Cyclic alkylene carbonates are produced by the homogeneous catalytic reaction of alkylene oxides with carbon dioxide during which process, polyglycols are formed. The catalyst is separated by distillation from the alkylene carbonate and is recycled to the reaction while associated with polyglycols. A purge stream is removed from the recycle to prevent an undue concentration of polyglycols in the reaction and catalyst is separated from the purge stream by acylation of the polyglycols enabling precipitation of the catalyst.