HYDROTREATING POLYESTER PRECURSORS

摘要

A process comprising contacting a liquid polyester stream with hydrogen in the presence of a hydrogenation catalyst comprising a metal supported on the surface of silicon carbide at a metal dispersion of at least 0.5% or graphite at a metal dispersion of at least 10% to produce a treated liquid polyester stream. The treated stream may be polycpndensed in the presence of a polycondensation catalyst to produce a polyester polymer having an It.V. of at least 0.55 dL/g. The liquid polyester stream desirably has a composition comprising: (a) terephthalic acid residues, isophthalic acid residues, and/or naphthalenedicarboxylic acid residues and (b) an average degree of polymerization of 0.5 to 20 and (c) an acid number ranging from 5 to 600.