TARGETED DUCT INJECTION FOR SO3 CONTROL

摘要

NO_x and SO₃ emissions from combustion of a sulfur containing carbonaceous fuel are reduced simultaneously. The combustion gases comprising NO_x and SO₂ are mixed with a NO_x control agent into the combustion gases at a point upstream of a selective catalytic reduction catalyst for reduction of NO_x. Following an SCR catalyst or other equipment that can oxidize SO₂ to SO₃ and prior to contact with an air heater for heating incoming combustion air, magnesium hydroxide is introduced in amounts and with droplet sizes and concentrations effective to form nano-sized particles in the effluent and reduce SO₃ caused by the oxidation of SO₂ in the catalyst. Computational fluid dynamics is employed to determine flow rates and select reagent introduction rates, reagent introduction location(s), reagent concentration, reagent droplet size and/or reagent momentum.