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

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

#161

Post by blaufast »

codecamper wrote: post #133
jfk13 wrote: post #89

Earlier quoted context omitted.

What do you anticipate will happen if we make cyanobacteria "immune to their natural predator", leading to their unchecked proliferation...?

Hilarious that nobody upvoted my post. I've been looking into the CO2 problem for more than 10 years & this seems like one of the most promising ideas... because it sounds possible to pull off. Yes, I have the same question for Dr. Church. How does he plan to control their population? Maybe something like this: https://news.mit.edu/2015/kill-switches-shut-down-engineered...

YSK those 'kill switches' just have to be abandoned by their host to stop working. They create a huge evolutionary pressure for this.

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

#162

Post by danans »

jaakl wrote: post #141
danans wrote: post #107

Earlier quoted context omitted.

> Ergo pulling 1 metric ton (10^6 grams) of C02 per day The CO2 footprint per capita in the United States is 15 metric tons [1], so at 300M population, that's 4.5e9 metric tons of CO2 per year. At 1 metric ton CO2 removed per day per tower, we would need 4.5e9/365 = 12.3M such cooling towers. Even if the efficiency increased 2 orders of magnitude it is still not enough, and I doubt there is a need for even 123,000 co…

Most of your yearly 15 tons is emitted via specific exhaust pipes, where capture part is quite easy problem, even without these cooling towers. The big problem is what to do with all of it: there is no commercial use/market, especially if you want that to be climate friendly, ie not dumped to atmosphere quite soon anyway. We'd need to think of it as toxic waste, similar to nuclear one, to be stored forever undergroun…

> The big problem is what to do with all of it

Which is why the primary way to deal with the CO2 problem isn't capture, but by reducing the amount emitted in the first place, via renewables + storage, more and better mass transit, EVs replacing ICEVs, heat pumps replacing furnaces, etc.

Compared to the CO2 reduction potential o

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

#163

Post by jsantos511 »

dojomouse wrote: post #144
jsantos511 wrote: post #119

Earlier quoted context omitted.

Great question - the carbon cycle definitely needs to be thought about in this scenario. The missing link here is in total embodied emissions that go into production of corn. There's data available to help piece together a comparison [1, 2], and I'd love to work through this and get back to you with what I find. At a high-level, CO2 production from corn isn't net-neutral because the production of a corn, and then eth…

I’d argue another consideration is the land occupied by the corn - it’s the real constrained resource, not the corn growing on it, and were the demand for corn displaced by something else (like direct air co2 capture) then that same land could sequester carbon far more effectively with e.g. trees.

Amazing point. We need more trees, and we have a lot of corn, so if we needed less corns, we could have more trees! Love it.

It'll also be interesting to balance the use of that land for trees vs. solar/wind as well. We'll need to put a lot of land to use to generate electricity, and some of corn's space might be occupied by that instead.

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

#164

Post by [deleted] »

jsantos511 wrote: post #29
dclusin wrote: post #8

Earlier quoted context omitted.

Feels to me like the intention of selling the gas is to offset operational costs until a carbon market for sequestering it underground becomes available?

Yes, and it also gives us the chance to develop sequestration pathways in parallel to fine-tuning the technology. And, if companies can use cleaner sources of CO2 than ethanol offshoots, that would be a net good for the planet as well.

[deleted]

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

#165

Post by elihu »

jsantos511 wrote: post #119
elihu wrote: post #95

Earlier quoted context omitted.

> 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 yo…

Great question - the carbon cycle definitely needs to be thought about in this scenario. The missing link here is in total embodied emissions that go into production of corn. There's data available to help piece together a comparison [1, 2], and I'd love to work through this and get back to you with what I find. At a high-level, CO2 production from corn isn't net-neutral because the production of a corn, and then eth…

Yeah, that's a good point. Ethanol from corn in particular doesn't have a great reputation.

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

#166

Post by PreCombustion »

Cooling tower "drift" is an air emissions PM2.5 permit matter in California. What is drift / carryover of the unsaturated and saturated material? Typically it happens associated with entrained water droplets; that's why e.g. salt water can't be used (among other reasons). More to the point, what fraction of the total capture energy are you eliminating? If you're changing evaporative efficiency in a forced-draft tower, you're incurring additional fan power or worse, increased fuel use in the process for which cooling is taking place. How do those balance against the fan power of a separate capture unit? But maybe the biggest matter: in other capture technologies, the heat of dissociation/regeneration and the compressor power to deliver to sequestration are very large. What change to the total energy budget are you proposing? When you're at scale, what fraction of total capture needed could be delivered this way?

Does putting CO2 in a bottle keep any CO2 out of the air for as long as a month? Removal times of hundreds of years are required for the capture process to contribute to climate.

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

#167

Post by codecamper »

jsantos511 wrote: post #134
codecamper wrote: post #44

Have you heard about George Church's idea? He says it's possible to modify the dna of cyanobacteria so that they become immune to their natural predator: the cyanophage. Apparently cyanobacteria consume an incredible amount of CO2 every year, but then right away release it again after the cyanophage kills them. Seems like a potentially workable idea, but I have not heard him give the details anywhere. He is at MIT &…

Sorry for the big delay in getting back to you! I'll look more into this - this isn't a solution I'm familiar with. Thanks for sharing, and thanks for your kind words and dedication to solving this problem.

His idea seems like a rough sketch. I don't know how deep he has thought about it. But he mentioned it in at least a few talks.

Would be awesome if you all just looked him up & went to talk with him.

He represents the "what bio can do" part of the equation. And bio does quite a lot already.

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

#168

Post by codecamper »

blaufast wrote: post #161
codecamper wrote: post #133

Earlier quoted context omitted.

Hilarious that nobody upvoted my post. I've been looking into the CO2 problem for more than 10 years & this seems like one of the most promising ideas... because it sounds possible to pull off. Yes, I have the same question for Dr. Church. How does he plan to control their population? Maybe something like this: https://news.mit.edu/2015/kill-switches-shut-down-engineered...

YSK those 'kill switches' just have to be abandoned by their host to stop working. They create a huge evolutionary pressure for this.

Are there examples of this happening?
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