A method for processing MgCl2 solutions including the steps of: providing an aqueous solution including 5-25 wt. % of MgCl2 and optionally organic contaminants to a step, wherein water and present, organic components are evaporated; withdrawing aqueous solution with a MgCl2 concentration of 25-35 wt. % from an evaporation step and providing it to a preconcentrator where it is contacted with a HCl containing gas stream at least 300 C.; providing aqueous solution with a MgCl2 concentration of 35-45 wt. % resulting from the preconcentrator to a thermohydrolysis reactor, being at at least 300 C.; withdrawing MgO from the thermohydrolysis reactor in solid form, and withdrawing a HCl containing gas stream from the thermohydrolysis reactor, said HCl-containing gas stream at least 300 C.; providing the HCl-containing gas stream with at least 300 C. to the preconcentrator; withdrawing a HCl-containing gas stream with a temperature of at most 150 C. from the preconcentrator.

A method for processing MgCl2 solutions including the steps of: providing an aqueous solution including 5-25 wt. % of MgCl2 and optionally organic contaminants to a step, wherein water and present, organic components are evaporated; withdrawing aqueous solution with a MgCl2 concentration of 25-35 wt. % from an evaporation step and providing it to a preconcentrator where it is contacted with a HCl containing gas stream at least 300 C.; providing aqueous solution with a MgCl2 concentration of 35-45 wt. % resulting from the preconcentrator to a thermohydrolysis reactor, being at at least 300 C.; withdrawing MgO from the thermohydrolysis reactor in solid form, and withdrawing a HCl containing gas stream from the thermohydrolysis reactor, said HCl-containing gas stream at least 300 C.; providing the HCl-containing gas stream with at least 300 C. to the preconcentrator; withdrawing a HCl-containing gas stream with a temperature of at most 150 C. from the preconcentrator.

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).

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).

The invention relates to a solid-material method for producing calcium dipropionate in a pressure-resistant solid-state mixing reactor by charging calcium oxide, calcium hydroxide or calcium carbonate or mixtures of these calcium compounds, and adding propionic acid by a reaction directly in the solid phase under a pressure that is increased above normal pressure.

The invention relates to a solid-material method for producing calcium dipropionate in a pressure-resistant solid-state mixing reactor by charging calcium oxide, calcium hydroxide or calcium carbonate or mixtures of these calcium compounds, and adding propionic acid by a reaction directly in the solid phase under a pressure that is increased above normal pressure.

The invention relates to a solid-material method for producing calcium dipropionate in a pressure-resistant solid-state mixing reactor by charging calcium oxide, calcium hydroxide or calcium carbonate or mixtures of these calcium compounds, and adding propionic acid by a reaction directly in the solid phase under a pressure that is increased above normal pressure.

The invention relates to a process for separation of organic acids from mixture of ammonium salts of one or more organic acids and other compounds via an integrated process. The process involves suspending mixture of ammonium salts of one or more organic acids and other compounds in dry hydrocarbon solvent/s or mixtures thereof; wherein the selected hydrocarbon solvent/s or mixtures thereof have boiling point more than 100 C. and forms an azeotrope with water. The reaction mixture thus obtained is dehydrated azeotropically followed by esterification of basic salt of the organic acids by addition of alcohol in presence of metal or metal salt; thereafter the individual esters formed are separated by distillation and hydrolysed to obtain corresponding organic acids having more than 98% purity.

The invention relates to a process for separation of organic acids from mixture of ammonium salts of one or more organic acids and other compounds via an integrated process. The process involves suspending mixture of ammonium salts of one or more organic acids and other compounds in dry hydrocarbon solvent/s or mixtures thereof; wherein the selected hydrocarbon solvent/s or mixtures thereof have boiling point more than 100 C. and forms an azeotrope with water. The reaction mixture thus obtained is dehydrated azeotropically followed by esterification of basic salt of the organic acids by addition of alcohol in presence of metal or metal salt; thereafter the individual esters formed are separated by distillation and hydrolysed to obtain corresponding organic acids having more than 98% purity.

The present invention relates to a method of concentrating an aqueous solution at low pressure under a zero osmotic pressure difference condition, and more particularly, to a method of concentrating an aqueous solution containing a solute to be concentrated, at low pressure under a zero osmotic pressure difference condition. The method of the present invention comprises the steps of: (a) discharging water of a solute-containing aqueous solution to be concentrated, from a reverse osmosis separator to the outside, and transferring the concentrated aqueous solution to a zero osmotic pressure difference concentrator; (b) further concentrating the concentrated aqueous solution using the zero osmotic pressure difference concentrator comprising a feed chamber and a draw chamber, which are separated from each other by a reverse osmosis membrane or a forward osmosis membrane; and (c) recovering the solute and water from the aqueous solution further concentrated in the zero osmotic pressure difference concentrator. When the method of concentrating the aqueous solution at low pressure under the zero osmotic pressure difference condition is used, the aqueous solution can be concentrated to the maximum saturation concentration of a solute or a solution concentration of 100% using a reduced amount of energy without having to use an extraction solvent. In addition, there is an advantage in that a separate osmosis draw solution does not need to be used.