Featured Research

from universities, journals, and other organizations

Boiler Modifications Cut Mercury Emissions 70 Percent Or More, Research Team Finds

October 4, 2005
Lehigh University
Lehigh University research team achieves reductions in emission of the toxic element by altering flue-gas temperature, size of coal particles burned and other physical conditions. They say their new technique could save a 250-megawatt power unit as much as $2 million a year in mercury-control costs. The researchers' findings will be reported in an upcoming issue of the journal Fuel.

Researchers at Lehigh University's Energy Research Center (ERC) havedeveloped and successfully tested a cost-effective technique forreducing mercury emissions from coal-fired power plants.

Related Articles

In full-scale tests at three power plants, says lead investigatorCarlos E. Romero, the Lehigh system reduced flue-gas emissions ofmercury by as much as 70 percent or more with modest impact on plantperformance and fuel cost.

The reductions were achieved, says Romero, by modifying the physicalconditions of power-plant boilers, including flue gas temperature, thesize of the coal particles that are burned, the size and unburnedcarbon level of the fly ash, and the fly ash residence time. Thesemodifications promote the in-flight capture of mercury, Romero said.

The ERC researchers reported their findings in an article titled"Modification of boiler operating conditions for mercury emissionsreductions in coal-fired utility boilers," which will be published in aforthcoming issue of the journal Fuel.

Mercury enters the atmosphere as a gas and can remain airborne severalyears before it precipitates with rain and falls into bodies of water,where it is ingested by fish. Because mercury is a neurotoxin, peoplewho consume large quantities of fish can develop brain and nervousailments. Forty-four states have mercury advisories.

Coal-fired power plants are the largest single-known source of mercuryemissions in the U.S. Estimates of total mercury emissions fromcoal-fired plants range from 40 to 52 tons.

The U.S. Environmental Protection Agency last March issued itsfirst-ever regulations restricting the emission of mercury fromcoal-fired power plants. The order mandates reductions of 23 percent by2010 and 69 percent by 2018. Four states - Massachusetts, New Jersey,Connecticut and Wisconsin - issued their own restrictions before theMarch 15 action by the EPA.

The changes in boiler operating conditions, said Romero, preventmercury from being emitted at the stack and promote its oxidation inthe flue gas and adsorption into the fly ash instead. Oxidized mercuryis easily captured by scrubbers, filters and other boilerpollution-control equipment.

The ERC team used computer software to model boiler operatingconditions and alterations and then collaborated with Western KentuckyUniversity on the field tests. Analysis of stack emissions showed thatthe new technology achieved a 50- to 75-percent reduction of totalmercury in the flue gas with minimal to modest impact on unit thermalperformance and fuel cost. This was achieved at units burningbituminous coals.

Only about one-third of mercury is captured by coal-burning power plantboilers that are not equipped with special mercury-control devices,Romero said.

Romero estimated that the new ERC technology could save a 250-megawattpower unit as much as $2 million a year in mercury-control costs. Thesavings could be achieved, he said, by applying the ERC method solelyor in combination with a more expensive technology called activatedcarbon injection, which would be used by coal-fired power plants toreduce mercury emissions. The resulting hybrid method, says Romero,would greatly reduce the approximately 250 pounds per hour of activatedcarbon that a 250-MW boiler needs to inject to curb mercury emissions.

The new ERC technology was developed by Romero, ERC director EdwardLevy, ERC associate director Nenad Sarunac, ERC research scientistHarun Bilirgen, and Ying Li, who recently received an M.S. inmechanical engineering from Lehigh.

The breakthrough follows years of work by ERC researchers in optimizingboiler operations to control emissions of NOx, CO, particulates andother pollutants.

For their mercury-emission research, the ERC group received atotal of $1.2 million in funding from a consortium of utilitycompanies, the Pennsylvania Infrastructure Technology Alliance and theU.S. Department of Energy.

It is expensive to check for levels of mercury emissions, says Romero,because mercury levels are measured in parts per billion, while NOxlevels are measured in parts per million.

The ERC tests were performed at a power plant in Alexandria, Virginia,and at two units of a power plant in Massachusetts. The ERC and WesternKentucky University will conduct tests next year at an additional unitfiring Powder River Basin sub-bituminous coals.

Romero discussed his group's findings at the 2004 PittsburghCoal Conference in Osaka, Japan, where he gave a paper titled "Impactof Boiler Operating Conditions on Mercury Emission in Coal-FiredUtility Boilers."

He has given half a dozen presentations on his group's findings so farthis year, including an address at the ICAC (Institute of Clean AirCompanies) Clean Air Technologies and Strategies Conference inBaltimore in March.

Story Source:

The above story is based on materials provided by Lehigh University. Note: Materials may be edited for content and length.

Cite This Page:

Lehigh University. "Boiler Modifications Cut Mercury Emissions 70 Percent Or More, Research Team Finds." ScienceDaily. ScienceDaily, 4 October 2005. <www.sciencedaily.com/releases/2005/10/051004084651.htm>.
Lehigh University. (2005, October 4). Boiler Modifications Cut Mercury Emissions 70 Percent Or More, Research Team Finds. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2005/10/051004084651.htm
Lehigh University. "Boiler Modifications Cut Mercury Emissions 70 Percent Or More, Research Team Finds." ScienceDaily. www.sciencedaily.com/releases/2005/10/051004084651.htm (accessed December 19, 2014).

Share This

More From ScienceDaily

More Matter & Energy News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations

Featured Videos

from AP, Reuters, AFP, and other news services

Building Google Into Cars

Building Google Into Cars

Reuters - Business Video Online (Dec. 19, 2014) Google's next Android version could become the standard that'll power your vehicle's entertainment and navigation features, Reuters has learned. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
AP Review: Nikon D750 and GoPro Hero 4

AP Review: Nikon D750 and GoPro Hero 4

AP (Dec. 19, 2014) What to buy an experienced photographer or video shooter? There is some strong gear on the market from Nikon and GoPro. The AP's Ron Harris takes a closer look. (Dec. 19) Video provided by AP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.


Breaking News:

Strange & Offbeat Stories

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News


Free Subscriptions

Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile

Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?

Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins