Featured Research

from universities, journals, and other organizations

Waste Makes Saleable Coal Product

Date:
March 24, 1999
Source:
Penn State
Summary:
High-value carbon products like activated carbons may become a commercially viable by-product of the new, environmentally friendly methods used to burn coal, according to a Penn State researcher.

Anaheim, Calif. --High-value carbon products like activated carbons may become a commercially viable by-product of the new, environmentally friendly methods used to burn coal, according to a Penn State researcher.

Related Articles


"To meet environmental standards for low nitrogen oxide (NOx) emissions, we have redesigned the way we burn coal," says M. Mercedes Maroto-Valer, research associate in Penn State's Energy Institute. "We resolved the environmental problem, but we created other problems."

Coal-fired plants now use low NOx burners to reduce emissions. These burners do the trick, but increase the amounts of unburned carbon left after combustion. Power plants are left with a mixture of fly ash and unburned carbon.

"Before low NOx emission requirements came into being, power plants marketed the fly ash remaining after burning to the cement industry. However, with the higher levels of unburned carbon, this waste by-product can no longer simply be sold," Maroto-Valer told attendees today (Mar. 23) at the annual meeting of the American Chemical Society in Anaheim, Calif. "Now power plants must dispose of the fly ash and carbon mixture and disposal is expensive."

Maroto-Valer; Darrell N. Taulbee, industrial support coordinator for the Center for Applied Energy Research, University of Kentucky, and Harold H. Schobert, professor of fuel science and director of Penn State's Energy Institute, are investigating both fuel and non-fuel uses of coal for the 21st century. One use for both combustion waste and anthracite coal is as activated carbon.

Wood is the traditional source for activated carbon which is sometimes called activated charcoal. Activated carbon traps impurities found in both gases and liquids in pores within the carbon. These carbon products have a huge market with 350,000 tons sold each year for water treatment, gas purification and gold extraction among others. Products as diverse as air conditioning systems, household water purification pitchers and cigarette filters use activated carbon.

"We know we can separate the fly ash from the unburned carbon, and sell the fly ash to cement manufacturers," says Maroto-Valer. "However, until recently, uses for the remaining carbon were unknown because no one had characterized the unburned carbon."

The researchers used both the unburned carbon and anthracite coal to create activated carbon and compared the results from both. After separation from the fly ash, they activated the unburned carbon with steam at 850 degrees Celsius. The unburned carbon contained few volatile components because it had already been heated while in the combustor. The researchers crushed the anthracite before treating it with steam.

"It appears that the unburned carbon is suitable for manufacturing activated carbon products," says Maroto-Valer. "We get high surface area after short activation times and with product yields over 70 percent."

Activated carbon from wood products has about 10 percent yield. The anthracite coal activated for the same amount of time as the unburned carbon had about 59 percent yield, but higher surface area, and the anthracite activated for slightly longer had 33 percent yield and even better surface area.

"If we activated the unburned carbon for longer, we would probably get better surface area at the expense of some yield," says Maroto-Valer.

While both anthracite and unburned carbon can produce acceptable activated carbon, unburned carbon is probably less expensive and better for the environment. Unburned carbon, separated from fly ash, does not need cleaning or crushing, nor does it need heating to remove volatile components. Also, while anthracite sells for about $50 a ton, the waste from power plants can be separated for $10 to $15 per ton, and the fly ash could be sold to cement manufacturers.

"The combustion of 920 million tons of coal generates about 80 million tons of fly ash and unburned carbon as combustion by-products," says Maroto-Valer. "Separating this waste and using both components is certainly more economical and environmentally friendly than simply disposing of the waste."


Story Source:

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


Cite This Page:

Penn State. "Waste Makes Saleable Coal Product." ScienceDaily. ScienceDaily, 24 March 1999. <www.sciencedaily.com/releases/1999/03/990324062002.htm>.
Penn State. (1999, March 24). Waste Makes Saleable Coal Product. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/1999/03/990324062002.htm
Penn State. "Waste Makes Saleable Coal Product." ScienceDaily. www.sciencedaily.com/releases/1999/03/990324062002.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NASA's First 3-D Printer In Space Creates Its First Object

NASA's First 3-D Printer In Space Creates Its First Object

Newsy (Nov. 26, 2014) — The International Space Station is now using a proof-of-concept 3D printer to test additive printing in a weightless, isolated environment. Video provided by Newsy
Powered by NewsLook.com
Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Reuters - Innovations Video Online (Nov. 26, 2014) — Innovative recycling project in La Paz separates city waste and converts plastic garbage into school furniture made from 'plastiwood'. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Blu-Ray Discs Getting Second Run As Solar Panels

Blu-Ray Discs Getting Second Run As Solar Panels

Newsy (Nov. 26, 2014) — Researchers at Northwestern University are repurposing Blu-ray movies for better solar panel technology thanks to the discs' internal structures. Video provided by Newsy
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
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.

Save/Print:
Share:  

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



Save/Print:
Share:  

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