Sulfur Trioxide Reduction Technology Demonstrated at Dominion Generation's Chesterfield Power Station

摘要

This paper presents modeling performed in support of a full-scale demonstration of a proprietary technology for the reduction of sulfur trioxide (SO{sub}3) emissions from power plant flue gases. The technology, trademarked CleanStack, was developed jointly by Marsulex Environmental Technologies, the Energy & Environment Research Center, and ALSTOM Power Inc., Air Preheater Company. Dominion Energy will host a demonstration of the technology at its Chesterfield Station Unit 5, utilizing one of the 350-MWe unit's two Ljungstrom air preheaters for the project. SO{sub}3 is considered a potential emission and opacity threat for high-sulfur coal-fired boilers which have retrofit selective catalytic reduction (SCR) technology for NO{sub}x reduction. The additional quantities of SO{sub}3 generated by the oxidation catalysis of SCR elements on SO{sub}2 have led to serious visible plume emissions from chimneys. The CleanStack technology utilizes the injection of ultrafine, alkaline particles upstream of the boiler's air preheater to aid in the condensation and subsequent neutralization of SO{sub}3. Collected SO{sub}3 is absorbed and disposed of with fly ash constituents. Advanced air preheater heating elements exhibit lower fouling tendencies and higher levels of cleanability to ensure reliable operation under CleanStack duty.