Gasoline made of carbon sucked from the air (2018) | Hacker News Reader

Gasoline made of carbon sucked from the air (2018)

nationalgeographic.com

49 pointsguerrilla89 comments

This article is about Carbon Engineering: https://carbonengineering.com/

There's also Prometheus Fuels which is a YC company doing the same thing: https://www.prometheusfuels.com/

The science is sound, but whether the process is economically viable remains to be seen.

I’ve been mulling entering carbon sequestration space using biochar but what’s mainly stopping me is the fact that no amount of industrialization can even put a dent in how much new carbon is being introduced every year when now in terms of burning newly pumped fossil fuel.

Isn't biochar more a play for soil protection?

Given that it’s pretty hard to reclaim carbon from it I’m thinking it’ll be a great way to just bury it and sell carbon sequestration credits (as a more legitimate sister to carbon credits).

What's your charring methodology?

I believe Charm industrial is using the biochar process, but producing oil and pumping it into the ground. Even in fields, it’s a solid idea.

And like you said, it’s recognized as being a very stable store of carbon for a very long time.

The trick is getting feedstock nearby so you aren’t pumping tons of CO2 into the air to acquire, move and process it.

Might make sense for air travel and cross-ocean shipping. Time will tell if pure hydrogen or e-fuels are more economical.

Also works as a backup of last resort for power systems through power to gas/x.

https://en.wikipedia.org/wiki/Power-to-gas

https://en.wikipedia.org/wiki/Power-to-X

> Also works as a backup of last resort for power systems through power to gas/x.

Yep. The current mode of operation to simply trim the output of solar and wind in case of oversupply is an utter waste when the power could be used in power-to-gas plants.

Unfortunately, the cost of building proposed power-to-gas plants is high enough that it doesn’t make economical sense to run them just a few hours a day.

Theoretically, if power-to-gas plants can be manufactured at scale, you could make gas generation plants further away from where energy is being consumed. We already have tons of infrastructure on this planet for moving gasoline around.

You could also keep ICE engines in use without worrying about their carbon footprint. Excess renewable power turns into fuel to be used in cars, boats, trains (diesel electric freight cars), and airplanes.

Using this tech for off peak leveling on the grid might not be cost effective, but it can certainly be used to support the existing infrastructure we have to allow for a more graceful transitional period.

Will the cost stay high in a large scale production?

I have never seen an estimate on that, or a plant design detailed enough for extrapolating it. Do you know how those plants are built?

Ammonia - NH4 - is often proposed as a solution for shipping. Note there is no carbon in the chemical formula, thus there is no carbon dioxide resulting from burning it.

Hydrogen will be made from renewables by 2030.

There is an N in that formula, though, so burning ammonia is going to result in nitrous/nictric oxide. NOx is also a greenhouse gas (indirectly, apparently), and the hazy brown component of smog. One of the oxides is laughing gas. On the whole, I think pumping CO2 into the atmosphere is better than pumping smog and laughing gas.

Solar power wasn't economically viable once, nor was Wind power.

Sucking fuel out of the air anywhere you like has to be more viable than sailing out to sea and building a huge rig to drill underwater for pockets of gunk that you then have to refine. Imagine an airport that creates its own fuel instead of needing constant resupply.

> Sucking fuel out of the air anywhere you like has to be more viable than [...]

Pretty sure it absolutely isn't.

obviously not, right now. but if this tech can be scaled up it would be.

yes, it's not a certainty. but solar power was once seen as only useful in space where you couldn't run a diesel engine. Then it got more efficient, and cheaper, and now it is cheapest form of energy per MW on Earth

> but if this tech can be scaled up it would be.

It's not that it is "not a certainty". It actually seems very unlikely that this could work.

> and now it is cheapest form of energy per MW on Earth

Thanks to fossil fuels, that have been used at pretty much every step of the process of building and transporting the solar panels. And then it only works with good weather. Not that solar is completely bad, but it does not look like it will be the replacement for fossil fuels.

It is not enough to be cheap as a marginal source of energy in a world with cheap fossil fuels. At some point it would need to work on its own...

Also https://terraformindustries.com/

Discussion of economics: https://terraformindustries.wordpress.com/2023/01/09/terrafo...

Seems like the natural gas angle may be better due to higher efficiencies of existing equipment (power plants) that burns natural gas. Maybe the same can be done with gasoline?

And of course you can't reasonably run a plane on natural gas AFAIK.

> And of course you can't reasonably run a plane on natural gas AFAIK.

https://en.wikipedia.org/wiki/Tupolev_Tu-155 , up to 2 hours flight, flew in 1980-s. Not much, but at least a proof of concept.

> A carbon price is a cost applied to industries that emit carbon pollution. British Columbia has a carbon price of C$35 a ton, and all of Canada will have a $10 price in September that will rise to C$50 in 2022.

Interesting, this is a seemingly proven? way of levelling the temporal playing field.

If the future costs of processing and burning oil could be accurately calculated. It could be the case that synthetic fuel is already cost competitive. A tax could attempt to represent that discrepancy.

Like a sugar tax or a tobacco tax, for which there are real personal, societal, and ultimately economic costs beyond the sticker price - these costs are accumulated and deferred, so it's hard to intuitively judge for the individual. Taxes against these poor choices help make the cost more intuitive, hypothetically they could even be proportional and immediate if those funds were used to treat those issues though e.g health care spending.

IIRC current estimations of a carbon price accurate to the social costs of a ton of CO2 are near US$185 [1]. It is probably unrealistic to assume that such a price is politically achievable within the next 10 years (even if all the income from such a tax is redistributed). Making gas more expensive is really not popular.

Another option is emissions trading, where a fixed amount of CO2 certificates are issued over some timespan (with the amount calculated to fit some emissions goal). The price is then determined by the market.

Of course this should also lead to high CO2 prices, which will be unpopular, but with proper protections against future changes to the system in place, politicians might be able to absolve themselves of responsibility and more or less put the blame on the market. I think that might make this more politically achievable (especially since possibly the effects on consumer prices might only appear a while after the relevant political decisions are already made).

[1]: https://www.nature.com/articles/s41586-022-05224-9

> Interesting, this is a seemingly proven? way of levelling the temporal playing field.

British Columbia generally uses the Carbon Tax revenue to offset other government revenues (eg: lowering income taxes; a Conservative candidate campaigned on this federally in 2017 [1]), while the federal policy provides a flat rebate to taxpayers. They both attempt to be "neutral" in one way or another. I'm not sure which is better.

That said, the Carbon Tax is a bit of a wedge issue (federally) in Canada, as different regions are more suburban and car-dependent than others as well as other provinces historically have produced oil. Your lifestyle and outlook to climate change policy often influences your feelings on the topic.

[1] https://en.wikipedia.org/wiki/2017_Conservative_Party_of_Can...

I get that this isn’t cost competitive on the energy side alone with a barrel of oil, but what about energy PLUS storage cost competitive to solar/wind?

Feels like if we didn’t have to invent new batteries but instead just turned excess solar and wind into carbon neutral gas “batteries” that would be a win.

Yes, storage is hugely expensive.

A barrel of oil is about 1,700 kWh. If we have an optimistic cost (https://atb.nrel.gov/electricity/2022/utility-scale_battery_...) of $300 per kWH capacity that is $510,000. Divide by say 5000 cycles that you can get out of a battery: it costs $102 in what is capital depreciation/wear to store one barrel of oil.

Of course projections show that reducing to 1/3 of that...eventually.

Check out terraform industries if you find this interesting.

They just released an interesting white paper detailing a lot of good progress:

https://terraformindustries.wordpress.com/2023/01/09/terrafo...

I think it’s interesting because they’re focusing on the cheapest and easily manufactured technologies instead of efficiency.

I had a similar realisation recently when comparing the house building industry in the US to that from here in Europe.

Because the US builds most of its residential housing out of wood it means that the Sun does most of the heavy lifting when it comes to "creating" the building materials out of which most of the US residential houses are built. The biggest cost related to energy when it comes to the US residential market is the opportunity cost of not having those trees back in the forrest still producing oxygen, plus the loss of forrest habitat as a result of ever-expending suburbias.

Meanwhile, in Europe most of the residential houses are built using cement, concrete and even bricks, all of these activities very energy intensive, you can't rely on the Sun's goodwill as the Americans do. Granted, you don't incur the opportunity costs of having to cut down trees/forests, but I have a gut feeling that the energy (and pollution) costs of building a house based on cement/concrete/bricks are a lot bigger than the opportunity costs you gain from not cutting down some trees in order to build the same house.

There's also a discussion to be made about costs related to house insulation and the loss of energy, where, I agree, European houses perform much better compared to the US houses made of wood.

All in all I think we need to "rediscover" economists like Georgescu-Roegen [1], people who had built almost all of their intellectual careers talking about this sort of stuff.

[1] https://en.wikipedia.org/wiki/Nicholas_Georgescu-Roegen

It's worth noting here that the root system of the tree remains and also that different trees/plantation systems have different carbon uptake profiles. There are ways to tune a production forest to have a lot of carbon uptake while allowing you to remove trees for production continuously, even to the extend where managed land is takes up more carbon than unmanaged land. Deserts are technically unmanaged land but they don't store more carbon and similarly a forest will stop being a carbon sink when the trees start decaying or the big trees stop growing while still outcompeting all the smaller, still growing, trees

I say this as someone living in Northern Europe in a wooden house: there’s a fairly good reason that the building industry uses brick rather than lumber here. The combination of humidity, temperature, and often densely-packed housing created both a skills base and a supply chain that has, over time, made it needlessly costly to build with lumber. And, a lot of our historic architectural styles prioritise brick, which is a huge pull factor when people are deciding on styles for new buildings.

It's not that simple.

The typical European brick & mortar home is much sturdier than your typical US wooden frame construction. Houses aged 100 or more years are no rarity. The US median age of 37 years or so is still relatively young on, e.g., the German market.

Interestingly, though, European wood-based construction companies (wooden houses are usually prefab here) distinguish themselves with their energy efficient wall construction techniques. A brick-and-mortar company can achieve the same level of efficiency by choosing the best available bricks but they will typically offer cheaper bricks with add-on insulation. It's definitely not the case that new wooden construction is less energy efficient - but of course that comes with a price.

> Houses aged 100 or more years are no rarity. The US median age of 37 years or so is still relatively young on, e.g., the German market.

Eh, there are plenty of old houses where people have been living for more than a couple of centuries; most of the new houses are people deciding to build new cities and suburbs in new places rather than churn on existing stock (not that there isn't some churn on existing stock).

Also, 100 years old isn't really that impressive. I've got a 100 year old house; it was build in the 1920s. Aside from a stone foundation rather than a cinderblock foundation and a few oddities (like a patch on the chimney where the kitchen stove used to vent), it's a boringly basic, familiarly modern house. It's even got original sheetrock (albeit with instructions printed on the back telling the installers how to use it).

Hell, the Empire State Building is almost 100 years old.

Wood houses can easily last 400+ years.

Building longevity is mostly a question of changing demands. Old buildings in major cities can’t compete with skyscrapers.

> I have a gut feeling that the energy (and pollution) costs of building a house based on cement/concrete/bricks are a lot bigger than the opportunity costs you gain from not cutting down some trees in order to build the same house

You've overlooked the cost of shipping the wood from the Americas.

Wood construction isn't used as much in Europe because it's much more expensive. Apart from a few pockets of environmentally important old growth forest, centuries of industry and warfare depleted European forest.

The UK set up the Forestry Commission after WW1 depleted forest cover to just 5%: https://www.thegazette.co.uk/all-notices/content/103379

Huh, is this why the timber framing with clay brick or wattle and daub infill is so classically (old) European? Less wood needed, but unnecessary in the US with its plentiful trees?

Possibly. I know Scotland's traditional "bothy" construction style developed to need only one piece of structural lumber - the roof beam. The walls would be stone (available everywhere), and around the single beam on the roof was thatch or slate.

On the other hand, places like Estonia, Norway, and Romania have museums of traditional wooden construction including all-wood "stave churches". Europe was an extremely non-homogenous place until the late 20th century.

Boswell&Johnson found almost no trees in the 1700s: https://www.electricscotland.com/history/journey/jour3.htm

Yo fellow stupidpoler

When it comes to leaving the trees in the forest, you have to take into account the fact that mature trees will produce less oxygen than growing trees, and if nobody cuts the old trees down, when they do fall themselves and succumb to decay, all of the captured CO2 will be consumed by aerobic organisms and thus released back into the atmosphere.

We're in 2023 so my question is : what happened to this since then ? It should be mainstream by now.

Here's a wild guess: it probably makes no economical sense in the current context

The reason it's not mainstream is most probably that the energy ratio between production and the output is terrible.

Also, technically, all hydrocarbons are made from Carbon sucked from the air.

This

There are other ways besides biology that hydrocarbons can be produced. Pure water placed between diamond anvils at high temperature and enormous pressure will spontaneously produce hydrocarbons. Titan's atmosphere is mostly hydrocarbons that didn't come from living things.

"Diamond dissolution and the production of methane and other carbon-bearing species in hydrothermal diamond-anvil cells" https://www.sciencedirect.com/science/article/abs/pii/S00167...

The energy ratio and cost being terrible doesn't matter for some PR usecases.

Imagine being able to sell Formula 1 this fuel so the whole industry can claim to be green and try and try to re-attract young crowds who are turned away by un-greenness?

The fuel could cost 100x as much, and it still wouldn't be a big issue.

Formula 1 is going to move to “sustainable fuel” in 2026, so you’re exactly right

"Imagine being able to sell Formula 1 this fuel so the whole industry can claim to be green and try and try to re-attract young crowds who are turned away by un-greenness?"

I loled. They could use ground unicorn for fuel, and I still wouldn't be interested.

I'm thinking that the demographic allegedly being turned away for "un-greenness" would be downright appalled at using ground up unicorn for fuel...

They state "It costs more than a barrel of oil right now, but in places with a price on carbon of $200 a ton, like what’s enabled through California’s Low Carbon Fuel Standard, we’re competitive". Today, the carbon price in the European cap-and-trade scheme is $81 per ton, and in California it's $29 per ton. So unless they've greatly improved efficiency, they don't have a profitable market.

The EU price is also only that high since about a year ago, two years ago it was about $23 per ton. Even if they were profitable at about $80 per ton, there was little time to scale up production.

"like what’s enabled through California’s Low Carbon Fuel Standard, we’re competitive"

That is not competitive, that is using government moopoly on violence to artificially raise the price of alternative product...

Competition would be done with out government force

From a theoretical standpoint you can argue that the "fair" price of fuel would include the costs of any environmental and economical damage done by burning that fuel: the cost of health issues from particulates, the infrastructure costs to deal with sea level rise, the costs from droughts that are worse because of increased CO2 in the atmosphere, etc. Just because those happen to somebody else than the person burning the fuel doesn't mean that the costs don't happen.

And the best way we currently have to price in those externalities is artificially rising the price of the offending product, to give alternatives a better chance to compete.

> that is using government [monopoly] on violence to artificially raise the price of alternative product

A less dramatic summary is the government is partially factoring in the negative externalities of carbon, through taxation or minimum pricing.

You call that violence, whilst downplaying the very real harm (actual death and destruction) caused by excess carbon in the atmosphere.

I can't have scrolled this far without reading these 3 letters, so here they are. ESG trading.

I call it violence when

1. The level of taxation is not connected at all to the cost of the externality. You know the externality exist so then you level that as the justification.

2. The taxation being collected is not being used to curb the harm of the externality, instead it is being used as a punishment for those that need or choose to use something the government has determined to be "bad"

If you want to ride in on an ethical horse of attempting to recover externality costs then the regulation needs to be done in such away that it both ties the amount of taxation to the actual cost of the externality, and any money collected from that taxation is used solely for the mitigation of harm caused by that externality

https://www.investopedia.com/terms/e/externality.asp

Some basic economics 101 reading can set you straight here.

It's a legitimate function of government to craft regulation when there are negative externalities distorting markets.

Sometimes government regulation makes markets more free. Crazy, I know, but please let it sink in.

If it helps: you can think of producers that rely on negative externalities as freeloading evil socialists who redistribute other people's wealth (without consent) to themselves.

That is one way to look at it, I disagree with this however even taking at face value you need to calculate the actual cost of the externality and then recover that

here they are saying "Well we need the price set to X to be competitive" that has nothing to do with calculating the cost of the externality, which may be lower (or higher) the taxation needed to bring this product to be price comparable

$200/ton is 20c/litre (assume specific gravity of 0.75, and fuel being 75% carbon by mass).

Here in Ireland, tax on petrol is around €1/litre (VAT + excise duty + "carbon tax", but it all goes to the same place). A 20c extra subsidy would not quite be noise, but it's less than the price fluctuates from quarter to quarter anyway.

Even if gasoline was free and didn't cause global warming it would still lose out to electric vehicles. Why? Because of the poisonous gases they exhaust. Almost every one alive has been habituated these gases and think "that's just the way it is." But EV's emit no poisonous gases. With EV's you could make a parking garage that's completely enclosed and heated with no problem. Downtown cores with only EV's will smell like springtime all year long. There is no going back to ICE vehicles in the cities of the world.

It's all about the cost equation - cost of producing this stuff where it's needed, when it's needed. Vs the cost of drilling, hauling, refining, shipping, storing ordinary fuels.

Trouble is, we've raised the scale on all those things to the point it's hard to compete with small local carbon-fuel plants. Small will always struggle to complete with huge.

Even in the far flung magical fusion driven mckendree cylinder spinning future, we will have gasoline. It will be expensive to make, messy, but it is some of the most shelf stable, energy dense, and human handlable energy storage in existence. The jerrycan will be a tool in the human toolbox forever and this is probably how it will get made.

Sounds funny, kind of recycling emissions - we burn gasoline, put carbon into the air, then we take carbon out and make gasoline that we burn again and the process restarts.

It's hard to see how 'sucking carbon from the air' will be cheaper than producing it from the much carbon richer renewable waste and bio materials being used elsewhere.

"Sustainable Aviation Fuel"/SAF has already dropped to just over twice as expensive as traditional fuel (or less depending on the current price of oil)

https://simpleflying.com/saf-cost-competitive-jet-fuel/

Biofuel isn't just from "waste," it's a significant percentage of our grain production. Making carbon-neutral fuels without agriculture would be a big reduction in our land usage, fertilizer runoff, and pesticide use, all of which are major environmental issues of their own.

There are no carbon neutral fuels 'with' agriculture.

Afaik, no bio-fuel scheme, including ethanol from sugar cane in Brazil, is carbon negative. I might be wrong or out of date, but my last dive into this resulted in an understanding that we'd be better off just using turning the carbons required to grow the things we would eventually turn back into energy and using it.

Agriculture as it currently stands globally is a carbon source from an LCA perspective, and that includes biofuels.

A bio-fuel can not be carbon negative, by definition. At most it can be neutral.

And yes, none is neutral either.

> my last dive into this resulted in an understanding that we'd be better off just using turning the carbons required to grow the things

But this is a huge jump, without subsidizing evidence, and known to be false.

Just because the fuel emits carbon, it doesn't mean it emits as much carbon as natural gas. Only corn ethanol fails at this and emits more than the original fuel.

Well we dont use natural gas to move things around I suppose is the point. My last foray into this was almost a decade ago, but when I did the work, I know that the physical movement of things (in the case I was working on it was jet fuel from oilseeds) was a very significant factor in the overall analysis. The moving of thing A from location X to location Y to convert it into product B, then to move product B to location Z to convert into product C ended up being more than enough to flip the whole thing over. I think the next biggest factor was the grid mix for the conversion steps. I think another conclusion was that if we could do it all on-site, it did pan out. If farmers could use marginal land, didn't have to move the seed offsite, and had the additional equipment to convert from oil -> bio-diesel, it might make sense for some growers. All of that understanding may well be obsolete now.

TLDR: Moving heavy stuff around burns a lot of fuel. If you have to move things from place to place, its just not worth it.

Unfortunately in addition to 2x the price, it's also 25% more emissions.

They will get crushed by a newfangled invention called "plants".

Heh. But good point.

What is the most efficient plant that can sequestrate the carbon at the same rate?

Same rate? Well hard to say, but micro algal reactors can get pretty efficient, albeit at high cost - but that's a moot point in this scenario.

Ah but we need to eat the plants. We can put factories that create fuel out of nothing in the middle of the ocean, where we can't grow corn.

Only one question, does it produce more CO2 than it captures?

It should be noted that this company is backed by major fossil fuel funders and companies, even with connections to some of the dirtiest fossil fuel productions on earth (tar sands): https://en.wikipedia.org/wiki/Carbon_Engineering

While I do think there is a need to develop DAC and e-fuels technologies, everything about Carbon Engineering feels like this is an effort by fossil fuel interests to give the impression of an easy solution that doesn't require too much change.

Indeed. For as long as it costs more than fuel, only greenwashers will buy it.

This is a red herring distracting you from the fact that oil is subsidized when it should be taxed.

> oil is subsidized when it should be taxed.

Our economy is based on oil. What you are proposing is an immediate economic collapse of whatever country decides to go that way.

I am not proposing it to be immediate. I am merely asking for a commitment to gradually reduce greenhouse emissions. Thankfully the US rejoined the Paris agreement.

For sure, however… look at the direction of this logic. For fear of an economic change, one is willing to place more burden on the planet and its humans/occupants.

Economic change largely means “less profit for corporations” and “more bailout for corps.” The poor are still poor just more poor-er…

Which usually translates to: “harder hits for consumers” as under capitalism, the profit is protected more than the people.

A good direction, imho, may be to edict (from gov) a directional change with a temporal bound, and financial hit for failing to meet that goal. So: “implement X by date or get fined and shut down.”

… ignoring that most nations have allowed corporations inroads to government halls making it virtually impossible to make any real changes that will help the people.

We’re screwed without drastic changes, it’s our fault, and it’s only going to get worse before it gets better.

Isn't all gasoline made of carbon sucked from air?

Reminds me of a little nugget I heard once, that trees grow out of the air not the ground, since they're mostly carbon-y foam which comes from CO2

Plants can often be understood as pumps that pull water from the ground to combine with atmospheric CO2 and sunlight to make sugars that they recombine to make more of themselves.

Part of Richard Feynman's "Fun to Imagine" series, I think. Video link: https://www.youtube.com/watch?v=P1ww1IXRfTA

I felt somehow betrayed when I learned that the oxygen trees release comes off the water that's used for photosynthesis, and not the carbon dioxide directly.

(Of course, the oxygen in the carbon dioxide ends up in new water molecules in a later step of photosynthesis, and that water either immediately or eventually finds itself in another photosynthesis reaction, so that carbon dioxide oxygen finds itself released into air sooner or later, but still.)

And when you lose weight it's mainly in the form of exhaled gas.

I like that a lot! I will remember it next time I’m willing myself not to stop.

It's all a question of time

Oil is ancient solar energy.

I'm curious about this.

The geologic carbon and kerogen cycle looks to be be:

  plankton + plants -> sedimentary rocks -> kerogen -> "liquid and gaseous hydrocarbons [via] catagenesis"

https://en.wikipedia.org/wiki/Fossil_fuel

However, relatively recently there has also been the discoveries of extraterrestrial sources of kerogen, including in meteorites, Martian samples and planetary nebulae:

https://en.wikipedia.org/wiki/Kerogen#Extra-terrestrial

It's not clear to me how much to attribute to how much terrestrial kerogen could be present during our planetary formation vs that which is continuously replenished during the carbon cycle.

Anyone know of studies of the relative contributions?

I posted this for a couple of reasons. I'd like to know, why is it still not economical? Has any progress been made? How much progress can be made (like how does this compare to plants? Maybe we're just better off going the algae route or whatever)?

In any case, maybe it's just a pipe dream but it would be really convenient if our needs for energy storage (that's how I see this) could be met with something that incentivizes cleaning up the environment. I don't see why it matters that oil companies are involved if they have the resources and power to do this. The fact that they obviously need to be reined in is as far as I can tell entirely orthogonal.

> why is it still not economical?

Entropy and energy.

- Entropy: dispersing is easy, collecting is hard.

- Energy: burning releases energy, putting it back together requires energy.

No, this is not a useful or interesting response. We have in many places at many times of the day extreme excesses energy (with free electricity and often negative prices in some regions), especially in places with high winds at night (when industry isn't consuming as much.) In many of these situations, our biggest problem is a lack of energy storage rather than power. There comes a point where the cost in losses becomes low enough, what is that point and what factors are involved.

I think the fact that unburning CO2 requires input of energy is a salient factor.

You can get 12 g of carbon for 22.4 L of CO2. 1 L (liquid) of gasoline weighs about 750 g. So to get 1 L of gasoline you will need to process at least 63 L of CO2, and since there are about 400 ppm of CO2 in air (that is, 400 / 1e6 = 0.0004), you will need to process 158,000 L of air for one L of gasoline. Assuming 100% efficiency. A box fan can do 70,000 L of air in a minute, so 26.6 L of gasoline/hr (7.0 gal/hr). At a price of $4/gal, this is $28/hr, if electricity is free, you have 100% efficiency, and you can sell the gasoline for retail prices without transporting it. Obviously, you'll need to scale this up. But how long does this take to recoup your capital investment in the equipment and R&D? And would it be more profitable just to buy some KO/AAPL/BERK/QQQ stock? Or buy some real-estate, or whatever other investment possibilities there are?

But is electricity really free? And for how long, in what location? What are the transport costs from that location? If you can only profitably produce 8 hours of the day (e.g. night, as hypothesized), it takes three times as long to pay back your investment. Multiply that by at least 2, since I think 100% efficiency is unlikely (I think 50% is unlikely, too, but I'll be generous).

There is also the problem of how do you ensure that you aren't "polluting" the area around your intake with CO2-free air.

Just a quick math note for other readers. There's a multiplication missing on the "at least 63L of CO2". That should be 22.4L*750g/12g = 1400L of CO2 I think.

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