Abstract: A method and reactor system for depolymerizing a polymer is described. The method comprises the steps of providing the polymer and a solvent in a reactor to obtain a reaction mixture, the solvent being capable of reacting with the polymer to degrade the polymer into at least repeating units; providing a reusable catalyst in the reaction mixture being capable of catalyzing said degradation; degrading the polymer in the reaction mixture at degradation reaction conditions to obtain a depolymerized mixture comprising at least light oligomers having from 2 to 4 repeating units inclusively; removing unreacted polymer, solid particles and optionally very heavy oligomers from the depolymerized mixture after exiting the reactor; recovering at least a part of the reusable catalyst from the depolymerized mixture; and recovering the light oligomers from the depolymerized mixture. During recovery of the reusable catalyst, the depolymerized mixture comprises heavy oligomers having at least 5 repeating units.

Abstract: A method and reactor system for depolymerizing a terephthalate polymer into reusable raw material are described, as well as a raw material obtainable by the method. The method inter alia comprises providing the polymer and a solvent such as ethylene glycol as a reaction mixture in a reactor. A heterogeneous catalyst, such as a metal containing particle, and/or a homogeneous catalyst is provided in the reaction mixture and the reaction mixture heated to depolymerize the polymer. Monomer comprising bis-(2-hydroxyethyl)-terephthalate (BHET), and 2-hydroxyethyl[2-(2-hydroxyethoxy)ethyl]terephthalate (BHEET) as byproduct are formed. The BHET is recovered from a depolymerized product stream exiting the reactor and a BHET-depleted stream is formed. A mass fraction of BHEET in the depolymerized product stream and/or in the BHET-depleted stream is monitored and adjusted to below a predetermined limit value of the BHEET-mass fraction in the depolymerized product stream.

Abstract: A method and reactor system for depolymerizing a terephthalate polymer into reusable raw material are described, as well as a raw material obtainable by the method. The method inter alia comprises providing the polymer and a solvent such as ethylene glycol as a reaction mixture in a reactor. A reusable catalyst complex comprising a catalyst entity, a metal containing nanoparticle, and a bridging moiety connecting the catalyst entity to the metal containing nanoparticle is dispersed in the reaction mixture and the reaction mixture heated to depolymerize the polymer into monomers comprising bis-(2-hydroxyethyl)-terephthalate (BHET). 2-hydroxyethyl[2-(2-hydroxyethoxy)ethyl]terephthalate (BHEET) is formed as byproduct. The BHET is recovered from the depolymerized product stream and a BHET-depleted stream is formed.

Abstract: The reactor system comprises a reactor vessel with at least one inlet and a first and a second outlet, which reactor vessel is configured for depolymerisation of a condensation polymer and which first and second outlet are configured for removal of a first and a second part of a reaction mixture. The reactor system further comprises a heat exchanger downstream of the first outlet. Herein the second outlet is arranged at a lower position of the reactor vessel than the first outlet. The first outlet is configured for removal of the first part being a dispersion and/or solution comprising said condensation polymer and depolymerisation products thereof in a solvent. Said first part is led to the heat exchanger. The second outlet is configured for removal of the second part including agglomerates. The reactor system is used for depolymerisation of a condensation polymer.