Equilibrium production of sodium carbonate from sodium bicarbonate
AssigneeTg Soda Ash, Inc.
InventorsThomas H. Neuman, Richard W. Chastain
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Abstract
A process for producing sodium carbonate and other sodium-based chemicals from an aqueous solution containing sodium bicarbonate by contacting an aqueous solution of a bicarbonate-containing composition with a gas that is predominately other than carbon dioxide in an amount and for a time adequate to cause a sufficient amount of carbon dioxide to leave the aqueous solution to reduce the amount of bicarbonate ion in the solution by converting the bicarbonate to carbonate as carbon dioxide leaves the solution and thereafter converting the remaining solution to other sodium salts.
Claims55
A method of reducing the bicarbonate content of an aqueous solution containing sodium bicarbonate comprising:
- contacting an aqueous solution that contains sodium bicarbonate with steam that has a temperature of below 90.degree. C. for a time adequate for the steam to cause a sufficient amount of carbon dioxide to leave the aqueous solution to reduce the amount of bicarbonate ion in the solution by converting the bicarbonate to carbonate as the carbon dioxide leaves the solution.
A method of producing sodium-containing salts from sodium bicarbonate-containing compositions in a generally energy-efficient manner, the method comprising:
- contacting an aqueous solution of a sodium bicarbonate-containing composition with steam that has a temperature of below 90.degree. C. for a time adequate for the steam to cause a sufficient amount of carbon dioxide to leave the aqueous solution to reduce the amount of bicarbonate ion in the solution by converting the bicarbonate to carbonate as the carbon dioxide leaves the solution;
- and
- thereafter converting the remaining solution to sodium salts.
A method of reducing the ratio of sodium bicarbonate alkalinity to total alkalinity to below about 0.09 for an aqueous solution containing sodium bicarbonate comprising:
- contacting the aqueous solution with steam at a temperature of below 90.degree. C. in an amount and for a time adequate for the steam to cause a sufficient amount of carbon dioxide to leave the aqueous solution to reduce the ratio of sodium bicarbonate alkalinity to total alkalinity in the solution to below about 0.09 by converting the bicarbonate to carbonate as the carbon dioxide leaves the solution.
A method of producing sodium-containing salts from sodium bicarbonate-containing compositions in a generally energy-efficient manner, the method comprising:
- contacting an aqueous solution of a sodium bicarbonate-containing composition with steam at a temperature below 90.degree. C. in an amount and for a time adequate for the steam to cause a sufficient amount of carbon dioxide to leave the aqueous solution to reduce the ratio of sodium bicarbonate alkalinity to total alkalinity in the solution to less than 0.09 and converting bicarbonate to carbonate as the carbon dioxide leaves the solution;
- and
- thereafter converting the remaining solution to sodium salts.
A method according to claim 51 wherein the step of converting the remaining solution to sodium salts comprises:
- heating the solution to evaporate water;
- and
- thereafter cooling the solution to a temperature of between about -3.degree. C. and 25.degree. C. to crystallize solid sodium carbonate decahydrate.
Dependencies are inferred from the claim text.