SOx additive systems based upon use of multiple particle species

A method of oxidizing SO2 to SO3, followed by absorbing said SO3 formed by the oxidation of SO2, said method comprising:

• (a) oxidizing SO2 to SO3 and (b) absorbing said SO3 formed by the oxidation of SO2 with first and second physically distinct particle species, wherein said first particle species includes an SO2→SO3 oxidation catalyst component and carries out a primary function of oxidizing sulfur dioxide to sulfur tioxide and said second particle species is physically separate and distinct from the first particle species and carries out a function of absorbing said SO3 produced by the oxidation of said SO2 to SO3;
• wherein:
• said oxidation catalyst component in the form of a particle that comprises:
• (i) a sulfur SO2-SO3 oxidation catalyst comprised of a metal selected from the group consisting of cerium, vanadium, platinum, palladium, rhodium, molybdenum, tungsten, copper, chromium, nickel, iridium, manganese, cobalt, iron, ytterbium, and uranium;
• and (ii) a binder made from a material selected from the group of metal-containing compounds consisting of calcium aluminate, aluminum silicate, aluminum titanate, zinc titanate, alumin-um zirconate, magnesium aluminate, magnesia, alumina (Al2O3), aluminum hydroxide, an aluminum-containiing metal oxide compound (other than alumina (Al2O3)), clay, zirconia, titania, silica, clay, clay/phosphate material and bastnaesite and which contains from no more than about 10 weight percent aluminum hydroxide, and no more than about 10 weight percent alumina (Al2O3);
• and
• said absorbent component is in the form of a second particle that comprises a metal oxide made from a metal-containing compound selected from the group consisting of hydrotalcite, magnesia, magnesium acetate, magnesium nitrate, magnesium chloride, magnesium hydroxide, magnesium carbonate, magnesium formate, magnesium aluminate, hydrous magnesium silicate, magnesium calcium silicate, calcium silicate, alumina, calcium oxide, and calcium aluminate.