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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)

#171

Post by yongjik »

jillesvangurp wrote: post #143
yongjik wrote: post #103

OK, I was curious so just did some math. Gasoline has energy density of 34.2 MJ/L, or 9.5 kWh/L[1]. Its retail price is about $3/gallon, or $0.8/L. So, assuming 100% efficiency, the energy source for making gasoline should be ~$0.084/kWh to break even. Energy Information Administration (EIA) estimates 2022's solar/wind generation cost at $73.7 and $55.8 per MWh [2], or $0.0737 and $0.0558 per kWh. Assuming wind power…

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. People won't buy gas-powered car if renewable electricity is much cheaper. So, basically, if renewables aren't cheap enough, you can't make profit. If they are cheap enough, they take away your customers.

I'm not convinced that anyone can make money out of this.

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

#172

Post by natch »

rhinoceraptor wrote: post #52
natch wrote: post #44

Earlier quoted context omitted.

>I strongly suspect that manufacturing hydrocarbon fuel out of air, water, and electricity If you already have electricity, that is all the energy you need. There is no need to use it to produce a toxic, polluting fuel that is used in highly inefficient internal combustion engines. Simply use electric motors, which are way more efficient.

Electric motors are efficient, but current battery tech is not. Hydrocarbon fuels will probably always win for weight to energy efficiency.

>Electric motors are efficient, but current battery tech is not. Hydrocarbon fuels will probably always win for weight to energy efficiency.

You are misinformed, or focusing on the wrong metric. There's a detailed rundown of efficiency for different technologies here:

https://me222.files.wordpress.com/2007/05/twentyfirstcentury...

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

#173

Post by adrianN »

rayiner wrote: post #94
ForHackernews wrote: post #60

Earlier quoted context omitted.

It has to be both. If we want to have any hope, we have to dramatically cut emissions AND we also have to invent magic new carbon-scrubbing technology and deploy it at a global scale in the next 30 years or so. https://www.vox.com/2016/10/4/13118594/2-degrees-no-more-fos... > As you can see, in either scenario, global emissions must peak and begin declining immediately. For a medium chance to avoid 1.5 degrees, the w…

Note that article is three years old and carbon emissions increased significantly over that time instead of going down as in the middle graphic. (It didn't even stay constant as in the first graphic, which would push the deadline to go to zero emissions to 2021.) So in reality we probably have to go to net zero by 2020.

Here is a nice graphic of reduction curves for staying within 1.5° warming: https://mobile.twitter.com/rahmstorf/status/1070717050430070...

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

#174

Post by D_Alex »

bjelkeman-again wrote: post #141
D_Alex wrote: post #130

Earlier quoted context omitted.

>The current cost of carbon capture is about $120 per ton I don't know where you got this from (citation?), but I am sure this is not the cost of capturing CO2 from the atmosphere via "technology" (trees - arguably yes).

Carbon Engineering claims it will be between US$94 and $232. https://www.nextbigfuture.com/2018/06/calgary-company-can-ca...

I have reviewed the original paper which from which the "$94-$232" estimate is obtained. You can find it here: https://www.cell.com/joule/fulltext/S2542-4351(18)30225-3

My comments are as follows:

1. Obviously, this is not the current cost, but an estimate for a hypothetical future plant.

2. You can get wildly differing estimates through a series of small discrepancies in the assumptions. Comparing the provided estimate (Table 2 in above link) to the estimates for other CO2 capture projects the following things stand out immediately: a) 7.5% CRF calculation should be ignored as unrealistic, 12.5% CRF is okay; b) O&M costs are low, for complex plant with caustic chemicals and high temperatures a fair assumption may be 6% of CAPEX per year rather than approx 3% c) 20% contingencies at the conceptual stage are too low, 40% would be perhaps defensible. Also, I don't see a basis for including Row D in the table, the commercial assumption is not justified.

Considering the above, if all goes well, plant number 100 might be able to capture CO2 for $200-300/tonne, better than the current claimed $600/tonne for a plant actually in operation, but nowhere near as good as other options.

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

#175

Post by adrianN »

fallingfrog wrote: post #117
rmcginnis wrote: post #96

Earlier quoted context omitted.

We use zero carbon solar and wind electricity. As long as the electricity source is zero carbon and low cost, it makes economic and practical sense to make zero carbon fuel.

Ok but why not just use the zero carbon electricity, if you have so much of it?

How do you put electricity in your tank?

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

#176

Post by D_Alex »

jillesvangurp wrote: post #154
D_Alex wrote: post #137

Earlier quoted context omitted.

>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 i…

Eh no. You are talking about carbon capture as a way to offset fossil fuel consumption. I'm talking about reducing fossil fuel consumption by instead producing non fossil fuels. Apples and oranges. The point of that is not to capture the carbon but to utilize it as fuel. With this technology, that is neither impossible nor prohibitively expensive/unecomincal. Unlike the six schemes you outline that are about not prod…

>The point of that is not to capture the carbon but to utilize it as fuel. >If you are capturing carbon, you might as well do it in a form where you can actually utilize it for fuel.

Do you understand that the Prometheus proposes to first capture the carbon and then convert it to fuel?

I have no objection to the "convert it to fuel" part. Just to the capture from atmosphere, which is the most inefficient way.

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

#177

Post by jessaustin »

rmcginnis wrote: post #83
graycat wrote: post #68

Likely a lot easier to make gasoline out of: (1) Crude oil. (2) Coal, water, and electric power. (3) Some biological reactions. To address the hidden agenda here, see https://www.youtube.com/watch?v=52Mx0_8YEtg

Hi Graycat, it actually may be easier to make fuel by mining air. We used to make fertilizer by mining guano and collecting animal droppings, but once Haber and Bosch figured out how to make ammonia from atmospheric N2, it just make more economic and practical sense. It's hard to mine oil, transport it, refine it, etc. Compare that to making it where and when you need it with no waste. I think it will be better.

As soon as PV is cheap enough, lots of fleets will convert to liquid anhydrous ammonia. Sure it's different than petrol/diesel, but it's already in wide use as a fertilizer and no technological breakthroughs are required to get it burning in ICEs. It's not yet economical but if PV keeps getting cheaper it will be. So it seems like the effort described in TFA is barking up the wrong tree?

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

#178

Post by kumarvvr »

Any carbon capture technology, will require infrastructure and components (which release carbon during manufacture), and use energy (no emissions if using renewable fuel). Any analysis ought to take the cumulative total of all the emissions produced during the lifetime of the product vs. the carbon captured.

Nature has already given us the most efficient, cheap form of carbon capture. Trees.

I hope there will be startups that extract and make fuel / energy from plants.

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

#179

Post by dagss »

rayiner wrote: post #5

This is really, fundamentally important technology. Emissions reduction will not work: https://www.scientificamerican.com/article/nations-are-not-r... > The authors of the report stated in a press release that the kind of drastic, large-scale action the planet desperately needs has yet to be seen, even though global emissions have reached record levels at 53.5 billion metric tons in 2017, with no signs of peaking. >…

This article has nothing to do with carbon recapture. The gasoline produced from carbon is then intended for burn...

This is simply an alternative electricity/power storage mechanism. But great to reduce emissions but is not intended for negative emissions (for which there is other tech)

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

#180

Post by D_Alex »

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?

Replace, as far as practicable, with fast trains and maybe Hyperloops.
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