Enhanced sorbent injection combined with natural gas reburning for a sox control for coal fired boilers

Claim 1

In a process for reducing gaseous SO X content of exhaust gases from a combustion installation, by injecting an aqueous dispersion of a particulate sorbent into said combustion installation in a zone outside of the combustion region such that said aqueous dispersion is initially exposed to a temperature exceeding about 2200° F.; the improvement comprising, prior to said step of injecting said aqueous dispersion into said combustion installation, the steps of (a) mixing substantially dry solid particulates with combustion gases from the combustion of hydrocarbon gas at a temperature in the range of about 1800°-1900° F. for 1.5-2.0 seconds to form a calcined solid sorbent capable of reacting with sulfur-containing gases; and (b) mixing said calcined solid sorbent to form an aqueous dispersion for injection into said combustion installation; wherein said solid particulates comprise calcium carbonate, calcium hydroxide, magnesium carbonate, magnesium hydroxide or mixtures of any two or more thereof.