Climeworks carbon dioxide capture device | Hacker News Reader

Climeworks carbon dioxide capture device

fastcompany.com

36 pointsprostoalex37 comments

Interesting approach, but the article is missing two magic numbers:

- the cost of the device and of course

- the energy needed to extract a certain amount of CO2 from the atmosphere. If more CO2 is released by producing the energy the device needs for CO2 capture, nothing is gained.

The feasibility hinges on those two numbers. Especially, is it more efficient to capture CO2 or spend the money instead on not producing it? If the needed electricity is produced by e.g. solar, is it more efficient to use the energy to capture CO2, or rather replace some coal power plants?

The second number is entirely moveable depending on the source of energy.

I would argue that (energy?) efficiency doesn't matter when dealing with energy extracted from the ground or from the sun or wind; what matters is the cost. The article doesn't mention the cost of extracting a ton of CO2 from the atmosphere, other than to say they have a ways to go on that front.

The "cost" of carbon emissions is estimated from $25-$125/ton (Social Cost of Carbon), and financial planning from fossil fuel companies like Exxon use a cost of $80/ton. (For some more familiar numbers, $80/ton equates to about $0.80/gallon of gas, or $0.035/kWh for combined-cycle natural gas electricity).

One could imagine carbon emitters paying for capture, or paying society for the costs that they impose on the rest of us. However, once you add that extra $35/MWh for natural gas electricity, renewables start to look pretty good. (For comparison, wind subsidies in Texas are around $24/MWh, so natural gas is getting a carbon subsidy than wind power gets. And unsubsidized wind and solar in the proper sites are extremely competitive cost wise.)

In any case, within the next few decades at least, it's going to be cheaper to use solar+wind+storage than it is going to be to burn coal and then extract the CO2.

This article dishes out too much hype.

Photosynthesis may be 0.5% - 2% efficient, but this new technology is "roughly 1000x as efficient as photosynthesis", which must make it 1000% efficient.

Further, the comparison with photosynthesis is similarly awful. This new thing collects and concentrates CO2, hoping there's an application for it that doesn't involve letting it go again. Photosynthesis essentially destroys CO2.

The real lede I'm looking for is how much energy it consumes and how much CO2 it processes, either today or someday. Guess there wasn't enough room in the article for that.

Yeah, the efficiency the article claims is "per square foot of space" which seems irrelevant. (Well, at least until you learn that they're going to need hundreds of thousands of these things to have a useful impact.)

But even worse is the complete and utter lack of any mention of the amount of energy needed to capture a ton of CO2.

Right. There's a point where it's cheaper to store renewable energy to use later rather than capture carbon dioxide using the surplus.

1/75,000,000 of our current emissions per device vs. not digging up coal and burning it for power. Which seems more reasonable to you?

This thing is not not really useful for climate change, instead it can provide CO2 gas we already concentrate for producing dry ice etc.

What is reasonable is not what happens the majority of the time.

The economics tell us that we need to continue to burn things. At the same time collection will get better. Hopefully the one will go down and the other up. I for one am hopeful about this.

We ultimately need to do both: burn less fossil fuels, and capture or sequester CO2 from the atmosphere faster than the planet does naturally. Otherwise, what we keep adding will stay around for a long time.

If we stopped all emissions instantly, temperatures would still continue to rise for decades due to the CO2 that is already in the atmosphere. We are going to need some kind of carbon capture technology especially considering that emissions are not likely to decline let alone stop any time soon.

Incidentally, it is my understanding that coal use is already declining rapidly. In many cases, it is being replaced by natural gas: certainly not ideal, but better.

We can achieve much of the carbon capture we need to by changing the way we do agriculture. Currently, our approach to agriculture - CAFO meat production, monocropping vast fields of corn, soy, and wheat - is a contributor to greenhouse gasses. It's eroding away the soil and the soil is one of the primary carbon stores. If we changed to relying more heavily on silvopasture and organic polycultures we could change it to act as a vast carbon capture mechanism.

Early studies suggest that diverse silvopasture can be just as productive as monocropped grain, but it means a major change in diets and the food production system world wide. It means less meat (but not no meat) and a diet focused more heavily on fruit and nuts rather than grains. This is a huge cultural shift and also a huge economic one, since much of the food industry is completely dependent on value added processed grains.

But if we start looking at how chesnuts, hazelnuts, walnuts, and acorns could be stored and processed into a greater variety of foods, then we can start the move towards agricultures that are just as productive and way healthier for the environment.

No-till, poly cropped grain production (corn, beans, and squash in the same field) can also act as a carbon sink, but it doesn't lend itself to mechanized harvest right now, so it would need to happen to a smaller degree.

Personally, I'm a bit skeptical, not least because of the cultural and economic shifts required. However, we're at the point where all potential avenues should be explored, so . . . go for it if that's your thing.

>We can achieve much of the carbon capture we need to by changing the way we do agriculture.

Based on your usage of "much" in this sentence and then detailed plans around crops, there must be some studies that quantify this to some degree. However, in my searching, I haven't found any such studies. Do you happen to have any favorites? Perhaps I need to dig into some of the IPCC references on land usage next.

> but it means a major change in diets and the food production system world wide.

Which basically means it's not going to happen. There are lots of ways to fix climate change that involve large scale changes to human behavior and habits. They're not viable because nobody is going to do them. The reason devices like this are valuable is that they promise to allow us to keep doing the things we're doing and stop or slow down climate change.

Build 75,000,000 of them.

Do a one-off -- if expensive -- engineering project, vs get everyone in the world to change their energy infrastructure given the huge incentives to cheat.

These things take a massive amount of energy to run, so you would need to build the clean energy infrastructure anyway.

At a rough estimate it takes about as much energy to pull CO2 from the air as you get from burning it in the first place. So, your also mining coal, building a power plant to run an extractor for ~zero net gain.

Not at all. Depending on how much CO2 it removes per unit energy expended, it may very well be feasible to power it with fossil fuels and still come out carbon negative -- we're just seeing the first iteration. (Thermodynamically, separating out CO2 is "cheaper" in terms of negentropy usage than combustion + mechanical energy extraction so the ratios are favorable.)

And even if not, and even if it only made sense with a clean-energy input, you would still only need to power that one engineering project's infra with the clean energy, which is much more feasible than replacing the entire world's infra.

A one-time giant solar array with CO2 condenser is still easier than all the infra swapout (which has its own CO2 costs) and international coordination necessary to end CO2 emissions.

it may very well be feasible citation needed.

Coal power plants which have much higher than normal CO2 concentrations in their smokestacks have looked into carbon capture and they can't pull it off without killing their power output.

Now, if we limit Fossil fuels to say Aircraft and Boats then we already solved the problem because their are a lot of natural and man made carbon sinks like your local dump. They are not enough simply because of the scale of fossil fuel usage.

Maybe they are coming from another angle, can it generate money?

There is one aspect of this that is not being fully addressed - storage of the captured CO2. Yes, pulling CO2 out of the atmosphere is a good thing, but storing it somewhere on Earth still poses a threat to the climate. A single mishap could bulk release years of stored CO2 gas and essentially undo all those collection efforts in a single day. Not to mention the potential for terrorist to target such stores.

Not when you store it in stone, as the article alludes to. I know that emissions from a local geothermal plant are being captured and stored permanently in basalt layers in Hellisheiði, Iceland.

I'm curious what volume of CO2 is used by the manufacturing industry, for chemical processes and feedstocks. Sourcing it from capture instead of burning natural gas to get it would reduce the footprint.

212 degrees is pretty specific. Is this just a gigantic water carbonation system?

212 degrees Fahrenheit is the boiling point of water. They are just heating the box to the highest point that they can still have liquid water until normal conditions.

That being said... does that mean they heat the box to a lower temperature in higher elevations?

Carbon is bad, but I think the coming methane releases will be the end of us.

Agreed - methane emissions from the thawing of tundra permafrost is alarming.

If they sell the CO2, what's the point?

They're hoping to sell the capture of CO2:

>Ultimately, the company wants to sell its ability to remove carbon dioxide from the atmosphere and store it underground, and it thinks that the market may be ready to pay sooner than the startup initially expected.

>“Based on our experiences now on the market, we are very confident that we will be able to develop a market in the very near future, maybe next year or in two or three years, to sell these negative emissions.

Well, for one, it would give companies the ability to quantify carbon tax credits in a tangible manner.

Build their business and manufacturing capacity, and reduce the carbon intensity of industrial CO2.

There is another device that takes sunlight energy and uses it to sequester carbon from the atmosphere. It's called a tree.

I wonder if they had thought of that?

>Planting trees or preserving existing forests is likely to also be a critical way to absorb CO2. “The best example of carbon dioxide removal technology that we know how to do now is grow more forest and to protect the carbon content of soils,” says Field.

also:

>“One CO2 collector has the same footprint as a tree,” says Wurzbacher. “It takes 50 tons of CO2 out of the air every year. A corresponding tree would take 50 kilograms of the air every year. It’s a factor of a thousand. So in order to achieve the same, you would need 1,000 times less area than you would require for plants growing.”

Now compare the EROEI between the two methods. One requires a lot of metal. The other one requires some planned land, a shovel and a seedling bank. I can have trees planted locally for 2$ each. I'd bet heavily that machine costs more than 2000$.

There's no energy return on devices like this, they are pure energy sinks.

I would agree that this machine is likely many multiples of $2000, but you're not counting the cost of the land in your part either (which varies wildly), but that doesn't mean that it's not worth investigating to see if it can be made cost effective.

I'm assuming that similar arrangements can be made to what local growing co-ops have made: If you are making land arable in the far future, you should not incur costs for land.

It's still a big Earth with room enough for both, but given the choice between one carbon-sucking techno-gizmo every km of barren land or 1km of forest lands, I'm going with the trees every time.

People that are down-voting this comment don't realize that it is right on the money. I looked into a local options to plant trees to offset my carbon use. There is an outfit planting one tree for roughly 2$. It's a land-reclaim effort making deserts into gardens on very long timescales. I need them to plant 43 trees yearly to offset my current carbon footprint. I'm decided that I will pony up just that for both me and the wife. If everyone did, global warming would not be as scary a prospect. 86$/year. Trees may be low tech, but they sure are a cost-effective measure.

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