Patent ID: 7495067

Claim:
A polycondensation process comprising: subjecting a polycondensation feed to polycondensation in a polycondensation reactor to thereby produce a polycondensation effluent, wherein said polycondensation feed comprises an ester oligomer and/or an ester polymer having a terephthalate moiety, wherein said polycondensation reactor comprises a plurality of substantially horizontal interconnected reactor sections that are vertically spaced from one another, wherein each of said reactor sections defines at least one reaction zone, wherein at least a portion of each of said reaction zones is defined within a substantially horizontal pipe, wherein said substantially horizontal pipes are vertically spaced from one another, wherein each of said substantially horizontal pipes is substantially straight, wherein a polycondensation fluid flows through each of said reactor sections, wherein said polycondensation fluid flows through at least a portion of said polycondensation reactor by force of gravity, wherein said polycondensation reactor comprises one or more connecting sections disposed between adjacent ones of said reactor sections, wherein each of said connecting sections defines at least one downward flow passageway through which at least a portion of said polycondensation fluid falls as it passes from an upper one of said reactor sections to a lower one of said reactor sections.