Heat Integrated Synthesis of PET Polymer Using Dual Reactive Distillation Technique

Abstract

There is an increased interest in heat integrated process as reduction in energy consumption
ultimately reduces the operating cost of process. Heat integration is defined technically as reduction in
energy consumption or recovery of heat either from connecting streams or within the system. In view of this
reactive distillation has emerged as a novel heat integrated process in which heat of exothermic reactions are
well utilised thus reducing the load on reboiler. Among the various synthesis process reported in reactive
distillation till now, synthesis of polymers is the most complex process especiallyfor polymers which are
synthesized by condensation polymerisation as it needs continuous removal of small molecules like water to
obtain higher concentration. In view of this, we have explored the synthesis of PolyethyleneTerephthalate
(PET) which was conventionally synthesized via esterification followed by polycondensation which requires
three reactors. To replace this uneconomical complex process, we have explored heat integrated dual
reactive distillation as a novel technique for the manufacturing of PET and proposed recovery of heat from
exothermic heat of reaction as well as circulation of by-product as a feed at operating temperature without
heating externally. It was observed that PET of 99% purity is obtained and an energy saving of 20% is
achieved