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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)

#41

Post by MuffinFlavored »

eganist wrote: post #13
MuffinFlavored wrote: post #9

Earlier quoted context omitted.

How much do today's "carbon recapture" methods need to grow? What's the timeline on them looking like? P.S. The first Google result for carbon recapture is titled "“Direct air capture” of carbon dioxide won't solve climate change" P.P.S From Wikipedia with a cited source: capturing and compressing CO2 and other system costs are estimated to increase the cost per watt-hour energy produced by 21–91% for fossil fuel pow…

I have to wonder how much of the innovation here will couple advancements in catalytic conversion with accepted inefficiencies in "storing" renewable energy by sourcing from the atmosphere. Because that's essentially what these initiatives are doing. They're seeking to artificially tighten the carbon cycle so that we can maintain the status quo indefinitely.

> so that we can maintain the status quo indefinitely.

Is that good enough? I've read that in China, they have some days where there are warnings to stay inside because there are random green substances in the air?

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

#42

Post by amluto »

paulsutter wrote: post #6
hn_throwaway_99 wrote: post #2

After reading this article, all I can say is ... ugh. What I really wanted to know was "Where does the energy come from?", and the article didn't answer that at all. The world doesn't really have a "carbon" problem, it has an energy problem, and right now carbon fuels are the cheapest, most abundant source of energy. Even if you somehow got carbon capture to work, you're still going to have to power it - with solar,…

I would bet photovoltaic. Lowest cost per watt, the process can likely be designed to tolerate day/night variations, and the plant can be located where the sun shines.

Or nuclear. A big nuclear plant could be built somewhere with cheap land, no earthquakes, and minimal weather. You don’t even need electric transmission infrastructure.

If the capital costs are low enough, cheap or free spot electricity could be used, too. California regularly has excess production.

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

#43

Post by bifrost »

b_tterc_p wrote: post #29
bifrost wrote: post #8

Earlier quoted context omitted.

At the end of the day - does it matter where it came from? They could be like Tesla and build a solar arm, or a wind farm, or do geothermal. You could pull it out of the grid and it'd still be better for the environment than pulling it out of the ground. TBH saying the world doesn't have a carbon problem contradicts all of the people fighting greenhouse gas emission based climate change so I'm curious as to your logi…

The logic is that you need to power the carbon extraction, and right now we use fossil fuels for power, so you wouldn’t be able to net reduce fossil fuels because you would be burning more than you extract. I think it’s naive though. There is a theoretical point at which it’s economical to just build excess renewable energy production and use the extra power to repair the climate.

I'd agree that outside of California it might be problematic, but we have so much renewable in the grid it'd be trivial to do properly. I also think using excess power to remove carbon is ultimately a good idea.

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

#44

Post by natch »

ThrustVectoring wrote: post #36

I strongly suspect that manufacturing hydrocarbon fuel out of air, water, and electricity is going to be a pretty significant part of the fight against climate change. The reason is fundamentally political. Newly industrialized countries have a lot of vital economic activity dependent on internal combustion engines, and cannot afford the luxury of replacing them with alternatives. The West does not have the political…

>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.

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

#45

Post by RcouF1uZ4gsC »

Hasz wrote: post #23
etaioinshrdlu wrote: post #17

Earlier quoted context omitted.

Your car doesn't need a mix of lots of hydrocarbons, it would run fine on pure hexane. Gasoline is a mix because it's made from natural crude which is also a mix... and there's not a strong reason to purify it further.

I imagine the engine is optimized to run on "average" gasoline for a given octane level, tuning compression ratio, spark timing, air mixture, etc. I'm not an ICE engineer, so I would love to know how much of a performance change can be expected from this guy's machine.

I believe the tuning is controlled electronically through software (this is what enabled VW Dieselgate). So a software update could enable the vast majority of cars to be able to use this fuel.

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

#46

Post by strainer »

natch wrote: post #32
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. >…

Well no, this is really, fundamentally wrong-headed technology. We already have more than enough petroleum to catastrophically ruin our environment. As AOC put it, climate change is our World War II. We won't solve it by sitting on our hands and being negative about the real solutions that are out there. > But the rest of the world has added 15 gigatons since 1990. That 15 gigatons represents a shift from desperate p…

It can be very useful for energy storage and keeping existing combustion plant usable. But the op does not seem to bear in mind the fact that it requires more energy input than it outputs in the form of a carbon neutral fuel, or that renewable technologies have by this date clearly demonstrated affordable solutions to carbon neutral power generation.

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

#47

Post by etaioinshrdlu »

Hasz wrote: post #23
etaioinshrdlu wrote: post #17

Earlier quoted context omitted.

Your car doesn't need a mix of lots of hydrocarbons, it would run fine on pure hexane. Gasoline is a mix because it's made from natural crude which is also a mix... and there's not a strong reason to purify it further.

I imagine the engine is optimized to run on "average" gasoline for a given octane level, tuning compression ratio, spark timing, air mixture, etc. I'm not an ICE engineer, so I would love to know how much of a performance change can be expected from this guy's machine.

You might find this youtube channel interesting: https://www.youtube.com/channel/UC2rzsm1Qi6N1X-wuOg_p0Ng/vid...

He has run a gasoline engine on a whole slew of fuels, including some that may be surprising, such as isopropyl alcohol, various solvents, crude oil, and a 50% diesel gas mix.

Gasoline engines can also run on pure propane, but the fuel pump, tank, and some other parts do need to be replaced.

I guess the point is that gasoline engines are not in general super sensitive, while they still could be more optimized for certain fuels.

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

#48

Post by Gibbon1 »

natch wrote: post #35
rayiner wrote: post #16

Earlier quoted context omitted.

The author of the article (who does not appear to be an expert in anything) overlooks that renewables only address part of the emissions picture. Even if the U.S. switched tomorrow to 100% renewables and 100% electric vehicles (including trains, cars, planes, and ships), and you ignore the CO2 emissions of making all those new power plants and vehicles, U.S. usage would only go down by 3.5 gigaton: https://www.epa.go…

>It won't change the CO2 emissions created by home and commercial heating, agriculture, and industrial uses, which add up to another 3.5 or so gigatons. So address each one in turn, or in parallel. You give no reason not to.

Lot of people use the 'golden hammer or nothing argument'

Meaning if a proposed solution is partial then we shouldn't do anything. It flies in the face of the reality that most solutions to complex problems involve chipping away at them.

Currently there is a host of technologies which emit to much CO2. Personal transportation is just one of them.

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

#49

Post by Gibbon1 »

strainer wrote: post #46
natch wrote: post #32

Earlier quoted context omitted.

Well no, this is really, fundamentally wrong-headed technology. We already have more than enough petroleum to catastrophically ruin our environment. As AOC put it, climate change is our World War II. We won't solve it by sitting on our hands and being negative about the real solutions that are out there. > But the rest of the world has added 15 gigatons since 1990. That 15 gigatons represents a shift from desperate p…

It can be very useful for energy storage and keeping existing combustion plant usable. But the op does not seem to bear in mind the fact that it requires more energy input than it outputs in the form of a carbon neutral fuel, or that renewable technologies have by this date clearly demonstrated affordable solutions to carbon neutral power generation.

When I read about these schemes to produce gasoline from CO2 and water or whatever I can't help but think someone needs a couple of semesters of thermodynamics beat into them.

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

#50

Post by hairytrog »

Is this more efficient and different compared to biofuel production using corn?

Both convert carbon in the air to carbon in a liquid fuel. Biofuels require the production of fertilizers etc. This membrane would require some energy source. The membrane would have to consume less energy than corn fertilizer / unit fuel produced to be effective.

I wonder how this is less a gimmick compared to biofuel.

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