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A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

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Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#191

Post by trickstra »

IgorPartola wrote: post #146
wehriam wrote: post #142

Earlier quoted context omitted.

Hi Rob! Is it possible to produce gasoline through atmospheric CO2 capture for less than traditional methods? Will CO2 capture be competitive in real costs?

I cannot see how you could take CO2 and make gasoline out of it using less energy than what the gasoline contains. At best, you will need to supply that energy via something like solar panels. Then it becomes a question of efficiency: how many Watts of gasoline can you produce per Watt of electricity you have? My guess is, not many.

you cannot. That would be a perpetuum mobile

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#192

Post by ramraj07 »

fallingfrog wrote: post #120
zamfi wrote: post #119

Earlier quoted context omitted.

They're going after the use case of gasoline as energy storage, not gasoline as primary energy production. The reason, today, that cars are powered by gasoline and not electricity is not the cost of the energy itself, but the cost of storing it. Obviously it would be better to use the electricity directly. But it's hard to get that electricity to a moving car on the road (or a plane in the sky).

It’s not that hard. You can just charge the car inductively with wires in the road, or better yet, just lay tracks for electric trains.

There's a difference between a regular car and a hotweels toy

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#193

Post by Cthulhu_ »

tonyedgecombe wrote: post #184
bobthepanda wrote: post #181

Earlier quoted context omitted.

Maybe cars, but the weight of batteries is a problem for larger vehicles that need long range, like a bus, truck, or plane. For those hydrogen might be better.

Trams, trains, high speed rail.

There's some bus lines with overhead lines as well. The problem is of course infrastructural, and you still need truck for the last X miles.

Which is where Tesla and that other electric truck company come in, of course.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#194

Post by trickstra »

IgorPartola wrote: post #150
onlyrealcuzzo wrote: post #127

Earlier quoted context omitted.

Thermodynamically, no. But is that the question? We're a long way away from consuming so much energy we thermodynamically scorch the Earth, right? It seems like they want to know if you can be mostly carbon neutral and generate existing fuels. If that's the case, then if you have access to a cheap form of renewable energy -- huge amounts of geothermal, tidal, or solar -- you could generate a ton of something-like-gas…

It is the question. You need to break up the CO2 molecule and reconstitute it as gasoline. That will take more energy than the gasoline had initially. So you have a process where you take say solar energy and convert it into gasoline chemical bonds. Great, what is your efficiency of this process? Because if it is close to 100%, great. But chances are it is much closer to 0, at which point you’d be better off just usi…

True, many people don't realize this. But carbon capture solutions don't necessarily need to be efficient - we are not doing it to make more energy, we are doing it to clean up the many decades of mess we already made in the atmosphere. So yes, we will have to spend energy, to clean that up, naturally. The most important part is that none of these solutions is exclusive and shouldn't be pictured as exclusive. We need to offset fossil fuels, lower our energy use, and suck CO2 from the atmosphere. All three of them.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#195

Post by trickstra »

ZhuanXia wrote: post #128
fallingfrog wrote: post #115

Earlier quoted context omitted.

It’s not thermodynamically possible to recapture carbon from the air without using more energy than was obtained by burning it the first place.

The esoteric read on this, then, is it is a bet on fusion.

And before that?

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#196

Post by whiskers08xmt »

IgorPartola wrote: post #146
wehriam wrote: post #142

Earlier quoted context omitted.

Hi Rob! Is it possible to produce gasoline through atmospheric CO2 capture for less than traditional methods? Will CO2 capture be competitive in real costs?

I cannot see how you could take CO2 and make gasoline out of it using less energy than what the gasoline contains. At best, you will need to supply that energy via something like solar panels. Then it becomes a question of efficiency: how many Watts of gasoline can you produce per Watt of electricity you have? My guess is, not many.

It can still be competitive with things like tar-sand extraction, which takes more energy than you get out of the oil. It's only economically viable because energy in gasoline/oil form is more valuable than the energy content itself, due to it's ease of transfer. Air sequestration might be a viable fuel source in regions where import costs of fuel are high, but energy is cheap.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#197

Post by Animats »

Carbon Engineering, in Canada, is already doing this on a pilot plant scale.[1] Converting CO2 to a fuel is chemically uphill, so you have to put energy in. This can work if you have cheap hydropower, which parts of Canada do. It's only feasible financially if there's a big subsidy for removing CO2 from the atmosphere.

[1] https://news.nationalgeographic.com/2018/06/carbon-engineeri...

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#198

Post by nordsieck »

bobthepanda wrote: post #181
nordsieck wrote: post #169

Earlier quoted context omitted.

> natural gas -> hydrogen and CO2 -> separate out CO2 -> geological CO2 storage. Everything I've seen about H2 tells me that electric cars are just better. Luckily for your theory, it's still possible to do what you want with electric cars - just carbon capture at electric power plants.

Maybe cars, but the weight of batteries is a problem for larger vehicles that need long range, like a bus, truck, or plane. For those hydrogen might be better.

> the weight of batteries is a problem for larger vehicles that need long range, like a bus, truck, or plane. For those hydrogen might be better.

China is already leading the world in electric busses. They work great. Busses are such good vehicles for batteries, that for some routes it may even make sense to run them with super-capacitors, with chargers embedded in the road at stops.

Trucks are always going to be a problem. This is probably the area where H2 might have the best shot. The big problem, however, is that they are a relatively small portion of vehicles. If they're the only ones running H2, it's probably not going to work.

Airplanes, for the most part, aren't going to be electric (although I've heard rumblings of short-range commuter electric aircraft being planned). I doubt they'll be hydrogen powered either. While they aren't as encumbered by the rocket equation as... rockets, they do feel pressure from additional weight. Additionally, the added volume of H2 compared to something like avgas (on a MJ normalized basis) would negatively affect the aerodynamic efficiency of airplanes. Probably going to stay with petroleum for the foreseeable future.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#199

Post by jillesvangurp »

yongjik wrote: post #171
jillesvangurp wrote: post #143

Earlier quoted context omitted.

A couple of issues with your numbers. 1) you are basing yourself on average grid prices in the US and the local cost of petrol. You should instead be looking at dedicated clean energy installations that you'd be using 100% for fuel production in places where that are optimal/ideal to do so. 2) those petrol costs exclude taxation that would apply in e.g. the EU. Current prices in e.g. Germany for a liter of petrol are…

You say as if 30% efficiency is an easy goal, but the most efficient fossil power plants reach ~60% (from what I've googled). That's the best efficiency we get for just burning fossil fuel, a technology perfected over a century. Here we're talking about a technology that might (or might not) have been proven in a lab. Also, a likely outcome of lower energy price is that consumers will simply bypass fossil fuels. Peop…

Petrol and diesel are not the only form of carbo hydrates in our economy. I agree EVs will likely replace ICE vehicles long before this scales. However, oil is used for a lot of other things as well in our industry, including e.g. plastics, solvents, etc. So having this will help on that front while also allowing us to continue to use combustion engines where that still makes sense. As an energy storage mechanism, petrol/diesel still offer pretty decent energy density. If it can be created cleanly and cheaply, the price won't matter that much. At 1 $/gallon, nobody cared about fuel cost. Hence the popularity of enormously inefficient cars in the US. This stuff has the potential to be cheaper still.

Re: A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19)

#200

Post by taneq »

bobthepanda wrote: post #181
nordsieck wrote: post #169

Earlier quoted context omitted.

> natural gas -> hydrogen and CO2 -> separate out CO2 -> geological CO2 storage. Everything I've seen about H2 tells me that electric cars are just better. Luckily for your theory, it's still possible to do what you want with electric cars - just carbon capture at electric power plants.

Maybe cars, but the weight of batteries is a problem for larger vehicles that need long range, like a bus, truck, or plane. For those hydrogen might be better.

I think that's backwards. Size and weight of batteries is more of a problem at smaller scales - electric motorcycles get up to around 220 miles (Zero SR) compared with electric cars at 370 miles (Tesla Model S). The Tesla Semi has an advertised range of up to 500 miles.
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