Friday, May 31, 2013

Clean Coal No Longer a Pipe Dream?

A new coal technology may be able to provide commercial electricity without emitting dangerous greenhouse gases.

Every one knows that climate change is a huge problem. If you don't think it is a problem then you are more in denial than the Swiss were during World War 2. But in addition to warming global temperatures, more intense hurricanes and desertification, we face the problem of ocean acidification. Very simply, the increases in atmospheric CO2 is turning the world's ocean (and lakes and ponds) into carbonic acid. The acid is dissolving coral and shellfish, disrupting the ecosystems that depend on those animals. Even climate change deniers can't deny acidification.

Solar and wind are getting cheaper and cheaper. But we still face the problem of how to run our TVs and microwaves when the sun doesn't shine. We also don't have the electric grid infrastructure to get the power from remote solar cells and windmills to American homes.

The coal industry has been pushing carbon capture technology. The emissions of coal fired power plants would be cooled down and passed through a solution which would bind with the CO2. But the world burns more than 8 billion tons of coal annually and this capture process is extremely expensive.

But there may be hope! We may have true clean coal technology soon! A group of researchers is in the process of commercialing coal direct chemical looping. What is that? Well, think about a fuel cell car. The hydrogen is not burning in a fuel cell. It is being oxidized, but it there is no fire and no loss of energy to heat. Instead the energy released is turned straight to electricity. Direct chemical looping is like that but with coal.

Very, very exciting. This technology may allow people to continue to use an extremely cheap, plentiful fossil fuel without causing further global warming.

1 comment:

  1. Cool stuff, but I have some concerns on both the front and back ends of this process. First, according to the OSU article "for CDCL, the fuel is coal that’s been ground into a powder, and the metal beads are made of iron oxide composites. The coal particles are about 100 micrometers across—about the diameter of a human hair—and the iron beads are larger, about 1.5-2 millimeters across." Materials are expensive and energy intensive to produce at such scales, so an overall efficiency would have to account for this. Second, there will still be the issue of what to do with that CO2 solution. If it is in fact very clean, maybe they could bottle it and add some flavoring! But more likely we'll need some large resevoir to bury it in, again, at some cost ... I still think that our only real way out of the energy crisis is the combination of non-fossil-fuel sources (wind, tidal, less solar) and more important, societal and behavioral adaptations to broadly improve efficiency. Things like living closer to work, using less disposable crap, and generally conserving, while difficult to motivate, would be true wins in that beyond the perceived inconvenience, there are no downsides.

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