Patent ID: 6984293

Claim:
An azeotropic distillation process for the recovery of at least one cyclic ester of a hydroxy organic acid from a feed stream comprising at least one of a hydroxy organic acid, an ammonium salt of a hydroxy organic acid, an amide of a hydroxy organic acid, or an ester of a hydroxy organic acid, comprising the steps of: mixing a feed stream and at least one azeotroping agent, thereby producing a mixture, wherein the feed stream comprises at least one of a hydroxy organic acid, an ammonium salt of a hydroxy organic acid, an amide of a hydroxy organic acid, or an ester of a hydroxy organic acid and wherein the at least one azeotroping agent is capable of forming at least one azeotrope comprising a cyclic ester of a hydroxy organic acid; and distilling the mixture by a method comprising the steps of (i) heating the mixture sufficiently to produce a first vapor stream comprising at least one azeotrope comprising the cyclic ester of the hydroxy organic acid and the at least one azeotroping agent; and (ii) separating the first vapor stream from the mixture.