Skip to content

So here’s an idiot question

One of those signs of wisdom – or perhaps senescence – is when you know you’ve no clue and go ask someone else.

So, extracting carbon from the air. Or, CO2. Hmm, expensive, high energy consumption.

But CO2 dissolves in seawater, we know that. Any CO2 extracted from seawater will soon be replaced with more from the atmosphere.

So, might there be a clever chemistry which makes it cheaper to extract CO2 from seawater?

Or even, what if you were doing something else to seawater – desalination plant, mining for lithium, that sorta stuff – would that get you part of the way there and give you a headstart on that CO2 extraction?

31 thoughts on “So here’s an idiot question”

  1. Grow kelp or other seaweeds that spend their life submerged photosynthesising from CO2 in the water.
    Periodically clear out an optimal amount of it and shove it overboard off the continental shelf.
    Carbon captured.

  2. Far easier if you start with methane as the feedstock, but I suppose that isn’t the point. Whatever you do with the CO2, you have to break two carbon-oxygen bonds since you don’t want oxygen in the product. It’s all lots of energy input for that as well as generating the H2 for the jet fuel forming reactions. Probably the only practical energy source for all that is nuclear. Would a solar farm ever be economic for that? Im not sanguine.

    I suspect only a subsidy farmer would seriously consider it anyway. I hope he doesn’t come and suck on my taxes for it.

  3. Bongo
    Would dumping industrial quantities of kelp not have an effect on the ecology? More/fewer predators, that sort of thing?

  4. Geoffers

    Do you work in the legal profession? Because the correct answer to your first question is no. Which might not be helpful.
    But dumping the kelp in holes in the earth’s surface so that the remaining kelp can grow more vigorously captures CO2 just as much as chopping down half the trees and shoving them in disused mines and quarries. Capturing and storing that CO2 is the aim of the game if you want the green grant moneys.

  5. Hi Bongo. No I’m not a lawyer, and I wouldn’t be chasing grants. I just wondered if the unintended consequences of your suggestion had been explored.

    CO2 collection is one effect, and food chain variances could be another. Because if kelp are doing their thing then anything else wanting the additional kelp’s resources are out of luck and what effect would that have?

  6. Fair enough Geoffers:

    It was just the negative question so favoured by legal types. “When you saw the hazard approaching did you not brake?”

    Yes, there will be unintended consequences of kelp harvesting and dumping in ocean trenches. But the green movement isn’t going to care about that. There will be unintended consequences of tree planting programmes on pasture but the Woodland Trust for example are not remotely bothered about them. It’s a climate emergency apparently so we can dispense with some considerations.
    We do have solid evidence though that pruning and coppicing promote growth.

  7. Why bother? CO2 isn’t a problem.

    Whether it is or isn’t is becoming irrelevant. The belief that it is a problem is endemic at all levels of significant influence on strategy, therefore “decarbonisation” of civilisation is going to continue for the forseeable.

    I’d rather have practical “net-zero” aviation fuel than no aviation fuel.

  8. It seems unlikely that industrial seaweed harvesting / transportation / dumping could remotely match the natural carbon sequestration provided by ocean phytoplankton. Up to half a mile depth of the ocean floor is dead phytoplanton shells.

  9. Bongo: Would dumping industrial quantities of kelp not have an effect on the ecology? More/fewer predators, that sort of thing?

    Who talks about dumping on the ecology? You will eat the kelp and you will love it – at least when the coalition between our green friends and the World Economic Forum takes over the world government!

  10. Save the kelp! It’s the favoured environment for seahorses, which are kind of underwater unicorns.
    Also I’d have something serious to say if I hadn’t had a few.

  11. ‘Why bother? CO2 isn’t a problem.’

    You have a point Jimmers. I’ve no expertise in Climatology or whatever, but I don’t think they’ve proved their case.

    More to the point, if they were serious about us all cooking by 2010 or 2020 or 2030, they wouldn’t adopt the idiot policies pushed by the California hippies in the 1960’s and 70’s. The fact is they’ve been promoting this nonsense for decades. Global warming—oops climate change is simply their latest excuse.

    If we were to attempt net zero by 2030, we’d have to make use of off-the-shelf tech. This means lots and lots and lots of nukes – nice simple 70 year old technology. Since we need a simple, flexible and easily handled energy storage system, this means hydrocarbon fuels.

    Obviously in addition to generating our electricity, the nukes would also power our oil refineries or synfuel plants. Since gas is a common fuel, they’d also make plenty of unnatural gas.

    But I feel that the true situation was expressed by a commentator in some green magazine, ‘Even if the fuss about climate change is wrong, we’d still get all those wonderful policies we’ve been pushing.’ Thus if I had to set policy, I’d simply do nothing.

  12. The oceans are already pretty good at sequestering carbon. The white cliffs of Dover are almost pure calcium carbonate. The skeletons of countless plankton.

  13. From wiki:
    “Phytoplankton depend on B vitamins for survival. Areas in the ocean have been identified as having a major lack of some B Vitamins, and correspondingly, phytoplankton.[19]”
    Scrub that kelp farming/coppicing/dumping then – plankton get their CO2 from the dissolved in water stuff too. I thought they were air absorbers for some reason.
    Just add the right nutrients to the parts of the ocean that are lacking.

  14. Iron fertilisation of the oceans, something I’ve been supporting for well over a decade now. Sadly, even doing experiments on it is illegal under international law.

  15. ‘Even if the fuss about climate change is wrong, we’d still get all those wonderful policies we’ve been pushing.’
    Lot of truth in that, isn’t there? The environmental movement as a remedy in search of a problem.
    Wonder how far one can trace it back? Certainly the Arts & Crafts movement. But does it actually start with the non-conformist churches?

  16. Geoffers: “Would dumping industrial quantities of kelp not have an effect on the ecology? More/fewer predators, that sort of thing?”

    Nope, as long as you make it sink down. Basically, anything that lives under 200m is carnivorous and wouldn’t even bother with the stuff after a first bite, if at all.
    Oceans are deep, mindbogglingly deep, you couldn’t even begin..etc. And only the first 200 meters down have any useful light for photosynthesis. Far less if the algea are having fun..

    Bongo, I wouldn’t ditch the kelp-growing. First of all, there’s plenty kelp species that are edible, and tasty. See also : Sushi and all the other things the Japanese do with it. Nowt to do with the hair-shirted Doomsayers. And done on an industrial scale already there…

    Plus the stuff can be processed as packaging. Some species are like natural plastic, and there’s some work being done here and there to make use of that fact for disposable stuff based in the “circular principle”. Woo-ish, but it’s a valid option that’s actually sane.
    Pretty good for ocean life as well, in general. It’s just the fishermen that will scream their heads off, since they won’t be allowed to use their trawler nets in those fields, and that’s where the fish will be.

    Dumping the stuff is a waste. Treat it as a proper crop, and figure out what you can use it for is much more sensible.
    It’s one of the ..aggravations.. around the Eco-Mania. Good ideas get lumped with the Woo.
    There’s plenty of ways we can use the ocean and not bollox things up.
    But the Madness has progressed to the point where if you do propose something entirely reasonable and sustainable you get lumped with the Mad Hatters, while the Mad Hatters still scream at you , because you dare use Mother Gaia.
    Currently it’s a lose/lose scenario.

  17. Didn’t know iron fertilisation of the ocean was illegal these days Tim. This does show how quick the Green push are to ban anything which might make their policies redundant.

    I do like the proposal to grind up peridotite and spread it over the ocean. Or just frack the slice of the mantle that’s accessible and pump in the CO2.

    Must admit I don’t know how far back the environmental movement goes BiS. I’d argue at least from Classical times. Making sacrifices to the naiad of the local stream perhaps.

  18. Easiest way to reduce peoplekinds carbon footprint? If all the nutters who believe carbon dioxide is a problem stop using anything remotely connected to the emission of CO2 (we could possibly tolerate them breathing. If they do it quietly. And far, far away).

    Hey presto, they get what they want, reduction in CO2 emmissions and we get cheaper fossil fuels and a quiet life.

  19. @Boganboy I’ve got a couple chemical engineering manuals from late 19th/early 20thC.

    Besides the Good Reading and learning Stuff, the thing that’s already apparent there is that there’s several places where…concern.. is expressed at the future availability of all those waxes and resins and latex, and… used, because projected future demand could well be well beyond the possible capacity the Colonies/Plantations could provide. The old “how much do you have to pave over..” conundrum.

    But at least there’s logical thought there.

    Between WWI and WWII and their aftermaths.. Well… People had other things on their mind than Mother Gaia..
    As far as I can tell, the modern Craze started with Greenpeace, which did have a point when they started.
    Around the ’60’s/’70’s “we” were most definitely quite busy Poisoning the Well in several ways, and Greenpeace played a major part in addressing that fact, in their own charming way.

    Problem with Greenpeace, of course, is that they became part of the Establishment, and never dialled down to …sane levels. And as part of the Establishment could never satisfy the Hardcore Ecofreaks.
    Those peeps came into prominence, at least here, around end ’80’s, early ’90’s. The tone at Uni at the time ….changed… Quite a lot of them were heavily into the New Age stuff, including the particularly …typical.. brand of Feminism it sported, and the whole Man as Terror of Gaia popped up its ugly head in bulk.

    I personally think the change from “reasonable” Activist to Religious Zealot happened somewhere around that time.
    Those peeps are most definitely the “old core” of all the miriad litigious/busybody foundations, action groups, and “social interest” lobby groups ’round these parts that popped up in the decade after, culminating in the current “Green Socialist” and “Party for Animals” political parties.
    You can trace their Uni years ( if any ) to exactly that period, without fail. The ones that didn’t go to Uni come from the ’90’s activist squatter scene ( which itself builds on the ’70’s Socialist Activist/Squatter movements). Also without fail.

    The younger generation(s) are even crazier, culminating in our swedish lizard-brain, but my best bet is that you can trace the roots of any “official” movement back to that period between roughly 1985 and 1995. and the …decline into irrelevance/Establishment… of Greenpeace.

  20. The process is known as serpentization. There’s an energy curve and once you’re over the hump, the process runs with no further energy input. The problem is that it’s slow. The ideal end product is methane, not jet fuel.

Leave a Reply

Your email address will not be published. Required fields are marked *