|Abstract Title:||Using Iodine Vapor Infusion to Improve SO2 Wet Scrubber Function and Mercury Capture|
|Presenter Name:||Michael Radicone|
|Company/Institution:||i2 air fluid innovation, inc|
|Session:||Energy/ Fossil Fuels|
Abstract Information :
Wet scrubber's that rid flue gases of SO2 from oil or coal combustion, will also remove mercury (Hg). The Clean Air Interstate Rule (CAIR) is a significant driver with the EPA's Clean Air Mercury Rule (CAMR) specific to addressing mercury. The wet FGD systems? ability to capture gaseous Hg in flue gas is appealing because of the Phase I mercury emissions cap of 38 tons/year. Flue gas contains differing percentages of the varied mercury species. The Hg 2+ portion is water-soluble and thus captured in wet scrubbers. It is the insoluble Hg 0 that is not captured by this technology and the total mercury captured in a wet scrubber is dependent on the amount of water-soluble Hg 2+ present. Plants may use halogen additives to promote the presence of the oxidized mercury species (Hg2+) which is then captured by the flue-gas desulfurization scrubber. Heat transferred from the exhaust gas to the wash water is removed by using a heat exchanger in a recirculating loop. It is subject to fouling caused by gypsum or sulfate which will impede water flow. The pressure drop will require increased energy demand by the water pump to achieve functionality. Iodine vapor infusion is a proven method for reducing foul within heat exchangers. Elemental iodine vapor bubbles are injected into the flow stream and propelled to mechanically sparge foulants while chemically imparting the iodine through the bubble membrane. The Hg 0 in the water is exposed to the iodine through this nano/micro bubble interaction. Being highly reactive, the iodine will offer greater reaction than iodide or iodate species. The technology imparts iodine bubbles during a short infusion limiting iodine expression and providing only a low ppb fluid residue. Benefits will include improved functionality, reduced iodine expression, improved energy use, reduced carbon intensity and increased mercury capture.