Back to results
US 6,190,636 B1Granted
Chloro-hydrogenation of sodium sulfate and other alkali-metal sulfates
OwnerMohammed N. I. Khan, M. Fazlul Hoqinventors
Life of this patent
Estimating the term…
Abstract
A novel method is described whereby chlorine and sodium sulfate waste by-products from chemical by-products are recycled to form useful chemicals. Sodium sulfate is first reacted to form a metal sulfate and sodium chloride. The sodium chloride may be used as a chemical feed in chlor-alkali plants. The metal sulfate is then reacted to form an ammonium sulfate or bisulfate which in turn is reacted with chlorine to form sulfuric acid. The sulfuric acid may be used a chemical feed in chlorine dioxide plants and in various other chemical processes.
Claims14
A method of recycling by-products from industrial processes comprising:
- reacting an alkali-metal sulfate with an alkaline earth metal chloride to produce an alkaline earth metal sulfate precipitate and alkali metal chloride solution;
- separating the alkaline earth metal sulfate precipitate from the alkali metal chloride solution;
- combining the alkaline earth metal sulfate precipitate with a reagent selected from the group consisting of ammonia/carbon dioxide mixtures, ammonium carbonate, and ammonium bicarbonate to produce ammonium sulfate and an alkaline earth carbonate precipitate;
- separating the alkaline earth carbonate precipitate from the ammonium sulfate;
- and
- mixing chlorine with the ammonium sulfate, ammonium bisulfate, or mixtures thereof to produce sulfuric acid, hydrochloric acid and nitrogen.
3 more elements
Dependencies are inferred from the claim text.