As jeffhoard had pointed out, "clean coal" may refer to coal burning processes that rely on carbon capture and storage to reduce the amount of carbon dioxide that is released into the atmosphere, and is generally what folks in the media are referring to. He also touched a bit on coal washing. As he also had pointed out, there are other meanings to the term.

"Clean coal" can also reference harder types of coal (e.g. anthracite), which tend to contain less sulfur and produce more energy and less pollutants when burned than softer types of coal (e.g. bituminous coal and lignite). Though, harder coals are rarer than softer coals in terms of their occurrence in the earth. Pennsylvania has one of the largest deposits of anthracite on Earth, but it sure doesn't help matters much that some of these veins have been burning underground for more than four decades.

"Clean coal" may also refer also refer to fitting the flues of coal-powered plants with "scrubbers." Scrubbers are used to reduce the amount of particulate matter that is released into the atmosphere. Scrubbers may utilize steam or devices containing sorbent materials to trap certain materials. Scrubbers tend not to reduce the amount of gasses released from burning coal into the atmosphere.

"Clean coal" may also be in reference to coal that is burned in combustion chambers. These chambers help prevent the formation of nitrous oxides.

As far as I and many other folks are concerned, no matter how little sulfur content "clean" coal may contain and how little carbon dioxide may released into the atmosphere because of clean coal practices, there are still many other environmental hazards that result from coal mining. Surface mining tears up mountains, making large areas subject to erosion, and is incredibly unsightly. Coal mines produce acid run-off, which harms many organisms. Mining places miners at incredible risks. Miners do not only have to worry about possible mine collapses, but are at great risk for many respiratory ailments.

I can't help but to wonder about the effect carbon capture and storage will have on the environment. Sure, it might end up reducing the amount of carbon dioxide in the air, but I can't help to wonder how subterranean organisms will be affected by high concentrations of carbon dioxide. And I imagine that this carbon dioxide would also chemically affect certain rocks, which would in turn affect the stability of rock layers and water in any nearby aquifers.

I know that you weren't asking for my opinion, but I am one of those folks who thinks that "clean coal" is an oxymoronic term.
Source(s):
http://www.helium.com/items/1127402-alternative-fuel-and-unaffordable-oil-a...
http://www.green-planet-solar-energy.com/forming-fossil-fuels.html
http://fossil.energy.gov/education/energylessons/coal/index.html
http://www.cbsnews.com/stories/2008/06/20/eveningnews/main4199506.shtml
http://www.washingtonpost.com/wp-dyn/content/article/2008/02/29/AR200802290...
my B.S. in Environmental Science and Studies


Permalink | Report