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Dominion Generation (DG) has installed selective catalytic reduction (SCR) systems on many of the large coal-fired generating units it operates. The catalyst used has an SO2 to SO3 oxidation rate of about 1%, which roughly doubles the SO3 concentration at the outlet of the boiler economizers. The magnitude of the increase was proportional to the […]

Flyash and condensed sulfur trioxide (SO3) are the major components of flue gas that contribute to the opacity of a coal plant’s stack emissions (stack opacity). Estimates are that 75% to 85% of bituminous coal-fired plants with selective catalytic reduction (SCR) and/or wet flue gas desulfurization (FGD) systems are likely to produce enough SO3 vapor […]

This month’s photo was submitted by David Carter, power generation supervisor at Springerville Generating Station. Readers of POWER may recall that Springerville Unit 3 — the first pulverized coal – fired unit built in the U.S. in more than a decade — was that magazine’s 2006 Plant of the Year. Located in northeastern Arizona, the […]

The January call for a national policy on greenhouse gas (GHG) emissions by a coalition that includes some of America’s largest companies and electric utilities—GE, Alcoa, Dupont, Duke, FPL, and PG&E—makes clear that carbon management is now as much of a raison d’être for CEOs as it has been for environmentalists. The momentum to reduce […]

China to buy four AP1000 reactors / Midwest Gen, Blagojevich reach pollution deal / Behold, the carpet gasifier / AREVA casks green-lighted by NRC / Brookfield Power upgrades Oswego Falls / Korea fires up 50-MW landfill gas project / Alstom lands big Russian deal / POWER digest / Correction

The compliance clock is ticking / First-class maintenance in a developing country / Bypass losses squander big bucks / Revised operating procedures

The financing of power generation projects increasingly depends on the execution of a long-term power-purchase agreement (PPA). A common prerequisite for considering a PPA to be “effective” is a “final and nonappealable” regulatory order approving it. Purchasing utilities justifiably insist on such certainty to immunize their PPAs from after-the-fact regulatory scrutiny and possible penalty. Unfortunately, […]

Arc flash is arguably the most deadly and least understood hazard faced daily by plant personnel. Research indicates that even the best safety plan, training regimen, and protective equipment may be no match for the heat and blast effects of an arc flash. Consider this article a wakeup call to retrofit every switchgear cubicle in your plant with a properly designed remote racking system. Forewarned is forearmed.

A quick and nimble boiler distributed control system can end up moving at the speed of molasses in winter after a low-NO_x retrofit. In one utility fleet, several units—despite being equipped with a modern DCS—were experiencing firing system time lags and degraded dynamic loading capability. Swinging steam pressures and opacity excursions were forcing operators to constantly remove the unit from the load dispatch. Read how a new boiler master design read the riot act to those unruly steam generators.

A systematic, performance-driven maintenance program for optimizing combustion can achieve great results. The challenge for an O&M staff is deciding which proven strategy and tactics for reducing NO_x and improving plant reliability to adapt and implement. The structured approach presented here has proven its worth at several plants that have wrestled with problems similar to yours.