Patent ID: 8609805

Claim:
A process for manufacturing copolyether glycol having a mean molecular weight of from about 650 dalton to about 5000 dalton, said process exhibiting an STY of greater than about 0.9 g polyol/g cat.hr, comprising the steps of: a) polymerizing feed comprising a tetrahydrofuran and at least one alkylene oxide in the presence of an acid catalyst and at least one compound containing reactive hydrogen atoms at a temperature of from about 50° C. to about 80° C. to produce a polymerization product mixture comprising OCE, copolyether glycol, at least one dimer of the alkylene oxide, linear short chain copolyether glycol and tetrahydrofuran; b) separating a majority of the tetrahydrofuran and the dimer of the alkylene oxide from the polymerization product mixture of step a) to produce a crude product mixture comprising OCE, copolyether glycol and linear short chain copolyether glycol; c) separating at least a portion of the OCE and linear short chain copolyether glycol from the crude product mixture of step b) to produce an OCE stream comprising OCE and linear short chain copolyether glycol, and a product stream comprising copolyether glycol; and d) recycling at least a portion of the OCE stream of step c) to the polymerization step a) such that the feed comprises from about 3 to about 15 wt % OCE.