Flue Walther process

A simplified flow sheet for the desulphurization of flue gas by the Walther process is presented in Fig. 3-3 ... 

Fig. 3-3. Desulfurizing of flue gas, Walther process, simplified flow sheet.

The Walther process is an aqueous ammonia FGD process that produces ammonium sulfate fertilizer granulate. Ammonia loss due to vaporization into the clean flue gas is controlled by the use of a second absorber vessel with a special mist elimination system specifically designed to remove the ammonia aerosol from the flue gas (Reijnen, 1990). 

Walther Also called Walther Ammonia. A flue-gas desulfurization process in which the gas is scrubbed with aqueous ammonia. Two scrubbing stages are used, operating at different pH values. The by-product is suitable for use as a fertilizer. Developed and licensed by Walther Company. Two plants were operating in Germany in 1987, one of which was experiencing serious operational problems. 

Martin, J. R., and Bechthold, H., 1982, An Alternative Technology for Flue Gas Desulfurization Walther Ammonia Process, Proceedings of the American Power Conference. April 26-28, Chicago, IL, pp. 413-422. 

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