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., thereby decomposing the magnesium chloride to magnesium oxide and hydrogen chloride, and recycling the hydrogen chloride generated in the thermal decomposition step to the acidification step. It has been found 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.

A method for conversion of magnesium chloride into magnesium oxide and HCl, comprising the steps of providing a magnesium chloride compound to a thermohydrolysis reactor, the reactor being at a temperature of at least 300 C., withdrawing MgO from the thermohydrolysis reactor in solid form, and withdrawing a HCl containing gas stream from the thermohydrolysis reactor, wherein the magnesium chloride compound provided to the thermohydrolysis reactor is a solid magnesium chloride compound which comprises at least 50 wt. % of MgCl2.4H2O. The process accordingly is fast and can be operated in a manner which is efficient both as regards apparatus and energy. It can also be integrated in a process for converting a magnesium chloride solution.

A method for conversion of magnesium chloride into magnesium oxide and HCl, comprising the steps of providing a magnesium chloride compound to a thermohydrolysis reactor, the reactor being at a temperature of at least 300 C., withdrawing MgO from the thermohydrolysis reactor in solid form, and withdrawing a HCl containing gas stream from the thermohydrolysis reactor, wherein the magnesium chloride compound provided to the thermohydrolysis reactor is a solid magnesium chloride compound which comprises at least 50 wt. % of MgCl2.4H2O. The process accordingly is fast and can be operated in a manner which is efficient both as regards apparatus and energy. It can also be integrated in a process for converting a magnesium chloride solution.

The invention provides a method for preparing a carboxylic acid, which method includes the steps of providing magnesium carboxylate, wherein the carboxylic acid corresponding with the carboxylate has a solubility in water at 20 C. of 80 g/100 g water or less; acidifying the magnesium carboxylate with HCl, thereby obtaining a solution comprising carboxylic acid and magnesium chloride (MgCl.sub.2); optionally a concentration step, wherein the solution comprising carboxylic acid and MgCl.sub.2 is concentrated; precipitating the carboxylic acid from the solution comprising the carboxylic acid and MgCl.sub.2, thereby obtaining a carboxylic acid precipitate and a MgCl.sub.2 solution.

The invention provides a method for preparing a carboxylic acid, which method includes the steps of providing magnesium carboxylate, wherein the carboxylic acid corresponding with the carboxylate has a solubility in water at 20 C. of 80 g/100 g water or less; acidifying the magnesium carboxylate with HCl, thereby obtaining a solution comprising carboxylic acid and magnesium chloride (MgCl2); optionally a concentration step, wherein the solution comprising carboxylic acid and MgCl2 is concentrated; precipitating the carboxylic acid from the solution comprising the carboxylic acid and MgCl2, thereby obtaining a carboxylic acid precipitate and a MgCl2 solution.

The invention provides a method for preparing a carboxylic acid, which method includes the steps of providing magnesium carboxylate, wherein the carboxylic acid corresponding with the carboxylate has a solubility in water at 20 C. of 80 g/100 g water or less; acidifying the magnesium carboxylate with HCl, thereby obtaining a solution comprising carboxylic acid and magnesium chloride (MgCl2); optionally a concentration step, wherein the solution comprising carboxylic acid and MgCl2 is concentrated; precipitating the carboxylic acid from the solution comprising the carboxylic acid and MgCl2, thereby obtaining a carboxylic acid precipitate and a MgCl2 solution.

The invention provides a method for preparing a carboxylic acid, which method includes the steps of providing magnesium carboxylate, wherein the carboxylic acid corresponding with the carboxylate has a solubility in water at 20 C. of 80 g/100 g water or less; acidifying the magnesium carboxylate with HCl, thereby obtaining a solution comprising carboxylic acid and magnesium chloride (MgCl.sub.2); optionally a concentration step, wherein the solution comprising carboxylic acid and MgCl.sub.2 is concentrated; precipitating the carboxylic acid from the solution comprising the carboxylic acid and MgCl.sub.2, thereby obtaining a carboxylic acid precipitate and a MgCl.sub.2 solution.

The invention provides a method for preparing a carboxylic acid, which method includes the steps of providing magnesium carboxylate, wherein the carboxylic acid corresponding with the carboxylate has a solubility in water at 20 C. of 80 g/100 g water or less; acidifying the magnesium carboxylate with HCl, thereby obtaining a solution comprising carboxylic acid and magnesium chloride (MgCl.sub.2); optionally a concentration step, wherein the solution comprising carboxylic acid and MgCl.sub.2 is concentrated; precipitating the carboxylic acid from the solution comprising the carboxylic acid and MgCl.sub.2, thereby obtaining a carboxylic acid precipitate and a MgCl.sub.2 solution.

A process for removing lactic acid from an aqueous lactic acid-containing magnesium chloride solution, the weight ratio of magnesium chloride to lactic acid in the aqueous lactic acid-containing magnesium chloride solution being at least 1:1, the process including the steps of subjecting the aqueous lactic acid-containing magnesium chloride solution to an evaporation step, resulting in the formation of a slurry of MgCl2.Math.MgL2.Math.4H2O in an aqueous magnesium chloride solution, then subjecting the slurry to a solid-liquid separation step, to separate the solid MgCl2.Math.MgL2.Math.4H2O from the aqueous magnesium chloride solution, resulting in the removal of lactic acid from the aqueous lactic acid-containing magnesium chloride solution in the form of MgCl2.Math.MgL2.Math.4H2O. The process makes it possible to efficiently remove lactic acid from aqueous lactic acid-containing magnesium chloride solutions, resulting in magnesium chloride solutions with a low lactic acid content which can be further processed as desired.

A process for removing lactic acid from an aqueous lactic acid-containing magnesium chloride solution, the weight ratio of magnesium chloride to lactic acid in the aqueous lactic acid-containing magnesium chloride solution being at least 1:1, the process including the steps of subjecting the aqueous lactic acid-containing magnesium chloride solution to an evaporation step, resulting in the formation of a slurry of MgCl2.Math.MgL2.Math.4H2O in an aqueous magnesium chloride solution, then subjecting the slurry to a solid-liquid separation step, to separate the solid MgCl2.Math.MgL2.Math.4H2O from the aqueous magnesium chloride solution, resulting in the removal of lactic acid from the aqueous lactic acid-containing magnesium chloride solution in the form of MgCl2.Math.MgL2.Math.4H2O. The process makes it possible to efficiently remove lactic acid from aqueous lactic acid-containing magnesium chloride solutions, resulting in magnesium chloride solutions with a low lactic acid content which can be further processed as desired.