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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)

#131

Post by snowmaker »

dflock wrote: post #61

So, you spend a load of energy to reform atmospheric CO2 back into hydrocarbon fuel - and then just burn it again, turning it back into CO2 and putting it back into the atmosphere? The end state of the atmosphere is, at best, the same as the starting state, but you've expended a load more energy for nothing. If the energy to run this process isn't zero-carbon, then this is going to be a big net emitter when done at s…

It depends on the alternative state of the universe. If the alternative state of the universe is you never drove the car, then you're right, this is not clearly better.

If the alternative state of the universe is you drove the same car but burned gasoline that was drilled out of the ground, then this is much better.

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

#132

Post by jillesvangurp »

D_Alex wrote: post #125

I wrote the comment below in response to another article, but it is applicable here. I should note that the technology to convert CO2 to say hydrocarbons is well known (and my current work is on making it economically interesting), my issue is with trying to extract CO2 from the atmosphere, which is very inefficient. ----- This is actually a very bad idea and a complete waste of money which should have been used for…

You are missing the point; this is a fuel production system that effectively removes the need to capture carbon: i.e. the notion of turning air into something you put in the ground too offset the carbon we are removing from it to burn. I agree that is not a valid economical proposition other than making people feel slightly less guilty about burning fossil fuels. It's actually a rather dumb idea since you are taking something that is expensive and wasteful and spend yet more to offset somewhat just how wasteful it is.

Producing fuel from the captured carbon, sidesteps the whole problem of needing fossil fuels at all. So, you are not offsetting anything; you are simply producing the fuel that you need in a way that is clean.

You seem to be arguing that it can't be done because 'numbers'. 1) those numbers lack citations 2) they are not set in stone. The question you should be asking yourself is how badly wrong your numbers are and what it would take to make the numbers right.

Turns out that this whole game of producing fuels from thin air is mostly a function of clean energy cost per kwh. Simply put, this is not constant. It varies wildly geographically. And it's also not constant over time. It's been dropping for decades at a rather impressive pace and projected to continue to do so. So, the only question is when will it become completely uneconomical to mine fossil fuels as opposed to simply converting co2 into whatever carbohydrates we need.

I'm guessing the persons behind Prometheus might be a bit optimistic here (i.e. suggesting it could be economical right now) but I wouldn't see that as a fundamental issue. If the answer is that those cost lines cross anywhere in the next decades, this would be still be an extremely lucrative investment. The mere possibility that this could be economical right now or in the very near term, makes this quite exciting.

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

#133

Post by InclinedPlane »

js2 wrote: post #4

There's no way this is a net energy producer right? So it only makes sense if it's powered by carbon-free sources? Basically this has two uses then: - As a stop gap till batteries and electric vehicles take over from ICE. Although if it generates carbon-neutral jet fuel that would be very useful. - Maybe as a carbon capture device, except that gasoline doesn't seem like a great way to store excess carbon. Although th…

The idea that electric vehicles will completely replace ICE vehicles is a hopeful one but faces a lot of roadblocks to get to 100% (or even 80%) and may ultimately be unrealistic. As such, it is dangerous to bank utterly on that goal in efforts to curb net CO2 emissions. So this is not just a stop gap but a backup plan, and more.

Additionally, as a replacement for "drilling oil out of the ground" as the first step in everything that makes use of gasoline and similar products (so jet fuel, heating oil, diesel, gasoline, lubricants, plastics, etc.) this is a good thing, not just from an emissions standpoint but also from a pollution and environmental impact (drilling, crude oil transport, etc.) aspect.

Even more importantly, this is a way to bridge the "energy storage" gap for green energy sources like wind and solar. Base electric power generation is a very second by second thing, hydrocarbon production can easily be an "average output over a week or a month" sort of thing, which is where wind and solar do well.

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

#134

Post by whatever1 »

The main question that I do not see addressed, is how many Joules of energy does the process need to make 1 Joule worth of liquid fuel.

If we need for example 2J of energy to make 1J worth of gasoline, then it means that we need to double the installation rate of renewable production facilities (wind, solar, biofuels), while the global energy demand increases. This makes it completely infeasible (and I did not consider cost at all in my analysis yet).

Edit: I just saw that the founder mentioned in the comments that they expect 50% efficiency at best. This unfortunately means that the liquid fuel product of this process will have at least double the cost of renewable energy.

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

#135

Post by strainer »

ip26 wrote: post #108
Gibbon1 wrote: post #90

Earlier quoted context omitted.

The energy return on energy invested is going to be abysmal. No more than 20% if that. That translates into synth gasoline at $30/gallon

Considering electric planes aren't feasible yet, how else do you plan to decarbonize airplanes?

Short range electric planes are being manufactured presently.

This wont be able to decarbonize anything until surplus carbon free energy is generated for it use - that need not take decades with proper governmental policies, but it means this technology will not lead the way.

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

#137

Post by D_Alex »

jillesvangurp wrote: post #132
D_Alex wrote: post #125

I wrote the comment below in response to another article, but it is applicable here. I should note that the technology to convert CO2 to say hydrocarbons is well known (and my current work is on making it economically interesting), my issue is with trying to extract CO2 from the atmosphere, which is very inefficient. ----- This is actually a very bad idea and a complete waste of money which should have been used for…

You are missing the point; this is a fuel production system that effectively removes the need to capture carbon: i.e. the notion of turning air into something you put in the ground too offset the carbon we are removing from it to burn. I agree that is not a valid economical proposition other than making people feel slightly less guilty about burning fossil fuels. It's actually a rather dumb idea since you are taking…

>You are missing the point; this is a fuel production system that effectively removes the need to capture carbon

No... the first step in the proposed process is to capture the CO2 from the air, what I describe in point 6 of my comment.

>You seem to be arguing that it can't be done because 'numbers'

No... It can be done. But it should not be done. Because 'numbers' tell you there are other things that should be done instead. Right now.

>those numbers lack citations... you should be asking yourself is how badly wrong your numbers are...

I work in this field. I have literally hundreds of possible citations. Pick a number you most disagree with, and I will provide you a citation. Alternatively, provide me a counter-citation and I will review and comment on it for you.

> The mere possibility that this could be economical right now or in the very near term...

Here is what I am trying to tell you: this cannot be economical until all the other, much more economical options which I have listed are pretty much fully used up. Considering that we have barely made a dent in the first of these, this will certainly not be economical in the near term, or in the medium term (and in my opinion, never, because biosequestration is so much cheaper).

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

#138

Post by bjelkeman-again »

aaronblohowiak wrote: post #124
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.

Hydrocarbons are better energy stores than batteries. If we can “charge your car” by pumping hydrocarbons into it, that is better than lugging around heavy batteries (maybe.) so, in a way, co2 -> gasoline via solar power (or nuke) is an overall win.

I personally doubt the energy cost for the conversion is so low that it makes sense, but would like to see that demonstrated. Then you are still burning hydrocarbons, which is a big health problem.

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

#139

Post by bit_logic »

I really hope this is successful because this would make a difference for climate change much quicker than transitioning to BEV cars. BEV cars are better overall, but there just isn't enough time with the rate climate change is happening.

This combined with a strong push for PHEV and hybrid cars could help climate change much faster. It makes sense on many levels:

* PHEV cars with 40+ miles EV range are great for those who can charge at home. It's enough to make most of the miles electric (such as commuting or getting groceries). And it's a much better use of limited lithium battery capacity. The battery in one Tesla could be used to build 10 PHEV cars.

* Many people still live in places with no overnight charging such as apartments and dense urban areas. The hybrid tech (perfected by Toyota) is the right solution here. Keep working on getting the mpg even higher.

* Government can really boost this by requiring X% of all gas to be carbon neutral and increasing that over time. They do this with 10% ethanol, but that was the wrong fuel. Start with 5% must be carbon neutral and increase 5% every year from there.

* Carbon tax, enough to make synthetic fuel like this competitive with fossil fuels from the ground.

BEV cars is a case of perfect being the enemy of good. When excluding external factors, BEV is clearly superior to ICE. But we don't have time to transition to BEV. We need to make progress on climate change now and this will get there faster.

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

#140

Post by zamfi »

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.

> It’s not that hard. You can just charge the car inductively with wires in the road

I’m sorry, are you proposing this solution as being cheaper than either gasoline or batteries?

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