Patent ID: 6939523
Filing Date: 2005-09-06
Classification: B01D

Abstract:
1. A method of removing SO 3 from off gases produced at an industrial plant which combusts sulfur containing fuels, the method comprising the steps of: providing a sulfur containing fuel as a power source for the plant; burning the fuel at the plant, thereby producing off gases containing SO injecting a calcium hydroxide slurry into the off gases in the exhaust duct at a point in the duct where the exhaust duct temperature is sufficient to evaporate water from the calcium hydroxide slurry but is low enough to avoid decomposing and converting the calcium hydroxide to oxide, the calcium hydroxide reacting with the SO removing the calcium sulfate in a particulate removal system; wherein the industrial plant also has a particulate removal system and a wet scrubbing system and wherein the calcium hydroxide slurry is injected into the exhaust gas upstream from the particulate removal system and from the wet scrubbing system; and wherein the calcium hydroxide slurry is introduced into the exhaust duct through at least one nozzle and wherein compressed air is also introduced into the nozzle to atomize the slurry and produce a plurality of lime slurry droplets, the lime slurry droplets having a particle size in the range from about 30-100 microns.