Balneus

Australian Lefty on Politics, Governance, Science and Info Management

Otways Carbon Capture: Dumb idea?

Posted by Dave Bath on 2008-05-25


We already have a proven and widely used means of carbon capture and storage that does not threaten a massive disaster as pumping CO2 underground does, yet the latte drinkers who consider themselves green hate it.

Ideally, carbon capture should be to a solid that will not degrade over time, and needs minimal technology to contain it.  Non-biodegradable plastic bags meet such requirements.  Further, if they are collected into one spot, they can be retrieved later, when technology allows efficient conversion to other useful items.

Pumping CO2 underground, however, is something that could be worrying, especially the current project in the Otway basin in my old stomping ground of South-Western Victoria.

Natural CCS disasters

There are numerous limnic eruption disasters where CO2 has wiped out all animal life in a fairly large area, the 1986 Lake Nyos event in Cameroon being perhaps the best known.

The CO2-rich cloud was expelled rapidly from the southern floor of Lake Nyos. It rose as a jet with a speed of about 100 km per hour.  The cloud quickly enveloped houses within the crater that were 120 meters above the shoreline of the lake.  Because CO2 is about 1.5 times the density of air, the gaseous mass hugged the ground surface and descended down valleys along the north side of the crater.  The deadly cloud was about 50 meters thick and it advanced downslope at a rate of 20 to 50 km per hour.  This deadly mist persisted in a concentrated form over a distance of 23 km, bringing sudden death to the villages of Nyos, Kam, Cha, and Subum.

Lake Kivu, which is much bigger than Nyos, and has 2 million people around it’s shores, is considered dangerous… so dangerous, that it is one lake under consideration for "outgassing" – pumping CO2 from the bottom of the lake into the air.

Mind you, the biggest CO2 eruptions are linked to massive global warming at the start of the Eocene, and the mass global extinctions of the Permian.

Otway Basin Project

The A$30 million pilot project to inject CO2 into a depleted gas field in the Otways basin might create conditions leading to something akin to a phreatic eruption, as the Otways are in a region that, on a UWA page, "was an active volcanic province in relatively recent times", a few thousand years ago, and with Richter 5.3 earthquakes hitting Cape Otway in my own lifetime (24 Dec 1960), and Warrnambool in 1903. (See map of earthquake epicentres in South-Western Victoria.)

CO2CRC.com.au, running this project, publishes a Lake Nyos fact sheet, and explains that the Otways are different (yes, of course!), and that therefore the Otways project is safe (not necessarily, because other mechanisms could be involved).  Perhaps CO2CRC were setting up a straw-man objection?  CO2CRC’s promotional materials about CCS being safe mention risks from heat and earthquakes as being real, but not a problem.  I’m more skeptical: and remember, we are talking about storage of geologically significant amounts of CO2 for a geologically significant time.

Indeed, those promotional materials indicate there are no guidelines for considering seismic safety yet in place:

Storage sites are selected because they are inherently stable, have effective seals, and are located away from areas of seismic instability. Criteria for considering seismic effects in site selection are being developed.

From a 2004 ABC Science report:

Bernie Joyce, from the University of Melbourne, presented a paper on volcanic hazards today at the 17th Australian Geological Convention of the Geological Society of Australia held in Hobart, Tasmania.  Volcanoes in Victoria, New South Wales and Queensland could erupt at any time, he told ABC Science Online ahead of the conference.

It’s also worth noting that many scientists are worried about clathrates (sequestered carbon in undersea "ice") causing massive releases of CO2, a positive feedback component of global warming, and linked to mass extinctions in the Permian, and the global warming at the start of the Eocene.

So, if CCS is an untested technology, and little thought is given to the dangers of containment failure (at least with a nuclear accident there are some medical treatments available – with CO2 eruptions everything is dead in seconds), then either we assess the dangers properly (a large and hot explosion simulating earthquakes and/or vulcanism near the pilot project would be required) or we’d be better off burying plastic bags.

Personally, rather than encourage activities (Carbon release) we know to be harmful by the promise of an unproven technology, I’d rather the money was spent on efficiency, wind/hydro/solar, or installing a Toshiba 4S Personal Reactor (picture, US Dept of Energy notes, and on sale soon costing half grid cost) in every residential block.


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5 Responses to “Otways Carbon Capture: Dumb idea?”

  1. Anne Cox said

    This is a great report, thanks. On 14th June I will be at a meeting to discuss the replacement of the Open University’s Environment and Technology first level course which I tutor.
    I will be printing this article and referring the course team to your blog for up to date info.

    Thanks a lot
    Ecoanne

  2. danny said

    “We already have a proven and widely used means of carbon capture and storage that does not threaten a massive disaster as pumping CO2 underground does…”

    For a minute there I thought you were going to say…

    !!! Trees !!!

    I was down the (Gold) Coast on the weekend and looking out the window could see the (quite large but not as big as an oil rig) desalination rig out in the middle of Kirra bay. On the drive home I saw a sign saying the water grid will be ready in a few months.
    Looks like we’re in for an engineered dystopia future alright.

    Did they have latte trees in the Garden of Eden? Maybe that’s the one the serpent was in.

  3. Dave Bath said

    Danny – yeah – “trees” is a good answer – but the “plastic bags” is also valid, but counter-intuitive idea (and I love counter-intuitive propositions – much more likely to prompt thinking in readers, which may in turn give rise to entirely unexpected solutions).

    Mind you, there are lots of other reasons for abolishing plastic bags, but then again, plastic bags are better than paper ones, or even the re-use bags you get in supermarkets that don’t have lids on them – because if it’s raining, the shopping gets wet if you are walking – so you’ll drive the car.

    The other thing about trees is that is depends what you do with them (furniture good carbon capture, burning bad!) and old growth forests (good for biodiversity) have pretty much stopped growing, and don’t take up anywhere near as much carbon as young trees. Indeed old growth forests can be net carbon producers (stuff rotting on the forest floor, etc).

    On desal (a bad idea IMHO), there’s an inquiry about to come up in Victoria: (main page and terms of ref) on securing Melbourne’s future water supply, but the government is making it hard to comment by requiring you to register your interest first by emailing enrc@parliament.vic.gov.au. I’ll be putting a special post on this at Balneus and The Wonkery and try an get people to (1) give me ideas and (2) sanity check my thoughts, or at least, prompt them to make a submission – although you’re a probable Qlder and have less interest in Vic.

  4. Dave Bath said

    Related "Scientific American Articles" … one old, one new:

    A counter view, that lots of small earthquakes can help seal sequestered carbon, has been reported since my post on Scientific American (2008-07-14). (Gotta point to decent rebuttals, updates and clarifications – I’m not omniscient!).
    Out of Sight, Out of Clime: Burying Carbon In a Vault of Sea and Rock

    The best place to store all that carbon dioxide from power plants might turn out to be volcanic formations off the U.S. west coast  ….  Such technologies have been demonstrated on a small scale to enhance the recovery of oil from tapped out fields;  pumping down the CO2 pushes up more of the black gold.  But geophysicist David Goldberg of Columbia University’s Lamont–Doherty Earth Observatory in Palisades, N.Y., and his colleagues found that pumping such CO2 into basalt rock beneath the ocean floor might be a better solution.

    Mind you, an earlier (2007-05-14) Sci Am Article "Future of ‘clean coal’ power tied to (Uncertain) success of carbon capture and storage" points to other worries (and I DIDN’T add quotes and braces in the title of this article, although bolding in the following quote is mine:

    The difficulty is capturing it at the power plant without sapping too much energy or pushing electric costs up too high… Adding carbon capture technology to that plant sucks up 40 percent of the power it can produce and adds at least 2.7 cents to the retail price of that electricity.  …. But even the small projects are already turning up surprises, such as the relative permeability of various rocks and the ability of CO2 to mix with saline and form carbonic acid, which eats away surrounding rock. And, of course, no one knows exactly how long the carbon dioxide could be contained.

  5. […] Lake Nyos disaster, I’ll point back to Australia’s work on burying CO2 … "Otways Carbon Capture: Dumb Idea?" […]

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