Carbon storage might not be so permanent

Okay, as far as the concept of carbon capture and storage goes,  the idea — technologically — is intriguing. What many readers of this blog don’t like is how the industry talks about this technology like it’s here today so, hell, let’s drill for even more oil and burn more coal. We’re a decade away from seeing even just a small number of large-scale CCS projects in operation, so talk today of coal plants or oil-sand operations being “CCS-ready” is nothing more than greenwashing. I would imagine most people don’t mind the Canadian government supporting R&D into CCS, but what they perhaps don’t like is that the investment is being made to the exclusion of everything else. Why, it’s reasonable to ask, take a silver-bullet approach to a technology that’s a decade away? Would it not be better to balance it with near-term measures and investment in technologies that are here today?

But let’s assume, a decade out, that all the promise of CCS pans out. Let’s assume it takes hold, that a vast network of pipelines is built, that we’re certain sequestration sites won’t leak, and that the percentage of CO2 we can capture from coal plants and industrial sites continues to improve. Let’s assume that two decades out we start to see a number of acquifers and old oil fields filled to capacity with CO2 and, finally, capped shut.

Think those storage sites will be forever permanent? Think again.

I was talking recently with someone heading up a government algae-based carbon recycling program. The goal of this program is to come up with an economic way to divert CO2-rich flue gases from industrial sites and coal plants to nearby enclosed algae farms. The algae would “eat” the CO2, grow quickly, and then be harvested to make a combination of products, from biodiesel and ethanol to protein feed for livestock. I’m probably not telling you anything new — there are dozens of companies out there trying to do the same thing.

But then this person, who shall remain nameless, says something that caught my attention. He called all those storage sites “gold mines of the future.” At first I didn’t get what he was saying, then I realized the significance of that comment. He was basically saying that, down the road, algae farms could be created right on top of CO2 storage sites. The farms could be designed to pump this CO2 back to the surface, giving them a predictable stream of relatively pure algae food. An earlier scenario would be to build these algae farms at CO2 pipeline hubs. Either way, it would be much more economical than building an algae farm/processing plant next to each and every coal plant or aluminum smelter.

There’s a part of me that loves this idea, and there’s a part that asks: Shouldn’t we leave this stuff alone? Sure, the biodiesel and ethanol and other chemical products made from this algae will presumably displace the use of oil down the road. But given that, long term, we’re going to need an 80 per cent reduction in CO2 emissions globally, developing infrastructure for this would seem to undermine this target.

It made me realize that short- and medium-term ideas, despite there merit, need to be considered as part of a larger long-term picture. CO2 stored, assuming we can ever make it work to the scale that’s necessary, is probably best if capped shut and left alone.

3 thoughts on “Carbon storage might not be so permanent”

  1. We are working on creating a centre of knowledge, capacity-building and research on the potential biochar has in the province of Ontario. Biochar is charcoal, formed by roasting plant material in an oxygen starved environment. This process is known as pyrolysis or gasification. The resulting remains of this process are not ash but char. Char has a high carbon content and it is almost inert. It is somewhat akin to a fossilization or mineralization of the carbon that originally made up the cellular structure of the plant. This is different from burning and different from decomposition, both being processes which release the carbon stored in the plant material back to the atmosphere through their chemical or biological processes. Such char has been found in soils and estimated to have been there in that unchanged state for in some cases thousands of years. If you stick a raw peanut onto a pin and ignite it, you will be gasifying or pyrolysing the peanut, since the oils boiling out of it keep oxygen away from the peanut’s surface. The oil’s vapours burning above the peanut provide the energy that chars the peanut below. When all the oils run out, the flame extinguishes and you are left with not ash, but a char structure resembling the former peanut. Once it cools you can crush it in your fingers and see that there is no ash, only what seems and is, mostly carbon. The carbon in the peanut has remained while the flammable gases have escaped. The flammable gases, which produce the amazingly long-lasting and bright flame, were multiple factors more than hot enough to roast another batch of cellulose equal in size and weight to the original peanut. This is an important aspect, since it means that that peanut could roast the next peanut, that peanut could roast the next, and so on. Even wood instead of peanuts as a feedstock produces this positive net energy output. This means that instead of releasing the carbon along with the energy as happens when burning wood, charring wood keeps the carbon but releases the energy. This means it not only sequesters carbon in a solid form -much safer against inadvertent releases, but it gives off more energy in the form of this syngas than it takes to release that energy via roasting. Experts have been therefore classifying it as a carbon-negative process. Furthermore there have been a number of field trials showing that such carbon can enhance otherwise weak soils, improving the options that farmers have in transitioning from or keeping from using, petrochemical soil additives. Watch for field trials of such Ontario produced biochar as spring approaches. Any readers interested in this from whatever angle should contact us, you can write to this address: jpwarren@interlog.com to connect to this group.

  2. Short and medium term planning is what has led us the current problem.

    Many technologies have been developed over many, many years but have been discarded as the cost at the time would have been prohibitive and we had relatively cheap fossil fuels to burn – the impact on the environment was not a concern. When you see the waste from burning fossil fuels – 57 years ago London suffered from smog due to the vast number of coal fires burning throughout the city.
    To quote the BBC website “Officials believe that as many as 12,000 people may have died in the great London smog of 1952.”
    A clean air act was implemented and London changed dramatically – how come we have not acted the same way with cars exhausts and many other polluting machinery?
    We just look at the short term – hence the power of the Native American saying “We borrow the earth from our children.”

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