Live data from Hacker News

$100M xPrize for Carbon Removal

xprize.org

411–420 of 469 posts

Re: $100M xPrize for Carbon Removal

#412

Earlier quoted context omitted.

Trees are nature's best solution after millions of years of evolution. The R&D cost is low as well as the complexity. The problem is that dead trees turn back into CO2 so there will need to be some kind of sequestration like burying lumber.

Even burying the lumber doesn't remove the coal from the cycle, just delays it by a few years. You'd need to get the carbon into a "not readily accessible to biological processes" form. Charcoal is probably an OK start, but something like calcium carbonate would be even more stable. And you can (probably) do better than trees, in terms of carbon captured per time unit. But I guess you'd have to run comparative studie…

Intensive cropping of bamboo for carbon capture sounds like it would cause as many ecological problems as it solves.

Re: $100M xPrize for Carbon Removal

#413
post #187

I get the feeling there's a "snake eating its own tail" aspect here. Assuming carbon sequestration can be done at scale, it will likely require energy, maybe even a lot of energy. So where's this energy going to come from? Well... global energy demand is increasing as-is and the winners are: coal, oil and "natural" gas (which is a fossil fuel): https://www.statista.com/statistics/222066/projected-global-... Even assu…

> carbon sequestration [will] likely require energy Yes, but that doesn't mean we won't need it. Take air planes. We can't just put batteries in there: too low energy density or something (I'm no physicist, but they won't fly very far is what I gather). But by capturing the CO2 (at exhaust, or atmospherically) that they put out, we can have both airplanes and a stable climate -- assuming it's all done right. Who want…

> Take air planes. We can't just put batteries in there: too low energy density or something

Actually for completion it is a feasible proposal [0] (Obviously not for jet propulsion though).

[0] https://www.airbus.com/innovation/zero-emission/electric-fli...

Re: $100M xPrize for Carbon Removal

#414
post #136

For startups going after Elon's prize, AirMiners partnered with XPRIZE and CDL to create the AirMiners Launchpad. Founders should check out https://launchpad.airminers.org/ Applications for Batch #2 close August 31st Also check out AirMiners, the hub for everything carbon removal at https://airminers.org/ And those who are interested in a 5 week group discussion on carbon removal basics check out Boot Up: https://boo…

Is there a job board on the AirMiners website or have you considered making one? My guess is there's a lot of people like myself who'd be very interested in helping out in this field, but have no tech idea of my own, and don't even know how or if my (software development) skills would even be useful. If you're able to attract entrepreneurs with ideas worth exploring, maybe also help them hold up their banners for others to flock to?

Re: $100M xPrize for Carbon Removal

#415

Soil. It's soil. Soil, in prodigious quantities. We need to be making it. Using human waste - food and faecal from our cities; Using whatever plant fixes the most CO2 in a useful form that we can turn into charcoal (quick trees? bamboo grass? something genetically modified?), releasing heat energy, and then fixing carbon in a useful matrix, for soil regeneration a la Terra Preta. I sort of made this post elsewhere he…

I highly recommend checking out https://twitter.com/BuildSoil if you're interested in learning more about this approach.

Thank you for this. What's amusing to me here is that each year I collect a load of chestnuts and try and plant them about. I do it for a variety of inane personal reasons - I hadn't appreciated that there are a load of useful reasons to do so too! ( https://wiki.buildsoil.net/index.php/Why_Chestnuts%3F )

.

Just don't leave bags of chestnuts outside - apparently foxes love them and will utterly lay waste to them. Who knew?

- ed: Oh, actually, it turns out I don't - Horse-chestnuts aren't the same species as sweet or Spanish chestnuts.. https://en.wikipedia.org/wiki/Aesculus_hippocastanum

Re: $100M xPrize for Carbon Removal

#416
post #392

Earlier quoted context omitted.

If you want to drive up the price of oil for everyone, then instead of buying some oil and putting it into storage, you can just tax it, gaining revenue (that can be used for subsidizing renewables) instead of spending money to buy oil. The problem is that driving up the price of oil for everyone significantly (so much that there would be a meaningful reduction in usage, not just a slight decrease) is politically una…

You are certainly right from a national perspective, but the climate crisis is a global issue. By reducing supply for everyone, this wouldn't give way to loopholes and cheating (as we see for instance with carbon credits). You are also right that raising prices was very unpopular in the past. But some things need to be done to curb fossil fuel use and support alternatives. High oil prices are the most effective way.

While climate crisis is a global issue, almost all the power for taking major, large-scale action resides at the national level. The international structure is (and is explicitly designed to be) nearly incapable of forcing major nations to do anything without their consent, so global agreements and major multilateral action (e.g. affecting the global oil supply) are feasible if and only if they are aligned with what's acceptable and desired by the separate nations.

In that regard, if we're looking at how to motivate change to actually happen, it is appropriate to look at the incentives that would/wouldn't make sense from the national perspective - because otherwise it's just empty PR and wishful thinking, proposals that have no chance to get implemented. And, to put it explicitly, climate change is not currently overriding most other aspects of national interests, far from it, it's not (yet?) the #1 or even #3 concern in most countries elections or unelected leader motivations.

Re: $100M xPrize for Carbon Removal

#417
post #192

What we need is a cryptocurrency that is somehow mined by pulling carbon out of the atmosphere.

how would you prevent people from creating carbon just to remove it?

Producers must somehow more than pay for sequesters to sequest. The technical details confound me right now.

Imagine if every CO2 molecule were somehow unique: carrying with it a physical hash that could cheaply identify the processes that produced it. In this scenario, such an economy would become feasible.

To reduce complexity and cost, it needn't be every molecule. Say just one in a quadrillion, at an exactly fixed rate.

Of course CO2 is actually generic, as far as I know. Yet with only one wave of the magic wand, an economic solution has appeared.

Assuming regulatory and societal support, which should be forthcoming in this current climate (pun intended).

Re: $100M xPrize for Carbon Removal

#418

Earlier quoted context omitted.

Even burying the lumber doesn't remove the coal from the cycle, just delays it by a few years. You'd need to get the carbon into a "not readily accessible to biological processes" form. Charcoal is probably an OK start, but something like calcium carbonate would be even more stable. And you can (probably) do better than trees, in terms of carbon captured per time unit. But I guess you'd have to run comparative studie…

Intensive cropping of bamboo for carbon capture sounds like it would cause as many ecological problems as it solves.

Not necessarily. Well, not necessarily more than doing the same with trees instead of bamboo.

But, yes, it'd require some care.

Re: $100M xPrize for Carbon Removal

#419

Earlier quoted context omitted.

Even burying the lumber doesn't remove the coal from the cycle, just delays it by a few years. You'd need to get the carbon into a "not readily accessible to biological processes" form. Charcoal is probably an OK start, but something like calcium carbonate would be even more stable. And you can (probably) do better than trees, in terms of carbon captured per time unit. But I guess you'd have to run comparative studie…

There's always some local maximum most efficient process. If you take into account process inputs trees would likely come out on top. A lot of carbon capture tech can capture lots of carbon but consumes a huge amount of power/energy intense resources. My unit would be kg / (W * m^2 * s)

IIRC, bamboo ends up as "less wasted" when you turn it into charcoal than most woods. And you'd need to do a lot more energy-intensive processing of the tree to get it into a for suitable for turning into coal. With bamboo, it's mostly "cut into suitable length". With wood, it's at least "cut into suitable length", but may also require splitting.

But, yes, my main reason for thinking bamboo is that it is pretty fast-growing under the right conditions.

And with a Watt actually being "kg * m^2 / s^3", your unit ends up being s^2 / m^4, which dimensionally looks less pleasant.

Re: $100M xPrize for Carbon Removal

#420
post #387
post #357

Earlier quoted context omitted.

I'm working on agri-forestry and biochar reactors on a hobby farm. Hybrid poplars mature within a decade, and a biochar reactor is a net-energy producing reaction that produces soil improving char as a byproduct. It won't save the world on it's own, but trees can be leveraged in powerful ways.

Hang on. That sounds carbon-neutral at best. Great for replacing fossil fuels, but not a carbon sequestration technique.

You can bury the char or plow it into fields as a soil ameliorant.

Or if you wanted you could literally just bury it. Then it becomes a coal plant in reverse

Post reply on HN