Musings of the Technical Bard

Lawrence Solomon has an excellent article in the National Post concerning the concept of carbon-capture and sequestration and the fact that the sequestration step is a problem that has not been shown to be particularly safe nor reliable.

Admittedly, CO2 has been injected into oil fields around North America in significant quantities to enhance oil recovery, and there has not yet been a major accident or release from these facilities or from the underground reservoirs themselves.   Additionally, facilities exist where a mixture of CO2 and H2S (itself highly toxic) have been injected into reservoirs for disposal to avoid having to make elemental sulfur from the H2S (which for many years was not economic).  Such facilities exist in Canada in  British Columbia, Alberta and Saskatchewan, and in the United States in Texas, Oklahoma and New Mexico to name a few.

The problem is that most of these facilities are injecting a few hundred tonnes of CO2 per day at the most – not the tends of thousands or millions of tonnes of CO2 that will need to be sequestered in order to reduce emissions without restricting economic activity.   Additionally, the scale and location of many of these facilities are such that even if there was an incident, the population densities are low and are unlikely to result in casualties.

As an engineer, I would like to believe that we can design these systems safely – but I know that we cannot design them to be absolutely safe, especially considering all the unknowns about the geology we would be injecting CO2 into.  Geologists have a lot of good data – but they cannot have the perfect knowledge to know where every little fault is, or what effect increased pressures (and changes in water chemistry) will have on the rocks…  So this is a large part of the uncertainty.  I will admit that many old natural gas reservoirs have held high pressures for millions of years – but they didn’t have a lot of holes punched through their cap rocks, nor were they subject to a rapid (in geological terms) depressuring (natural gas production) and repressuring (CO2 sequestration) – so we cannot be certain that something horrendously bad could happen.

So the question of spending billions of dollars on a quest to achieve something to stop a problem we can’t be certain is even real (and that any sequestration will be far to small to be effective in any event) is one I think the answer to is obvious.  Don’t waste our money and don’t risk it.