MEJORAS INTRODUCIDAS EN UN PROCESO CONTINUO DE ESTERIFICA- CION DIRECTA.

摘要

A continuous process is disclosed for direct esterification of terephthalic acid with ethylene glycol to form low molecular weight polyester with recovery of excess glycol from reaction off-gases. The terephthalic acid is mixed with an excess of glycol, the mixture is reacted at 280.degree.-315.degree.C in reaction product circulated from a reactor through an external heater and back to the reactor, and reaction product is withdrawn from the reactor for polymerization to high molecular weight polyester. Vapor formed in the reactor are fed into the bottom of a rectification column where the excess glycol is recovered for direct reuse. The vapor feed is sprayed with condensate at 140-195.degree.C in the bottom of the column to remove solids and maintain conditions suitable for obtaining less than 0.05 percent glycol in overhead distillate and 0.3 to 10 percent water in glycol condensate.