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.

Abstract: The present invention relates to an improved, fully-integrated continuous process of enhanced process operability for manufacturing copolyether glycols having enhanced physical properties by polymerization of a reaction mixture comprising tetrahydrofuran and at least one alkylene oxide in the presence of an acid catalyst and at least one compound containing reactive hydrogen atoms. The copolyether glycols manufactured by the present process have enhanced physical properties of increased alkylene oxide incorporation, average molecular weight and polydispersity, as well as reduced crystallinity, color, oligomeric cyclic ether content, and linear oligomer having an average molecular weight of up to about 400 dalton content.

Abstract: An improved process for selective vapor phase oxidation of n-butane to maleic anhydride involving the use of a recirculating solids reactor having a reaction zone and a catalyst regeneration zone wherein n-butane is converted to maleic acid in the reaction zone by use of a vanadium/phosphorous oxide (V/P/O) catalyst in oxidized form and the reduced vanadium/phosphorous oxide catalyst is regenerated by contact with oxygen in the regeneration zone. Replenishment of the inherent catalyst losses associated with the catalyst recycling process is accomplished by adding to the catalyst in the regeneration zone vanadium/phosphorous oxide catalyst precursor at a rate of addition that effectuates in situ calcination and activation of the vanadium/phosphorous oxide catalyst precursor while simultaneously maintaining the desired operating temperature of the n-butane to maleic anhydride conversion reaction. Such a process is useful in maintaining the high operating capacity of the reactor over an extended period of time.