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

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

#381

Post by jonnycomputer »

Robotbeat wrote: post #196
solarkraft wrote: post #64

Earlier quoted context omitted.

An EV makes several times the motion from the same energy input. > Even electric vehicles aren't carbon neutral, because they're mostly charged by coal power.Even electric vehicles aren't carbon neutral, because they're mostly charged by coal power. Is thus an invalid/irrelevant argument. I can get excited about jet fuel however, since battery powered planes are considerably less practical than their traditional coun…

This is a completely accurate comment. Why is it downvoted? I assume the company is operating in the US. In the US only 27% of electricity is from coal and falling. https://www.eia.gov/electricity/monthly/epm_table_grapher.ph... And in California (where nearly half of the US's electric vehicles reside--with EVs achieving a nearly 8% market share last year among light vehicles), it's MUCH less than that. There's only…

If this process were to only make transoceanic shipping carbon neutral it would be well worth it.

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

#382

Post by js2 »

sanj wrote: post #369
alexeldeib wrote: post #358

Earlier quoted context omitted.

re: waste heat, I've been thinking forever that someone must capture this. I've generally assumed the economics don't work out or no one has cracked it outside of scenarios like regenerative braking. We waste so much energy that we could capture and put back to use.

Regen braking doesn’t use waste heat. It converts mechanical energy back to electrical.

And in so doing, reduces waste heat due to friction, which is likely what the parent commenter meant.

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

#383

Post by seppel »

lutorm wrote: post #359
averros wrote: post #275

Well, producing solar panels and such also requires energy input, and these do have limited lifetime. What is the real full-cycle energy conversion ratio is? Secondly... continuous distillation doesn't necessarily require lots of energy, since a lot of it could be recycled with counterflow heat exchangers and heat pumps instead of plain heaters (i.e. hot output and hot waste are used to heat up input to close to the…

* producing solar panels and such also requires energy input, and these do have limited lifetime. What is the real full-cycle energy conversion ratio is? I wonder what this is, too, but a typical 300W panel with 20 year lifespan will generate something like 20MWh over its lifetime. You can't possibly use anywhere near that much energy to manufacture it.

My personal pet theory is that the energy consumption is more or less equivalent to the price. So as long as the solar panel is not economically viable, it does not provide an energy surplus.

20MWh is not much, it's $500-$3000 worth of energy, depending on taxes and stuff. Can you buy, install, connect, maintain, clean a 300W solar panel for 20 years for this price?

Edit: Also, 20MWh is quite high. That's 9h of perfect sun, each day, the whole 20 years.

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

#384

Post by js2 »

rmcginnis wrote: post #311
0000011111 wrote: post #307

As a person with a background in Environmental Studies, a c o2 to fuel conversion technology such as this sounds revolutionary! I am most curious about the fundementals. Can you give us more specifics on the process such as; 1. What is the scale of the operation? Does this process need to be done at a large scale to work out economically? 2. Take a Boeing 737 for example which has a fuel capacity of ~6,875 Gallons. H…

The smallest scale at which we can operate profitably is probably in the 100,000 gallon/year range, although that could go down over time. We will make modular, mobile systems that don't have to be very big to be profitable. One shipping container will likely be able to do 100,000 gal/yr for example. The electricity required will be approx. 60 kWh/gallon.

60 kWh is about 200 mi of range in a gen 2 Chevy Volt, while a gallon of gasoline is worth about 40 miles. Just trying to put the efficiency in context using something I'm familiar with.

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

#385

Post by danieltillett »

This can’t work because of Jevon’s paradox [0]. Every barrel of gasoline created by this process just displaces a barrel of fossil gasoline, pushing down the price of gasoline at the margins resulting in increased consumption.

CO2 neutral gasoline can only work if you can get the cost below the marginal cost of production of fossil gasoline such that the oil stays in the ground. This is a massive ask on thermodynamic grounds.

0. https://en.wikipedia.org/wiki/Jevons_paradox

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

#386

Post by stephen_g »

lutorm wrote: post #359
averros wrote: post #275

Well, producing solar panels and such also requires energy input, and these do have limited lifetime. What is the real full-cycle energy conversion ratio is? Secondly... continuous distillation doesn't necessarily require lots of energy, since a lot of it could be recycled with counterflow heat exchangers and heat pumps instead of plain heaters (i.e. hot output and hot waste are used to heat up input to close to the…

* producing solar panels and such also requires energy input, and these do have limited lifetime. What is the real full-cycle energy conversion ratio is? I wonder what this is, too, but a typical 300W panel with 20 year lifespan will generate something like 20MWh over its lifetime. You can't possibly use anywhere near that much energy to manufacture it.

I read something about this a little while ago - if I recall the analysis correctly the energy payback was in the order of 1-2 years for the average (300W or so) panel. Not bad for a 20 year life, but we will need recycling advances in the meantime as we will have so many panels reaching end of life in the next decade.

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

#388

Post by malyk »

TaylorAlexander wrote: post #306
NortySpock wrote: post #276

Earlier quoted context omitted.

In the US, gas taxes are low (I think I pay 15 cents per gallon tax on a total of $2.50 per gallon). Taxes are low as here in the US (a) many people hate taxes and (b) with such a low population density, commerce is very reliant on road vehicles. So raising taxes has an outsized impact on commerce.

California has higher gas taxes. Our gas is currently about $3.70 a gallon where I live.

$4.29 for premium yesterday in oakland.

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

#389

Post by frosted-flakes »

rmcginnis wrote: post #42
Damorian wrote: post #30

Earlier quoted context omitted.

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.

There is a good chance we will make jet fuel in the next 2-3 years. There appears to be a lot of demand for it. We're starting with gasoline because it's a much bigger market / impact, but it's not that hard to make jet fuel too.

And if synthesizing jet fuel turns out to be viable, I could easily see governments 10–20 years from now requiring airlines to use it, the way they are for automobiles.

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

#390

Post by mrob »

danieltillett wrote: post #385

This can’t work because of Jevon’s paradox [0]. Every barrel of gasoline created by this process just displaces a barrel of fossil gasoline, pushing down the price of gasoline at the margins resulting in increased consumption. CO2 neutral gasoline can only work if you can get the cost below the marginal cost of production of fossil gasoline such that the oil stays in the ground. This is a massive ask on thermodynamic…

Jevon's paradox only applies because governments subsidize fossil fuels by failing to correct the market failure of their externalities. If they were taxed appropriately to compensate for the damage they do then synthetic hydrocarbon fuels would probably be viable in the cases where batteries are unsuitable because of insufficient energy density (e.g. long-distance aviation).
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