Carbon removal technology reaches early milestone | Hacker News Reader

Carbon removal technology reaches early milestone

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20 pointssailingparrot10 comments

Not going to lie, 4000 tons annually is kind of disappointing. Even if you had 100,000 of these plants (that's three times more than the number of starbucks on the planet), that is still less than the gigatons of removal required to make a significant dent in the CO2 already present in the atmosphere. Not to mention I bet these are far more expensive to create/maintain than a Starbucks...

Clean sequestration of plant matter and significant emissions reductions are really the only paths forward.

The most expensive/capital intensive part of Direct Air Capture is the CO2 extraction, since CO2 is relatively low concentration in air.

Conversion of waste biomass into biochar is both more capital efficient and energy efficient, since the plants themselves facilitate the CO2 extraction.

You just need a lot of surface area to grow that many plants.

Does conversion to "biochar" allow recovery of the nutrients you need to grow more plants? Or are we also sequestering nitrates, phosphorous, etc. as well?

Yes it does, the pyrolysis conditions (the process to make biochar) will influence what % of nutrients are recovered in a plant available form. We could actually capture gigatons using only the leftover waste from our current commercial agricultural production.

> Vastly larger DAC facilities are on the horizon. Carbon Engineering Ltd., a Canadian firm, is planning two plants that could each capture up to 1 million metric tons of carbon dioxide annually. A 100-acre facility is expected to break ground in the Permian Basin next year. The other, slated for construction in Scotland, could begin operations in 2026.

> By comparison, it would take over 1.2 million acres of U.S. forestland to sequester an equivalent amount of carbon over the same time period, EPA data shows.

Assuming these numbers are actually realistic, and you have an abundance of available carbon neutral energy (whether that's solar, wind, thermal, small-scale nuclear, etc.), it doesn't seem too far fetched (on a cursory glance) to hit gigaton scale carbon removal. 100 acres per megaton/yr of carbon dioxide would mean 400 sq. km of plant per gigaton of removal capacity.

That's a minimum 1000 of these giant facilities to even scratch the surface of what the article mentioned would be required to see dramatic improvements in climate change. The article mentioned the first one of those will take ~5 years from now to come online. In that time, we will have emitted far more carbon than can ever be captured by those facilities.

I don't think we have the time to wait for (minimum) 1000 of these facilities to come on line. I mean, they would help some, no doubt, but proper forest management and logging is existing knowledge, and the best part is the forests can mostly manage themselves. Forests are scaleable, and could be huge carbon sinks given the right speciation. The logging companies would be paid to cut the forests down, and sink them to the bottom of the ocean/turn them into biochar. Additionally, something similar could be done with kelp-forests (and I believe a startup already is doing just this). Scale is the issue here, what better way to scale planet-wide than self-reproducing carbon-capture technology (plants)?

I was mainly thinking of construction resulting from unilateral action. Obviously we aren't going to lazily get there building one at a time.

Forest building is great, but to sink similar amounts of carbon, you'd need to plant tens of billions of acres of new plants every year. Essentially, the same amount of plants that we're burning the ancient corpses of.

Right, I just think scaling construction of these facilities would require infrastructure that could take a decade plus to get right.

You are right forestry is not the place we should focus right now. The main problem right now is turning off coal plants, among other CO2 reduction strategies.

Its impossible to 'put back in' what we are digging out of the ground. Burning 1 unit of coal generates 2.5 units of C02.

We would have to replicate the Azolla event or Carboniferous period to meaningfully reduce CO2 concentrations in the atmosphere.

We need to abandon coal immediately and electrify all transport. Probably going to need a lot of nuclear and renewable energy along the way with a bit of gas to fill in the troughs.

The great side effect will be that cities will be dramatically more pleasant places to live and human health will improve, due to the improvement in air quality.

We should also get smart about flexible energy demand, ie. allowing cars and appliances to discharge or charge depending on grid conditions.

CO2 carbon might have a market for use inside buildings, but its hard to imagine how we will meaningfully dispose of the excess CO2 (just one human generates 1tonne of CO2 annually), and its certainly cheaper to just spend that money on carbon output reduction.

It’s not a « or » it’s a « and ». We need to move toward 0 GHG emission as fast as possible, using the solutions you proposed among others. But even assuming the most optimistic transition plan, we are already too late, and too much GHG will already have been released to avoid significant negative impact. That is where carbon removal comes in. It can also help buy some limited amount of time for the transition.

I do not think any of the carbon removal startups that exist today are trying to scale to offset the entirety of our current annual footprint, they are building à complementary solution.

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