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

news.ycombinator.com

161–170 of 589 posts

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

#161

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,…

One cool thing is that one could build huge power plants in the middle of nowhere, and not worry as much about transmission losses. Oil fields are already typically in the middle of nowhere, and fuel travels and stores easily.

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

#162
post #146

How small can you scale it? Net energy metering for small-scale solar is not particularly widespread, and the terms are getting progressively less favorable over time. If you can make an inexpensive unit to turn a few kW of excess production for a few hours a day into fuel at 50% efficiency, you might be able to sell it in some markets. Think of it as a 25% round-trip efficiency battery with immense capacity that can…

Our current prototype is the size of a refrigerator. One of the cool things about our tech is that it can work well at small scale. We don't have to get to a billion dollar plant to get the economics right. We could make a system to fit in your garage and make fuel at home. This isn't our focus right now because we want to solve the problem of CO2 emissions from fuel, so need to scale as fast as possible. That's the commodity gasoline market.

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

#163
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.

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

#164

This is really cool! I hope that you can rise above the comments of the "this isn't good enough" or "zero carbon or bust" crowd. This type of innovation is what we need to move the needle in a realistic manner and that helps to build on the infrastructure that we already have in place. I'm excited to see what comes of this in the coming years!

Thanks!

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

#165

Earlier quoted context omitted.

We expect a gallon of gasoline to require approx. 60 kWh of electrical energy. If the price of that electricity is below 5 cents, the economics work. If the price is lower, the efficiency of the conversion could also be lower if that optimized other costs (like capital). Electricity is routinely below 5 cents now at utility scale (wholesale), which is where we will want to be.

60 kWh capacity EV will get you (realisticaly) 200 miles. A gallon of petrol - 40 miles (realistcally and using UK gallon). According to Tesla their charging is 92% efficient so reduce that 200 to 184 miles. Your process is 4.5 times less efficient than just putting that electricity into the EV? Is that right? If so - and your process is carbon neutral (big if) - what's the point in a future where EVs dominate?

4.5 is not so much. Gasoline is very energy dense, stores well (especially synthetic) and transports well. This is great - gas will be around for a long time to come - if we can shift the source of it to something better, I'm all for it.

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

#166

Earlier quoted context omitted.

>If we replace fossil gasoline with renewable gasoline, that reduces CO2 emissions Nitpick: It will leave carbon emissions unchanged, but may reduce the amount added to the carbon cycle. What kind of production quantity are you looking at? Small batch aviation fuel for a niche "green" airline? Every semi truck on the road in America? The neighbor kid's go-kart? You give an "efficiency" of 60ish %, but I don't know ho…

We are going for the whole gasoline, jet fuel, and diesel market. The 100% efficient energy content of gasoline is approx. 34 kWh/ gallon. At 60% efficiency in converting renewable electricity to chemical energy, that would be approx. 57 kWh/gal.

Please think twice about diesel - NOX is a killer. On the other hand, I expect particle emissions to be much lower with your fuel.

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

#167

Earlier quoted context omitted.

If we want to stay below 2 degrees C in warming, we don't have time to replace the existing vehicle fleet (approx. 1.2 billion cars, trucks, buses, etc) with electric vehicles. If we instead replace the fuel, this can be fast enough. Even if all vehicles are electric in the future, this is still the right thing to do now.

My issue is that this is a step in the wrong direction, it is incentivizing the current dirty status quo. Why would anyone replace their dirty engine if they can feel good about by using your 'cleaned' fuel. I agree we need to do something now, but this is just putting off the inevitable. Re-engineering dirty fuel sources doesn't buy us time to resolve this. It is procrastinating, shuffling titanic deckchairs. The ma…

The energy density of batteries is nowhere near as good as oil - the laws of physics limit how good batteries can get (there is some room for improvement, but oil is still better by a large margin).

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

#168

Very promising but I'm going to hold out until I actually see this being applied in places like South Korea, literally suffocating from a combination of both local and foreign smog from Korea's favorite neighbor. You can't really fault me because we've often seen groundbreaking, extraordinary claims, and very little of it is actually realized. Sort of like how we get news about how somebody found a cure for AIDs or C…

I totally agree on skepticism. We are working hard to prove our economics. We are targeting selling renewable gasoline from the air for a profit next year. It will be much better for air quality too!

How will this improve the global average of air quality? If you are removing the CO2 from the air then reintroducing it back into the same environment (assuming it is not repurposed in another sector e.g. jet fuel, commercial containers) wont the net effect be the same?

I understand this will concentrate the pollution significantly and may even reduce it in the short term, but wont the average effects be the same?

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

#169

Earlier quoted context omitted.

We expect a gallon of gasoline to require approx. 60 kWh of electrical energy. If the price of that electricity is below 5 cents, the economics work. If the price is lower, the efficiency of the conversion could also be lower if that optimized other costs (like capital). Electricity is routinely below 5 cents now at utility scale (wholesale), which is where we will want to be.

60 kWh capacity EV will get you (realisticaly) 200 miles. A gallon of petrol - 40 miles (realistcally and using UK gallon). According to Tesla their charging is 92% efficient so reduce that 200 to 184 miles. Your process is 4.5 times less efficient than just putting that electricity into the EV? Is that right? If so - and your process is carbon neutral (big if) - what's the point in a future where EVs dominate?

> what's the point in a future where EVs dominate?

EVs won't dominate some important uses for a long time, e.g. aviation and marine shipping.

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

#170

Earlier quoted context omitted.

We expect a gallon of gasoline to require approx. 60 kWh of electrical energy. If the price of that electricity is below 5 cents, the economics work. If the price is lower, the efficiency of the conversion could also be lower if that optimized other costs (like capital). Electricity is routinely below 5 cents now at utility scale (wholesale), which is where we will want to be.

60 kWh capacity EV will get you (realisticaly) 200 miles. A gallon of petrol - 40 miles (realistcally and using UK gallon). According to Tesla their charging is 92% efficient so reduce that 200 to 184 miles. Your process is 4.5 times less efficient than just putting that electricity into the EV? Is that right? If so - and your process is carbon neutral (big if) - what's the point in a future where EVs dominate?

In the long term, electric vehicles may indeed replace ICE cars. That would be awesome. One way to see what we're doing is to make sure the path to that future is good. We can't burn fossil fuels while we wait to replace the existing vehicle fleet with electric cars. By using zero carbon we make sure that we are solving the problem right away.
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