Method to enable recycling of polyester waste material and a system for applying the method

Abstract

A process for recycling a stream of polyester waste material by depolymerising the polyester by alcoholysis, includes first and second consecutive stages of depolymerisation, in which the polymer waste material is subjected in a continuous manner, in the first stage, the polyester waste material is continuously fed to an extruder operated at a temperature above the polyester melting temperature, while a first amount of alcohol is co-fed to the extruder, to produce a fluid mixture including a melt of the at least partly depolymerised polyester, and in the second stage, the fluid mixture is continuously fed to a continuously stirred tank reactor (CSTR) operated at a temperature above the polyester melting temperature, while co-feeding a second amount of alcohol to the CSTR, a residence time in the CSTR being used to provide at the CSTR outlet a continuous stream of polyester depolymerised into an oligomeric ester.