The actual science:

> Here we report a catalytic system composed of 1-ethyl-3-methylimidazolium-functionalized Mo3P nanoparticles coated with an anion-exchange ionomer that produces propane from CO2 with a current density of −395 mA cm−2 and a Faradaic efficiency of 91% at −0.8 V versus reversible hydrogen electrode over 100 h in an electrolyser.

This is almost too good to be true... they demonstrate commercially viable reaction rates, efficiencies and timescales.

They have presumably applied for a patent for it, so in 20 years when the patent expires this will become the standard thing to do with recovered CO2 I'd guess.

There’s no clear indication whether that would require some CO2 or a concentrated atmosphere of CO2 without O2. Extracting CO2 from the atmosphere at 0.4% is expensive.

If this is meant to use concentrated CO2 coming out from a furnace, would that need to be local, piped in over a long distance, or using bottles? Are there use cases where we must burn propane because we can’t replace that process with electricity?

Whatever happened to a similar announcement from Stanford in 2019?[1]

[1] https://news.stanford.edu/2019/10/17/new-catalyst-helps-turn...

I wonder can they use the same membrane/catalyst for the inverse process: oxidize propane with atmospheric oxygen, release water and CO2, and instead of heat directly produce electricity without too much energy wasted in the process?

If yes, the consequences for energy storage might be significant. The energy density of propane is 49.6 MJ/kg. Apparently, Li-Ion batteries are about 0.8 MJ/kg, more than 50x the difference.

Electrolyzer reactions tend to be reversible...

If they could do the reverse (water+propane to CO2+hydrogen+electricity) at the efficiency claimed (91%), they can replace all gas turbine generators (who typically have efficiencies of only 60% at best)

actual paper: https://www.nature.com/articles/s41560-023-01314-8

The press in my corner of the world is going to have a field day with this, considering that over 13% of passenger cars around here are dual-fueled with petrol and LPG (so mostly propane) - they put it even in hybrids.

Hilariously enough even at this rate of adoption few underground garages allow entry for such vehicles.

I suppose it won't see adoption in cars anytime soon because looking at electricity prices it can't hope to be less expensive than fossil fuels.

Probably the best time to be a propane and propane accesories salesperson.

FYI, there’s a startup doing CO2 → Methane conversion called Terraform Industries.

https://terraformindustries.com/

I asked the cofounder of his thoughts here:

https://twitter.com/ccorcos/status/1694021803654693342

> 1-ethyl-3-methylimidazolium-functionalized Mo3P nanoparticles coated with an anion-exchange ionomer

How hard/expensive are all their materials to produce at scale?

Molybdenum is not as rare and expensive as platinum, so that’s certainly a win.

Stupid question, if we find a commercially viable way of converting CO2 into fuel is there a danger of "global cooling" because people will get too greedy with this?

Doing quick napkin math it looks like to process a ton of CO2 it will require 1.6kW of energy, burning that amount of propane generates at 50% power plan efficiency you get ~3kW of energy generation...

8CO2+24H2O+24e→3C3H8+16O2.

Moles of CO2=1000×1000/44.01≈22726moles.

Total moles of electrons= 24/8×22726≈68178moles.

Total charge=68178×96485≈6.58×10^9C.

E=Q×V=6.58×10^9×0.8≈5.27×10^9J.

E_actual=5.27×10^9/0.91≈5.79×10^9J.

E_actual=5.79×10^9/3.6×10^6≈1608kWh.

----------------------------------

Moles of propane= 3/8×22726≈8522moles.

Mass of propane=8522×44.1≈375,670g≈376kg.

Total energy content=376×50.35≈18,932MJ.

Usable energy= 10,791/3.6≈2,997kWh.

It's a great idea for places like northern Canada where many technologies like solar don't work during a sunless winter. Wind is OK but it's complex to set up and maintain in such isolation. Diesel tends to be an easy solution but endless propane would be great if the regulator didn't freeze.

Propane also needs to be compressed from what I can see to about 200psi. Not a huge amount but it would take special equipment and power to run a pump.

Propane always struck me as a potential lower carbon aviation fuel since it easily liquifies under modest pressure, making the whole system lighter and more compact than natural gas or hydrogen.

Batteries would AFAIK need a 2-4X power/weight density improvement to do anything more than short haul electric flight. Short haul electric planes are possible today but not beyond a few hundred miles range.

So, we could take concentrated CO2 from a furnace, and instead of releasing it into the atmosphere directly, convert it to Methane, and then burn that incrementally?

Or could we possibly fit an exhaust-gas tank onto our engines that holds all the combustion products, and is collected and recycled at the gas station?

It would be great if natural gas is replaced with propane for households. Just imagine to fill up your ICE/LPG car at home, and to have a real wok burner without the need to change gas tanks.

Offtopic... does anybody have a good link to find papers that have been written after sci-hub stopped adding papers?

My desire to read papers like this outstrip my funds to do so.

C3H8 + 5O2 => 3CO2 + 4H20

reminder that propane burns into CO2 - this process doesn't actually unlock any new energy source, it merely just reverses a reaction that has already taken place (presumably with electricity or some other form of energy)

this isn't some kind of miracle infinite energy source to solve climate change woes, more like an interesting way to convert one usable form of energy (electricity) into another (a petrochemical)

What form of CO2 does this work with? I suspect highly concentrated, not the minuscule amounts in ambient air.

Too early. I'm still healing from the super-conductor that wasn't.

I don't like those techs because they don't guarantee that they will offset fossil fuel extraction.

What's really needed it's culture change on growth and consumption.

The best technology is light technology.