A E Staley Manufacturing Company

Other

Tate & Lyle Ingredients Americas LLC

Istvan Kovacs

Michael Charles Milner Cockrem

David Heidel

Idris Mohamednur

Avraham Baniel

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 contains 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.

Azeotropic distillation of cyclic esters of hydroxy organic acids

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 which contains the organic acid and/or organic acid amide. The feed stream 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 in the feed stream. The mixture of the feed stream and the azeotroping agent is heated to produce a vapor stream. The heteroazeotrope is a component of that vapor stream. 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 azeotroping agent is part of the second phase. The liquid stream can be further distilled or, alternatively, the two phases of the liquid stream can be separated. The first phase can be removed from the remainder of the liquid stream resulting in recovery of the organic acid and/or organic acid amide. The recovered organic acid and/or organic acid amide can be further purified and/or concentrated from the first phase.

Azeotropic distillation process for producing organic acids or organic acid amides

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. The complexed first immiscible basic extractant is contacted with a displacing acid. The first immiscible basic extractant has a greater affinity for the displacing acid than it does for the strong contaminant or the product organic acid, and as a result, product organic acid and strong contaminant are displaced over a period of time from the complexed first immiscible basic extractant, producing a second effluent stream that comprises a major amount of product organic acid and a third effluent stream that comprises a major amount of strong contaminant.

Process for purifying an organic acid

Disclosed herein are methods for the recovery of an organic acid, such as a heat stable lactic acid, from a feed stream which contains at least one of an organic acid amide, an organic acid ammonium salt, or an alkylamine-organic acid complex. The feed stream 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 of the feed stream and the azeotroping agent is heated to produce a vapor stream. The azeotrope is a component of the vapor stream. The vapor stream can be condensed to a liquid stream, and the organic acid is recovered in the liquid stream that is produced. When the azeotrope is a heteroazeotrope, the vapor stream can be condensed into a liquid stream, which can be separated into a first phase and a second phase. The first phase contains the highest concentration of organic acid and the second phase contains azeotroping agent. The organic acid can be further purified and/or concentrated from the separated first phase or from the liquid stream.

Growing community of inventors

Madison, WI, United States of America

Istvan Kovacs