摘要 |
A process for the production of ammonium sulfate in a multistage contactor (or column) inclusive of liquid cyclone recycle. A gas, or gases, which contains sulfur dioxide, e.g., a flue gas, is contacted with ammonia in an oxygen and water environment in a column comprised of three sections (zones). Sulfur dioxide is contacted in vapor phase in a central section of the contactor with a stoichiometric excess of ammonia in the presence of oxygen and water vapor to produce ammonium sulfate. A scrubbing section for the removal of ammonia from the effluent gas by countercurrent contact with water or acid solution is provided in the upper section of the contactor. Liquid cyclones are utilized in the lower section of the contactor where product ammonium sulfate is removed as a slurry, crystalline ammonium sulfate is removed from the slurry, and liquid is returned as recycle to the contactor.
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