Abstract: The invention relates to a method for the removal of the cyclic diester of a 2-hydroxy alkanoic acid from a vapor containing said diester, wherein the vapor is contacted with an aqueous solution so that the diester dissolves in said solution. According to the invention, the method is characterized in that the solution is an alkaline solution, preferably having a pH above 10. The problem of the formation of slurries of the diester in the aqueous solutions can be prevented by the present invention. The method can be applied with great advantage in the production or conversion of lactide.

Abstract: The present invention pertains to a fermentation process for the production of an organic acid salt including the steps of fermenting a microorganism in a fermentation medium in a fermentation reactor to form a fermentation broth having an organic acid salt, wherein part of the organic acid salt is present in the solid state and part of the organic acid salt is dissolved in the fermentation broth; withdrawing at least part of the fermentation broth from the fermentation reactor, providing the broth to a hydrocyclone, and withdrawing a top effluent and a bottom effluent from the hydrocyclone; providing the bottom effluent from the hydocyclone to a solid/liquid separation step, to form a solid fraction and a liquid fraction, providing at least 30 vol.% of the total of the top effluent from the hydrocyclone and the liquid fraction from the solid-liquid separation step to the fermentation reactor.

Abstract: A method for manufacturing carboxylic acid that includes the following steps is provided. First, subjecting an aqueous mixture, including carboxylic acid and at least 5 wt. % dissolved magnesium chloride, to a forward extraction step using a first organic liquid, including an organic solvent, the organic solvent being selected from the group of C5+ ketones, thereby obtaining an organic carboxylic acid solution and an aqueous waste liquid including magnesium chloride. Second, subjecting the organic carboxylic acid solution to a back extraction step wherein the carboxylic acid is extracted from the organic carboxylic acid solution into an aqueous liquid, thereby obtaining an aqueous carboxylic acid solution and a second organic liquid. Third, subjecting the aqueous waste liquid including magnesium chloride derived from the forward extraction to a thermal decomposition step at a temperature of at least 300° C., thereby decomposing the magnesium chloride to magnesium oxide and HCl.

Abstract: The invention pertains to method for recovering polycarboxylic acid from an aqueous mixture including the steps of: providing an aqueous mixture including polycarboxylic acid and at least 5 wt. % dissolved halide salt, based on the total weight of water and dissolved material in the aqueous mixture; extracting the polycarboxylic acid from the aqueous mixture into a first organic liquid including an organic solvent selected from the group consisting of ketones and ethers, thereby obtaining an organic polycarboxylic acid solution and an aqueous waste liquid including the halide salt; and extracting the polycarboxylic acid from the organic carboxylic acid solution into an aqueous liquid, thereby obtaining an aqueous polycarboxylic acid solution and a second organic liquid. The method according to the invention allows a combined purification and concentration step for feed solutions of polycarboxylic acids.

Abstract: A method for recovering lactic acid from an aqueous mixture including the steps of: providing an aqueous mixture including lactic acid and at least 5 wt. % dissolved magnesium chloride, based on the total weight of water and dissolved material in the aqueous mixture; extracting the lactic acid from the aqueous mixture into a first organic liquid including an organic solvent selected from the group consisting of C5+ ketones, diethylether and methyl-tertiary-butyl-ether, thereby obtaining an organic lactic acid solution and an aqueous waste liquid including magnesium chloride; and extracting the lactic acid from the organic lactic acid solution into an aqueous liquid, thereby obtaining an aqueous lactic acid solution and a second organic liquid. The method according to the invention allows a combined purification and concentration step for feed solutions of lactic acid.

Abstract: A process for the preparation of a monovalent succinate salt includes: a) fermenting a carbohydrate source to succinic acid by means of a micro-organism, b) adding a alkaline earth metal hydroxide, carbonate and/or hydrogencarbonate, the alkaline earth metal being calcium or magnesium, as neutralising agent during the fermentation in an aqueous medium and causing the formation of calcium succinate or magnesium succinate, c) reacting the alkaline earth metal succinate salt in an aqueous medium with a monovalent hydroxide, carbonate and/or hydrogencarbonate base to form an alkaline earth metal hydroxide, carbonate and/or hydrogencarbonate and a monovalent succinate salt, d) separating the monovalent succinate salt from the alkaline earth metal hydroxide, carbonate and/or hydrogencarbonate, and e) recycling the alkaline earth metal hydroxide, carbonate and/or hydrogencarbonate to step b.

Abstract: The invention relates to a method for the removal of the cyclic diester of a 2-hydroxy alkanoic acid from a vapor containing said diester, wherein the vapor is contacted with an aqueous solution so that the diester dissolves in said solution. According to the invention, the method is characterized in that the solution is an alkaline solution, preferably having a pH above 10. The problem of the formation of slurries of the diester in the aqueous solutions can be prevented by the present invention. The method can be applied with great advantage in the production or conversion of lactide.

Abstract: This invention relates to the controlled acidification of food products, like dairy products, meat etc. By acidification, food products are protected against harmful microbiological cultures and food can get a certain texture, e.g. the coagulation of dairy products or the drying and texture formation of dried sausages. The invention comprises a new method of acidifying food products in a controlled way. Using lactic- or glycolic acid oligomer/derivatives and salts or derivatives thereof achieve this controlled acidification.

Abstract: A process for manufacturing dialkyl lactamide including reacting lactide and dialkylamine selected from one or more of dimethylamine, diethylamine, and methylethylamine to form a reaction mixture which includes dialkyl lactamide selected from N,N-dimethyl lactamide, N,N-diethyl lactamide, and N,N-methylethyl lactamide, N,N-dialkyl lactoyl lactamide, and dialkylamine, subjecting the reaction mixture to a separation step to form a product stream including N,N-dialkyl lactamide, a first recycle stream including dialkylamine and a second recycle stream including N,N-dialkyl lactoyl lactamide, feeding the recycle streams to the reaction step, and isolating the product stream. The process allows the manufacture of N,N-dimethyl lactamide, N,N-diethyl lactamide, and N,N-methylethyl lactamide on a commercial scale.

Abstract: A process for the preparation of a monovalent succinate salt includes: a) fermenting a carbohydrate source to succinic acid by means of a micro-organism, b) adding a alkaline earth metal hydroxide, carbonate and/or hydrogencarbonate, the alkaline earth metal being calcium or magnesium, as neutralising agent during the fermentation in an aqueous medium and causing the formation of calcium succinate or magnesium succinate, c) reacting the alkaline earth metal succinate salt in an aqueous medium with a monovalent hydroxide, carbonate and/or hydrogencarbonate base to form an alkaline earth metal hydroxide, carbonate and/or hydrogencarbonate and a monovalent succinate salt, d) separating the monovalent succinate salt from the alkaline earth metal hydroxide, carbonate and/or hydrogencarbonate, and e) recycling the alkaline earth metal hydroxide, carbonate and/or hydrogencarbonate to step b.

Abstract: A process for manufacturing dialkyl lactamide including reacting lactide and dialkylamine selected from one or more of dimethylamine, diethylamine, and methylethylamine to form a reaction mixture which includes dialkyl lactamide selected from N,N-dimethyl lactamide, N,N-diethyl lactamide, and N,N-methylethyl lactamide, N,N-dialkyl lactoyl lactamide, and dialkylamine, subjecting the reaction mixture to a separation step to form a product stream including N,N-dialkyl lactamide, a first recycle stream including dialkylamine and a second recycle stream including N,N-dialkyl lactoyl lactamide, feeding the recycle streams to the reaction step, and isolating the product stream. The process allows the manufacture of N,N-dimethyl lactamide, N,N-diethyl lactamide, and N,N-methylethyl lactamide on a commercial scale.

Abstract: The invention relates to a method for preparing a complex of an organic amine and lactic acid in a reactor, characterized in that a water-miscible organic amine is brought into contact with magnesium lactate in an aqueous medium in the reactor to form the complex and precipitated magnesium hydroxide, after which the magnesium hydroxide is separated from the complex.

Abstract: The present invention relates to an improved process for the preparation of lactic acid and or lactate from a magnesium lactate comprising medium. In said process, magnesium lactate is reacted with a hydroxide of sodium, calcium, and/or ammonium at a pH range between 9 and 12, preferably between 9.9 and 11, to form a lactate of sodium, potassium, calcium and/or ammonia and magnesium hydroxide. With the process according to the invention a lactate salt is formed and magnesium hydroxide. It is essential that said so-called SWAP reaction is conducted within a specific pH range: It was found that when conducting the SWAP reaction at a pH range between 9 and 12 magnesium hydroxide particles are formed which can easily be separated from the lactate salt solution formed.

Abstract: The present invention relates to a method for the purification of an ?-hydroxy acid on an industrial scale, in which the method involves: (a) subjecting an aqueous stream containing mainly ?-hydroxy (1) to an extraction step, with the formation of an aqueous place containing mainly ?-hydroxy acid (2), (b) concentrating the aqueous phase containing mainly ?-hydroxy acid (2) by means of evaporation of water under reduced pressure, with the formation of a concentrated ?-hydroxy acid solution in water (3), and (c) subjecting the concentrated ?-hydroxy acid solution (3) to a crystallization, with formation of pure ?-hydroxy acid (4), where (i) the concentrated ?-hydroxy acid solution (3) is directly cooled in a melting crystallization device, and/or (ii) the concentrated ?-hydroxy acid solution (3) is diluted with water and crystallization is brought about in one or more cooling crystallization devices and/or evaporative crystallization devices, and/or (iii) crystallization is brought about in one or more adiabati

Abstract: The invention relates to a method for preparing a complex of an organic amine and lactic acid in a reactor, characterized in that a water-miscible organic amine is brought into contact with magnesium lactate in an aqueous medium in the reactor to form the complex and precipitated magnesium hydroxide, after which the magnesium hydroxide is separated from the complex.

Abstract: The present invention relates to a method for the purification of an ?-hydroxy acid on an industrial scale, in which an ?-hydroxy acid with a color (fresh) of not more than 10,000 APHA units is subjected to (a) a crystallization step followed by (b) a distillation step.

Abstract: The invention pertains to a method for purifying glycolide comprising the step of distilling crude glycolide under reflux using a distillation column having a ratio S/C×L>1.1 and S2/C2L>0.4 m, wherein S stands for the inner surface of the column in m2; L×C stands for the outer surface of the column in m2, wherein L stands for the length of the column in m; and C stands for the average circumference of the column in m, to obtain glycolide having a purity expressed as a turbidity <10 NTU as measured by the method according to DIN 27027/ISO 7027 of a solution of 1 g of said glycolide in 5 ml of acetone.

Abstract: The invention relates to a method for the purification of a fermentatively prepared ?-hydroxy acid on an industrial scale, in which an ?-hydroxy acid with a color (fresh) of not more than 10,000 APHA units is subjected to at least two crystallization steps, with the crystallization steps being carried out in cooling crystallization devices, melting crystallization devices, evaporative crystallization devices and/or adiabatic crystallization devices.

Abstract: The present invention relates to an improved process for the preparation of lactic acid and or lactate from a magnesium lactate comprising medium. In said process, magnesium lactate is reacted with a hydroxide of sodium, calcium, and/or ammonium at a pH range between 9 and 12, preferably between 9.9 and 11, to form a lactate of sodium, potassium, calcium and/or ammonia and magnesium hydroxide. With the process according to the invention a lactate salt is formed and magnesium hydroxide. It is essential that said so-called SWAP reaction is conducted within a specific pH range: It was found that when conducting the SWAP reaction at a pH range between 9 and 12 magnesium hydroxide particles are formed which can easily be separated from the lactate salt solution formed.

Abstract: The invention relates to a method of purifying lactic acid esters, wherein an impure lactic acid ester is subjected to a melt crystallization. The impure lactic acid contains not more than 10 wt. % of impurities, based on the total amount of ester, and has a chiral purity of more than 90%. The ester is derived from lactic acid and a C1–C18 alcohol.