VARIABLE PRESSURE DROP UP FLOW-PRE-POLYMERIZER (UFPP) SYSTEMS AND METHODS

摘要

Disclosed are processes and systems for manufacturing polyethylene terephthalate (PET) and pre-polymer. The processes and systems use a variable pressure drop up-flow-pre-polymerizer configuration. The pressure profile in the UFPP can be selected to beneficially change the relative reaction rates of the polymerization and esterification reactions. This design maximizes the esterification carried out in the UFPP, while still producing a pre-polymer with the optimum carboxyl end groups concentration {e.g., about 30 µ equiv./g to 60 µ equiv./g) to maximize finisher productivity. This can result in a reduction of the size and cost of the esterifier required for a given plant throughput.