Abstract: A continuous flow process and system for depolymerizing plastic. A heterogeneous mixture of solid plastic particles, a solvent, and a catalyst are pumped continuously through a heating zone at a flow rate resulting in a particle speed sufficient to keep the plastic particles in suspension. The heterogeneous mixture is heated in the heating zone and maintained in a hold zone to complete depolymerization of the mixture into a homogeneous solution containing a liquefied reaction product. The homogeneous solution is cooled to solidify and precipitate a solid reaction product. The solid reaction product is separated from the solvent to be recycled. Contaminants are removed from the solvent, and the solvent is recirculated for use as a constituent of the heterogeneous mixture.

Abstract: A continuous flow process and system for depolymerizing plastic. A heterogeneous mixture of solid plastic particles, a solvent, and a catalyst are pumped continuously through a heating zone at a flow rate resulting in a particle speed sufficient to keep the plastic particles in suspension. The heterogeneous mixture is heated in the heating zone and maintained in a hold zone to complete depolymerization of the mixture into a homogeneous solution containing a liquefied reaction product. The homogeneous solution is cooled to solidify and precipitate a solid reaction product. The solid reaction product is separated from the solvent to be recycled. Contaminants are removed from the solvent, and the solvent is recirculated for use as a constituent of the heterogeneous mixture.

Abstract: A process and a system for depolymerizing plastic, such as waste polyester, into marketable monomers. A heterogeneous mixture of plastic particles, a solvent, and a catalyst are pumped continuously through a heating zone at a flow rate just high enough to maintain a particle speed great enough to keep the plastic particles in suspension. The temperature of the heterogeneous mixture is raised in the heating zone and maintained in a hold zone to complete depolymerization of the mixture into a homogeneous solution containing a liquefied plastic monomer. The homogeneous solution is cooled to solidify and precipitate the monomer. The precipitated monomer is separated from the solvent to be recycled. The solvent is recirculated to be reused as a constituent of the heterogeneous mixture.

Abstract: A process and a system for continuously depolymerizing plastic is disclosed. The system may comprise a mixer for producing a heterogeneous reaction mixture comprising plastic particles and a solvent, a pump for transmitting the reaction mixture at a particle speed sufficient to maintain the plastic particles in suspension in the solvent, a heating apparatus for heating the reaction mixture to its reaction temperature, a hold tube for maintaining the reaction mixture at or above the reaction temperature to facilitate conversion into a homogeneous reaction solution, and a settling tank to allow a solid reaction product to precipitate from the homogeneous reaction solution once cooled.

Abstract: A process and a system for depolymerizing plastic, such as waste polyester, into marketable monomers. A heterogeneous mixture of plastic particles, a solvent, and a catalyst are pumped continuously through a heating zone at a flow rate just high enough to maintain a particle speed great enough to keep the plastic particles in suspension. The temperature of the heterogeneous mixture is raised in the heating zone and maintained in a hold zone to complete depolymerization of the mixture into a homogeneous solution containing a liquefied plastic monomer. The homogeneous solution is cooled to solidify and precipitate the monomer. The precipitated monomer is separated from the solvent to be recycled. The solvent is recirculated to be reused as a constituent of the heterogeneous mixture.

Abstract: A continuous flow process and system for depolymerizing plastic. A heterogeneous mixture of solid plastic particles, a solvent, and a catalyst are pumped continuously through a heating zone at a flow rate resulting in a particle speed sufficient to keep the plastic particles in suspension. The heterogeneous mixture is heated in the heating zone and maintained in a hold zone to complete depolymerization of the mixture into a homogeneous solution containing a liquefied reaction product. The homogeneous solution is cooled to solidify and precipitate a solid reaction product. The solid reaction product is separated from the solvent to be recycled. Contaminants are removed from the solvent, and the solvent is recirculated for use as a constituent of the heterogeneous mixture.

Abstract: A microwave heating apparatus with a tubular waveguide applicator and reactive and resistive chokes to decrease leakage. Microwave-transparent centering elements maintain articles to be treated centered in the applicator. Articles, such as individual cylindrical articles or continuous cylindrical strands, advance through the applicator in a direction in or opposite to the direction of propagation of microwaves. The resistive chokes have conductive vanes coated with a dielectric material that absorbs microwave energy that leaks through the reactive chokes to allow for large openings for large-diameter articles. The waveguide applicator is operated in the TE01 mode to concentrate microwave heating energy along the outer circumferences of the articles.

Abstract: A microwave heating apparatus with a tubular waveguide applicator forming a heating chamber and with microwave-transparent centering elements to maintain product to be treated in proximity to the centerline axis of the chamber. Product is conveyed through the chamber in a direction in or opposite to the direction of propagation of microwaves. Cylindrical chokes at product entrance and exit openings into the chamber prevent microwave leakage and allow for large openings for large products. In some versions, a low-loss inner tube in the chamber coaxial with the tubular applicator is used to confine product to be heated in proximity to the centerline axis of the chamber to be heated effectively by microwaves with a TM01 field pattern.

Abstract: A microwave heating apparatus with a tubular waveguide applicator and reactive and resistive chokes to decrease leakage. Microwave-transparent centering elements maintain articles to be treated centered in the applicator. Articles, such as individual cylindrical articles or continuous cylindrical strands, advance through the applicator in a direction in or opposite to the direction of propagation of microwaves. The resistive chokes have conductive vanes coated with a dielectric material that absorbs microwave energy that leaks through the reactive chokes to allow for large openings for large-diameter articles. The waveguide applicator is operated in the TE01 mode to concentrate microwave heating energy along the outer circumferences of the articles.

Abstract: A microwave heating apparatus with a tubular waveguide applicator forming a heating chamber and with microwave-transparent centering elements to maintain product to be treated in proximity to the centerline axis of the chamber. Product is conveyed through the chamber in a direction in or opposite to the direction of propagation of microwaves. Cylindrical chokes at product entrance and exit openings into the chamber prevent microwave leakage and allow for large openings for large products. In some versions, a low-loss inner tube in the chamber coaxial with the tubular applicator is used to confine product to be heated in proximity to the centerline axis of the chamber to be heated effectively by microwaves with a TM01 field pattern.