Abstract: The invention pertains to a method for providing a succinic acid solution, comprising the steps of —providing a first magnesium succinate containing medium with a magnesium succinate concentration of 18-23 wt. % to a first acidification reactor where it is contacted with hydrogen chloride to form a solution of succinic acid, magnesium chloride and hydrogen chloride, —providing a second magnesium succinate containing medium with a magnesium succinate concentration of 25-50 wt. %, and contacting it in a second acidification reactor with the solution of succinic acid, magnesium chloride and hydrogen chloride withdrawn from the first acidification reactor, to form an aqueous mixture comprising magnesium chloride and succinic acid with a succinic acid concentration of at least 18 wt. %. The method according to the invention makes it possible to obtain a solution comprising succinic acid and magnesium 20 chloride with an increased succinic acid concentration.

Abstract: A method for producing lactide including the steps of: providing a solution of lactic acid in a volatile organic solvent, subjecting the solution to an evaporation step to remove volatile organic solvent and water, resulting in the formation of a composition including lactic acid oligomer, adding catalyst to the composition including lactic acid oligomer, and bringing the mixture to reaction conditions, to form lactide. It has been found that the process results in the efficient production of lactide with a high production rate and a good product quality.

Abstract: The invention pertains to a method for preparing succinic acid which comprises providing an aqueous magnesium succinate solution to an acidification step, wherein the magnesium succinate solution is acidified by the addition of hydrogen chloride, thereby obtaining an aqueous solution comprising succinic acid and magnesium chloride and subjecting the aqueous solution comprising succinic acid and magnesium chloride derived from the acidification step to a treatment step with active carbon followed by precipitating succinic acid from an aqueous mixture comprising succinic acid and magnesium chloride resulting from the active carbon treatment step in a precipitation step to form solid succinic acid. It has been found that the method according to the invention leads to succinic acid crystals with better properties than a comparable method wherein no active carbon treatment is used.

Abstract: The invention pertains to a method for providing a succinic acid solution, comprising the steps of—providing a first magnesium succinate containing medium with a magnesium succinate concentration of 18-23 wt. % to a first acidification reactor where it is contacted with hydrogen chloride to form a solution of succinic acid, magnesium chloride and hydrogen chloride,—providing a second magnesium succinate containing medium with a magnesium 3 succinate concentration of 25-50 wt. %, and contacting it in a second acidification reactor with the solution of succinic acid, magnesium chloride and hydrogen chloride withdrawn from the first acidification reactor, to form an aqueous mixture comprising magnesium chloride and succinic acid with a succinic acid concentration of at least 18 wt. %. the method according to the invention makes it possible to obtain a solution comprising succinic acid and magnesium 20 chloride with an increased succinic acid concentration.

Abstract: The invention pertains to a method for preparing succinic acid comprising the steps of —providing an aqueous magnesium succinate solution to an acidification step, wherein the magnesium succinate solution is acidified by the addition of hydrogen chloride, thereby obtaining an aqueous solution comprising succinic acid and magnesium chloride; —subjecting an aqueous solution comprising succinic acid and magnesium chloride derived from the acidification step to a treatment step with active carbon, —precipitating succinic acid from an aqueous mixture comprising succinic acid and magnesium chloride resulting from the active carbon treatment step in a precipitation step to form solid succinic acid and a magnesium chloride solution, —separating the solid succinic acid from the magnesium chloride solution —subjecting the magnesium chloride solution to a thermal decomposition at a temperature of at least 300° C.

Abstract: A method for producing lactide including the steps of: providing a solution of lactic acid in a volatile organic solvent, subjecting the solution to an evaporation step to remove volatile organic solvent and water, resulting in the formation of a composition including lactic acid oligomer, adding catalyst to the composition including lactic acid oligomer, and bringing the mixture to reaction conditions, to form lactide. It has been found that the process results in the efficient production of lactide with a high production rate and a good product quality.

Abstract: The invention is directed to a method for recovering carboyxlic acid from an magnesium carboxylate containing aqueous mixture, including the steps of: contacting the aqueous mixture with an acidic ion exchanger, thereby forming a carboxylic acid mixture and an ion exchanger loaded with magnesium ions; contacting the ion exchanger loaded with magnesium ions with a hydrochloric acid solution, thereby forming a magnesium chloride solution; and thermally decomposing the magnesium chloride solution at a temperature of at least 300° C., thereby forming magnesium oxide (MgO) and hydrogen chloride (HCl).

Abstract: The invention is directed to a method for recovering carboyxlic acid from an magnesium carboxylate containing aqueous mixture, including the steps of: contacting the aqueous mixture with an acidic ion exchanger, thereby forming a carboxylic acid mixture and an ion exchanger loaded with magnesium ions; contacting the ion exchanger loaded with magnesium ions with a hydrochloric acid solution, thereby forming a magnesium chloride solution; and thermally decomposing the magnesium chloride solution at a temperature of at least 300° C., thereby forming magnesium oxide (MgO) and hydrogen chloride (HCl).

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.