Dynawave/Membrane WESP- A Low Cost Technology forReducing SO2, SO3,Hg+2 and Particulate from Coal-firedPower Plants

摘要

Achieving multi-pollutant emissions reduction within one device offers cost advantages, reducedspace requirements, and less complexity. This paper will document the advantages of aDynaWave?/Membrane WESP system to capture SO2, SO3, Hg+2, and Particulate for CoalFired Boilers of 350MW or less in size.Wet gas scrubbing followed by wet electrostatic precipitation is an ideal process for significantlyreducing SO2, SO3, Hg+2, and particulate emissions. Separate installations of these twotechnologies can present problems of space, capital cost, high field installation costs, andcomplexity. The DynaWave?/Membrane WESP is a modular type construction, is easilyinstalled, and reduces foot-print. Design benefits of the DynaWave/membrane WESP technologywhich reduce costs will be described.Using low cost lime/limestone as a reagent, the DynaWave? Reverse jet scrubber provides SO2reduction to 15 ppm. Unique reverse jet nozzles inject scrubbing liquid counter-current to theinlet gas. Liquid collides with down coming gas to create the Froth Zone, a region of high masstransfer. Features and benefits of the DynaWave? Wet Gas Scrubber will be highlighted.The membrane WESP included in the package has demonstrated high collection efficiency forSO3, Hg+2, and particulate in several pilot-scale testing and full-scale testing. Performance dataof the DynaWave? Scrubber and the Membrane WESP will be presented.The membrane WESP has capability to cool the saturated gas stream and operate as acondensing WESP. The WESP performance is enhanced by condensing water out of the gasstream which results in the unit requiring no make-up water. This allows the use of lower gradestainless steels for materials of construction. The details of this capability will be described.Combined in a skid mounted, modular package, these two proven technologies offer highreliability, excellent efficiency even for high inlet loadings, and demonstrated low maintenance.Recommendations will be made to show how the DynaWave?/Membrane WESP system can beused in coal-fired power plants of 350MW or less in size. This combined system also offers acost effective solution to help coal-fired power plants be ready for CO2 technology.