantee that the pieces of polymer to be depolymerized are always wetted by the reagents and accumulations in particular areas of the reaction chamber are avoided, avoiding dynamic accumulations of liquid parts having characteristic dimension greater than the penetration capacity of the microwaves;
- and a pressurization system configured to adjust the pressure inside the reaction chamber both above and below atmospheric pressure;
- wherein the reactor is provided with:
- at least one solid phase inlet, connected to a polymer supply duct to supply the reaction chamber with said polymer material to be treated;
- a first liquid phase inlet, connected to a reagent supply duct, to supply the reaction chamber with said liquid reacting composition;
- a second liquid phase inlet, connected to an auxiliary supply duct, to supply the reaction chamber with auxiliary components;
- at least one reaction product outlet, connected to an outlet duct, to remove from the reaction chamber reaction products formed in the reaction chamber;
- at least one liquid phase outlet, connected to an extraction duct provided with a filter and with a drawing pump, to remove from the reaction chamber a liquid stream and retain in the reaction chamber solid residues separated from the liquid stream;
- at least one gas phase outlet, connected to a gas outlet duct provided with a vacuum pump and connected to a condenser, to extract a gas phase from the reaction chamber;
- a service inlet and a service outlet, connected to respective ducts of the pressurization system to introduce and extract inert gas into/from the reaction chamber.
9 more elements
A method for depolymerization of polymers selected from polyesters, polyamides, polyurethanes, and polycarbonates, comprising:
- a reagent supplying step, in which a reaction chamber, defined inside a reactor vessel and extending along and around an axis, is supplied with a polymer to be treated and a liquid reacting composition for a depolymerization reaction of the polymer;
- a depolymerization reaction step, in which microwaves are sent into the reaction chamber by means of a guide device housed in the reaction chamber to distribute the microwaves in the reaction chamber along and around the axis and activate the depolymerization reaction;
- in the reaction step, the polymer and the reacting composition contained in the reaction chamber being mixed and kept stirred by means of a mixing device rotating around the axis so as to dynamically distribute within the reaction chamber, both along the axis and radially with respect to the axis, a mixture formed by the polymer and the reacting composition, and so as to ensure constant uniform mixing of the liquid and solid components contained in the reaction chamber and to guarantee that the pieces of polymer to be depolymerized are always wetted by the reagents and accumulations in particular areas of the reaction chamber are avoided, avoiding dynamic accumulations of liquid parts having characteristic dimension greater than the penetration capacity of the microwaves;
- the reaction chamber being pressurized at a predefined pressure during the reaction step;
- at least one liquid phase extraction step, in which the liquid phase contained in the reaction chamber is pushed out of the reaction chamber and passes through a filter which separates solid residues, which are retained in the reaction chamber, from a liquid stream;
- and a drying step for drying said solid residues retained in the reaction chamber, said drying step being performed in the reaction chamber.
3 more elements
Dependencies are inferred from the claim text.