Process for manufacturing propylene oxide

Abstract

A process for the recovery of molybdenum catalyst from the epoxidation reaction product of olefins with organic hydroperoxides. The active form of the glycol-molybdate epoxidation catalyst is removed from the process stream with an anion ion exchange resin. The ion exchange resin can be either a weak base or strong base type. The preferred embodiment of the invention produces a concentrated epoxidation catalyst in the “ammonium” form that is suitable for recycle to the catalyst preparation vessel. The ammonia form is converted into the active form by evaporating the water and ammonia from the recovered catalyst in the presence of a glycol. The preferred configuration of the ion exchange process is a “Lead-Lag” system. Two vessels will be in service while the third is in the regeneration mode recovering the epoxidation catalyst. A fourth polishing vessel can also be included as a “guard bed” to prevent leakage of the molybdate catalyst into the process stream. Since the ion exchange kinetics are slow compared to an aqueous system, the preferred embodiment uses a fractal fluid distribution system.

Dependencies are inferred from the claim text.