Ammonia-Based Flue Gas Desulfurization

Flue gas desulfurization (FGD) systems using lime or limestone as the chemical reagent are widely used throughout the world for SO₂emissions control at coal-fired power plants. Ammonia-based systems, however, are emerging as a viable alternative to address limitations with respect to liquid and solid waste generation and handling. Efficient Ammonia-Based Desulfurization Technology (EADS) does not generate any liquid waste streams or undesirable solid byproducts that require disposal; rather, the closed-loop process produces a salable ammonium sulfate fertilizer byproduct which can reduce more than 50 percent of the operating cost.

Typical Lime/Limestone Forced Oxidationv  Wet Scrubbing Process Schematic Efficient Ammonia Desulfurization Process Schematic If an LSFO process had been applied to this project along with commercial sales of the byproduct gypsum, the annual operating costs would be $14,642,000. In comparison, the EADS process can essentially eliminate these costs while generating a profit of over US$500,000 from the sale of ammonium sulfate (at US$90/ST), netting total annual savings of approximately $15,000,000. Conclusion The EADS technology enables power plant and industrial boiler operators to meet strict environmental regulations while providing economic benefits. EADS is available under several business models, including engineering packages with supply of key equipment and parts, project engineering, procurement and construction, Build-Operate-Transfer and Build-Operate-Own.