I’ve heard suggestions involving burying, sticking in oceans, filling mines with it, blowing it into oil wells. While the oil well option sounds like it might work a bit (they currently pump salt water into a lot of ‘em to keep the flow going): I don’t really see how you can capture all (or even a significant portion) of the CO2 and stuff it in there (last time I checked the oil rigs weren’t exactly near to power stations either). None of these options sound like a particularly permanent solution or likely to be able to account for a decent chunk of the emissions.

Here’s a novel idea: if you want the CO₂ back in the ground so much: don’t dig the bloody stuff up in the first place! Yet still the politicians believe this will surely work, yes that’s right they have lots of faith in this energy industry quackery. It’s akin to the cigarette industry saying people don’t need to stop smoking because one day there’ll be a cure for cancer soon enough.

Whatever the solution it’ll most likely be expensive, require large changes to infrastructure and require quite a bit of energy to do. Yet it has widespread professed support from the energy industry, you know: the same industry that baulks at anything other than coal (e.g. solar, wind, tidal, nuclear) because of the above reasons (too expensive, requires new infrastructure and still requires energy to build everything).

A Time article by Bryan Walsh points out another issue with Coal fired power stations: the ash left over after you burn it (and have the goblins and fairies take away the CO₂ in little balloons or something) is pretty nasty stuff. In an accidental spill of coal ash/water a power plant in Tennessee Valley, USA has “released 100 times more waste than the Exxon Valdez disaster“, wiped out property and polluted the waterways with all of the nasty stuff that still lurks in coal after it’s been converted into airborne pollutants and power for those flat screen TVs and air conditioners we all know and love.

So not only do you have massive amounts of this toxic slurry to get rid of still but the information has been floating around for years that coal power stations release more radioactive substances into the atmosphere than nuclear ones, and the ash also contains the nasty radioactive stuff. To what extent that is true is a bit trickier to figure out due to the battle of misinformation that went on back a few decades ago. Given anything dug out of the ground tends to have radiation of some sort (e.g. household bricks leak small amounts of radiation) it stands to reason that coal would have that too, difference is that it is getting burnt (so would release that into the air in some quantities) but the real problem is the heavy metals and other “hostile to humans” stuff in the ash by the sounds of it.

I found a fact sheet that has an analysis of some coal from the USA and what it typically contains (from Radioactive Elements in Coal and Fly Ash:
Abundance, Forms, and Environmental Significance). Their conclusion:

Radioactive elements in coal and fly ash should not be sources of alarm. The vast majority of coal and the majority of fly ash are not significantly enriched in radioactive elements, or in associated radioactivity, compared to common soils or rocks. This observation provides a useful geologic perspective for addressing societal concerns regarding possible radiation and radon hazard.
The location and form of radioactive elements in fly ash determine the availability of elements for leaching during ash utilization or disposal. Existing measurements of uranium distribution in fly ash particles indicate a uniform distribution of uranium throughout the glassy particles. The apparent absence of abundant, surface-bound, relatively available uranium suggests that the rate of release of uranium is dominantly controlled by the relatively slow dissolution of host ash particles.
Previous studies of dissolved radioelements in the environment, and existing knowledge of the chemical properties of uranium and radium can be used to predict the most important chemical controls, such as pH, on solubility of uranium and radium when fly ash interacts with water. Limited measurements of dissolved uranium and radium in water leachates of fly ash and in natural water from some ash disposal sites indicate that dissolved concentrations of these radioactive elements are below levels of human health concern.

I don’t think having the water/ash mix free and easy through the waterways would really constitute an environment that you’ll be able to control the pH or final destination of the particles much. Subsequent human/animal ingestion of said particles probably won’t be great either, but seems fairly upbeat about the danger it poses “below levels of human health concern”. So perhaps the radiation won’t kill you, but all the other nasty stuff might.

Regardless of how nasty and in what way the ash is, I think everyone knows coal is a dirty industry. Deadly if you consider how many people die in coal mines worldwide. We built our modern world on burning whatever crap we could (wood, dung, peat, coal, oil, gas) and now we need to clean our act up. While we continue to be stuck burning things to release their energy there’s likely to be stuff pumping into the atmosphere that we can’t sensibly prevent (at least not without using a significant chunk of that energy we’re trying to produce in the first place) so the best course of action is simply not commit ourselves to having to burn the stuff in the first place.

Containing and collecting gasses will always be tricky or require energy to convert them into something that won’t just float on up to mess up the climate so how about something a bit less aesthetically challenged and which we know works:

Renewable energy is much prettier huh? (in Germany, near border of belgium. )

Perhaps then we’ll spend less time on CO₂ pie in the sky solutions and more on something real,
Nathan