This guidebook exclusively features air emissions articles, including full charts, photographs, graphs and step-by-step instructions, previously featured in POWER magazine.
Available in a PDF format. 89 pages.
Table of Contents
Combined Mercury and SO3 Removal Using SBS Injection
Though no single mercury capture approach is best for all plants, when you can capture two (or more) pollutants with one sorbent, it’s worth a careful look.
Keeping Pollution Control Devices Online with Good Operating Practices
In order to comply with the Clean Air Act and subsequent regulations covering emissions, coal-fired utilities have installed multiple pollution control
devices. Understanding key operating aspects of this equipment can help you avoid costly maintenance activities and forced shutdowns.
Big Bend’s Multi-Unit SCR Retrofit
Tampa Electric will soon complete a comprehensive selective catalytic reduction project on all four units at its Big Bend Power Station that will make Big
Bend among the cleanest coal plants in the U.S. The project—the centerpiece of the company’s 10-year, $1.2 billion air quality improvement program—is
on schedule to meet all of its air quality improvement goals by mid-2010.
Big Stone Remodels ESP into Pulse Jet Fabric Filter
Short of replacement, what are your options when your original electrostatic precipitator fails to meet your current emissions and opacity requirements?
The management of Big Stone Plant chose the unconventional, yet economic approach of building a pulse jet fabric filter inside the casing of
the old electrostatic precipitator. The upgrades restored plant availability and prepare the plant to meet the next regulated reductions in particulate
Real-Time Control of Coal Quality Improves Reliability
Poor lignite fuel quality had plagued the Red Hills Power Plant since it began operation eight years ago. The solution: real-time measurement of coal
properties that has allowed Red Hills Mine to carefully monitor fuel quality and adjust fuel collection processes to ensure that only high-quality fuel is
delivered to the plant. Now all delivered fuel is consumed, and plant reliability is much improved. It’s a classic win-win project.
Dry Injection of Trona for SO3 Control
In 2006 and 2007, POWER ran a three-part series on the formation of SO3, O&M issues caused by SO3, and sorbent injection control for SO3 control.
Three years later, many plants still struggle with their SO3 mitigation systems or remain undecided on which mitigation path to follow. This article explores
the advantages of dry sorbent injection technology.
Determining AQCS Mercury Removal Co-Benefits
The U.S. Environmental Protection Agency is expected to propose an emissions standard for mercury and other hazardous air pollutants emitted by
coaland oil-fired electric generating units in March of 2011. The anticipated rule would require emission control to meet the various standards using
maximum achievable control technology, as determined by the prescriptive requirements of the Clean Air Act. In response to the expected rule-making,
utilities will be required to make technology decisions in order to ensure compliance. One cost-effective approach to compliance may be the use of
“co-benefits” from air quality control systems (AQCSs) already in service that are designed to remove other pollutants.
Circulating Fluid Bed Scrubbers Bridge the Gap Between Dry and Wet Scrubbers
Circulating fluid bed (CFB) dry scrubbing technologies provide distinct advantages over conventional spray dryer absorber scrubbers for removing
SO2 from flue gases. The CFB also competes well against wet limestone flue gas desulfurization processes typically favored for large boilers firing
high-sulfur coals. With high SO2 removal rates in a dry treatment process, the CFB scrubber appears to be the best of both technologies: a waterstingy
scrubber with high SO2 removal rates.
ReACT Reduces Emissions and Water Use
Regenerative activated coke technology (ReACT) is an integrated multipollutant control approach that removes SOx, NOx, and Hg from coal-fired plants
by adsorption with activated coke to attain emissions levels found at natural gas–fired plants. One big advantage of this technology is that it uses only
a fraction of the water used by conventional wet flue gas desulfurization. A recent license agreement brings this technology to the U.S.
Use Dry Fog to Control Coal Dust Hazards
Fogging systems have been successfully used in the material-handling industry for more than 30 years to control explosive dust at transfer points.
Today, fogging systems are an EPA Best Demonstrated Technology for subbituminous coal preparation plants.
Turning the Heat Up on Carbon Emissions
In June the White House issued a “Climate Action Plan” that increases the pressure on power generators to reduce carbon emissions. U.S. utilities
have already announced the retirement of 60 GW of coal-fired generation by 2020 as a result of current regulations. Unless technological innovation can
beat the regulatory clock (which seems unlikely), more early retirements are ahead.
Advanced SCR Catalysts Tune Oxidized Mercury Removal
Catalysts used in selective catalytic reduction (SCR) systems in utility boilers provide high NOx removal efficiencies that routinely exceed 90%. A major
co-benefit of applying SCR to coal-fired power plants is that the SCR catalyst also oxidizes the vapor phase mercury from an elemental form to a
soluble ionic form, which can be readily captured in a downstream flue gas desulfurization process. Mitsubishi Heavy Industries and Cormetech have
developed an advanced SCR catalyst technology with high mercury oxidation activity capable of achieving 95% oxidized mercury over a wide range of
An SCR Can Provide Mercury Removal Co-Benefits
Complying with various state (and expected federal) requirements governing mercury removal from the stack gas of coal-fired power plants has usually
been achieved by adding an expensive activated carbon injection system. Now there is another alternative: a catalyst that features higher mercury
oxidization activity than conventional catalysts while maintaining the same SO2 to SO3 conversion activity—and all at a lower operating cost. Full-scale
installations are under way at several Southern Company plants that burn a variety of coals.
Improve Plant Efficiency and Reduce CO2 Emissions When Firing High-Moisture Coals
Improving efficiency at existing coal-fired power plants anywhere in the world is a path of no regret: A more efficient power plant uses less coal, has
lower emissions, and experiences lower variable costs. Great River Energy’s Coal Creek Station has demonstrated that by recycling low-grade waste
heat with DryFining, it can reduce emissions, including CO2, and improve plant performance when burning wet coal.
Treating WTE Plant Flue Gases with Sodium Bicarbonate
An economic evaluation plus real-world analysis of plants that converted from lime-based flue gas treatment to sodium bicarbonate treatment found
that although lime systems are more familiar, sodium bicarbonate systems can be more economic for some waste-to-energy (WTE) plants when all
costs and operating scenarios are considered.
The Big Picture: Power Revenues
Solid Fuels: Moving Material and Managing Emissions
In today’s solid-fueled power plant, managing emissions and moving materials more defines the task than the traditional work of making megawatts.
Rethinking Wind’s Impact on Emissions and Cycling Costs
Recent reports by the National Renewable Energy Laboratory and others suggest that the emissions-reducing benefits of renewable energy sources
such as wind and solar may have been overstated and the cost of cycling fossilfueled plants underestimated. These findings may change how utilities
and policymakers weigh the costs and benefits of wind and solar energy
SCR Reheat Burners Keep NOx in Spec at Low Loads
Optimal NOx removal by a selective catalytic reduction (SCR) system requires the inlet gas temperature to remain within a prescribed range. How does
a baseload unit meet NOx permit limits when it’s cycled and SCR inlet gas temperatures dip?