Commercial Plant Starts Pulling Carbon from the Air | Hacker News Reader

Commercial Plant Starts Pulling Carbon from the Air

nytimes.com

This kind of direct air capture that relies on consuming CO2 from diffuse, open-air atmosphere conditions will never be effective enough to be worth it. The concentration is simply too low, and the atmosphere too large. The costs quoted in the article are 5-10x other carbon mitigation technologies (presumably not even accounting for carbon intensities in the mining and logistics necessary to produce such facilities).

However targeted, point-source applications that are effectively scrubbers for carbon-intense processes make a lot of sense because of the opportunities for high-concentration collection and recirculation for multiple passes across the substrate.

I'm wondering if Heirloom is putting any effort into the latter approach. The article only reports on open-air facilities.

Yeah in order to make a difference we'll have to flatten an entire continent and litter it with such plants. Plus their renewable energy sources. Not to mention the cost and energy usage of manufacturing and maintaining it all. Plus the environmental impact of all those sites in other ways than just CO2.

There's just no point. It's a pipe dream for those who are still looking to continue business as usual.

Until we really have Terawatts of basically free renewable energy to spend and we're already CO2 neutral globally, it's way more efficient to just not emit the CO2 in the first place.

I think it's good they keep a finger on this tech and experiment with it but I don't view it as something even remotely useful to bring CO2 levels down. First we need to stop emitting.

It's the only way to lower CO2 levels though, right? Not emitting doesn't get you that.

Direct air capture is not the only way to lower CO2 levels, although you are right that point capture of emissions doesn't lower levels by itself. An example of another technique for CO2 reduction is enhanced olivine weathering, or bioenergy + capture. These are called negative emission technologies in general.

Trees are net-negative by larger margins than any other technology we have invented, pretty much any way you want to quantify it (efficiency per kilogram of tree/tech, efficiency per dollar of tree/tech, etc.).

I would imagine there's an upper limit to how many trees could be planted, and they might use more space. That won't really work if carbon emissions are an ongoing concern. But by all means let's do as much as we can. https://climate.nasa.gov/news/2927/examining-the-viability-o...

Yes but for now we're still emitting so much that we're effectively only reducing emissions. There's no real point until there are no more emissions to cut which is much easier and energy-efficient to do than capturing.

The point would be to get the technology working really well.

The most valuable carbon capture would be to do something that turns atmospheric co2 into a solid construction material, like bricks.

Reading between the lines what I'm saying is: Your benchmark is to do better than wood. If you can make bricks faster than a tree can grow wood, this will become an investment rather than money pit.

why not simply let trees do it?

maybe trees aren't as cool as whatever they're doing???

Well trees don't do it at night.

But yeah they don't require energy to build them, can be made with simple seeds, integrate really well with local ecosystems (much better than anything man-made), don't need maintenance, self-propagate and cause more benefits like ecosystem diversity, limiting floods and wind.

They do have some drawbacks too though like serious flammability. And we can't burn them afterwards or we'll get all the CO2 back.

I think the work Livingcarbon is doing is very cool here, actually. at least genetically engineering better photosynthesis seems like a plausible approach and their demos so far seem like they are working.

The industrial approach to trees is not a good one though. You end up with plantations of tree monoculture.

Japan actually has an issue now where former tree plantations have overgrown and cause extremely high levels of pollen during allergy season, the forest floors of these plantations are dead due to the overgrowth blocking sun, etc. https://m.youtube.com/watch?v=VC4gRGPbTqE

You only get monoculture if you plant only one type of trees.

The whole planet used to be covered in them and it was not a problem.

That took many years. And as far as I am aware that would be the exception in the history of modern reforestation.

The needs of industry and government (which is what you’re targeting if you want to replace construction materials) are optimizing for speed to grow (and hit arbitrary targets), and suitable properties for building, and generally that means they pick a very limited selection of trees that grow fast, sometimes as few as one type of tree.

Which is also a good plan! However, most people don't understand the complex care that forest's require.

Most forests in North America evolved millions of years ago to deal with fire to reproduce and keep invasive species culled. Humans interfere with these process in several ways (::grunt::, logging bad, ::grunt::, fire bad, ::grunt scratch::). Studies need to be conducted where we could substitute fire for logging without impacting wildlife. Certain forests would be better candidates for this, but it's also important to make sure slow-growth forests have adequate fire protection to prevent runaway fires.

There's already a lot of momentum with sustainable logging in North America, but it is something that needs to be done in South America and Asia as well.

Logging creates _a lot_ of useful products for people to use, but it requires continuous monitoring and research to keep it green.

https://news.ycombinator.com/item?id=38187573

Because it doesn't scale, at least for the purposes of removing CO2 from the atmosphere.

> why not simply let trees do it?

You’d have to sequester them such that they don’t biodegrade. This involves deep burial, difficult for a solid, or submersion, which means ruining a deep-sea habitat (and creating a carbon time bomb).

Deep burial? We have a housing crisis! We should be using them to build houses!

The cost of raw wood is not a big contributor to the cost of housing. The shortage of land where people want to live and are legally allowed to build is the biggest problem. Behind that, cost of construction labor.

The carbon in the wood used to build houses will slowly (or rapidly in the most unfortunate cases) release back into the atmosphere by various mechanisms.

Planting a forest is carbon neutral after it reaches maturity, in a ~few years. It reaches an equilibrium and stops net removal of CO2.

If you want nature to do it you need to engineer some way for the carbon to disappear basically forever.

You missed the last stages in the cycle: cut down the trees, build stuff with the wood, and plant new trees. If you can use the wood as a construction material that lasts a long time then you’ve succeeded at carbon sequestration.

Building things is already happening. You're not going to affect that really at all by planting more trees, that's a big complex system.

How about something much faster growing like algae? Then harvest the algae, seal it in a plastic wrapper and sink it to the bottom of the ocean?

> why not simply let trees do it?

because money

They could do better than bricks. They are making a component of mortar or concrete. This is already a construction material.

https://en.wikipedia.org/wiki/Calcium_oxide

To get quicklime you have to burn at high temperatures, which is currently done using coke, so concrete is actually as high as 8% of carbon dioxide emissions.

> "At the California plant, workers heat limestone to 1,650 degrees Fahrenheit in a kiln powered by renewable electricity. Carbon dioxide is released from the limestone and pumped into a storage tank."

Yes.

I am pretty sure the OP is talking about storing carbon into the material itself, not producing it as an output and capturing it; hence the comparison to wood, which is carbon negative

Trees aren't really carbon negative, but carbon neutral over an extended lifespan. They die and turn back into atmospheric CO2 (perhaps becoming even worse methane along the way) while their leaves continually do this over a short period.

But the trees usually do this over a timescale of 20-220 years (less when there are fires or climactic change), so are much better than nothing. But they don't count as "permanent".

They release their carbon when they decompose, but that's not really relevant if the wood is furniture or building materials.

A tiny percentage of trees by volume. And a lot of that ends up in landfills either right away or after a few decades, where it starts to release GHGs.

I keep thinking it should be paper/cardboard! But also jet fuel is probably ideal too.

This appears to me like an elaborate "carbon laundering" scheme?

Producing concrete involves decomposing limestone into calcium oxide and CO2, which is done in a furnace powered by fossil fuels and then just released into the atmosphere. Concrete cures by capturing some of that CO2 again.

This plant takes more limestone, decomposes it using "renewable energy" (i.e power that could have been used to displace non-renewable sources, but isn't), but stores the CO2 in a tank, which is then just put back into concrete. Concrete that would have naturally slightly offset itself anyway?

The net effect is surely just a bit worse than nothing?

Yup, carbon credit programs like this one look really good come annual report season because of all the double-counting we get to do: both producers and consumers of carbon get to claim reduction quantities through carbon credits. But ultimately it doesn't meaningfully reduce the amount of carbon being produced as the costs are just passed onto the customers of those carbon producers to maintain profitability.

Seems like recreating coal forests would be relatively sane. Everyone likes bogs.

Dump in a deep lake/seabed that has 4C water year round at the bottom?

Good they are finally starting this. Ever since I heard that this won't work cause it's too small, I started thinking that this will be what saves us after we go way over the edge as humanity. Hopefully I am wrong, but if not then hopefully at least we see many more of these to try and save ourselves at the 11th hour.

I am happy to see progress in the right direction, but I can't help but feel the 11th hour was sometime in the 80's.

Worst case: it might at least save a few large buildings or containered cities.

https://archive.li/AZ1fA

My bet is on geo scale engineering to mitigate temperature. Full of risk, but a better plausible path than pulling out 450+ ppm.

... Or we could plant trees like chestnuts that take CO2 out of the air and provide lots of food to humans and animals.

We dump > 36 billion tonnes of it a year, if you make it solid where exactly are you going to store it?

Whatever the answer is, unfortunately we have to regardless

Dig a deep, deep pit and bury it all?

Build a really tall pipe and push it all into space?

Or dump it in water for reclamation (or use what you dig from the pit to do that).

In the walls of new buildings.

This is so pointless, they pull carbon dioxide out of the atmosphere and then they release it back into the atmosphere. They use it to cure concrete the production of which released a comparable amount of carbon dioxide into the atmosphere and which would otherwise just absorb about the same amount of carbon dioxide from the atmosphere during curing.

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