Fuel from the sky: Cheap hydrocarbons from CO2 direct air capture and sunlight | Hacker News Reader

Fuel from the sky: Cheap hydrocarbons from CO2 direct air capture and sunlight

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37 pointsjoak23 comments

A few years ago the U.S. Navy reportedly was experimenting with producing jet fuel from air and seawater aboard aircraft carriers, using the electrical power from the carriers' nuclear reactors. I wasn't able to find anything recent about the project.

https://patentyogi.com/aircraft/us-navy-plans-produce-jet-fu...

Also: https://www.pnas.org/doi/pdf/10.1073/pnas.1902335116

My thought was similar for land based versions of this too. Their quote about the engineering difficulties being soluble in cheap electricity seems like coupling this to nuclear is a no brainer (assuming the US government can streamline nuclear in the coming decade like it has teased)

Solar is a lot cheaper than nuclear though: Everyday the production of solar electricity has to be curtailed when the amount of kWh produced exceeds the demand. Those kWh in excess, by definition cannot be sold and are hence free (as in free beer)

I like that rendering of the 1MW system.

And you can see they are making progress in the lab on the technologies for each of the modules, with some very accomplished operators.

There is a lot of advanced back-of-the-envelope math and toward the end it says they can estimate breaking even with about 500 of the 1MW systems delivered.

Now when you make 500 of anything you really can not make money on every single one, and what the world really needs most of all is the carbon capture.

What I would like to see built is the 1MW scale carbon capture unit in the rendering, and expect it would take fewer than the full array of solar cells to operate.

That little system could give out some real numbers itself, and de-risk decision-making for the other modules at that scale. Even if there is no salable fuel output to offset operating costs, this would be the ideal demo and at least it would be actually removing atmospheric CO2 each time it was functioning.

And it would cost less to build and be faster to do than one of the hundreds of complete 1MW fuel-producing systems they are going to be building ASAP anyway.

Excerpt: «Putting 50 GT of CO2 into the atmosphere every year isn’t easy or cheap. Coal, oil, and gas are buried deep underground in ever-diminishing pockets of ever-diminishing quality. By contrast, CO2 is present in air everywhere, and too much of it.»

«If we want to pave the world with DAC synthetic fuel plants, we’re going to have to engineer them to deliver ludicrous profits»

Do they actually address how it’s going to be “cheap”? Stopped reading because I couldn’t find it and given it’s the big issue you’d think they’d put it front and center.

Stopped reading at "carbon capture". It does not make sense at this point. There just isn't a lot of CO2 in the atmosphere (currently ~400ppm), and it is a very unreactive molecule. Any method of extracting it from the atmosphere is fighting against entropy and adding energy to molecules would be extremely inefficient. We should use all the renewable energy we have to reduce the emissions from our grid first. For a more near-term possible mitigation of global warming, geoengineering approaches such as reflective aerosol particles make much more sense.

From the atmosphere, sure. But, if they can succeed in building a viable conversion system, then hot exhaust from factories or other sources can be used instead of air.

It could be a closed source system too, for example, in industrial applications that need a lot of heat. An almost closed cycle system may be viable. I have no information about the speed of the reaction, but I guess systems can be scaled.

Also, a good amount of heat is produced in the sabatier reaction process itself, which can be used for other systems.

Conversion of atmospheric CO2 to usable fuel can become a cheap battery for solar plants.

Edit: Such a system already exists, even if as an idea.

https://www.carboncommentary.com/blog/2017/7/24/exytron-the-...

The article is talking about atmospheric capture even if it doesn’t use those exact words.

They are not here to mitigate global warming. They plan to make big money.

There is a market for natural gas, they have a precise estimate of costs (including carbon capture) and their costs are lower than fracking. No new tech. No big upfront investments. Just deploy and get rich.

Given the motivations of most humans, "deploy and get rich" seems like a good way to deal with CO2. The reason we're in this mess is because being CO2 neutral doesn't pay. If someone can find a way to profitably produce fuel while extracting CO2 from the atmosphere CO2 levels will be falling in no time.

I hope this works. I also suspect that the inaccuracies of estimation will completely make or break this concept. If they can't achieve their theoretical efficiencies, or have other losses they didn't account for, the economics will fall apart.

This is the fundamental problem with almost all "green" tech. The economics aren't there. The cost of fossil fuels ignores the cost of cleaning up. If there was serious money to be made in green tech, there would be serious investment. It feels like we're turning a corner in seed investment - but that's probably more because of hype rather than market fundamentals.

Is all the stuff that works no longer "green" tech or something?

Which stuff is that? Obviously there's been massive energy reductions across all sorts of industries - LED lights, hybrid cars, improved building standards - but they've clearly not solved the greenhouse gas problem. Solving that problem means making it more profitable to keep carbon in the ground than removing it.

Their pitch is that there will be so much cheap electrical power available (via cheap solar PV) that they'll be able to supply methane cheaper than fracking or any other fossil source.

Notably, given that assumption, any process that could be electrified, will already be electrified (because super cheap solar PV). And anything that can just use hydrogen will just use cheap hydrogen. So this methane won't be used for anything that could be done with cheap electricity or hydrogen.

So, you are correct, it's not worth doing this instead of rolling out more renewables, since this needs those renewables to both exist and be cheap, but they're planning for the world after the cheap renewables get rolled out, at which point they can provide cheap, carbon-neutral methane (and/or other hydrocarbons), for any use that isn't directly electrifiable (e.g. making plastic, space rocket fuel).

This only further increases demand for renewables, driving them further down the price curve.

Even with cheap Solar, many regions will still need Gas or similar fuel for electricity and heat generation in winter. If that gas can be transported and used with existing infrastructure, that'd be a huge bonus. So there's definitely a market, the question just is how to be cheaper than natural gas.

Yes, they put a cost on everything. The solar panels, the capture, water electrolysis, Sabatier reaction, etc... All very predictable. And how much they'll be making per year selling their gas at market prices. And they already signed a contract with a gas company. They are making money as soon as they start producing. In a year or so. What seemed impossible is not.

Good idea, would have preferred SMR for power though.

Anyways, Atmospheric Processors like in Aliens? F..K YEAH!

Agreed, it doesn’t even seem worth considering solar given the scales necessary but people are fearful creatures.

Solar is a lot cheaper though. Curtailment is the key word. The production of solar electricity has to be curtailed everyday when the amount of kWh produced exceeds the demand and cannot be stored. Those kWh are free.

This will lead to global cooling crisis

As a skier, this is my dream :)

It's a scam.

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