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The impact of direct air carbon capture on climate change

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Re: The impact of direct air carbon capture on climate change

#131

Post by dv_dt »

pfdietz wrote: post #56
dv_dt wrote: post #30

If you're going to continue to burn fossil fuels, it seems better to burn it in a plant that inherently captures the carbon then trying to wrangle it back after it's release. The interesting part of the Allam cycle for power generation is that supercritical co2 is the working fluid for the turbine, and when you burn the fuel it increases the mass in the closed circuit. Both the size and the efficiency of the plant al…

That would be true, if the power plant has high capacity factor, and if it stationary, and if it is located near a place where the CO2 can be sequestered. But if you (say) have peaking turbines that are intended to take over when renewables or short term storage are not available, they may have very low capacity factor. It could be economical to have them release the CO2 into the atmosphere, then steadily scrub that…

I'm for pursuing both options really. There are likely solution areas where both would be a win. And we really know not enough about the end direct cost of either until sufficient numbers are built out - and we should build out both to at least 10x what the prototypes do. The real problems are governmental policy, and then financial policy to get the attention and scaling going on any of these solutions.

Re: The impact of direct air carbon capture on climate change

#132

Post by mturmon »

virmundi wrote: post #129
mturmon wrote: post #128

Earlier quoted context omitted.

This is incorrect, it’s well established that methane is a more potent GHG. See the reply here: https://news.ycombinator.com/item?id=21485738

What’s not taken into conservation with that comment is that methane at those altitudes does not impact much because the energy is radiate back to space.

You have doubled down on a casual assertion ("methane is not a significant greenhouse gas") because you don't understand radiative transfer in the upper atmosphere. It's OK, radiative transfer is complex. Your options are to accept this consensus, or do a lot more study than you have.

Re: The impact of direct air carbon capture on climate change

#133

Post by throwawayhhakdl »

pjc50 wrote: post #87
throwawayhhakdl wrote: post #36

Earlier quoted context omitted.

I would aggressively vote and promote a us presidential candidate who stated they would negotiate an arrangement to do this for financial compensation on coastal equator countries- and failing that, a hostile military invasion to force it upon them. Probably no need for the latter, but having it on the table makes the former easier to negotiate. This process could release deadly nickel into the water. It probably wou…

> and failing that, a hostile military invasion to force it upon them. Eco-fascism! I mean, once you're willing to murder people to reduce carbon emissions, there are simpler ways to do it. But make sure you've got suitable carbon offsets for the invasion and the crematoriums. > optimistic message "Good news: America is going to improve the world at gunpoint again!"

> Eco-fascism! I mean, once you're willing to murder people to reduce carbon emissions, there are simpler ways to do it. But make sure you've got suitable carbon offsets for the invasion and the crematoriums.

I think this disingenuous. I am fully aware this is not a virtuous path (noting again that I think it could be done easily and more preferably with economic solutions). From a utilitarian perspective it is massively moral. It would likely minimize suffering of the target populations too.

Yes yes killing billions would reduce carbon emissions but that’s clearly not a good solution and not comparable. Using military might to force coastal equator nations to comply with what is plausibly our only chance at saving the planet is very low on the scale of shit countries have done for self betterment.

Crematoriums imply killing is a first order goal. Killing is a bad thing in the eyes of this plan that is trying to be minimized.

Re: The impact of direct air carbon capture on climate change

#134

Post by gok »

rayiner wrote: post #126
jarvist wrote: post #6

I'm not sure if this article hammers home the key point: extracting carbon from the air always takes more energy that was gained by burning the fossil fuel to make that carbon. This is inevitable due to the entropy cost of de-mixing CO2 from the air, and from the limited efficiencies of thermal power generation (~33-40% for a coal power plant, perhaps 20% in an internal combustion engine), and limited efficiency of t…

> So it only makes sense to spend energy on sucking CO2 out of the atmosphere, once you've already de-carbonised everything which you possibly can. The actual point is much narrower than that. It doesn't make sense to spend energy on sucking CO2 out of the atmosphere, unless: 1) You use an energy source that produces less carbon than the amount you're taking out; and 2) You're not displacing demand that must then be…

> if you build a surplus of renewable power … it makes sense to use that to suck out CO2

Although it's unclear that resources to build carbon capture infrastructure wouldn't be better spent on (say) energy storage.

> China plans to ban EVs by 2040

I think they plan to require EVs by 2040...

Re: The impact of direct air carbon capture on climate change

#135

Post by minikites »

WhompingWindows wrote: post #122
spodek wrote: post #42

Not a word about the most effective, cheapest strategy: reduce emissions? Most Americans could reduce their emissions by 75% while improving their standard of living by buying less junk, wearing a sweater in the winter, eating more healthy, and other low hanging fruit that will make them more active, healthy, connected to their communities, etc. Reduce consumption by half. There, I just saved us $300 million. How is…

Personal choice is a very small aspect here. Americans can not choose to have lower carbon cement, steel, manufacturing, shipping, airliners, etc. Yes, we can do a lot by not flying ourselves, buying less items, eating less meat, but at the end of the day: MOST of our solutions are going to come from corporations and government.

Exactly. An individual can live their entire life taking short showers, abstaining from meat, and generally living like it's the 15th century and all of their efforts are erased when the Keystone XL pipeline sprays 300,000 gallons of oil over North Dakota.

https://time.com/5731775/north-dakota-keystone-pipeline-spil...

Re: The impact of direct air carbon capture on climate change

#136

Post by 40four »

DanTheManPR wrote: post #118
40four wrote: post #105

I've been interested in these types of technologies lateley. > that many people are extremely pessimistic about climate change. They can’t imagine any solution – often, they become mesmerized by what appears to be an insoluble collective action problem – and fall into fatalistic despair. More and more, I find this description matches my thoughts on climate change. I'm really beginning to think the problem might requi…

We are geoengineering already, so we are going to have to deliberately geoengineer our way out of the problem.

>we are going to have to deliberately geoengineer our way out of the problem

Agreed, I'm really starting to think this will be the only way.

Re: The impact of direct air carbon capture on climate change

#137

Post by triceratops »

minikites wrote: post #135
WhompingWindows wrote: post #122

Earlier quoted context omitted.

Personal choice is a very small aspect here. Americans can not choose to have lower carbon cement, steel, manufacturing, shipping, airliners, etc. Yes, we can do a lot by not flying ourselves, buying less items, eating less meat, but at the end of the day: MOST of our solutions are going to come from corporations and government.

Exactly. An individual can live their entire life taking short showers, abstaining from meat, and generally living like it's the 15th century and all of their efforts are erased when the Keystone XL pipeline sprays 300,000 gallons of oil over North Dakota. https://time.com/5731775/north-dakota-keystone-pipeline-spil...

Oil pipeline spills make me furious, but they don't have the exact same effects as carbon emissions. It's not a useful comparison.

Re: The impact of direct air carbon capture on climate change

#138

Post by triceratops »

shartshooter wrote: post #53
spodek wrote: post #42

Not a word about the most effective, cheapest strategy: reduce emissions? Most Americans could reduce their emissions by 75% while improving their standard of living by buying less junk, wearing a sweater in the winter, eating more healthy, and other low hanging fruit that will make them more active, healthy, connected to their communities, etc. Reduce consumption by half. There, I just saved us $300 million. How is…

Because it’s also the least effective strategy. The reality is getting nearly everyone to change their behavior just isn’t gonna happen. Even if everyone in America went vegan, showered once a day and biked everywhere wouldn’t change much with impoverished countries coming out of the third world. If you can’t get them to change then it doesn’t really matter. Big problems require big, comprehensive solutions. For that…

> Even if everyone in America went vegan

> we don’t have the political will.

Something tells me that achieving the first would more easily lead to the second. For a politician whose constituency is mostly vegans, their work on climate change will determine whether they keep their seat. If their constituents are pickup-truck-driving, McMansion-owning suburbanites, it's not going to be a priority.

I recognize that getting everyone to go vegan isn't possible or maybe even desirable. But let's not pretend that willing personal sacrifice isn't at least part of the solution.

Re: The impact of direct air carbon capture on climate change

#139

Post by pfdietz »

jandrewrogers wrote: post #130
pfdietz wrote: post #54

Earlier quoted context omitted.

A properly engineered DAC system will be much less expensive than the number they found. https://www.cell.com/joule/fulltext/S2542-4351(18)30225-3

That paper only looks at the energy/cost balance of the plant, not the chemical feedstock. Production of that feedstock is energy intensive, the recycling is not 100% efficient per the paper (i.e. it will constantly have to be replenished), and the industrial infrastructure to produce those chemicals at the necessary scale to materially reduce atmospheric carbon simply doesn't exist. Any cost model for large-scale DA…

Not at all -- the cost of makeup streams for chemicals are included in the O&M cost (table 2).

Re: The impact of direct air carbon capture on climate change

#140

Post by ncmncm »

xorfish wrote: post #104
relieferator wrote: post #43

Earlier quoted context omitted.

From what I can recall, landfills produce more methane than any other process. How about we build a carbon capture next to every landfill, divert the methane and burn it to run the DAC?

Or you just burn the trash directly.

Releasing CO2 and NOx.
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