Posted on 02/13/2013 1:43:52 PM PST by Red Badger
A technology for generating electricity from coal without pollution achieves a milestone.
Coal is abundant and cheap, but burning it is a dirty business. This week researchers at Ohio State University announced a milestone in the development of a far cleaner way to use the energy in coal—a process called chemical looping that has the potential to reduce or eliminate a wide range of pollutants, including carbon dioxide and smog-forming nitrogen oxides.
One version of the technology ran continuously for over a week in a 25-kilowatt test facility, the researchers reported, the longest any such process has run. The successful test clears the way to ramp up the technology in a one-megawatt demonstration plant that’s being planned in collaboration with the energy company Babcock and Wilcox.
In ordinary coal plants, coal is pulverized to make a fine powder and then burned in air to produce steam to drive turbines. This process makes very hot flames that can create the pollutant nitrogen oxide, and the carbon dioxide generated is difficult to isolate and capture because it makes up only a small fraction of the exhaust gases.
In chemical looping, coal doesn’t react with air. Instead, it’s exposed to oxygen-bearing materials such as iron oxide. The coal reacts with these materials, and the energy bound up in coal breaks the bond between the oxygen and the iron. The reaction produces nearly pure carbon dioxide gas and iron metal (along with the mineral wüstite). Electricity is generated when the iron is moved out of the reaction chamber and is essentially burned—that is, allowed to react with oxygen in air. This releases heat to produce steam.
This rather convoluted process has at least two advantages. It produces a pure stream of carbon dioxide that’s easy to capture and ready to be stored underground. And the burning of iron in air also takes place at lower temperatures that don’t produce nitrogen oxide.
The process was originally suggested as a way to improve the efficiency of power plants. Now the hope is that it could, if deployed at a large scale, be one of the cheapest ways to reduce carbon dioxide emissions, leading to only a small increase in the cost of electricity.
An alternative approach to producing high-purity carbon dioxide streams is to burn coal in pure oxygen. But the equipment for producing pure oxygen is expensive.
Liang-Shih Fan, a professor of chemical and biomolecular engineering at Ohio State, says that his process could prove inexpensive. He says others have had difficulty using iron oxide because of its limited ability to carry oxygen. But he’s developed a new type of reactor that enhances the practical oxygen-carrying capacity of the iron oxide, decreasing the amount of material needed and improving the economics.
The Ohio State researchers are also pursuing another version of chemical looping, in which coal is gasified and the resulting combination of hydrogen and carbon monoxide gases, called syngas, reacts with the iron oxide (see “Using Rust to Capture CO2 from Coal Plants”). Construction has started on a 250-kilowatt pilot plant to test that approach. The recent test eliminates the gasification step by using pulverized coal instead of syngas, so it could potentially be cheaper.
The work is funded by the Department of Energy’s National Energy Technology Laboratory, which helped develop the fracking technology behind the current natural gas boom in the United States. NETL is also funding another approach to chemical looping, which uses calcium sulfate rather than iron oxide. That technology, which is being developed by Alstom, was demonstrated in a three-megawatt facility last year. The Ohio State work is at an earlier stage, but Fan says his approach could use far less material, making it more practical.
Bump
The article fails to make proper attribution.
The name Wüstite was suggested to MIT as an honor for President Obama's effort in killing the coal industry (the name itself was the nickname given Obama by his brothers at Manscountry in Chicago).
No, no no, you have it misspelled! It’s WAS-TITE.......
Chris Dorner says that's racist.
Okay, burn FIRST, THEN pulverize into a fine powder........
Curious how they “react” the coal with the iron oxide.
Do they just mix the two and heat them, and then the oxygen transfers from the iron to the coal? How hot does it have to get? Could this be a low-energy way to recycle rusty metal into iron?
And then they’ve got something like pure iron - how do they get it to “burn” in the oxygen in the air? It doesn’t seem to burn (rust) very quickly in normal experience. Does iron dust burn if you light it with a match?
Thorium can be extracted from coal. It can then be used to power a Liquid Fluoride Thorium Reactor. Once the thorium is extracted the “waste” coal can be liquefied into synfuel using the heat from the reactor.
That should give us about 500 years of total energy independence just on our coal reserves alone.
Thorium is an abundant resource. So abundant that it could supply the planets total energy needs for literally hundreds of thousands of years.
Cheap, efficient, and green energy. All we have to do is convince our government to allow a reactor to be built.
Wait....never mind.
A couple of years ago I met a scientist who was inventing a FUEL CELL that utilized coal.
No burning or heat or steam involved. It was about 90% efficient.
Any process which depends on storing CO2 underground is not a good one. It will be expensive and those who still believe that CO2 is creating catastrophic climate change won't be satisfied that it won't leak out causing chaos.
CHAOS, I tell you.
How much Federale money did they suck off the Gov't tit? They did all this "work" to figure out how to remove CO2 from the coal burning making>>>>electricity process. All because Obama style socialist want to make a huge power grab in the name of global warming or climate change or whatever they call it this week
When I was about 7 or 8 yrs old a neighbor, high school age,
was filing an axe. He asked me if steel would burn, I said no. He burned the filings from the axe. He joined the army
and got sent to Alaska in 1950. Did not see him again until about three months ago. He had moved back to my old home
town and I was visiting there. Steel burns,
How is that even possible?........
http://pubs.rsc.org/en/content/articlelanding/2012/ee/c2ee03198a
http://en.wikipedia.org/wiki/Chemical_looping_combustion
Possible thru cool electrochemistry.
There are many fuel cells that run on hydrocarbons.
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