Process for producing ammonia and sulfur dioxide
AssigneesKuraray Co., Ltd., Kyowa Gas Chemical Industry Co., Ltd., Jgc Corporation
InventorsYouji Takenouchi, Katsuhiko Nishiguchi, Kunio Abe
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Abstract
A process for producing NH.sub.3 and SO.sub.2 from ammonium sulfate, which comprises (i) reacting ammonium sulfate with a metal oxide or hydroxide at a temperature of not more than 200.degree. C. to form NH.sub.3, water and a metal sulfate and recovering NH.sub.3, (ii) decomposing the metal sulfate in the presence of a reducing agent to form a metal oxide and SO.sub.2 and recovering SO.sub.2, and (iii) recycling the metal oxide to step (i) as such or after it is converted to a metal hydroxide.
Claims10
A process for producing NH.sub.3 and SO.sub.2 from ammonium sulfate, which comprises
- (i) reacting ammonium sulfate with magnesium oxide or hydroxide at a temperature of not more than 200.degree. C. to form NH.sub.3, water and magnesium sulfate heptahydrate or an aqueous solution or slurry containing magnesium sulfate in a concentration of at least 15% by weight;
- recovering NH.sub.3 ;
- (ii) heating the magnesium sulfate heptahydrate or the aqueous solution or slurry containing magnesium sulfate in a concentration of at least 15% by weight to 100.degree. to 200.degree. C. in a closed system and maintaining it at this temperature for at least 60 minutes;
- and separating and recovering the resulting solid product from the resulting liquid,
- (iii) decomposing the solid product in the presence of a reducing agent to form magnesium oxide and SO.sub.2 and recovering SO.sub.2, and
- (iv) recycling the magnesium oxide to step (i) as such or after it converted to magnesium hydroxide.
Dependencies are inferred from the claim text.