A way to reduce atmospheric concentrations of CO2?
A reader of mine recently e-mailed with a list of ideas on how to deal with our energy and environmental crises. One that struck me as interesting, and I hadn’t given it much thought before, was to use biomass — or municipal solid waste, for that matter — directly as a fuel for generating electricity, combined with the ability to capture and sequester carbon emissions from that approach. In the case of “clean coal,” this ability to capture and store carbon might make a generating plant greenhouse-gas neutral, but in the case of biomass it would actually take carbon out of the atmosphere and put it back into the ground. “Ultimately, I think that we need to put the carbon back where it came from,” said the reader.
Then, today, I was reading reports about British Columbia’s new energy plan, which calls for proposals to produce electricity from sawmill waste, forest slash and trees that have been killed by the notorious pine beetle. The ambitious and comprehensive plan also requires that all new electricity projects, including coal plants, be greenhouse-gas neutral. To do that with coal, however, means employing carbon capture and sequestration (CCS) technology. And if you’re going to do that with coal, why not do it with biomass and actually suck CO2 out of the atmosphere?
After a few Google searches, I realized there’s been a lot of good research in this area. For example, in 2005 a paper published in a journal called Biomass and Bioenergy concluded that gasifying biomass and then using CCS on the carbon emissions “could be roughly cost competitive with more conventional methods of achieving deep reductions in CO2 emissions from electric power.” David Keith, from the department of chemical and petroleum engineering at the University of Calgary, co-authored the paper.
This got me thinking more enthuastically about the potential for CCS. I’ve been down on it because, for one, I’m not convinced yet that permanent sequestration is possible to verify or monitor, or that it actually works. Also, in connection with coal, I thought it merely encouraged our use of fossil fuels at a time when we need to start thinking hard about ways to wean ourselves from them. I do, however, see tremendous potential in gasifying wood and municipal waste and capturing that carbon, if only because it helps to reverse — not just halt or slow down — the growth of atmospheric CO2 concentrations. It’s also a terrific way of getting some value from, and giving more purpose to, the pine beetle-devasted forests of British Columbia.