Patent ID: 7714174

Claim:
A process for the manufacture of a polytrimethylene ether glycol, comprising the steps of: (a) polycondensing reactant comprising a diol selected from the group consisting of 1,3-propanediol, 1,3-propanediol dimer, 1,3-propanediol trimer and mixtures thereof, in the presence of an acid polycondensation catalyst to form a polytrimethylene ether glycol and an acid ester of the acid polycondensation catalyst; (b) adding water to the polytrimethylene ether glycol and hydrolyzing the acid ester formed during the polycondensation to form a hydrolyzed aqueous-organic mixture containing polytrimethylene ether glycol and residual acid polycondensation catalyst; (c) forming an aqueous phase and an organic phase from the hydrolyzed aqueous-organic mixture, wherein the organic phase contains polytrimethylene ether glycol and residual acid polycondensation catalyst, (d) separating the aqueous phase and the organic phase; (e) optionally adding base to the separated organic phase to neutralize residual acid polycondensation catalyst by forming salts of the residual acid polycondensation catalyst; (f) removing residual water from the organic phase; and (g) in the event that a base is added in step (e), and optionally otherwise, separating the organic phase into (i) a liquid phase comprising polytrimethylene ether glycol, and (ii) a solid phase comprising the salts of the residual acid polycondensation catalyst and base which is unreacted, wherein a hydride compound (1) is added at least once during at least one of said steps (b), (c), (d), (e), (f) and (g), and/or (2) is contacted with polytrimethylene ether glycol from step (g).