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Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

news.ycombinator.com

181–190 of 589 posts

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#181

> we expect 50-60% overall efficiency at maturity What efficiency are you at now and what happens to your startup if you never reach that "maybe too optimistic" 50-60% goal?

We will know what our starting efficiency is before next year, when we start to produce and sell fuel. Anything above 25% works economically, and that has already been demonstrated.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#182
post #111

Interesting proposition. 1. Why would your process be more cost effective and/or efficient than the commercially available processes for alcohol production? Surely if the magic sauce is the nanotube alcohol/water separation then conventional alcohol sources from fermentation will start using it at some point and will be able to produce same fuel but cheaper and/or more efficient. Maybe you can show that [photosynthes…

I'd imagine retrofitting power plants to process their exhaust is itself an extremely expensive process.

Maybe they could setup their devices around plants anyways tho.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#183

Earlier quoted context omitted.

There is no waste. The only inputs are water, CO2, and electricity. The only outputs are fuel and oxygen.

With respect, that answer skirts the question of what happens to the water. You said you're using the nanotube membrane to separate petro products from the water. What do you do with the water left over? What state is the water in when the process is complete? Potable? In need of treatment by traditional water treatment facilities?

[deleted]

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#184

Earlier quoted context omitted.

Demonstrated overall conversion efficiencies for CO2 to fuels are already in the 25-50% range, depending on the fuel. We are confident we can get to at least 50% for our process. We will not be taking renewable power away from other uses - in the short term we'll be using marginally useful power (wind at midnight, solar at noon, etc), as we need the power to be low cost, and any time it has higher value uses, it won'…

Thanks for the reply, I get the load balancing part now, I did not think about that. I was thinking a lot recently about flying and how we could make it work in the (hopefully) greener future. This is definitely a more sensible way of doing it than electric jets, good luck with your company!

Thanks!

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#185
If you really think the underlying economic problem with electrochemical CO2 to alcohols as fuel is the separation at the end you are in for a world of (economic) hurt. Not that improving the aforementioned separation isn't useful or valuable, its just not the lynch pin.

Take a really hard look at your economics, in particular throughput and capital amortization (which scales proportionally to uptime!). Good comparison industries are chlor-alkali, fuel cell, and water-electrolyzer. Aqueous Cu catalyzed CO2 reduction - even if you are best in class for FY and efficiency and durability - have atrocious current densities, diffusion limited, by the standards of anything considered commercializeable.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#186
post #112

I read in the Bloomberg article that the machine itself hasn't yet created "enough gasoline to power his Golf even a single mile". I assume you've already made enough to power an engine in the separate steps? How long before you think you'd be able to make a video taking gas from the machine and pouring it into a tank?

We are doing the system shakedown now, and have started making fuel. We'd like to do a demo in the next few months, as long as it doesn't divert us from our timeline. Everything we're doing has been demonstrated separately, including the CNT membrane alcohol extraction, so there isn't really a technical risk here. Everything we need to do now is focused on proving the economics.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#187

Here's what I don't understand - You're taking CO2 out of the atmosphere using renewable energy sources. Thermodynamically, this will take at least as much energy as it took to burn them. You did not mention how energy efficient your energy storage method is right now (50-60% at maturity sounds really optimistic, when plants are only a few %), but, in the short term, while we're still mostly using carbon-based fuels,…

Demonstrated overall conversion efficiencies for CO2 to fuels are already in the 25-50% range, depending on the fuel. We are confident we can get to at least 50% for our process. We will not be taking renewable power away from other uses - in the short term we'll be using marginally useful power (wind at midnight, solar at noon, etc), as we need the power to be low cost, and any time it has higher value uses, it won'…

How do the unit economics look for using your tech as a battery store and then burning excess fuel for grid energy when demand is high?

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#188

By law, gasoline gets cut with ethanol, degrading engine performance. If I buy gas from you guys will it be legal to put 100% gasoline into my engine? If so that's a "killer app," (so to speak) for people who care about their engines, even if it is more expensive in early development stages.

Why do you say ethanol degrades performance? Ethanol is an anti-knocking agent when added to gasoline, so it actually enables higher performance.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#189

Is this something that could be turned into a consumer-scale machine? I understand a lot of the high fuel cost on islands is simply from shipping the fuel there - producing it on site with this tech would be a huge benefit.

Yes, we could definitely do remote location fueling stations, like remote airstrips, etc. Right now we're focused on replacing as much fossil fuel as possible with zero carbon fuel, so that has us focused on the commodity gasoline market. Later we may do small distributed systems as well.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#190
> If the cost of our equipment is also low, then we believe we can not only make zero carbon fuel, but actually compete on price with fossil fuel.

even if it can compete with fossil fuel, do you think it will also be competitive with BEV?

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