Control of combustion system emissions

A process for controlling combustion system emissions from combustion systems in which a carbonaceous-fuel is combusted, said process comprising the steps of:

• introducing a carbonaceous fuel and air into a furnace to provide a combustible fuel/air mixture and combusting the fuel/air mixture at a furnace combustion region to provide combustion products in the form of flue gases containing pollutant compounds including SOx, Hg, As, and CO2, wherein the temperature within the furnace combustion region is from about 2500° F. to about 3000° F.;
• introducing into the furnace combustion region a calcium-containing reagent to expose the calcium-containing reagent to the furnace combustion region temperature to thereby calcine the calcium-containing reagent within the furnace combustion region into a plurality of calcium oxide particles to provide a scavenging agent in particulate form for scavenging combustion product components, wherein the calcium oxide particles are in the form of a plurality of discrete, substantially non-agglomerated calcium oxide particles having a particle size of less than about 3 microns;
• contacting the calcium oxide particles with the combustion products to react the calcium oxide particles with pollutants contained in the combustion products to capture SOx and toxic metals that are present in the combustion products;
• and
• transporting the flue gases and particles from the combustion region and through the furnace to a furnace exit.