How Does Carbon Capture Actually Work?

Carbon capture and storage (CCS) or carbon capture utilisation and storage (CCUS) form a major part of a lot of governments' net-zero plans and also roadmaps like the IEA's Net-Zero by 2050 roadmap that the published recently. But so far, we have had very few successful carbon capture projects, even though many smart and motivated people have been trying very hard for about 30 or 40 years.

I've been hearing contradictory things about carbon capture. It's apparently a mature technology, but on the other hand we are expecting an imminent breakthrough that will see costs drop and adoption rise. This sounded strange to me, but since I didn't actually know how carbon capture works, it was hard to get an idea about where the technology maturity is right now, and how its likely to develop. So I tracked down a chemical engineer - Marc Allen - who has been working in industrial gases and sustainability for the last 20 years. And Marc answered all my questions about what kinds of carbon capture there are, what applications they can be used for, and how carbon capture actually works.

Bookmarks:
00:00 Intro - can carbon capture possibly scale up as quickly as many project?
00:21 IEA Net-Zero by 2050 road map and Ketan Joshi's historical vs future projections
01:25 Cute infographics did not help me understand how CCS works
02:19 Post combustion carbon capture
02:44 Oxyfuel carbon capture
02:51 Blue hydrogen from natural gas or coal
03:22 Amine absorption carbon capture simple infographic
04:30 Amine absorption process diagram
05:20 How much CO2 can be captured?
07:24 Molecular sieve carbon capture
09:22 Membrane carbon capture
10:18 How much energy does carbon capture use?
11:19 CCS is good for hard-to-abate sectors
13:03 CCS needs a higher price on carbon to be economic
13:59 Summary and future video topics

A big thank you to Marc Allen from Engeco for his patient explanations!

Sources:
Quest, Petra Nova and Boundary Dam on MIT database:
LNG processing U.S. Government Accountability Office from Washington, DC, United States, Public domain, via Wikimedia Commons

Thanks for watching the video How Does Carbon Capture Actually Work?
#technology #engineering #educational

[phillipsmith]

I’d be interested in bio char as a CCS technology as I understand it charcoal sequesters carbon for geological timescales. I assume char does the same. Given the scale required is it viable or even helpful? For example if we converted all our combustible food and agricultural waste to char, would that remove enough Carbon from the carbon cycle to make a dent in atmospheric CO2

[EngineeringwithRosie]

Sorry to everyone who saw this video twice in their feed. I had a problem with my audio export that several viewers were kind enough to point out very quickly, so I took down the original video and replaced it with this one with the audio fixed. I hope this doesn't piss off the YouTube algorithm too badly!

[mrtmat]

I'm grateful for serious, scientific, expert-driven content like this. Thank you.

[dj_laundry_list]

One of the best youtube channels to date. I hope you reach 10m subs

[PeterJFlower]

Brilliant video. Most people gloss over this and now I can see why. Well done Rosie.

[MartinHoeckerMartinez]

I wish a little more time was spent on how the thermodynamics set the limit on how much energy you need to extract and concentrate CO2 that is mixed into an exhaust stream or the atmosphere. The entropy difference between the mixture and the separated gas streams (one enriched in CO2 the other depleted) sets a minimum energy requirement for separation. Sorting into streams that are 10%/90% of the original CO2 composition is easier than 1%/99% which is easier than 0.1%/99.9%. How much capture/enrichment is enough? Is that level of sorting viable?

[robertcormia]

Well done, technically accurate, easy to understand, and correct that the electric power industry doesn't see the value in capturing carbon dioxide, otherwise we'd be doing it already. But a price on carbon, or a value on captured carbon dioxide, could make the difference.

[Ikbeneengeit]

This is one of the best green energy channels on YouTube, thank you

[rubidot]

Loving your channel, Rosie. I've been watching, listening to and reading about CCS for quite some time now, but this is the first I've seen CCUS mentioned, although many have discussed uses for captured carbon rather than storage.

[AlRoderick]

There's a good video on amine systems on Smarter Every Day in his series on nuclear submarines, that's the primary system they use to scrub carbon dioxide from the air on the boat. Regrettably they just vent the CO2 overboard, but it is just from the crew's breath and not fossil sources so it's not strictly pollution.

[tommclean]

Thanks for explaining the capture part of CCUS. Very interesting. I suspect that by the time the price on carbon gets high enough to justify CCUS then the economics of renewable power generation and storage will make it redundant. Already there is a solution for industrial high heat applications called electric arc furnaces. Thanks again.

[dasautogt]

Thanks Rosie... took my knowledge further up the curve. Looking forward to next addition.👍

[davehayes]

Thanks Rosie. Good stuff.
That's the Carbon Capture part.
Looking forward to the Utilisation and Storage part of the puzzle.

[vernonbrechin]

I'm glad to find your fine Channel. I'm glad to see you take a critical look at some of these technologies that are so often presented as being largely faultless. I especially liked your mention that these capture plans have been around for almost 30 years but as yet they have yet to make even a small dent in our CO2 emissions. This is a factor rarely mentioned by most of the proponents. You could also mention some of the plants that no longer capture the CO2, or are about to end that process because it turned out to be not economically viable.

When you do your video regarding the storage aspects of those commercial plants, that have succeeded in capturing a significant portion of their flu gas CO2, you should mention those where the CO2 has been pumped into played-out fossil fuel source reservoirs to extract more fossil fuels that are burned, releasing more CO2 back into the atmosphere. That was part of the original plan since that process would help pay for the extraction of the CO2 from the flu gas. Typically, the promoters of the CO2 extraction part fo the process never mention the end use of the extracted CO2.

[voltaaire]

I'm a chemist. 13:03 *The economic solution is to find large scale uses for the carbon as carbon dioxide.* Carbon dioxide, CO2, can be used with caustic, magnesium metal, and hydrogen.
With caustic, NaOH, we get soda ash, Na2CO3, which has many uses. One use is for neutralizing water acidity safely. This process leaves CO2 as bicarbonate, HCO3-, in the ocean restoring its alkalinity. With burning magnesium metal for heat, CO2 is an oxidizer. This process leaves carbon as soot/carbon. The magnesium as MgO can be reused to regenerate Mg metal, an energy/fuel.
With renewable hydrogen we can make methane, CH4, which is a synthetic fuel gas with many uses. The hydrogen is left as fresh/drinkable water which has many uses including agriculture.

[anwyl]

ooh! I made a pressure swing molecular sieve thing at home! Doesn't really do much since it's just using a coke bottle as a pressure vessel, but it was a fun project for understanding.

[STOLSPEED]

Coal is carbon that was captured by plants millions of years ago, on a massive scale, at the right cost. The best example of good CCS. Prepared the atmosphere to be just right for us. That carbon should stay where it is. Once we burn the coal we'll never manage to capture all that carbon again.

[zarfmouse]

ETA: I just realized you address this at the very end. I look forward to your future video on transport and storage!

This was helpful to learn about but I wish there had been some discussion of the storage piece. Once the CO2 is captured how are we certain that it's not going to be re-released? How are we certain we aren't building ticking time bombs of CO2 release some decades or centuries from now?

The fossil energy industry loves to create externalities. Isn't stored CO2 another externality that isn't accounted for in the costs?


These are much more interesting questions to me than the chemical engineering behind the capture process. We can easily measure how much was captured vs. emitted. But how do we measure how much was successfully stored and safe essentially forever?

[Hcs]

I just finished writing a technical report on the viability of CCS technology as a climate change mitigation strategy. I wish I had seen this video a few days ago! Great explanation!

[RickCarr]

It is absolutely feasible. The facility I work at makes hydrogen via steam-methane reforming process, then scrubs the entrained CO2 with amine. The end result is >99% pure hydrogen, which is routed to the hydroprocessing units. The pure CO2 is routed via pipeline to a vendor which adds it to carbonated beverages. The process is energy intense, which adds to the cost of gasoline. But consumers absorb the cost, as they always have.
Great video BTW. Thanks for sharing.