ALKANOLYSIS PROCESS

摘要

The present invention provides an improved process for converting a diester of polyether polyol, e.g., PTMEA, to the corresponding dihydroxy product, e.g., polytetramethylene ether glycol (PTMEG) continuously in a reaction zone, such as, for example, a reactive distillation system, for achieving virtually complete conversion of PTMEA to PTMEG, and recovery of PTMEG free of unreacted or unconverted PTMEA and alkanol ester by-product.

主权项

1. A process for converting the diester of a polyether polyol to a corresponding dihydroxy polyether polyol comprising steps of:
(1) contacting the diester of a polyether polyol and a C1 to C4 alkanol with catalyst having the formula (R1)4NOR2, wherein R1 and R2 are the same or different, and wherein each R1 is independently selected from the group consisting of methyl, ethyl and combinations thereof, and R2 is selected from the group consisting of hydrogen, methyl, and ethyl, in a reaction zone to convert at least a portion of the diester to the dihydroxy polyether polyol, (2) recovering reaction zone effluent from step (1) comprising the dihydroxy polyether polyol and catalyst from the reaction zone, (3) thermally treating the recovered reaction zone effluent from step (2) at a temperature sufficient to convert at least a portion of the catalyst to a trialkylamine having a boiling point lower than the boiling point of the dihydroxy polyether polyol, and (4) flashing the thermally treated reaction zone effluent of step (3) to produce a stream comprising trialkylamine and a stream comprising dihydroxy polyether polyol.