Pulling carbon out of the air (and out of coal smokestacks) just might be possible
Admittedly, no one thinks clean coal is oxymoronic and misleading more than I do. That said, we do appear to be hell bent on funding carbon capture and sequestration systems for coal-fired power plants. The real problem with CCS, of course, isn’t so much the capture part as the sequestration part. What do you do with all that carbon that you’re pulling out during coal combustion. The main technologies under consideration involve pulling the carbon out of the exhaust gases, then liquifying it and injecting it underground. That last part is a technology originally developed by the oil industry for keeping dying oil wells productive (the carbon dioxide forces more oil out of the ground). Cost aside, the problems with applying that technique are pretty obvious — every coal-fired power plant would need to be sited somewhere near an appropriate storage location or we’d need to build a network of tubes to shift the liquified CO2 around. That, as Winnie-the-Pooh would say, is not a good plan.
So, if President Obama is going to insist on shoveling money into CCS research, I recommend he have Energy Secretary Chu get in touch with these folks. Via Science Magazine ($ub req):
If international agreements can’t slash carbon dioxide emissions fast enough to tame global warming, how about sucking it out of the air? Technology using chemicals that bind CO2 already exists, but it’s so expensive that using it on a large scale could increase energy demand — and the cost of energy — by at least one-third.
… However, researchers in the Netherlands report a new copper-based catalyst that can capture CO2, convert it to a different form, and then release it with a small fraction of the energy other techniques require. “This is an important fundamental advance,” says William Tolman, an inorganic chemist at the University of Minnesota, Twin Cities. “But there’s a long way to go before you could turn it into a catalytic process” for reducing atmospheric CO2, he adds.
Sure, sure, it’s not ready for industrial applications — but still very promising. The article seems to be talking in terms of a free-standing method for pulling carbon out of the air, but it strikes me as an ideal solution to the S part of CCS. The researchers converted that carbon to an oxalate, which is the building block of various chemicals, from wood alcohol to antifreeze. The important aspect here is that you want to fix that carbon in some permanent manner — not reuse it as fuel or something, which would release it right back into the atmosphere. By turning the carbon into a solid or room temperature liquid, you make storage that much easier. If I had to choose a path of research to throw a billion or two at, this would be it.