Method, device and use for reprocessing substantially polyalkylene terephthalate

• Main Authors: Scholl, Stephan, Brepohl, Esther, Eichert, Carsten, Biermann, Lars
• Format: Patent
• Language: English
• Published: 27.08.2024
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; MAKING GRANULES OR PREFORMS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PREPARATION OR PRETREATMENT OF THE MATERIAL TO BESHAPED; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIALCONTAINING PLASTICS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

A method and a device for reprocessing waste products containing substantially polyalkylene terephthalate, particularly polyethylene terephthalate and/or polybutylene terephthalate, in a continuous process by means of depolymerizing is provided. A solid alkali hydroxide and/or alkali earth hydroxide, particularly sodium hydroxide, is added to the waste products for producing a reaction mixture, suitable for recycling multilayer systems and colored material nearly entirely chemically into the starting materials at a high throughput and high quality, in order to be able to produce new polyalkylene terephthalate products from the recycling products without limitation. An alkylene glycol is additionally added to the reaction mixture as a reactant, wherein the alkylene glycol is an alkylene glycol produced as a product of the intended depolymerizing, particularly MEG. No further reactive components are added to the reaction mixture.