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Carbon Removal Technologies

carbon.ycombinator.com

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Re: Carbon Removal Technologies

#431

Post by btilly »

deialtrous wrote: post #333
btilly wrote: post #234

Earlier quoted context omitted.

Not doing anything has a certainty of turning the ocean to a mild acid, with disastrous effects that are already becoming visible in coral bleaching and shellfish die offs. And carbon that is already in the atmosphere and not yet dissolved is only going to make it worse. We are at the point of choosing between what disasters we will suffer, rather than figuring out how to not have a disaster.

Why are we so concerned about ocean acidification from CO2, when past CO2 levels were far higher than now and all of the shellfish species that currently exist lived back then too? Wouldn't it be a good idea to consider the massive quantities of known toxins we pump into the oceans rather than fixating on a red herring?

Your question assumes that the oceans had to have been acidic because CO2 was high. This assumption is wrong.

You don't get acidification as long as CO2 levels change slowly enough that it mixes down to the bottom of the ocean and then gets buffered by calcium bicarbonate being dissolved there and mixing back to the top. But this mixing takes place on the scale of a thousand years. This is no big deal for CO2 level changes taking place over geological time. But it doesn't help shellfish with sudden increases of CO2 taking place on a scale of decades or centuries.

Re: Carbon Removal Technologies

#432

Post by cbkeller »

drankula3 wrote: post #289
matznerd wrote: post #230

Earlier quoted context omitted.

I am working on a non-profit that is utilizing Schuiling's research and is actually getting this project done. We are scouting beaches right now for a "wiggle" tank, which is a sort of see-saw like device where we can gather data to affirm the real world dissolution rate. The chemistry, however, is sound that each 1 ton of olivine will sequester 1.25 tons of carbon. By the end of 2019 we hope to have our first olivin…

> Raw olivine is currently ~$20-$25/ton and the average us person puts out 15-20 tons of CO2/year. Globe-scale carbon sequestration would increase demand for olivine massively. Would mining operations be able to scale appropriately without prices going through the roof?

Geologist here. Can't speak to the economics, but there's no shortage of mineable olivine, mostly in areas where mantle lithosphere that was formerly below oceanic or island arc crust has been "obducted" on the continental crust and thrust up to the surface (the mantle is mostly olivine). These are called ophiolites, and they're not uncommon in places where you used to have a destructive plate boundary: https://en.wikipedia.org/wiki/Ophiolite

Re: Carbon Removal Technologies

#434

Post by philipkglass »

joe_the_user wrote: post #395
philipkglass wrote: post #367

Earlier quoted context omitted.

Some of the active countermeasures contemplated, like ocean fertilization and accelerated olivine weathering, also tackle acidification if they work at scale. Solar radiation management does nothing to fix acidification though it can possibly interrupt feedback loops that would make acidification even worse. I agree that many technologies for replacing fossil usage have now achieved or are close to economic superiori…

The problem is that while solar energy may have already achieved superiority over the net cost of finding, drilling-off and extracting hydrocarbons, solar energy is not going achieve superiority over hydrocarbons people already have . The cost of already found oil is just the cost of pumping it out of the ground and with easy fields, no energy source is going to beat that (the cheapest Saudi cost less $10/barrel to p…

Yes, it's harder to out-compete fossil projects that have already been built, already paid off their capital costs, and incur just operational costs going forward. Some of those fossil projects (like Saudi oil fields that cost only $10/barrel) are not going to be economically forced into early retirement by any foreseeable lower-emissions energy source.

Note that there is also quite a bit of already-built fossil capacity that can be retired early by economic pressures. Not every big fossil project has operational costs as low as Saudi oil.

For example, the Navajo Generating Station is the largest American coal plant west of the Mississippi River. It was built in the 1970s. It has a stable, low cost for coal since it is supplied by the nearby dedicated Kayenta Mine. Just a few years ago it was planned to run until 2044. But the falling costs of gas and renewables have made it economically uncompetitive. It's now going to close at the end of 2019, 25 years early:

https://www.azcentral.com/story/money/business/energy/2017/0...

I agree on the broader point that fossil fuel emissions won't be curbed quickly without active regulator intervention. Since that intervention may arrive late-or-never in different nations, it's one of the reasons that I believe active carbon dioxide removal measures will be necessary in addition to emissions reduction efforts.

Re: Carbon Removal Technologies

#435

Post by gdubs »

gustaf wrote: post #72
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.

This is Gustaf from YC. I wrote the first Carbon Removal RFS. Planting tree is actually a great carbon removal technology. Unfortunately most forest owners in the world don't know or don't have incentive to care the about the carbon impact the forest have on the climate. Biggest reason forests are taken down is to grow cattle for beef. If you are working on a startup to reverse this we'd like to fund it too

In many ways it’s the soil itself:

https://www.nature.com/scitable/knowledge/library/soil-carbo...

Re: Carbon Removal Technologies

#436

Post by richardw »

lowdest wrote: post #29
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.

Trees ultimately burn or rot, releasing a large portion of that carbon back into the atmosphere. Cutting them down and burying them to grow more would be ideal, but takes additional work. Someone want to engineer a tree with enormous, deep roots? Basically make the trees self-burying.

Make more stuff from wood. Replace lots of throwaway plastic goods with wood that lasts. Slow the rate at which it rots. Engineer landfills to retain the carbon.

Re: Carbon Removal Technologies

#437

Post by hannasanarion »

bskinny129 wrote: post #323
hannasanarion wrote: post #314

Earlier quoted context omitted.

Not if they're treated with preservatives and built into houses. Every wood-frame house and piece of wooden furniture is carbon sequestration.

As long as those houses don't burn down...

What percentage of houses burn down out of all houses ever built? I think not that many. Most probably stand for a hundred years and then are torn down and their component parts recycled.

Re: Carbon Removal Technologies

#438

Post by state_less »

gustaf wrote: post #80
all_usernames wrote: post #71

I recently heard about Carbon Engineering, a B.C. Canada based firm that is extracting carbon from the atmosphere and making liquid fuel -- they call it "recycled fuel." Apparently it can be used in existing combustion engines. And it is already up and running. Something on the order of 10,000 of these industrial plants could get us carbon neutral rather quickly. https://www.cbc.ca/news/canada/british-columbia/b-c-co…

Carbon Engineering and Climeworks are two incredible companies working on Direct Air capture and Air-to-Fuel and we'd like to fund more companies like them. There are less than 5 companies worldwide that are serious about getting Direct Air Capture to scale. The world need more bets that that on such a promising technology

You could put compressors next to windmills so that on days there is too much wind, you could start up the compressors and make dry ice, liquid nitrogen or some liquid air feed stock.

Cheap energy seems like the key ingredient. The compressor equipment to do the task seems within reach.

One could reverse the process and feed the air (de)compressor gas to make energy on low wind days. I'd be interested to know what the round trip efficiency could be. You could optionally use the compressed products as feed stock in some other industry. Perhaps use blocks of CO2 to make methane or a room temperature liquid gas.

Re: Carbon Removal Technologies

#439

Post by philipkglass »

louprado wrote: post #420

"It's time to invest and avidly pursue a new wave of technological solutions to this problem - including those that are risky, unproven, even unlikely to work". I had a recent crackpot idea that falls into the "unlikely to work" category since my background is not chemistry. Given that a modern automobile's tailpipe emissions are mostly C02 + H20, those molecules can be converted into ethylene (C2H2) using known effi…

There's an even worse third constraint:

3) The energy content of the hydrogen tank needs to be greater than the energy content of the fuel tank.

And if you were going to add such a huge hydrogen tank to the car, and keep it filled, it would be simpler to use the hydrogen itself as fuel. Many people have indeed proposed hydrogen powered cars. Hydrogen powered cars in turn don't look like they have a very bright future because battery electric vehicles are reaching mass production first, and because batteries are more energetically efficient than storing/transforming energy via hydrogen.

Re: Carbon Removal Technologies

#440

Post by thereisnospork »

louprado wrote: post #420

"It's time to invest and avidly pursue a new wave of technological solutions to this problem - including those that are risky, unproven, even unlikely to work". I had a recent crackpot idea that falls into the "unlikely to work" category since my background is not chemistry. Given that a modern automobile's tailpipe emissions are mostly C02 + H20, those molecules can be converted into ethylene (C2H2) using known effi…

The short answer is that while that reaction works in a beaker, it is too slow, inefficient and fragile. Plus there's also the thermodynamic perpetual motion machine in using the energy from a combustion reaction to reverse that combustion reaction.

Basically you'd need a second car worth of engine to generate the electricity to convert 1/3ish of the co2 from the first engine to ethylene (the rest winds up as methane, ethane, and CO.). Plus storage, maintenance and misc.

There are a few reviews by Hori that are more or less the gold standard on the chemistry if you want to read more. Unfortunately the literature is full of fud though.

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