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Carbon Removal Technologies

carbon.ycombinator.com

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Re: Carbon Removal Technologies

#261

Post by aoner »

angel_j wrote: post #149

Energy is needed to separate CO2 into carbon and oxygen. At the individual molecular scale, this can't be much. How many can I separate at once with my hands? If we invent a device that helps us to physically separate oxygen from carbon, humans and farm animals could do it. It would be like milling grain, or washing clothes. Idea: create filters which are big enough for carbon to pass through, but not oxygen. Then "s…

What if we would make such an advanced filter, and then make it mandatory in cars. That way cars would 'clean' the air. You'd need to find a process that scales though, so that the 'dirty' filters are processed in a way to get out the carbon and use it somewhere.

Re: Carbon Removal Technologies

#262

Post by cheapsteak »

tgb wrote: post #246
GreeniFi wrote: post #2

We already have carbon removal technology. They’re called trees. [Edit] I’m not being facetious. 40% of emissions are as a result of poor land management. We’ll need all the technological help we can get, but if we can’t manage land as carbon stores - not sources, we’re not going to win this race.

So this might be a dumb question, but if I landfill paper instead of recycling it, does it degrade? If not, is that a poor man's form of carbon sequestration? A cursory glance suggests this is correct [1], though you'd need to know a lot more to say that it was more carbon efficient than recycling. [1] http://www.allaboutbags.ca/degradeinlandfill.html

Was the carbon not already sequestered when it was in the form of a tree?

Re: Carbon Removal Technologies

#263

Post by PeterisP »

francisofascii wrote: post #181
ISL wrote: post #108

Earlier quoted context omitted.

If you'd like to fund trees, one could start buying land and start protecting trees. Spending that money on intensive lobbying and forest advocacy in rapidly-deforesting countries could have an impact, too. The trick, of course, is that neither of these techniques compound for the individual nor a startup. They are pure charity for the planet.

So does anyone know why this isn't happening more? Surely there are plenty of super wealthy tech titans, Hollywood stars, etc. that care about climate change. They could buy up rural land that is suitable for forestry and start planting trees, or prevent deforestation. Even small time donors could make an impact. Land in the US is cheap, right? What am I missing?

Land isn't that cheap compared to the (not that large) effect, especially if we want that effect to be meaningful in the short term.

Buying land and planting trees there will cost something like $2000 per acre and retain something like one ton of CO2 per acre per year (an order of magnitude estimate - depending on details both the cost and CO2 effect can be very different).

Industrial carbon capture at power plants can do that for something like 70$ per ton. That's much cheaper than forestry, but that's still not good enough. ycombinator is obviously looking for technologies that scale better than these existing approaches, something that might achieve large scale carbon removal at maybe $10/ton or less, at which stage the option "just pay a lot of money to reverse the effect of our emissions" might be plausibly considered affordable to our society.

Re: Carbon Removal Technologies

#264

Post by jasonlaramburu »

jonathannorris wrote: post #219
romed wrote: post #147

Earlier quoted context omitted.

Not just houses but any kind of building. There is an architectural movement called Mass Timber where the buildings are not just framed in wood but are virtually solid wood. It actually solves a lot of problems around building cavity thermodynamics, by eliminating the cavities. A large scale mass timber building sequesters a huge amount of carbon.

There is enough landmass in Northern Canada / Russia to do this on a mass scale. Could you coat the trees in something to greatly reduce their likelihood of burning? Therefore not having to use biochar or some other form of carbon storage.

You would also have to coat them in something to prevent decomposition. Assuming that worked, over time you would take a ton of nutrients out of the system and the primary forest would eventually become grassland.

Maybe if you were growing trees specifically for this purpose on degraded land it could work.

Re: Carbon Removal Technologies

#265

Post by perlgeek »

jf- wrote: post #63

Here’s my crazy idea: nuclear powered high pressure differential centrifugation. Under centrifugal force fluids separate into bands based on mass. The same principle as oil and water separating under gravity. Use giant centrifuges to spin compressed air until it separates into bands, then extract the bands corresponding to greenhouse gasses. I don’t know the energy requirements for this or if there is a better way of…

I really like the idea.

However, I get the impression that gas centrifuges are really high-maintenance. Is that right? Or does that only apply to the Uranium enrichment case?

Re: Carbon Removal Technologies

#266

Post by btilly »

wallace_f wrote: post #152
thereisnospork wrote: post #118

Earlier quoted context omitted.

Sure we could curtail CO2 emissions, but that means lowering people's quality of life which is a hard sell.

Studies on happiness--as hard as that is to objectively study--show it is more closely related to social status than absolute and total consumption. In other words, the SUV or sports car apparently has more to do with making people happy by making them look to be of higher social status than the actual utility of those goods. This is also demonstrated in the South Park episode Smug, which criticizes hybrids. From a p…

For talking about links between wealth and happiness, it matters greatly what absolute level of wealth you are talking about. Within first world countries, the link between between wealth and happiness is weak. But when comparing between countries that are rich versus on the brink of starvation, the correlation is one of the strongest known.

This may seem contradictory makes sense if you think of it in terms of Maslow's hierarchy of needs. If you are at the base level of meeting your physiological needs for food and shelter, wealth directly helps you meet those needs and makes them happier. If you can take care of that, the law and order that brings you safety is again correlated with being in a wealthier society. But beyond that, the correlation vanishes because wealth doesn't give you love, esteem or self-actualization.

Re: Carbon Removal Technologies

#267

Post by SketchySeaBeast »

lostapathy wrote: post #134
SketchySeaBeast wrote: post #25

Earlier quoted context omitted.

Isn't that tearing them down, not putting them up?

Isn't that ok, though? If I build a building out of wood, or print a book in a library, that carbon is sequestered at least as long as the building or book exists.

That's true, but you've netted zero on carbon. You need to put up more trees if you want to remove carbon. I mean, by all means tear em down, but you gotta keep putting them up.

Re: Carbon Removal Technologies

#268

Post by jasonlaramburu »

nanomonkey wrote: post #221
jasonlaramburu wrote: post #198

The post mentions the significant logistical challenges associated with moving large quantities of biomass and biochar. What about a mobile biochar production system? ie a device that could be delivered to a farm and towed through the field to convert waste biomass in-situ into biochar and till it directly into soil?

Tilling the soil actually releases quite a bit of CO2, some of the best practices are "no till" methods. But to your point, biochar retorts can and should be used at the source of the biomass, instead of burning fossil fuels to transport the biomass to a dedicated facility. Many small scale gasifier generators are designed to do just that. The problem with all solid fuels is that material handling is difficult (you n…

How can you get biochar into the soil without tilling?

Re: Carbon Removal Technologies

#269

Post by tgb »

Tuna-Fish wrote: post #64
Retric wrote: post #26

Earlier quoted context omitted.

Because the earth is effectively a black body it cools down at T in kelvin^4. This means you need to block a huge amount of energy ~2% of the sun to get around global warming. Sticking something at L1 looks elegant, but you cant just toss junk there it needs serious station keeping making it far more expensive than many assume. PS: Unfortunately, as a side effect you reduce the energy of all plant life by ~2% solar p…

Earth-Sol L1 is probably a bad place for a solar shade. That's where a solar shade of any given size is the most efficient, but the cost of getting it there is much more than the cost of having more, less efficient ones. A better choice is something akin to a semi-sun-synchronous Molniya-style-orbit. That is, orbit that is somewhat highly elliptical (so a satellite on it spends most of it's time near apogee, and zips…

Is L1 the most efficient for a fixed size? The difference is ~6000 km for LEO versus 1.5 million km for L1 to the Earth's center and the r^2 law means you need to put a lot more area in L1 than in LEO, even after discounting for the fact that in LEO it'll be on the wrong side of the Earth half the time. Filling up appreciable fractions of LEO might have it's own problems.
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