Process to prepare bis (2-hydroxyethyl) terephthalate

摘要

This invention refers to a process to prepare very high purity bis(2-hydroxyethyl) terephthalate, using waste polyethylene terephthalate (PET) as the starting product. More specifically, the process is used to prepare BHET through the reaction of 5 waste PET with excess ethylene glycol (EG), and preferably at a temperature of 190-210 DEG C, in the presence of a transesterification catalyzer. This is followed by a series of separations and crystallisations (for which three different methods are proposed) to obtain a pure, chemically defined 10 product that does not contain any of the impurities that may be found in the starting PET.