Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Efficient method to capture carbon dioxide from the atmosphere

helsinki.fi

Post reply on HN
Print view View original

281–290 of 349 posts

Re: Efficient method to capture carbon dioxide from the atmosphere

#281

Post by newyankee »

hannob wrote: post #102
caturopath wrote: post #97

Earlier quoted context omitted.

Plants seem to manage it okay.

They don't, and they can't cheat physical realities either. Plants only filter out very small amounts of CO2 from the air over relatively long timeframes. That's why crop-based biofuels require such enormous amounts of space.

Which is something that when I try to explain to some 'environmentalists' do not get the point.

The other benefits of a biodiverse green belt are great, but if tomorrow I have a concrete system that captures CO2 at 10x the level of trees over lifetime in a similar density, guess what I would like my futuristic city to look like.

Re: Efficient method to capture carbon dioxide from the atmosphere

#282

Post by adgjlsfhk1 »

nine_k wrote: post #270
TSiege wrote: post #185

Earlier quoted context omitted.

This is called Carbon Capture and Storage and so far it has never been worth it energetically. And the only companies doing it are oil companies in a process known as enhanced recovery which pushes more co2 out than is pushed in. The OP was right. Better to leave it in the ground

You can have 100% renewable energy. You can't realistically produce cement or steel without using and exhausting large amounts of CO2. This has to be addressed, even if it costs energy (which, as we agreed, can be 100% carbon-neutral).

there is no world in which it is cheaper to produce steel releasing CO2 and recapturing than fobbing off recapture until later. the thermodynamics just don't work.

Re: Efficient method to capture carbon dioxide from the atmosphere

#283

Post by carbonguy »

jmward01 wrote: post #277
ctoth wrote: post #129

Earlier quoted context omitted.

The implicit model in "just emit less" is that human coordination problems are easier than engineering problems. That's historically backwards. We're extremely good at building things. We're terrible at getting everyone to sacrifice simultaneously for diffuse future benefits. Please generalize this!

I strongly beg to differ. Building is the easy part. It is the political will that isn't. Try to build a train in California and it takes decades and you have a hundred different entities sabotaging you. Put five more lanes on a freeway and no drama, it just happens. We got to the moon when the political will was there but the engineering was still basically science fiction but once the political will dried up, even…

I think you're actually agreeing with ctoth i.e. people think the engineering is difficult and politics is easy, BUT that's backwards if you look at history (which you then do). Political will IS the difficult part, and at least the three of us agree on that.

Re: Efficient method to capture carbon dioxide from the atmosphere

#284

Post by adgjlsfhk1 »

rayiner wrote: post #256
crucialfelix wrote: post #250

Earlier quoted context omitted.

Developing world generally has a lot more sunlight, and now very cheap solar energy.

It's not cheaper when you factor in the batteries, the need for sophisticated electric grids, etc. China and India continue to build huge amounts of coal power. It's not because they're too stupid to buy the cheaper option.

it is still cheaper. In the past decade, China has gone from their electricity being from 66% coal to under 58% this year, with the amount of wind and solar climbing from 12% over the same period. Their coal usage has gone up in absolute terms, but at current rates of solar and wind expansion that will reverse itself in the next 5 years with coal plants used increasingly as peaker plants. The only reason China is building coal plants still is that global pv production isn't sufficient to transition all power to it immediately.

Re: Efficient method to capture carbon dioxide from the atmosphere

#285

Post by msandford »

hannob wrote: post #102
caturopath wrote: post #97

Earlier quoted context omitted.

Plants seem to manage it okay.

They don't, and they can't cheat physical realities either. Plants only filter out very small amounts of CO2 from the air over relatively long timeframes. That's why crop-based biofuels require such enormous amounts of space.

They're pretty amazing for the amount of capital cost. $50 in seed and an acre of land can sequester several to over a dozen tons of carbon per year. It might not be space efficient but it requires basically zero infrastructure.

Re: Efficient method to capture carbon dioxide from the atmosphere

#286

Post by belorn »

condiment wrote: post #45

At current rates of emissions, we’re only about 20 years away from people needing to install CO2 scrubbers in their homes. Soda lime, or calcium hydroxide, is the current state of the art. We use that in an anesthesia and in saltwater aquariums and in scuba rebreathers. An idealized system can capture 500 mg per gram, but in practice you only capture around 250mg/g. This outperforms the method in the article but it’s…

Comparing it to sofnolime (the more common used scrubber material for rebreathers), the cost sits around $10 per kg.

Cost will be the biggest question. A reusable scrubber need to be cheap enough that the reduce efficiency is worth it.

Re: Efficient method to capture carbon dioxide from the atmosphere

#287

Post by rgmerk »

net01 wrote: post #7

What are the use cases of CO2 appart for making my Coke fizz?

All the vaguely plausible industrial use cases for CO2 are a rounding error compared to the amount coming out of vent stacks and engine exhausts.

The one exception is making synthetic fuels, but in the vast majority of applications it’ll be cheaper to use electricity from clean sources (renewables/fission/fusion/unicorn farts) directly rather than pay all of the efficiency losses of electricity -> thermal -> chemical -> thermal -> (end use).

Ballpark, running a car on synfuels takes 10x the energy of running it on batteries charged directly from renewable sources.

Re: Efficient method to capture carbon dioxide from the atmosphere

#288

Post by jmward01 »

carbonguy wrote: post #283
jmward01 wrote: post #277

Earlier quoted context omitted.

I strongly beg to differ. Building is the easy part. It is the political will that isn't. Try to build a train in California and it takes decades and you have a hundred different entities sabotaging you. Put five more lanes on a freeway and no drama, it just happens. We got to the moon when the political will was there but the engineering was still basically science fiction but once the political will dried up, even…

I think you're actually agreeing with ctoth i.e. people think the engineering is difficult and politics is easy, BUT that's backwards if you look at history (which you then do). Political will IS the difficult part, and at least the three of us agree on that.

I guess my internal LLM hallucinated what I was expecting to read!

Re: Efficient method to capture carbon dioxide from the atmosphere

#289

Post by gus_massa »

dheera wrote: post #245
lefra wrote: post #183

Earlier quoted context omitted.

The ocean has already absorbed 30% of the CO2 humanity has emitted. It causes issues: ocean acidity rises, which reduces plankton ability to grow. Plankton being the base of the ocean food chain, all ocean life gets impacted. You'd need to find a way to sequester carbon without it leaching in the water. https://marine.copernicus.eu/ocean-climate-portal/ocean-carb...

Random idea: What if we just sequestered it into elemental carbon pellets and let it sink to the bottom of the ocean? It should not react with the water.

One idea is to charcoal the wood, it makes it harder to decompose and is similar to pure carbon. I'm not sure if it's better to send it to the bottom of the ocean or just to a big hole on land.

Re: Efficient method to capture carbon dioxide from the atmosphere

#290

Post by 8bitsrule »

hannob wrote: post #102
caturopath wrote: post #97

Earlier quoted context omitted.

Plants seem to manage it okay.

They don't, and they can't cheat physical realities either. Plants only filter out very small amounts of CO2 from the air over relatively long timeframes. That's why crop-based biofuels require such enormous amounts of space.

'Very small'?? Depends on your perspective.

"The amount of CO2 removed from the atmosphere via photosynthesis from land plants is known as Terrestrial Gross Primary Production, or GPP. It represents the largest carbon exchange between land and atmosphere on the planet. GPP is typically cited in petagrams of carbon per year. One petagram equals 1 billion metric tons, which is roughly the amount of CO2 emitted each year from 238 million gas-powered passenger vehicles."

The article: https://www.technologynetworks.com/applied-sciences/news/pla...

The paper: doi: 10.1038/s41586-024-08050-3

Post reply on HN