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

Launch HN: Noya (YC W21) – Direct air capture of CO2 using cooling towers

news.ycombinator.com

Post reply on HN
Print view View original

91–100 of 168 posts

Re: Launch HN: Noya (YC W21) – Direct air capture of CO2 using cooling towers

#91

Post by jsantos511 »

kensouris wrote: post #78

What about the energy balance? If your capture is exothermic you will warm up the cooling water and your client will not have enough cooling for their process. When you regenerate, do you need to add energy? How much CO2 is generated by the energy you need?. If you have to add heat to regenerate, how do you now cool the water back down to the temperature required by your client? Most industrial cooling systems use ca…

The energy balance is going to be critical, I agree!

We are still working on finalizing all the inputs for this process, including regeneration amounts, amount of heat added, etc. Based on our early modeling, it seems the amount of heat generated from the capture will be negligible since the amount of CO2 moving through our system is much smaller than the amount of water available to provide cooling.

Our chemicals have anti-scaling properties, and we're working to understand corrosion across many different material types to ensure we don't cause more problems than we're solving.

Re: Launch HN: Noya (YC W21) – Direct air capture of CO2 using cooling towers

#92

Post by jsantos511 »

networkimprov wrote: post #75
jsantos511 wrote: post #27

Earlier quoted context omitted.

The US is home to over 2M cooling towers: https://www.nsf.org/news/road-map-improve-response-legionnai... Using the numbers we've calculated with our first partner plant, we're expecting to be able to capture 0.5-1 ton/day with their 25 ton cooling tower. This is a very small tower - for perspective, UCSF operates a 5,400 ton cooling tower to operate their small electricity co-generation plant, and cooling towers at…

What percent of current US CO2 production is 730M tons?

US CO2 consumption is ~64M tons / year, so 730M tons >> current US production. Next step for managing CO2 production is geologic sequestration to ensure we have something to do with all the CO2 we capture!

Re: Launch HN: Noya (YC W21) – Direct air capture of CO2 using cooling towers

#93

Post by mattmaroon »

jsantos511 wrote: post #67
mattmaroon wrote: post #55

Earlier quoted context omitted.

Yeah I mean, clearly removing CO2 from the environment (provided were not burning fossil fuels to do it) can’t be bad. For now it seems like you’re just shuffling the source of the problem, but i I see what you mean about ethanol sans-CO2. Is that a realistic thing in the near term? If CO2 is all just a byproduct (I.e. nobody is producing it just to sell it) then it would seem that whatever source of it consumes the…

Ethanol sans-CO2 is definitely realistic, but the timing is what's up in the air (no pun intended). There are a few different teams that have developed materials that enable ethanol production from CO2 (!!!) and are starting to scale [1, 2 as examples]. We're still working on finalizing our comparisons of our process to current CO2 production processes. From what I can tell currently, our process requires significant…

Awesome. Good answers. Thanks and good luck!

Re: Launch HN: Noya (YC W21) – Direct air capture of CO2 using cooling towers

#94

Post by ajhurliman »

jsantos511 wrote: post #32
ajhurliman wrote: post #11

Earlier quoted context omitted.

I was about to post the same question. I wonder how Airgas gets their CO2.

Most commercial CO2 that is used in the market today is actually produced as a by-product of ethanol production: https://www.attisbiofuels.com/by-products/carbon-dioxide

Interesting, thanks!

Re: Launch HN: Noya (YC W21) – Direct air capture of CO2 using cooling towers

#95

Post by elihu »

jsantos511 wrote: post #13
toomuchtodo wrote: post #4

If you're not injecting the CO2 underground in a stable form, how does this reverse climate change? It sounds like it's simply a cheaper option in some circumstances for sourcing CO2 from the air (compared to traditional solutions by Airgas). Not to take away from your efforts! I think this is a fine improvement to CO2 process needs if you can replace more expensive air extraction techniques, but it doesn't contribut…

Great observation - somewhere between most-to-all of the CO2 that goes into beer, food production, etc ends up back in the atmosphere. Our initial model is the first key step towards the additional solutions we're designing to remove carbon from the atmosphere. The use of CO2 that is sourced from the atmosphere is better from an environmental perspective than the use of CO2 sourced from offshoots of an ethanol plant.…

> The use of CO2 that is sourced from the atmosphere is better from an environmental perspective than the use of CO2 sourced from offshoots of an ethanol plant.

I thought that most ethanol is made from fermentation of corn, sugar, or whatever, and the carbon in that process came from the atmosphere originally. So, environmentally whether you make CO2 as a byproduct of ethanol production from CO2-absorbing crops or you extract CO2 straight from the air, it seems essentially the same because in both cases the carbon came from the atmosphere originally. What am I missing?

Re: Launch HN: Noya (YC W21) – Direct air capture of CO2 using cooling towers

#96

Post by shafyy »

simonebrunozzi wrote: post #54

Might be a dumb question, but: how can this be possibly cheaper than planting trees?

Keep in mind that planting trees != planting trees. It's much more important to let natural vegetation grow on land than to plant random trees. For that, the most important thing we need to do is to reclaim land. Currently, 45% of land is used for livestock agriculture. You see what I'm getting at :-)

Re: Launch HN: Noya (YC W21) – Direct air capture of CO2 using cooling towers

#97

Post by baybal2 »

I want to warn readers, and people not aware of high school physics.

Capturing CO2 is one thing, but doing anything with it later completely different.

Just capturing CO2 does not involve returning the energy debt of carbon-oxygen bond, but doing anything with it later does, and usually many times the electric energy gained from combustion.

In other words, making anything useful out of it will require you to expend many, many times more hydrocarbon energy than if you didn't, or just synthesized directly.

Anybody claiming the opposite have either never finished a high school, or is an utter fraud, and, unfortunately,the number of such has been skyrocketing recently, pampered by windfall of environmental grants, and investments signed off by equally ignorant, or corrupt people.

Re: Launch HN: Noya (YC W21) – Direct air capture of CO2 using cooling towers

#98

Post by bmm6o »

baybal2 wrote: post #97

I want to warn readers, and people not aware of high school physics. Capturing CO2 is one thing, but doing anything with it later completely different. Just capturing CO2 does not involve returning the energy debt of carbon-oxygen bond, but doing anything with it later does, and usually many times the electric energy gained from combustion. In other words, making anything useful out of it will require you to expend m…

Yes, but presumably the buyers know what they can do with the CO2. I do think that knowing what happens next is important if you're interested in reducing atmospheric CO2.

Re: Launch HN: Noya (YC W21) – Direct air capture of CO2 using cooling towers

#99

Post by monopoledance »

jsantos511 wrote: post #84
simonebrunozzi wrote: post #54

Might be a dumb question, but: how can this be possibly cheaper than planting trees?

The short answer is that we absolutely need more trees than we currently have, but trees alone won't be able to get us there. Trees are great at capturing CO2 from the sky, but they suffer from an impermanence issue. Trees capture CO2 for the duration of their lifespan, but when they die, they decompose and release that captured CO2 back into the atmosphere. They also require dedicated use of large swaths of land to…

I don't think this is the complete picture. In an intact old forest, a lot of bio-matter doesn't decompose in time, but rather gets buried in the anaerobic zone. In a healthy forest the first few centimeter soil are so biologically active just about 30cm down there is very little oxygen left to house much life. That's also why murder victims don't decompose very fast, when the murderer buried them deep in forest soil.

Granted this still depends on the forest's life, but it is beyond an individual tree's lifecycle.

Re: Launch HN: Noya (YC W21) – Direct air capture of CO2 using cooling towers

#100

Post by carbonguy »

avernon wrote: post #28

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 completel…

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.

Post reply on HN