Dynawave/Membrane WESP- A Low Cost Technology for Reducing SO_2, SO_3,Hg~(+2) and Participate from Coal-fired Power Plants

摘要

Achieving multi-pollutant emissions reduction within one device offers cost advantages, reduced space requirements, and less complexity. This paper will document the advantages of a Dyna Wave™/Membrane WESP system to capture SO_2, SO_3, Hg~(+2), and Paniculate for Coal Fired Boilers of 350MW or less in size.Wet gas scrubbing followed by wet electrostatic precipitation is an ideal process for significantly reducing SO_2, SO_3, Hg~(2+) , and paniculate emissions. Separate installations of these two technologies can present problems of space, capital cost high field installation costs, and complexity. The DynaWave™/Membrane W;ESP is a modular type construction, is easily installed, and reduces foot-print. Design benefits of the Dyna Wave/membrane WESP technology which reduce costs will be described.Using low cost lime/limestone as a reagent, the Dyna Wave™ reverse jet scrubber provides SO_2 reduction to 15 ppm. Unique reverse jet nozzles inject scrubbing liquid counter-current to the inlet gas. Liquid collides with down coming gas to create the Froth Zone, a region of high mass transfer. Features and benefits of the Dyna Wave™ Wet Gas Scrubber will be highlighted.The membrane WESP included in the package has demonstrated high collection efficiency for SO_3, Hg~(+2), and particulate in several pilot-scale testing and full-scale testing. Performance data of the Dyna Wave™ scrubber and the Membrane WESP will be presented.The membrane WESP has capability to cool the saturated gas stream and operate as a condensing WESP. The WESP performance is enhanced by condensing water out of the gas stream which results in the unit requiring no make-up water. This allows the use of lower grade stainless 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 high reliability, excellent efficiency even for high inlet loadings, and demonstrated low maintenance. Recommendations will be made to show how the DynaWave™/Membrane WESP system can be used in coal-fired power plants of 350MW or less in size. This combined system also offers a cost effective solution to help coal-fired power plants be ready for CO_2 technology.