Saturday, August 12, 2006

Carbon dioxide capture and sequestration

Some very interesting articles about carbon capture and sequestration have been recently published. Rising levels of carbon dioxide have been implicated in global warming. Current levels of CO2 are at around 380 parts per million (ppm). Anything above 550 ppm is thought to be very damaging to the planet.

That level will be surpassed if we continue burning coal for power. The world's energy needs are growing at a rate that can only be met through coal burning (nuclear power would be the ideal solution, but for the moment nuclear is persona non grata thanks to environmentalists). Expect a doubling of coal fired plants in the next 25 years, along with increased levels of CO2 gases.

What can be done? Certainly alternative fuels are on everyone's list of dream solutions, but they remain unobtainable. Therefore, some method of mitigating the damage from coal plants must be found.

That method may be CO2 sequestration (some form of pumping liquified CO2 back into the earth or under deep-sea sediments). I've blogged on the subject here and here, and just came across two articles on Nature's website.

The first provides background on the problem with coal-fired plants, and a detailed discussion of land based sequestration. It also goes into the mammoth task of collected, purifying, transporting, and then pumping the enormous quantities of CO2.

The second deals with turning excess CO2 into a form of charcoal that is then mixed in with soil, producing a sort of super-rich soil, while also sequestering the CO2. The process is said to remove more CO2 from the atmosphere than enters it. Sounds pretty far out, but should it be economically feasible, it could deal with all of the carbon emitted by the burning of fossil fuels. Not that such a scale is likely, and there are other problems with the process, but it does show the possibilities for dealing with global warming.

While it remains to be proven that Man is mostly resonsible for global warming, it is up to us to be ready with solutions should the dire predictions prove true.