Abstract: An improved method for removing formaldehyde from a crude butynediol product stream comprising the step of providing a crude butynediol stream containing butynediol and formaldehyde. A pH control agent is then mixed with the crude butynediol stream to form a treated product stream, wherein the pH of the treated product stream is raised to a level that limits the reaction of butynediol and formaldehyde to form acetal complex and decrease the solubility of trace metals. The treated product stream then flows into the inlet of a continuous distillation column. Finally, a concentrated formaldehyde stream from the overhead stream of the distillation column and a concentrated butynediol stream from the distillation bottoms stream that is essentially free of formaldehyde and acetal complex are both recovered.

Abstract: A method for preventing pressure build-up across a catalyst separation in a polyether polyol reactor comprising the steps of feeding reactants that comprise a monomer or co-monomers to be polymerized to form the polyether polyol into a continuous feed reactor, flowing the product stream through a catalyst separation system within the reactor, wherein the catalyst separation system is comprised of a plurality of filters, wherein each filter comprises an outer surface and an inner surface defined by a plurality of spaced-apart elements, and wherein the distance between the spaced-apart elements is smaller than the minor dimension of the suspended catalyst and recovering the filtered polyether polyol product and catalyst fines from the reactor outlet.