Patent ID: 7943094

Claim:
A process comprising: subjecting a reaction medium comprising terephthalic acid to esterification in an esterification zone defined within a horizontally elongated substantially empty esterification vessel, wherein said esterification vessel has a length-to-diameter (L:D) ratio less than 10:1, wherein said reaction medium enters said esterification vessel via a fluid inlet and is subjected to esterification to produce a liquid product and a vapor by-product, wherein said liquid product exits said esterification vessel via a liquid outlet, said liquid outlet is horizontally spaced from said fluid inlet by 1.25 D or more, said reaction medium is agitated and flows substantially horizontally through said esterification vessel, and further wherein the vapor by-product flows through said esterification vessel generally above said reaction medium and exits said esterification vessel via a vapor outlet that is horizontally spaced from said fluid inlet by 1.25 D or more, and wherein the reaction medium in the esterification vessel undergoes little or no mechanical agitation inside the esterification vessel.