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Electrolyzer efficiently converts CO2 into renewable propane fuel
- berbec 3y agoactual paper: https://www.nature.com/articles/s41560-023-01314-8 https://www.nature.com/articles/s41560-023-01314-8
- Animats 3y agoWhatever happened to a similar announcement from Stanford in 2019?[1] [1] https://news.stanford.edu/2019/10/17/new-catalyst-helps-turn-carbon-dioxide-fuel/ https://news.stanford.edu/2019/10/17/new-catalyst-helps-turn...
- tuetnsuppe 3y agohttps://en.m.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust https://en.m.wikipedia.org/wiki/Abundance_of_elements_in_Ear... Ruthenium and Iridium are known stable catalysts that are also among the most rare elements. Their structure used Ru. This new paper seems to propose only abundant materials. If it can be used at scale and proves to be stable that would be an important advancement.
- londons_explore 3y agoThe 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.
- PaulHoule 3y agoNot sure people really want that much propane. But really, this kind of process is still being pursued for e-Fuels despite horrific economics https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_process https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_proces... The economics are so awful because of a complex network of reactions, there are processes that build up larger hydrocarbons and break them down and you have to balance these just right to get liquid fuels and not paraffin wax or methane. Some kind of single-entity fuel has always seemed to make more sense to me: methane isn't that good of a destination because it's not that easy to handle or liquefy, propane is quite easy to handle in comparison.
- colechristensen 3y agoThe remaining issue is the durability of the catalyst.
- londons_explore 3y agoThey demonstrate 100 hours. That's plenty for commercial viability - replacing the catalyst every 4 days is very doable. And it's likely that the catalyst lasts far longer but the experiment only went on 4 days.
- neltnerb 3y agoEspecially if it can be regenerated, then it's really a non-issue.
- ur-whale 3y ago>The remaining issue is the durability of the catalyst. And its cost. Or more generally, where the catalyst sits in the supply chain (how easy it is to produce at scale, can it be recycled, is it expensive, what is the waste management for it, etc...)
- londons_explore 3y ago1-ethyl-3-methylimidazolium-functionalized Mo3P nanoparticles don't sound very off-the-shelf...
- jokoon 3y agoI 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.
- tticvs 3y agoIf the price is competitive the market will guarantee it. Otherwise regulations can. Why would you oppose technological solutions in favor of ideological ones? Unless of course you don't care about solving the problem...
- colechristensen 3y agoEnergy policy based on being "nice" will never have significant longevity.
- deleted 3y ago[deleted]
- reacharavindh 3y agoWe(as humanity) has done this several times in the past. If there is an alternative we could regulate our way out of not harming ourselves. It sure takes time but it has happened in the past. Cue. Asbestos, use of Lead pipes, use of CFCs, now ongoing reduction of single use plastics.
- tchaffee 3y agoExcept it already has. Car emissions regulations are a good example. Not just regulations on manufacturers either. Look at London's ultra low emissions zones quickly pushing folks to go electric.
- westmeal 3y agoWould be nice if instead of using car emissions as a boogeyman they focused on the cargo shipping industry who burn metric fuck tons of bunker oil instead of using alternative fuels. Instead you just get taxes in the guise of 'fixing the environment' by penalizing the working class who in reality contribute very little to co2 and nox emissions.
- murkt 3y ago> 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.
- 01100011 3y ago1-ethyl-3-methylimidazolium is a fairly simple molecule and already used in industry.
- londons_explore 3y agoElectrolyzer 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)
- murkt 3y agoReversed electrolyzer would be called a fuel cell then? What are their typical efficiencies?
- londons_explore 3y agoYep. Fuel cell efficiency varies widely, but the efficiency of the reverse process is a good guide - typically efficiency is fairly symmetrical.
- fodkodrasz 3y agoGas turbines scale much better than fuel cells, and can achieve great power density, are durable, can be produced without too much exotic materials needed, are a proven technology. If you can solve the storage of intermittent renewable production as conversion to propane, you already won!
- londons_explore 3y agoAt a current density of 395mA/cm² @0.8V, these already won on the power density and scalability front. 500 stacked 0.5mm layers of this would make 400 volts for an ev battery or stationary AC generator. It would have a power density of 6.3 kilowatts per litre, far exceeding both lithium batteries and gas turbines.
- fodkodrasz 3y agoDid they? Are they capable to be scaled to 100 MW scales with MTBF of years already?
- 3y ago
- flakinur 3y agoDoing 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.
- scarytom 3y agoBurning the propane takes you back to CO2, which you then turn back into propane again and repeat? If your napkin maths is correct, and the process is net energy positive, doesn't this violate the principle of conservation of energy? It must take at least as much energy to turn carbon dioxide into propane as you generate when you burn that propane to generate carbon dioxide.
- sveme 3y agoIsn't the input electrical energy and the output of burning the propane heat? If you convert the heat back to electrical energy, you get much less than you input into the reaction.
- 8fingerlouie 3y ago> If your napkin maths is correct, and the process is net energy positive, doesn't this violate the principle of conservation of energy? In theory, yes, but you need to take into account all the energy that goes into the process, which includes the catalyst, and also the actual capture of the CO2. The way i read it, this is "just" a way of turning already captured CO2 into fuel again in an efficient way. Still, it does seem a little bit too good that you can obtain 3 kWh of energy by spending 1.6 kWh, but i guess time will tell.
- goodcanadian 3y ago
- war-is-peace 3y agoC3H8 + 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)
- nine_k 3y agoBut this is perfect. A complete reversion of the reaction, without any additional interesting inputs or intermediate stages. You can imagine a closed-cycle, isolated "battety" that discharges into sparkling water, and charges back into fuel and oxygen. This is exactly the miracle solution that can turn CO₂ back into fuel, which can be burned again in existing ICEs and gas turbines, then turned into fuel again, powered by solar electricity. Collecting and concentrating the CO₂ is going to be a task in itself, but things like power plants or steelmaking furnaces offer high-concentration, pre-heated CO₂.
- war-is-peace 3y agothat would be cool, but wouldn't something simpler like electrolysis of water into hydrogen/oxygen work much better? I haven't the effort to do the math, but it would require less steps, less complexity, and less cutting edge catalysts with unknown lifetimes
- nine_k 3y agoNo. It's hugely inefficient, so it requires more solar power. Hydrogen is hard to store and use; unlike propane, it penetrates through plastics and even metals. Hydrogen is a good rocket fuel if you need top performance and cost is no object. Propane is very convenient, and can be reused across the existing LNG infrastructure.
- mtrimpe 3y agoHydrogen is very difficult to use as a direct fuel source. This recent video gives a good overview of all the challenges a hydrogen engine has to overcome: https://youtu.be/DGL5g91KwLA https://youtu.be/DGL5g91KwLA
- UberFly 3y agoToo early. I'm still healing from the super-conductor that wasn't.
- b112 3y agoOr, the superconductor that is in US or maybe Chinese government labs.
- atoav 3y agoPk-99? All the scientists that know about material science were sceptical. The material isn't that hard to make, the actual testing is the hard part. But of course maybe there is a secret superconductor somewhere in some lab. Maybe there is also a invisble teapot circling the moon. We will never know.
- hoseja 3y agoWhat form of CO2 does this work with? I suspect highly concentrated, not the minuscule amounts in ambient air.
- bertil 3y agoThere’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?
- avar 3y ago"Must" is debatable, but I've got a propane patio heater of a fairly common model here (NL) that tops out at 13000 watts. If it were electric it would require a 13k/220 = 60 amp connection, triple the domestic wiring standard here.
- bertil 3y agoYou’d need a lot less power if you use infrared lights… Still: better grid connection or home batteries are much less complicated to install than a whole new CO2 conversion set-up, plus we are going to need those if people are going to drive electric cars. The cost (energy or money) of capturing CO2 in the atmosphere into concentrate for that catalytic process.
- mschuster91 3y agoYou have a lot of industrial processes that produce highly concentrated CO2 - for example, cement production which is responsible for about 8% of worldwide CO2 emissions.
- bertil 3y agoI’m not convinced that the overall cycle is sustainable: cement >> concentrated CO2 >> electrolysis >> propane >> burn into the atmosphere still leaves that 8% of CO2 in the air.
- ivan_gammel 3y ago
- mdoliwa 3y agoStupid 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?
- sigio 3y agoBurning the propane will release the same amount of Co2 again... So I doubt it will change much
- hnhg 3y agoOnly if more fuel is created than is used, which would seem to be a waste of energy. On the whole, it should be a balanced loop and should net off.
- yetihehe 3y agoTheoretically it would be possible, but we would just release some carbon from other sources, there's a lot of it in various rocks if fossil fuels somehow expired (we still have a lot of those).
- 01100011 3y ago- CO2 isn't the only greenhouse gas. - This process produces hydrocarbon fuel. It will be burned and the carbon will return to the atmosphere. I suppose propane could become a chemical feedstock. Then the carbon could theoretically be tied up for a while.
- malfist 3y agoEven if it winds up back in the atmosphere, it's displaced an equivalent amount of new CO2 going into the atmosphere. Pulling enough CO2 to make a kilogram of propane and then burning that kilogram of propane for electricity is still better than burning a kilogram of freshly fracked propane. One offsets consumption. One just adds consumption.
- bluGill 3y agoOnly if your source of electric doesn't add CO2. If you burn coal to make propane you are worse off CO2 wise than using regular propane. We have a lot of wind and solar, but most places they are still a minor part of the electric mix (if this applies to you, it wouldn't be hard to get a lot more wind/solar in your grid).
- shmde 3y agoProbably the best time to be a propane and propane accesories salesperson.
- dghughes 3y agoIt'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.
- bluGill 3y agoPropane will turn to liquid before it reaches 200psi at normal temperatures. The exact pressure depends on temperature. This is basic chemistry, though probably a part you forgot about as it is simple and doesn't come up much '
- dghughes 3y agoFrom what I could find at 1 atmosphere propane is liquid but it has to be -42C. At 21C propane has to be at 850kPa (123 psi) to liquefy it.
- Derbasti 3y agoSo, 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?
- rocqua 3y agoIt's easy to capture at places that produce lots of CO2. Say fossil fuel electricity plants, and apparently also the production of Cement. Long term, these sources will hopefully dissapear. But short term, concentrated sources of CO2 are sadly still quite abundant. It would be cool if, long term, the CO2 released by burning this in home furnaces for heating can mostly be re-captured.
- modo_mario 3y ago>It's easy to capture at places that produce lots of CO2. Not easy enough apparently, the US gov started subsidizing/taxcutting this because there was demand for CO2 in enhanced oil recovery but the price was too high.
- XorNot 3y agoThis doesn't work. You need energy to convert CO2 back into propane. The CO2 is coming from fossil fuels, which you're still ultimately going to burn again to get energy back...putting the CO2 back into the atmosphere. Only now you've thrown away some of the energy in losses doing the CO2 to propane conversion. This would lower the efficiency of a fossil fuel powerplant, and this increase the CO2 emitted overall.
- Tade0 3y agoThe 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.
- Const-me 3y agoI 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.
- biomcgary 3y agoIf it is possible, this would make off-grid living nearly trivial (from my perspective in the US Southwest). Solar panels to generate electricity, this system to create propane or electricity, and a large off-the shelf propane tank for cloudy days (or weeks!).
- civilitty 3y ago> and a large off-the shelf propane tank for cloudy days (or weeks!) Months. I have a residential sized propane tank for gas and backup power that only gets refilled once a year at most. Worst case scenario I can go off grid for two to three months in the summer on a generator (tested frequently) and this is a pretty standard size for exurban houses in California.
- meragrin_ 3y ago> I have a residential sized propane tank for gas Could you elaborate on that? I imagine most people do not have any concept of that. Are you talking basketball, person, tiny car, SUV, or something else in terms of size? I'm imagining something between tiny car and SUV.
- compumike 3y agohttps://www.amerigas.com/about-propane/propane-tank-sizes https://www.amerigas.com/about-propane/propane-tank-sizes I've most commonly seen the 120 gallon size at homes that use it for a water heater.
- api 3y agoPropane 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.
- ccorcos 3y agoFYI, there’s a startup doing CO2 → Methane conversion called Terraform Industries. https://terraformindustries.com/ https://terraformindustries.com/ I asked the cofounder of his thoughts here: https://twitter.com/ccorcos/status/1694021803654693342 https://twitter.com/ccorcos/status/1694021803654693342
- molszanski 3y agoWe can add another company in the sector to the bunch: https://www.prometheusfuels.com/news/dude-wheres-my-fuel https://www.prometheusfuels.com/news/dude-wheres-my-fuel I am curious how do they compare
- j-a-a-p 3y agoIt 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.
- bluGill 3y agoFor most home applications all your need is to replace the jets in the appliance - $.25 in parts. Stoves and dryers commonly come with both sets, and I've seen furnaces that can be converted. I've never seen a water heater than can be converted, though it is in theory possible. The hard part is an entire neighborhood must be converted at once. You have all summer to convert the furnace, but things used all summer like stoves, or water heaters have to be done for the entire neighborhood in one day. This means a lot of logistics to get the right parts and labor in place to do the work. Though if people are willing to accept propane takes outside their house you can delay a bit, but it needs to be done before everyone needs heat.
- rini17 3y agoYou forgot heat pumps, that is what will be everyone switching to. It's more efficient to burn propane centrally in a power plant and use the electrical grid to power heat pumps than distribution/burning of propane locally.
- bluGill 3y agoWhile heat pumps are a great idea, where I live they don't work on the coldest days so you need some other backup. Burning propane on those cold days is more efficient than a central power plant.
- tastyfreeze 3y agoOfftopic... 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.