Abstract: A process is disclosed for purifying an aqueous feed stream comprising a product organic acid, such as lactic acid, and a strong contaminant, such as pyruvic acid or oxalic acid. The molar concentration of the product organic acid in the feed stream typically is at least 20 times greater than the molar concentration of the strong contaminant. The aqueous feed stream is contacted with a first immiscible basic extractant that has at least a 3-fold greater affinity for the strong contaminant than for the product organic acid. The majority of the strong contaminant and some product organic acid become complexed with the first immiscible basic extractant. The complexed first immiscible basic extractant is separated from the aqueous stream, thereby producing a first effluent stream that comprises product organic acid and that has a greater ratio of molar product organic acid to molar strong contaminant than the aqueous feed stream did.

Abstract: A process is disclosed for purifying an aqueous feed stream comprising a product organic acid, such as lactic acid, and a strong contaminant, such as pyruvic acid or oxalic acid. The molar concentration of the product organic acid in the feed stream typically is at least 20 times greater than the molar concentration of the strong contaminant. The aqueous feed stream is contacted with a first immiscible basic extractant that has at least a 3-fold greater affinity for the strong contaminant than for the product organic acid. The majority of the strong contaminant and some product organic acid become complexed with the first immiscible basic extractant. The complexed first immiscible basic extractant is separated from the aqueous stream, thereby producing a first effluent stream that comprises product organic acid and that has a greater ratio of molar product organic acid to molar strong contaminant than the aqueous feed stream did.

Abstract: Disclosed herein are methods for the recovery of at least one of an organic acid or an organic acid amide, such as a heat stable lactic acid or lactamide, from a feed stream comprising the organic acid and/or organic acid amide. The feed stream that comprises the organic acid and/or organic acid amide is mixed with at least one azeotroping agent. The azeotroping agent is a hydrocarbon capable of forming at least one heteroazeotrope with the organic acid or the organic acid amide. The mixture comprising the feed stream and the azeotroping agent is heated to produce a vapor stream that comprises the heteroazeotrope. The vapor stream can be heated further to separate components or it can be condensed into a liquid stream. The liquid stream is capable of being separated into a first phase and a second phase. The first phase contains the highest concentration of the organic acid and/or the organic acid amide and the second phase comprises the azeotroping agent.

Abstract: Disclosed herein are methods for the recovery of an organic acid, such as a heat stable lactic acid, from a feed stream comprising at least one of an organic acid amide, an organic acid ammonium salt, or an alkylamine-organic acid complex. The feed stream that comprises the organic acid amide, organic acid ammonium salt, or alkylamine-organic acid complex is mixed with at least one azeotroping agent. The azeotroping agent is a hydrocarbon capable of forming at least one azeotrope with the organic acid that is produced by the thermal decomposition of the amide, ammonium salt, or complex in the feed stream. Preferably the azeotrope is a heteroazeotrope. The mixture comprising the feed stream and the azeotroping agent is heated to produce a vapor stream that comprises the azeotrope. The vapor stream can be condensed to a liquid stream, and the organic acid is recovered in the liquid stream that is produced.

Abstract: Cyclic esters of hydroxy organic acids can be produced and recovered via azeotropic distillation. In certain embodiments cyclic esters, such as glycolide and lactide, can be produced from a fermentation broth or other feed stream that comprises 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 using azeotropic distillation. The hydroxy organic acid of the feed stream or the hydroxy organic acid derived from the feed stream by decomposition is reacted to produce the cyclic ester. In other embodiments a crude composition of a cyclic ester of an organic ester can be purified using azeotropic distillation.

Abstract: A process is disclosed for producing an organic acid and optionally for simultaneously producing an ester of the organic acid.