How Thermodynamics Holds Back Negative Carbon Tech

Direct Air Capture (DAC) has been getting more and more attention over the last few years. Could we avert climate change by pulling carbon dioxide out of the atmosphere? Could we not just stop, but actually *reverse* the damage done? Unfortunately, most don't fully appreciate just quite how much CO2 we've emitted and the outrageous scale of the problem facing us. Today, we apply the fundamental principles of thermodynamics to question whether this is even feasible.

Written & presented by Prof. David Kipping. Edited by Jorge Casas. Fact checking by Alexandra Masegian.

THANK-YOU to D. Smith, M. Sloan, L. Sanborn, C. Bottaccini, D. Daughaday, A. Jones, S. Brownlee, N. Kildal, Z. Star, E. West, T. Zajonc, C. Wolfred, L. Skov, G. Benson, A. De Vaal, M. Elliott, B. Daniluk, M. Forbes, S. Vystoropskyi, S. Lee, Z. Danielson, C. Fitzgerald, C. Souter, M. Gillette, T. Jeffcoat, J. Rockett, D. Murphree, T. Donkin, K. Myers, A. Schoen, K. Dabrowski, J. Black, R. Ramezankhani, J. Armstrong, K. Weber, S. Marks, L. Robinson, S. Roulier, B. Smith, J. Cassese, J. Kruger, S. Way, P. Finch, S. Applegate, L. Watson, E. Zahnle, N. Gebben, J. Bergman, E. Dessoi, C. Macdonald, M. Hedlund, P. Kaup, C. Hays, W. Evans, D. Bansal, J. Curtin, J. Sturm, RAND Corp., M. Donovan, N. Corwin, M. Mangione, K. Howard, L. Deacon, G. Metts, G. Genova, R. Provost, B. Sigurjonsson, G. Fullwood, B. Walford, J. Boyd, N. De Haan, J. Gillmer, R. Williams, E. Garland, A. Leishman, A. Phan Le, R. Lovely, M. Spoto, A. Steele, M. Varenka, K. Yarbrough, A. Cornejo, D. Compos, F. Demopoulos, G. Bylinsky, J. Werner, B. Pearson, S. Thayer, T. Edris, A. Harrison, B. Seeley, F. Blood, M. O'Brien, P. Muzyka, E. Loomans, D. Lee, J. Sargent, M. Czirr, F. Krotzer, I. Williams, J. Sattler, & J. Smallbon.

REFERENCES

MUSIC
► Hill - A Slowly Lifting Fog [0:00]
► Falls - Life in Binary [3:24]
► Hill - Northern Boards [8:03]
► Hill - To Quiet the Drumming Inside My Head [11:13]
► Hill - Chasing out the Chaos [15:29]
► Chris Zabriskie - Cylinder Seven [19:23]
► Joachim Heinrich - Y [22:53]

CHAPTERS
0:00 Climate Change
2:44 Removal Requirements
3:38 Possible Solutions
5:03 Introducing DAC
5:43 Climate Anxiety
7:12 DAC Principles
8:14 Scalability
9:29 Thermodynamics
12:08 Progressive DAC
13:32 RCPs
15:09 Simulations
17:03 Energy Requirements
19:34 Efficiency
21:21 Conclusions
24:35 Outro and credits

#DirectAirCapture #ClimateChange #NetZero

[jrfish]

Did my PhD on CCUS and have been working in the area in various capacities for last 15 years. DAC is the absolute hardest way to do CO2 removal, but likely needs to be done. The good thing is that regeneration of the sorbent or solvents can be done with low grade heat, in places like TX it might even be done via solar heat not needing electric at all. Unfortunately, compressing the CO2 for storage is also quite consuming. The other major issue is moving the air through the device. The chemistry is fairly easy to understand, but the engineering for reduction of energy is quite hard.

[Mr_Stone]

There is also research into capturing co2 bound in sea water, where it's concentration is much higher (sCS^2 process). Which would in turn reduce the co2 in our atmosphere, because they can use their giant surface area to bind more. Additionally, the co2 would be bound in limestone instead of gaseous form.

[ADINSX]

Video was released 8 minutes ago*. Within those 8 minutes, 10 climate-change-denial comments were posted, the earliest being posted within 3 minutes of the video's release. Video is 25 minutes long.

Tells me everything I need to know about climate-change deniers.

*: not counting the time it took for me to read the comments and post this one

[MarkfrmCanada]

The frustrating thing to me is that we've had a major piece of the solution available to us for generations now, yet haven't used it. Further to that, the loudest opponents of its use have generally called themselves environmentalists. Nuclear energy is our best tool to take fossil fuel use offline.

At this point nobody who expresses anti nuclear energy views has any credibility to call themselves an environmentalist.

[TanyaLairdCivil]

It seems absurd to argue that we can double our energy production and devote all of that extra production to carbon capture. But what if we didn't dismiss it, and asked, "can we actually do this, and how could we do so cheaply?"

There is one conceivable way we could solve this, that I don't see discussed much. There is a method firmly grounded in thermodynamics that we could use to generate absurd amounts of energy for relatively low costs - extremely large nuclear reactors.

Fission plants are interesting in that the fuel costs are a rounding error in their overall budget. All the cost is in building the plant. But fission reactors, like any heat engine, tend to be more efficient the larger you make them. And in particular, they tend to be cheaper the larger you make them. There's a reason the nuclear industry has tended towards large GW-scale reactors. These are the economies of scale needed to make fission practical.

But what if we went larger? A lot larger. Orders of magnitude larger. Imagine if we built terawatt-scale fission reactors. Think of how cheap we could make large amounts of energy if we were able to build such massive reactors.

Why hasn't anyone done this before? Because for most cases, it's not practical. A TW-scale reactor is largely useless for the electricity market. Even if it can make electricity for a very low unit cost, there simply won't be a TW's worth of electricity demand within a reasonable distance. You would have to ship that energy hundreds or even thousands of kilometers, and line losses would eat you alive. Even though monster reactors might be able to produce huge amounts of energy cheaply, we don't use them because the market within a practical transmission distance can't soak up a TW's worth of production.

But CCS is one of the few cases where such monster reactors might actually make sense. You avoid crippling line losses by building your monster reactor right next door to your big CCS plant. And you can put your CCS equipment almost anywhere (or anywhere suitable geology exists.) So in principle we could construct some monster reactor and CCS plant right next door to a uranium or thorium mine, power all the mining and processing equipment with said reactor, and make the whole process as efficient as possible by minimizing transportation needs.

We have access to the energy needed to do this. The US has alone has enough depleted uranium sitting in warehouses that we could probably cover the whole process with this. And beyond that, reactors can be built to work off thorium, natural uranium, etc.

Ideally, you would design such a reactor to specifically meet the needs of large-scale CCS. For example, you might design them to operate with unenriched uranium and thorium, large breeder reactors. Also, you might be able to skip the electricity production process entirely. As you note, often for CCS most of the energy budget goes into heating whatever compound your plant uses to absorb CO2. So you could have a plant that has a primary cooling loop going through the reactor core, passes through a heat exchanger, and gives the water to a second fluid loop that provides the heat needed for the CCS equipment. You could design the reactor to primarily serve as just a heat source directly, and thus avoid the large thermodynamic losses necessary in thermal electricity production.

And you can go further. When you start really thinking on this scale, a lot of things become possible. For example, it's likely there isn't a foundry in the world that can build reactor vessels large enough to make such monster TW reactors. But when you're thinking on this scale, simply building the necessary foundry, right on site, to produce such vessels becomes a practical option. You avoid the transportation nightmare of transporting a TW reactor vessel long distance by building your reactor vessel foundry right on site. If we want to seriously talk about atmospheric CCS, we're talking on a scale that involves dedicating a few percentage of total global GDP to the project. And when you start thinking on that scale, all sorts of options open up. If the technology to do what you need hasn't ever been scaled to the necessary level, you have the funds to scale it. If a foundry that can build a reactor vessel large enough doesn't exist, you can build that foundry. If enough nuclear engineers and technicians to run such a complex don't exist, you can pay the entire education cost of an entire cohort of students to get the training they need.

It's a bit like the original Manhattan Project. Building a nuclear weapon in 1940 seemed impossible, the logistics were insurmountable. But when you start throwing around a budget big enough to construct entire cities from scratch, a lot of things that were once impossible suddenly become possible.

[thagrintch]

The amount of time, effort, research and content your pour into your videos is outstanding. Thank you, David, for your passion on this extremely important topic. You have a way with words; your writing and your delivery show exactly just how passionate you are. And of course, thanks for keeping that beautiful "Life in Binary' song going in your background music! I will be showing this video to my science students!

[TerryClarkAccordioncrazy]

Capturing co2 while we're still burning fossil fuels is like mopping the floor with a tissue while the bath is overflowing.

[randalljsilva]

Advanced nuclear, nuclear, nuclear!! Even though you didn’t mention the word once or show a picture of one, your entire video is actually an advertisement for advanced molten salt nuclear reactors. You successfully argued we need way more energy than we currently generate in order to terraform our own planet (whatever direction it needs to go) and that must be clean, safe, and simple—ergo molten salt nuclear reactors that first burn our current stockpiles of nuclear waste and then burn thorium.

[martynkentfrancis]

Outstanding and thoughtful analysis, as always from Cool World 🙏

[richardfabrinnielsen]

You totally forget to talk nuclear. That is the gamechanger.

[nicolasuribestanko]

Long story short, we're with a capital F.

[miko]

Hello, Professor.

I am in the industry of RE development, working in one of the world's biggest global developers. Even though what you are saying is 1000% correct from a scientific and engineering point of view, the most simple fact that with today's global economic system and how it's driven, add to that the worse fact of being unable to commercialize then Carbon capture systems and by that I mean that you can't get an income out of it, it is almost impossible to have the world's eye turning towards these types of projects. It will have to be either coming from a governmental initiative or a non-profit org. working on collecting donations for this to be picked up by a willing developer. It is a sad fact that everything is driven by money and every good action can be halted by global economic short-comings.

I have been calling for my superiors to act according to our mission statement and lobby governments to create a fund aiming to have said "experiments" as they call it, materialized, continually researched, developed further and maintained for a better future for our children.

[zerochance]

Profound video. Thoughtful, compassionate, scientifically/technically on point, and well spoken. Beautifully done.

[zigajavornik]

As an automation engineer I wish that I would see work opertunity to work on these issues... Thanks for harsh reality and a good video.

[Scrogan]

Pasture naturally absorbs a lot of CO2 and doesn’t decay. Hadrian’s wall looks so short today because the earth around it has risen, that stored carbon right there. Pasture is a quicker carbon sink than forests are, but the Kyoto protocol doesn’t measure carbon absorption by plants that are too small, so everyone focuses on trees instead. Creative accounting has permeated the world with the wrong incentives.

[SnaketheJake]

Children’s anxiety comes from the adults. There is more to this story than we know. And I’m sure that the truth has been inflated.

Let’s just start at nuclear.

[Nightscape_]

I am happy I don't watch news or talk politics, I never have to think about climate change. I just go about my life, trying to join the middle-class homeowners and not die in poverty.

[roro-mmcc]

And that's not even including the energy that would also be required to transport and store the captured carbon. So even the 100% efficiency scenario for capture would require more energy being diverted into transport and storage. Where/how are we going to store trillions of tons of CO2 securely to prevent it re-escaping into the atmosphere?

[adammanneh]

Wasn't expecting a new Cool Worlds video, on this rainy Tuesday evening! ☺

[jasol]

Open discussions about mitigation strategies and technologies, such as Carbon Capture & Storage (CCS) and Direct Air Capture (DAC), are crucial in raising public awareness of what could very well be humanity's last 'controllable' stand against irreversible damage to our biosphere.

While these technologies offer potential solutions, they also highlight the immense energy demands and politically divisive challenges we must overcome as a global community.

Climate destabilization is a threat that transcends borders, requiring united efforts on a global scale. It's truly encouraging to see the quality of scientific, data-backed conversations like this that underscore the significance of addressing climate instability as a collective endeavor.