Polymerization-inhibited distillation

This invention relates to a process for producing high-purity alkylene carbonates. More particularly, it relates to a distillation process in which alkylene carbonate distillates are produced, and in which a reduced amount of polyether polycarbonate impurities are formed during the distillation procedure. Identified herein are inhibitors which may be added to the boiling pot portion of a distillation apparatus prior to or during the distillation of an alkylene carbonate. The inhibitors retard the occurrence of undesirable reactions of the alkylene carbonate with itself and impurities present in the pot, and hence greatly reduce or minimize the formation of undesirable by-products which otherwise tend to reduce overall yields of alkylene carbonate recovered by the distillation process. Higher distillation temperatures at higher pressures over the prior art are possible without attendant losses of significant amounts of recovered alkylene carbonate, which confers heretofore unseen flexibility in alkylene carbonate distillation.