PPII Projects

The PPII projects focus on technologies enabling coal-fired power plants to meet increasingly stringent environmental regulations at the lowest possible cost. With many plants threatened with shutdowns because of environmental concerns, more effective and lower cost emission controls can keep generators operating while improving the quality of the nation's air and water [5]. A brief description of the ongoing projects and their objectives is provided here.

Sunflower Electric Power Company, with GE Energy and Environmental Research (formerly Energy and Environmental Research Corporation), will be demonstrating a unique combination of high-tech combustion modifications and sophisticated control systems with the goal of reducing NOZ emissions to 0.15 to 0.22 lb/MM Btu [53]. The project will be performed on Holcomb Station (Garden City, Kansas), a 360 MW, pulverized coal-fired boiler firing subbituminous coal. The reduction in NOZ emissions will be accomplished by modifying existing low-NOz burners, separating the overfire air, installing fuel flow measurement transducers, balancing the combustion air, and using neural network controls.

Otter Tail Power Company, with Montana Dakota Utilities, NorthWestern Public Service, W.L. Gore & Associates, Inc., and the University of North Dakota Energy and Environmental Research Center, will be demonstrating, in a full-scale application, a hybrid technology that increases the particulate matter capture in coal plants up to 99.99% by integrating fabric filtration and electrostatic precipitation [54]. The advanced hybrid particu-late collector (AHPC), discussed in Chapter 6, combines the best features of an electrostatic precipitator (ESP) and a baghouse in the same housing, providing major synergism between the two methods to overcome the problem of excessive fine particulate emissions that escape collection in an ESP and the re-entrainment of dust in a baghouse. The demonstration is being performed on Big Stone Power Plant's (Big Stone City, South Dakota) 450 MW cyclone-fired boiler and is a scale-up from a 2.5 MW slipstream test program that was performed at the plant.

Tampa Electric Company and Pegasus Technology, Inc., will be demonstrating control of boiler fouling on Big Bend Power Station's (Apollo Beach, Florida) 445 MW unit using a neural-network soot-blowing system in conjunction with advanced controls and instruments [55]. Ash and slag deposition compromise plant efficiency by impeding heat transfer to the working fluid, leading to higher fuel consumption and higher emissions. The process optimization is targeted to reduce total NOZ generation by 30% or more, improve heat rate by 2%, and reduce particulate matter emissions by 5%. As compared to competing technologies, this system could be an extremely cost-effective technology that has the ability to be readily adapted to virtually any pulverized coal-fired boiler.

In the fourth PPII project that is under way, Universal Aggregates LLC (a joint venture between CONSOL Energy, Inc., and SynAggs, Inc.)

will design, build, and operate an aggregate manufacturing plant that converts 115,000 short tons/year of spray dryer by-products into 150,000 short tons/year of lightweight masonry blocks or lightweight concrete [56]. Only ~18% of flue gas desulfurization residue in the United States is recycled, with the remainder landfilled. This process will reduce plant disposal costs and the environmental drawbacks of landfilling by producing a salable byproduct. The demonstration will be located by the Birchwood Power Facility in King George County, Virginia.

The two projects under negotiation with the DOE also pertain to emissions reduction. In one project, CONSOL Energy, Inc., is proposing to demonstrate a multipollutant control system that can cost-effectively reduce NOZ, SO2, acid gases (i.e., hydrochloric and hydrofluoric acids), and mercury from smaller coal-fired power plants using single-bed, in-duct SCR combined with low-NOz combustion technology [57]. In the second project, proposed by TIAX, a hybrid system composed of lower cost components from three established NOZ reduction systems (i.e., fuel-lean gas reburn, SNCR, and SCR) will be developed and demonstrated to reduce NOZ emissions to 0.15 lb/MM Btu at lower costs than conventional SCR [58].

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