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

news.ycombinator.com

21–30 of 589 posts

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

#21
post #15

This is really cool, I have a two questions the last one maybe a bit sillier than the first: - I'm not a chemist, maybe you said this implicitly, but roughly at what rate would this capture a kilogram of carbon? - Why did you choose the name 'Prometheus' the titan who created man, gave us fire, and as punishment for the latter part, had his liver eaten out by a vulture every day for eternity?

> had...for eternity

Has?

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

#22

IMHO this is a waste of time. You are wasting clean energy sources to make dirty ones -- at best a 50-60% loss of energy. And you end up with dirty fuel, that further produces CO2, in which the cycle repeats, with a net loss. In the near future, cars and trucks will be electric. This is shuffling deckchairs on the titanic. Why not put 100% of your efforts into electric vehicles powered by 100% renewable sources?

Like someone said in another comment, you'll still have existing gas-powered vehicles(current cars, jet aircraft, etc.) for some time, and they have to get that gas somewhere. Better from a net zero source than to add to our carbon debt.

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

#23

How could the math possibly work out on this? If a gallon of gas holds 33.70 kWh of energy, and you can get cheap electricity for $0.1/kWh, you're looking at $3.37/gallon if you have a magical process that converts with 100% efficiency. Even if you hit your efficiency goal, which would be impressive, who is paying $7/gallon for gas? Just buy an electric car. This can only possibly be useful when all of the oil is gon…

It would not make sense today, but in 10 to 15 years, with climate regulations, having a carbon neutral jet fuel might start making a lot of sense.

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

#24

how many watts today is required to produce one liter of fuel using both your membrane and the conventional way requiring distillation? What are your long-term watts/liter targets ? Maybe a non-membrane version could be attempted that used renewable energy (sunlight) to do the boiling? Certain geographic regions might have the right combination of plentiful sunlight, water, and wind to minimize all these costs?

It will take approx. 60 kWh/gallon of fuel, or just under 16 kWh/Liter. As long as this electricity is from zero carbon sources and is inexpensive enough, it works. Distillation and other thermal processes typically need to burn fossil fuels. The difference between renewable electrical energy only vs using thermal is really more a difference of kind than of degree. It's really hard to do a thermal process that is truly zero carbon, and hard to do it economically as well.

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

#25
post #4

So you are competing with batteries? I suppose batteries have much higher roundtrip efficiency, but maybe there are other advantages to your technology, like being able to rely on combustion engine cars?

The main advantage of renewable gasoline over batteries is that we can decarbonize the existing vehicle fleet without replacing it. Also, the very high energy density of gasoline, diesel, and jet fuel will make sense for a long time in Jet aircraft, long haul trucks, and ocean container ships, for example.

The very high density is in hydrogen - actually.

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

#26

IMHO this is a waste of time. You are wasting clean energy sources to make dirty ones -- at best a 50-60% loss of energy. And you end up with dirty fuel, that further produces CO2, in which the cycle repeats, with a net loss. In the near future, cars and trucks will be electric. This is shuffling deckchairs on the titanic. Why not put 100% of your efforts into electric vehicles powered by 100% renewable sources?

To buy an electric car i need £20,000 which I don’t have. Even if I had the money or access to credit, I don’t have a parking space near my house, so I can’t charge the car.

All fixable things, but will take tens of years. Let me use carbon neutral petrol

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

#27

IMHO this is a waste of time. You are wasting clean energy sources to make dirty ones -- at best a 50-60% loss of energy. And you end up with dirty fuel, that further produces CO2, in which the cycle repeats, with a net loss. In the near future, cars and trucks will be electric. This is shuffling deckchairs on the titanic. Why not put 100% of your efforts into electric vehicles powered by 100% renewable sources?

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.

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

#28
Would you be willing to share vague details of your roadmap?

Specifically; How many barrels of ready to burn gasoline are you outputting per day in 6 months? 1 year? 3 years?

The fact that the general fuel is going to be sold and re-burned means this is at best carbon neutral, so from a cynical environmentalist point of view, what's the point? This can't help anyone unless you pump the synth-gas into the ground and sequester it, but that isn't VC-backed viable.

If you are using some sort of membrane to pull out distillates without heat, why wouldn't you just sell that to existing petro-chemical companies for their distillation processes? What non-thermal-energy related benefits come with this membrane?

The poster gave important information in another thread: 60kWh per gallon of gas, aiming for ~5 cents per kWh, ~$3.00 per gallon into distribution channels. That makes it instantly cheaper than petrol in, at minimum, the UK

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

#29

How could the math possibly work out on this? If a gallon of gas holds 33.70 kWh of energy, and you can get cheap electricity for $0.1/kWh, you're looking at $3.37/gallon if you have a magical process that converts with 100% efficiency. Even if you hit your efficiency goal, which would be impressive, who is paying $7/gallon for gas? Just buy an electric car. This can only possibly be useful when all of the oil is gon…

Don't skate to where the puck is, skate to where the puck is going to be.

Electric cars can't compete against gasoline cars until the price hits about $6/gallon. And considering that crude prices are relatively low, but gas in CA is almost $4/gallon in the Bay Area, it doesn't take much time for normal rates to hit $6/gallon in the next 10 years or so.

At that price, it becomes more economic and that's the time frame probably what they're targeting as well.

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

#30

How could the math possibly work out on this? If a gallon of gas holds 33.70 kWh of energy, and you can get cheap electricity for $0.1/kWh, you're looking at $3.37/gallon if you have a magical process that converts with 100% efficiency. Even if you hit your efficiency goal, which would be impressive, who is paying $7/gallon for gas? Just buy an electric car. This can only possibly be useful when all of the oil is gon…

It would not make sense today, but in 10 to 15 years, with climate regulations, having a carbon neutral jet fuel might start making a lot of sense.

I expect I'll see new battery powered aircraft before I see today's aircraft powered by kerosene synthesized from water and carbon dioxide in the air. And we'll probably see more rail/car before then since the massive cost increase on airline tickets from this will destroy the industry.
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