The present invention is an improved filtration system, filtering method and unique chemical composition for capturing mercury and other pollutants in flue gases generated by process gas streams. The improved filtration system may take various forms depending on the type of filter system most desired for a particular application; however, the filter system includes at least a filter element or elements and an adsorbent component having a composition suitable for capturing mercury on the downstream side of the filter element.
1. A non-aqueous, dry, solid state adsorbent composition for the capture and binding of elemental and oxidized mercury pollutants carried in a gas stream, said composition comprising:
a binding agent comprising at least one binding compound having a component selected from the group consisting of an anion of a halide, an anion of a thiocyanate, an anion of a sulfide, an anion of a polysulfide, an anion of selenium, an oxyanion of selenium, an anion of tellurium, an oxyanion of tellurium, an anion of phosphorous, and an oxyanion of phosphorous; and
a promoter compound having a component selected from the group consisting of a multivalent metallic cation and a multivalent metalloid cation, said promoter compound having a standard aqueous reduction potential Emf value at 25° C. less than −0.56 volts,
wherein said composition is capable of chemical reaction with elemental and oxidized mercury to bind said elemental and oxidized mercury.
2. The composition of claim 1 , wherein said promoter compound comprises at least one material selected from the group consisting of a carboxylate salt of Zn(II) and a carboxylate salt of Mg(II).
3. The composition of claim 1 , wherein said binding agent comprises at least one compound selected from the group consisting of potassium iodide, copper iodide, zinc iodide and copper thiocyanate.
4. The composition of claim 1 , wherein said binding agent comprises potassium iodide and said promoter comprises zinc acetate.