First, a definition of terms. When the report says "sequestration," it's referring to geological sequestration of carbon dioxide, essentially injecting the stuff into underground wells. There have been many other methods of carbon sequestration suggested, everything from feeding it to algae to sucking it from the air with giant, artificial trees, but the report doesn't go into those methods. So let's stick with the topic at hand – burying it. The crux of the study's argument is that we've drastically underestimated the amount of space we'll need to do so:
So, let's assume the study is correct and we need between 500 to 2000 percent more space for geologic CCS. No problem, if there's one thing the U.S. has, it's space a plenty, right? Not so fast. The study concludes:Published reports on the potential for sequestration fail to address the necessity of storing CO2 in a closed system. Our calculations suggest that the volume of liquid or supercritical CO2 to be disposed cannot exceed more than about 1 percent of pore space. This will require from 5 to 20 times more underground reservoir volume than has been envisioned by many, and it renders geologic sequestration of CO2 a profoundly non-feasible option for the management of CO2 emissions.
The size of a small state? Holy Delaware! As the country moves toward more and more plug-in vehicles, we'll be slowly moving away from carbon-rich liquid fuels, but if the nation continues to get a large portion of its grid power from burning coal, and if CSS really is as unfeasible as this report suggests, start looking for those giant, carbon dioxide-sucking trees to start popping up like dandelions.In applying this to a commercial power plant the findings suggest that for a small number of wells the areal extent of the reservoir would be enormous, the size of a small U.S. state. Conversely, for more moderate size reservoirs, still the size of Alaska's Prudhoe Bay reservoir, and with moderate permeability there would be a need for hundreds of wells. Neither of these bodes well for geological CO2 sequestration and the findings of this work clearly suggest that it is not a practical means to provide any substantive reduction in CO2 emissions, although it has been repeatedly presented as such by others.
[Source: Treehugger | Image: americaspower – C.C. 2.0]