[avernon]

I love this. I started laughing when I read the description. I laughed because a Harvard physicist (funded by people like Bill Gates) had the same idea to use cooling towers for their DAC project in Carbon Engineering (linked in your post). But as you say, it is still expensive. They are bragging that their design took hundred of man years!

And then you two guys come in with the idea that in hindsight seems completely obvious, use all the cooling towers already out there! The most start up thing ever.

I used to be an engineer at an ammonia plant. Many of them already capture and sell CO2 from their process. So they have the infrastructure to compress and sell CO2 already on site. The plant I worked at was in Augusta, GA. Might be worth checking out ammonia plants as a growth market.

[jsantos511]

Thanks for the tip on ammonia plants! Ammonia is one of the top sources of CO2 sold commercially, second to ethanol plants.

I have nothing but respect for what Carbon Engineering has done. In many ways, they opened people's eyes to what's possible when it comes to direct air carbon capture. The more people doing carbon capture, the better - we have 1T tons of CO2 to capture, and we need as many shots on goal as possible to get there!

[avernon]

I think most process engineers at an ammonia plant would be interested to hear about it because it is an elegant solution. I'd focus any pitch on working with them to make sure your process will not interfere with their process. The people that run these plants are highly incentivized based on run time and they run them at 99.9% type uptimes. They'll think its cool and good for PR as long it they feel like there is no chance to have their plant disrupted or equipment damaged by more corrosive CW.

[jsantos511]

Makes sense - thanks for the recommendation!

[epistasis]

If it's the startup I'm thinking of, they've done most of their work on the downstream process of converting CO2 to useful things, rather than focusing on capture. The energy used in capture of CO2 is only a fraction of the cost of changing CO2 into a sequesterable form or fuel form.

That said, this is a really great idea, as heat pumps will be increasingly used for all sorts of temperature management. Cutting 10% off of costs by using somebody else's fans could be great, as long as hauling the CO2 filters off and replacing them is cheap.

[carbonguy]

I'm no engineer; that said, I think you're being slightly unfair to the Carbon Engineering folks, as paper [3] that OP linked states that CE's design reflects "reflects roughly 100 person-years of development." That doesn't strike me as outrageous in this context (30 people working for ~40 months?), although I'll grant I don't have a ton of perspective on industrial process development.

That said, OP's idea does have merit. avernon, I think you hit the nail on the head with your comment downthread regarding the main concern being avoiding disruption to existing plant processes where this kind of tech might be installed - I would be worried specifically about how radically raising the pH of cooling process water would affect mineral deposition, for example, but then that in turn would surely depend on how a given plant had set up its cooling system to begin with.

Nevertheless, it seems very likely that this idea could in itself knock about $4/t off of the cost of CO2 relative to the CE estimate ($212M saved for their air contactor design amortized over 30Mt of CO2 captured during a CE plant lifetime) which in the best case is around 5% of the cost of the CO2 capture.

[avernon]

Since you are piggybacking on their system, you'd save on peripheral equipment costs and operating costs, too. The subsystems surrounding these cooling water systems are immense. They need river/lake access for water, giant pumps to feed the makeup water into the system, giant fans running all the time, and even larger pumps to circulate the cooling water after. There is a lot of nickel and dime complexity/cost in things like water purification. I'd be shocked if it only knocked 5% of the cost off.

Plus many facilities have surplus low pressure steam you could use to regenerate your fluid.