ECO^® System Benefits

The Electro-Catalytic Oxidation (ECO) technology offers several operational and economic benefits in comparison to a solution offering equivalent SO2 and NOx removal performance.

Superior Emissions Control and Flexibility:

• The system provides high removal of NOx (90 percent), SO2 (99 percent), and mercury (80-90 percent).
• The integral wet electrostatic precipitator (ESP) captures SO3 and fine particulate matter to BACT standards.
• The process is suitable for high- and low-sulfur coals.
• Captured mercury is isolated from the fertilizer co-product stream for separate disposal.
• The modular design can be adapted to different boiler sizes and configurations, and is suitable for retrofit and new plant applications.
• The system is constructed as an independent unit and then tied-in to the plant during a short outage.

Attractive Economics and Reduced Risk:

• In contrast to traditional SO2 scrubbing technologies, the ECO system does not produce any new solid waste streams or a wastewater stream. This eliminates the need for permitting associated with landfill disposal or a wastewater treatment system.
• In contrast to selective catalytic reduction (SCR) systems for high NOx removal, which are located high in the boiler outlet gas path upstream of the air preheater, the ECO reactor is positioned at ground level after the ESP or fabric filter. ECO systems require significantly less steel and man-hours of labor for installation, thereby reducing capital costs and risk of construction cost escalation.
• ECO is not prone to operating problems common to SCR systems, such as ash plugging, fouling, catalyst poisoning due to trace impurities, or premature catalyst deactivation.
• ECO subsystems can be located remotely from the absorber island, providing increased installation flexibility.
• The revenue generated by the sale of the ammonium sulfate fertilizer co-product offsets the reagent cost and part of the plant's operating expenses.
• Mercury collection is achieved downstream of primary particulate (ESP or fabric filter) and SO2 collection. As a result, ash sales are unaffected.

Hedge Against Future Environmental Regulations:

• The integral wet ESP removes acid mists and fine particulate matter, which are likely to be subject to more stringent regulation in the future. For some new plants under development, a wet ESP downstream of an SO2 scrubber is required by the air permit.
• The ECO technology offers the potential to cost-effectively remove carbon dioxide (CO2) for sequestration. Powerspan has conducted laboratory testing of a CO2 capture process, and is proceeding with plans for a pilot test at FirstEnergy's R.E. Burger Plant. Powerspan is working in cooperation with the U.S. Department of Energy to develop the CO2 capture process.