[HN Gopher] Electrolyzer efficiently converts CO2 into renewable...
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       Electrolyzer efficiently converts CO2 into renewable propane fuel
        
       Author : conse_lad
       Score  : 301 points
       Date   : 2023-08-22 04:34 UTC (18 hours ago)
        
 (HTM) web link (scienceswitch.com)
 (TXT) w3m dump (scienceswitch.com)
        
       | ccorcos wrote:
       | 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
        
         | molszanski wrote:
         | We can add another company in the sector to the bunch:
         | 
         | https://www.prometheusfuels.com/news/dude-wheres-my-fuel
         | 
         | I am curious how do they compare
        
       | flakinur wrote:
       | 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=1000x1000/44.01[?]22726moles.
       | 
       | Total moles of electrons= 24/8x22726[?]68178moles.
       | 
       | Total charge=68178x96485[?]6.58x10^9C.
       | 
       | E=QxV=6.58x10^9x0.8[?]5.27x10^9J.
       | 
       | E_actual=5.27x10^9/0.91[?]5.79x10^9J.
       | 
       | E_actual=5.79x10^9/3.6x10^6[?]1608kWh.
       | 
       | ----------------------------------
       | 
       | Moles of propane= 3/8x22726[?]8522moles.
       | 
       | Mass of propane=8522x44.1[?]375,670g[?]376kg.
       | 
       | Total energy content=376x50.35[?]18,932MJ.
       | 
       | Usable energy= 10,791/3.6[?]2,997kWh.
        
         | rocqua wrote:
         | According to this article: https://www.rechargenews.com/energy-
         | transition/the-amount-of...
         | 
         | The cost of carbon capture straight from the air is about 10GJ
         | per Tonne (they quote 8.8 and 14 from competing sources). Which
         | is about 2800 kWh That would put a serious damper on the
         | efficiency, but might make it viable even when 'easy' sources
         | of CO2 (like the exhaust of fossil power plants) are no longer
         | available.
        
         | rmu09 wrote:
         | Please don't refer to power as energy or use units of power
         | when you really mean energy, it is bad enough when this happens
         | in more traditional media.
        
         | scarytom wrote:
         | Burning 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 wrote:
           | Isn'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 wrote:
           | > 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.
        
             | sveme wrote:
             | Heat pumps can create 3 - 5kWh of heat from 1kWh of
             | electrical energy.
        
               | 8fingerlouie wrote:
               | Heat pumps do not create heat, they simply move heat from
               | one place to another, which is an entirely different
               | beast.
               | 
               | Using a traditional resistive heater, you're roughly
               | creating 1 kWh of heat by spending 1 kWh of electricity
               | (there is some loss), but with a heat pump you're moving
               | heat, which is also why heat pumps become much less
               | efficient the colder the temperature as there is less
               | heat to move, and many residential heat pumps include a
               | regular resistive heating element as a backup.
               | 
               | There's a great explanatory video on how heat pumps work
               | here : https://www.youtube.com/watch?v=7J52mDjZzto&pp=ygU
               | gdGVjaG5vb...
        
               | sveme wrote:
               | Good point, thanks for the correction.
        
               | RetroTechie wrote:
               | Correction: heat pumps _pump_ heat from 1 place to
               | another. As in: place where it gets pumped out of, gets
               | colder.
               | 
               | Fundamentally different process from exothermal chemical
               | reaction, or electric heating using resistive wire.
        
             | goodcanadian wrote:
             | This is just an educated guess, but . . .
             | 
             | Burning propane produces CO2 AND water. I think the missing
             | bit is the energy required to split the water into hydrogen
             | and oxygen before the hydrogen is used as an input to
             | produce the propane.
        
         | rocqua wrote:
         | That is when using propane for electricity.
         | 
         | I think there is a lot more value in burning propane for
         | heating houses. Especially in places (like Europe where I live)
         | that are already build to use gas for heating.
         | 
         | Especially if you consider the massive gas-storage facilities
         | that are common here. We have 12 billion cubic meters of gas-
         | storage here in the Netherlands, on a yearly consumption of 40
         | billion. That means we could use 'green propane' to load-shift
         | about 30% of our heating from winter to summer. That would be
         | amazing.
        
           | j-a-a-p wrote:
           | And if you sneeze at propane it becomes liquid (-42C). Not
           | sure how natural gas is stored though.
           | 
           | Heating use is indeed very obvious, and so is transportation
           | use. Many countries have an elaborate distribution network
           | for LPG and fitting a car to run on LPG is also very easy.
           | 
           | BTW, hot air balloons also run on propane.
        
             | papercrane wrote:
             | > Not sure how natural gas is stored though.
             | 
             | Mostly stored underground, but it's also shipped and stored
             | in a liquefied state at -162C. Propane is one of the
             | components of natural gas, so I would think any facility
             | that is able to store natural gas should be able to store
             | propane easily.
        
         | amluto wrote:
         | My napkin says you have 8C on the left and 9C on the right, so
         | your stoichiometry is off. I haven't tried to check any of the
         | rest.
         | 
         | I'm guessing the major error is that the -0.8V is "versus
         | reversible hydrogen electrode ", so it's a half-reaction and
         | you need to fill in the correct other half reaction, and there
         | is probably H2 involved. Then you would dig out some free
         | energy values to see how efficient it is.
         | 
         | (I only read the abstract.)
        
           | flakinur wrote:
           | Thx for the catch!
           | 
           | Fixed the math using chat gpt :P.
           | 
           | Reaction: 3CO2 + 12H2 -> C3H8 + 6O2
           | 
           | Number of moles of electrons (n): n = 3 * 4 = 12
           | 
           | Total charge (Q) in Coulombs: Q = (-395 * 1 * 100 * 3600 *
           | 0.91 / 1000) * 12 * 96485
           | 
           | Voltage (V): V = -0.8
           | 
           | Total energy for given current density: E = Q * V
           | 
           | Moles of CO2 in 1 ton: n_CO2 = (1000 * 1000) / 44.01
           | 
           | Total charge for 1 ton of CO2: Q_total = (12 / 3) * n_CO2 *
           | 96485
           | 
           | Adjusted charge considering Faradaic efficiency: Q_adjusted =
           | Q_total * 0.91
           | 
           | Total energy for 1 ton of CO2: E_total = Q_adjusted * V
           | 
           | Convert to kWh: E_kWh = E_total * 2.778e-7 E_kWh [?] 17707.4
           | kWh
        
             | jwilk wrote:
             | > 3CO2 + 12H2 -> C3H8 + 6O2
             | 
             | 6 O on the left, 12 on the right.
             | 
             | 24 H on the left, 8 on the right.
        
             | amluto wrote:
             | https://www.engineeringtoolbox.com/co2-emission-fuels-
             | d_1085...
             | 
             | Gives a specific CO2 emission for propane of 13.8 kg carbon
             | / kWh fuel, so your numbers are at least vaguely credible.
             | But your reaction is devoid of CO2, so talking about tons
             | of CO2 is still odd.
        
       | shmde wrote:
       | Probably the best time to be a propane and propane accesories
       | salesperson.
        
         | westmeal wrote:
         | I tell ya hwuhat that right there is a CLEAN BURN.
        
         | codeulike wrote:
         | Good for Strickland Propane for sure
        
       | j-a-a-p wrote:
       | 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.
        
         | bluGill wrote:
         | For 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 wrote:
           | You 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.
        
       | war-is-peace wrote:
       | 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)
        
         | nine_k wrote:
         | But 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 wrote:
           | that 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 wrote:
             | No.
             | 
             | 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 wrote:
             | Hydrogen 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
        
               | war-is-peace wrote:
               | thanks
        
         | [deleted]
        
         | rocqua wrote:
         | The value lies in the fact that we already have a lot of
         | infrastructure (including storage) that uses propane.
         | 
         | By switching from fossil propane to this green propane we can
         | indirectly 'electrify' entire swaths of energy consumption.
         | 
         | It's scary to me how good this is. Because if it works, we can
         | effectively continue as normal. Which is not to be expected,
         | and might cause us to slack off since the pressure is gone.
        
         | lost_tourist wrote:
         | It would work well with wind and solar as energy storage, or
         | even tidal or geothermal. Making it great for storing power
         | from variable power systems. Propane is extremely easy to
         | distribute.
        
       | tastyfreeze wrote:
       | 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.
        
       | berbec wrote:
       | actual paper: https://www.nature.com/articles/s41560-023-01314-8
        
       | dghughes wrote:
       | 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.
        
         | bluGill wrote:
         | Propane 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 wrote:
           | From 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.
        
       | londons_explore wrote:
       | 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.
        
         | Slava_Propanei wrote:
         | Or in less than 20 years when the patent is licensed. No point
         | in sitting in it for 20 years.
        
         | walnutclosefarm wrote:
         | Recovered CO2 if it's recovered from the atmosphere.
         | Essentially all concentrated CO2 today is recovered from fossil
         | fuel consumption, and while turning that into propane and then
         | burning the propane (in a ship or home furnace, e.g.) would get
         | double duty out of the carbon, it would still release it into
         | the atmosphere. So, the real question is the combined
         | efficiency of carbon capture from the atmosphere + catalytics
         | propane production followed by propane combustion. It may
         | pencil out for processes that require combustion heat, or where
         | the portability of propane vs electricity are a huge win. Maybe
         | as a storage medium for electricity production between
         | renewables. All depends on numbers.
        
           | danmaz74 wrote:
           | If you capture the CO2 produced when burning the propane, you
           | can get more than double duty. If you used this process to
           | store energy into propane when electricity is cheap, and then
           | produce electricity by burning propane when electricity is
           | expensive, you could potentially have a system with close to
           | 0 CO2 emission. Compared to batteries, storing propane and
           | CO2 even for months looks very cheap.
        
             | gus_massa wrote:
             | Organic reactions have a very low efficiency. Most of them
             | only less than a 50%. Batteries have a better efficiency in
             | the conversion.
        
               | ajuc wrote:
               | Humanity uses around 25 000 TWh of electric energy
               | yearly.
               | 
               | With batteries storing that is technically possible but
               | it would take the whole world decades to build the
               | required infrastructure.
               | 
               | With propane or other similar hydrocarbons it's around 2
               | million tonnes. 4 million if you account for 50%
               | efficiency of turbines (we have better ones BTW).
               | 
               | 4 million tonnes of gas seems like a lot, but currently
               | USA has about 5850 bcf (1.6*10^14 liters) of underground
               | gas storage ready, at 1.8 kg per m3 you could store about
               | 300 million tonnes of propane. Enough to power the
               | electricity grid of the whole world for 75 years.
               | 
               | So it's a choice between spending billions and turning
               | our whole industrial output to it for years - or just
               | using a fraction of what's already there in a slightly
               | different way :)
               | 
               | Another point is - once you have one kind of hydrocarbons
               | - you can burn them in adapted ICEs or transform into
               | other hydrocarbons to be able to use existing cars.
               | Suddenly you can continue to use the whole infrastructure
               | we built in the last 100 years as if nothing happened
               | with net 0 carbon footprint.
               | 
               | It's the only thing that makes sense, really.
        
               | philipkglass wrote:
               | I think that you slipped some decimal places.
               | 
               | Propane has a thermal energy content of 13778 watt-hours
               | per kilogram [1]. That's (25000 * 10^12) / 13778 =
               | 1,814,486,863,115 kilograms, or 1.8 billion tons. 3.6
               | billion tons of propane if you recover electricity at 50%
               | efficiency. That would make the 300 million ton
               | underground storage equivalent to one month of global
               | electricity demand. That's still a lot of storage, of
               | course.
               | 
               | [1] https://en.wikipedia.org/wiki/Energy_density#In_chemi
               | cal_rea...
        
               | ajuc wrote:
               | Thanks, should have double checked. I always mess up long
               | and short scale when combining from different sources.
        
               | SoftTalker wrote:
               | At some point, cheap trumps efficient.
               | 
               | Propane is easy to store, easy to transport, propane
               | storage tanks are cheaper than batteries, require no
               | high-tech manufacturing or rare earth elements, and I'd
               | guess the energy storage density is higher.
               | 
               | Many (most) existing cars could be converted to run on
               | propane and the engines will last longer and emissions
               | will be lower as it's a cleaner-burning fuel.
        
               | 93po wrote:
               | Some newer battery cell chemistries are using very very
               | little rare earth elements
        
               | pengaru wrote:
               | A propane tank is basically just the hollow shell of a
               | battery, made of even cheaper mild steel since weight is
               | far less of a concern. There's no contest in this
               | department.
               | 
               | Not that I'm in favor of combustion engines persisting.
        
               | 93po wrote:
               | I'm not saying your arguments don't hold. Just that the
               | calculations may be closer than stated
        
             | DistractionRect wrote:
             | Ah, a perpetual motion machine.
             | 
             | This assumes that co2 recapture and propane synthesis
             | require less energy than is produced by burning propane.
             | 
             | This is maybe a workload for excess solar, making renewable
             | propane with electric that would otherwise be wasted
        
               | gregable wrote:
               | I think the suggestion is that it's a battery with low
               | long term storage costs, not that it's 100% efficient
               | round trip.
        
             | walnutclosefarm wrote:
             | Sure, and that is an option if you're using propane as
             | storage for renewable electricity, or for large scale
             | industrial uses like cement production. You won't get to
             | full recycle, but you can get close. It's not an option for
             | propane as transportation or heating fuel, however.
        
           | Robotbeat wrote:
           | It's kind of annoying that this is always brought up as a
           | gotcha. Direct air CO2 capture is not a massive contributor
           | to the total energy usage. It's still dominated by
           | electrolysis itself. The numbers aren't that hard to find,
           | either. A kilogram of propane has a specific energy of 50MJ
           | and emits 3kg of CO2. Assuming this electrolysis is 50%
           | efficient, that requires 100MJ to make. CO2 direct air
           | capture is about 4.3MJ/kgCO2, or about 13MJ/kgPropane
           | compared to the 100MJ/kgpropane of electrolysis. So it's
           | still a pretty small fraction of the total energy costs.
           | 
           | EDIT: note that burning that propane in a cheap generator is
           | only gonna net you 10MJ/kg of electricity, maybe 17MJ/kg in a
           | large expensive generator. So the roundtrip efficiency is
           | just 9-15% efficient. But it potentially saves you a LOT in
           | storage costs if you're only cycling this storage once or
           | twice a year.
           | 
           | (Note that propane is a great way to store hydrocarbons as
           | the pressure is low but it's self pressurizing and thus it
           | doesn't get water ingress or have any of the storage
           | difficulties of gasoline and diesel, which last only 3-6
           | months or 6-12 months respectively. It's also very clean
           | burning compared to those two.)
        
             | walnutclosefarm wrote:
             | I wasn't looking for a "gotcha." Just saying that you need
             | to consider all the input costs to know how this pencils
             | out.
             | 
             | 50% is almost exactly the paper's claimed efficiency for
             | the lab cell, so it's a reasonable number.
             | 
             | Overall, I'm very enthusiastic electrocatalytic methods for
             | producing hydrocarbons as a combustion fuel source for
             | applications where direct electric technologies are not
             | feasible. I'd much rather seen money and energy going into
             | making something like this work, than all the effort on
             | hydrogen. Propane, or any hydrocarbon in the 3C-8C range,
             | is a way better fuel for any fossil fuel replacement energy
             | system than hydrogen.
        
         | harvie wrote:
         | Can you please explain these numbers of layman terms?
         | 
         | Let's say my car burns equivalent of 100kWh worth of LPG, how
         | many kWh of propane i can recover from the exhaust gas and how
         | many kWh of electricity i need to provide for that?
        
           | spatular wrote:
           | You'd need to spend at least 110kWh to convert CO2 back to
           | propane, maybe much more. No matter what you do, LPG -> CO2
           | -> LPG cycle has to be energy-negative.
        
           | LeifCarrotson wrote:
           | You wouldn't recover the propane at the exhaust of the car.
           | Instead, you'd have a fixed hydro/solar/wind renewable energy
           | installation, spending ~25 kWh on an atmospheric capture
           | program, or less if you can get it from more concentrated
           | flue gasses coming off an industrial furnace/ammonia
           | plant/cement plant, and then ~200 kWh to convert that CO2 by
           | this process into 100 kWh worth of LPG.
           | 
           | It's not viable (in terms of energy availability, packaging,
           | or economies of scale) to run that sort of cryogenic high-
           | pressure CO2 purification and storage system on the exhaust
           | pipe of a vehicle. I could _maybe_ imagine a solar
           | installation with this attached being viable at, say, a
           | remote farm with LPG-powered agricultural vehicles, or if I
           | stretch my imagination to scifi timescales (and think about
           | the number of remarkable compressors installed at scale in
           | HVAC systems) to suburban homes with rooftop solar.
        
         | eesmith wrote:
         | > They have presumably applied for a patent for it
         | 
         | They have one in this space: "Methods and devices using tri-
         | transition metal phosphides for efficient electrocatalytic
         | reactions" at
         | https://patents.google.com/patent/US20220154354A1/en with
         | abstract:
         | 
         | ] Methods and devices for generating hydrogen gas with an
         | electrocatalytic energy conversion cell by introducing a tri-
         | transition metal phosphide catalyst at or on an electrode of
         | the electrocatalytic energy conversion cell. The
         | electrocatalytic energy conversion cell includes a first
         | electrode including a tri-transition metal phosphide catalyst,
         | such as MO3P, a second electrode of an anodic material, an
         | electrolyte disposed between the first electrode and the second
         | electrode, and an electric potential source connected to both
         | electrodes. Oxidation and reduction reactions, such as hydrogen
         | evolution reactions, occur at the first electrode.
         | 
         | (Google Patents says "M03P", the PDF says "MO3P" in the
         | abstract, but the text clearly has "Mo3P".)
         | 
         | Even if this isn't exactly the technology discussed -
         | Supplementary Figure 20 shows how ImF-Mo3P catalyst improves on
         | "pristine Mo3P nanoparticles" - the authors have several other
         | related patents, so I have no doubt a patent was filed for this
         | technology as well.
        
         | colechristensen wrote:
         | The remaining issue is the durability of the catalyst.
        
           | londons_explore wrote:
           | They 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 wrote:
             | Especially if it can be regenerated, then it's really a
             | non-issue.
        
           | ur-whale wrote:
           | >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...)
        
             | sschueller wrote:
             | How much CO2 is generated to make one is the other
             | question.
        
             | londons_explore wrote:
             | 1-ethyl-3-methylimidazolium-functionalized Mo3P
             | nanoparticles don't sound very off-the-shelf...
        
               | bluGill wrote:
               | The question is can we make it cheaply enough at the
               | required scale. Lots of things area off the shelf today
               | that were not in the past. Other things used to be common
               | and are not made anymore.
        
               | biomcgary wrote:
               | Chemistry can sound complex, but the compound mentioned
               | is relatively simple for an organic chemist. Metal
               | nanoparticles are fairly routine. Since this is a
               | catalyst, not that much would be needed (relative to the
               | likely difficulty of making it). Probably a rounding
               | error in terms of the expense of the entire system.
        
         | varispeed wrote:
         | Hopefully any patent will not be granted. That's not how you
         | make progress. Understandable that competition would have a
         | head start without incurring the substantial R&D costs, but we
         | should rather strive to make R&D tax deductible, rather than
         | maintaining harmful patent system. This way business that
         | incurred substantial R&D expenditure could claw it back from
         | the sold product. This also incentivises businesses actually
         | using their R&D rather than shelving a patent and then going on
         | fishing expeditions to see if someone come up with the idea
         | independently and executed it only to slap them with a lawsuit.
         | 
         | Patents? Nope.
        
         | pdabbadabba wrote:
         | > in 20 years when the patent expires...
         | 
         | Well, only if the patent-holder makes no effort to maximize the
         | return on its investment in those 20 years. But if the
         | technology is really that effective and the patent-holder is
         | even a little bit economically rational, then presumably the
         | patent holder will be the one pushing hardest to _make_ this
         | the standard thing to do with recovered CO2 well before the
         | patent expires.
         | 
         | Not that patents are all roses and puppy dogs. But this is too
         | big a part of the picture to just ignore.
        
           | retrocryptid wrote:
           | The patent-holder has licensed the technology to company with
           | a large sunk cost in handling petroleum from the ground. I
           | suppose SHV Energy _could_ decide to put up a solar farm
           | driving CO2 - > C3H8 catalysis, but where's the money in it
           | for them? I would like to be happily surprised, but my guess
           | is it's some form of green-washing.
        
             | r00fus wrote:
             | Carbon credits. Tesla was only viable in the early years
             | all due to carbon credit purchases.
        
             | jncfhnb wrote:
             | That's backwards is it not?
             | 
             | A fossil fuels company has deep incentive to minimize the
             | harm of fossil fuels. A solar company has incentives to
             | make fossil fuels as bad as they can.
             | 
             | Even if you generally perceive fossil fuels guys as bad
             | guys.
             | 
             | Regardless. Any company has incentives to do this if
             | someone (government) will pay for it. It doesn't really
             | harm any profits.
        
               | Werewolf255 wrote:
               | Right, and the ones who are best able to figure out
               | regulations are, of course, the businesses themselves!!
               | 
               | Look how well that's worked out for the financial sector.
               | Nothing but good faith actors there. Immaculate.
        
               | tourgen wrote:
               | [dead]
        
               | jncfhnb wrote:
               | I'm not saying fossil fuels companies should be in charge
               | of regulating fossil fuels companies.
               | 
               | I'm saying that fossil fuels companies are incentivized
               | to sell useful co2 converters because this enables them
               | to sell more fossil fuels.
        
               | deciplex wrote:
               | > A fossil fuels company has deep incentive to minimize
               | the harm of fossil fuels.
               | 
               | They have a deep incentive to capture the regulatory
               | framework that might hold them accountable for that harm,
               | which they have accomplished.
        
               | SiempreViernes wrote:
               | Yes, the sentiment is so completely ignorant of what they
               | have actually done during the last four decades that I'm
               | now on like the third or fourth take...
        
               | hinkley wrote:
               | <hysterical laughter>
               | 
               | No they've decided to go the route of tobacco companies,
               | deny everything and party while the sun is shining. By
               | the time the lawyers show up they're counting on being
               | dead or too old to stand trial.
        
               | SiempreViernes wrote:
               | > A fossil fuels company has deep incentive to minimize
               | the harm of fossil fuels
               | 
               | You... you're aware that the _actual_ , historically
               | realized, attitude of fossil fuel companies has been to
               | _deny any harm exists_ , right? Deny it to the tune of
               | 200 million dollars as recently of 2019, and for good
               | reason! That spending bought them lots of political
               | inaction since the science was settled in like 1990, you
               | know: the days where keeping staying below 1.0 degrees
               | warming was a realistic goal.
        
               | deciplex wrote:
               | what is historical fact compared to what my imagination
               | tells me should have happened?
        
               | jncfhnb wrote:
               | I am aware of that, yes. This doesn't change the calculus
               | of today.
               | 
               | CO2 conversion tech is a path to selling more fossil
               | fuels.
        
               | deciplex wrote:
               | Why spend on tech that might not be a sure thing when
               | bribery has been working for decades?
        
               | jncfhnb wrote:
               | Because that's a gross oversimplification of things that
               | sounds punchy but isn't particularly realistic.
        
         | mhb wrote:
         | > 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.
         | 
         | And how many years would it have taken if a patent wasn't an
         | incentive?
        
           | hedora wrote:
           | It's a public university, and government funded research. so
           | fewer?
        
             | rayiner wrote:
             | The history of everything from MIPS to BBN shows that a
             | major piece of the puzzle is creating incentives for high
             | caliber people to go into public university research, and
             | then invest in commercializing the resulting technology.
             | The government funding only provides the kickstart.
        
       | Const-me wrote:
       | 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.
        
         | sbierwagen wrote:
         | Propane fuel cells have been around for a while:
         | https://www.wattfuelcell.com/portable-power/watt-imperium/
        
           | Const-me wrote:
           | Do you know how much WATT Imperium costs? No information on
           | their web site.
           | 
           | AFAIK both fuel cells like that, and the inverse carbon
           | capture machines, are technically possible for decades now.
           | The issue is high cost due to precious metals in the
           | catalyst.
           | 
           | Apparently, these guys have solved the issue with much
           | cheaper stuff for the catalyst, molybdenum phosphide.
        
         | biomcgary wrote:
         | If 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 wrote:
           | _> 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_ wrote:
             | > 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 wrote:
               | 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.
        
       | UberFly wrote:
       | Too early. I'm still healing from the super-conductor that
       | wasn't.
        
         | bbarnett wrote:
         | Or, the superconductor that is in US or maybe Chinese
         | government labs.
        
           | atoav wrote:
           | Pk-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 wrote:
       | What form of CO2 does this work with? I suspect highly
       | concentrated, not the minuscule amounts in ambient air.
        
       | mdoliwa wrote:
       | 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?
        
         | dist-epoch wrote:
         | That would be an easy problem to solve. We are very good at
         | heating up the atmosphere.
         | 
         | More CO2 should also stimulate plant growth, CO2 is a bit of a
         | limiting factor there.
        
         | bluGill wrote:
         | Yes, and before humans the earth was on a cooling trend, though
         | only measurable on a geological time scale (millions of years).
         | A little plant matter gets converted to charcoal and then coal
         | every years. Though biology mostly trys to get at that carbon
         | first.
        
         | hnhg wrote:
         | Only 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.
        
         | sigio wrote:
         | Burning the propane will release the same amount of Co2
         | again... So I doubt it will change much
        
         | yetihehe wrote:
         | Theoretically 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 wrote:
         | - 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 wrote:
           | Even 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 wrote:
             | Only 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).
        
         | Udo wrote:
         | The application of this is not in energy production or -
         | realistically - CO2 capture on a global scale. This takes huge
         | amounts of energy to do and requires a sophisticated chemical
         | synthesis in the background in order to replenish the catalyst.
         | 
         | Pretty much the only reason to do this would be because you're
         | specifically interested in generating propane. For example, it
         | could be very useful for ISRU on other planets, or to generate
         | propane "for free" from a solar setup.
         | 
         | If your goal is energy production, you'd just use the output of
         | solar panels directly without this costly step in the middle.
         | If you want to store energy locally, electrolyzing water into H
         | and O would be hugely more cost effective. But _propane_ is a
         | more dense fuel that would be useful for mobile applications
         | such as ships and cars, and can also be used as a raw material
         | in chemical synthesis.
        
         | marcosdumay wrote:
         | Taking the carbon from the atmosphere will always be more
         | expensive than from some carbon-rich rocks that form a huge
         | fraction of the Earth's crust.
         | 
         | In fact, our most effective ways to take carbon out of the
         | atmosphere today all involve a step of letting some mineral
         | turn into one of this carbon-rich ones, and extracting it from
         | there.
        
           | idiotsecant wrote:
           | It'll always be more expensive to extract carbon from the
           | atmosphere, but if it produces a valuable byproduct and the
           | power to run the process is very cheap (excess solar) it
           | might still pencil out.
        
             | marcosdumay wrote:
             | I fail to see anything that doesn't apply equally to the
             | rocks.
        
               | neolefty wrote:
               | When you have surplus photovoltaic capacity -- an
               | increasingly common situation -- you could turn it to
               | electrolysis. You still have to pay for the equipment,
               | but it sounds like it could be pretty cheap.
               | 
               | It would cut out the cost of mining, and possibly a lot
               | of transportation costs, if you can use the products
               | nearby.
        
         | pjc50 wrote:
         | No: the atmospheric CO2 is at the bottom of the energy hill. In
         | order to turn it in to fuel you need to pump in all the energy
         | originally extracted from the fuel, then some more.
         | 
         |  _After_ you 've re-expended the entire 20th century's worth of
         | fossil fuels energy equivalent in sucking CO2 out of the
         | atmosphere, not burned it, and stored it in a country-sized
         | propane tank, then maybe we're back to 19th-century
         | temperatures.
        
           | bluGill wrote:
           | The earth is not a zero sum game, we get energy from the sun.
           | Photosynthesis reverses the process turning co2 into sugar
           | and o2.
        
             | pjc50 wrote:
             | And? So?
        
               | bluGill wrote:
               | That means co2 is not the bottom of the energy hill.
        
               | api wrote:
               | In the photosynthesis case the bottom of the energy hill
               | is helium in the sun's core.
        
               | XorNot wrote:
               | Well and also the CO2 isn't acting as a fuel, it acts as
               | a battery or resource.
               | 
               | Plants make sugar from CO2, and also burn that sugar back
               | to CO2 (plants respire overnight - they're not pure CO2
               | consumption machines).
        
               | Udo wrote:
               | "Bottom of the energy hill" is a chemist's short hand way
               | of saying that we can't practically extract energy from
               | CO2 reacting with anything useful, meaning chemically
               | this is at the bottom end of reactions that happen
               | without energy input. To convert it into something
               | reactive, you need to invest energy to split it up again
               | into its constituent parts, which is what happens during
               | photosynthesis.
        
               | bluGill wrote:
               | "Bottom of the energy hill" is a useful term in a lab.
               | However the earth is not a chemistry lab. We cannot
               | ignore photosynthesis outside of a lab as it is a factor
               | that exists.
        
               | Udo wrote:
               | _> We cannot ignore photosynthesis outside of a lab as it
               | is a factor that exists._
               | 
               | I apologize if this wasn't clear. It's an expression
               | about energy potentials, and as such it's _not_ just
               | useful in a lab, it 's an essential piece of information
               | about the substance.
               | 
               | For example in the original context of this comment
               | thread, a person asked whether there was a danger of
               | people exhausting our atmospheric CO2 because they got
               | too greedy with this technology - a question that can in
               | fact not be answered meaningfully without talking about
               | energy deltas. The fact that CO2 cannot be practically
               | processed in a way that releases energy is the _only_
               | pertinent information when talking about this.
        
       | Tade0 wrote:
       | 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.
        
       | bertil wrote:
       | 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?
        
         | _hypx wrote:
         | It's funny to see people suddenly say this is doable, even
         | though many posters in the past have claimed that it is totally
         | impossible.
         | 
         | The problem ultimately is that CO2 capture from the air is
         | another expense that has to be paid, both in terms of cost and
         | energy. Sure, if the entire process becomes so cheap and widely
         | available that this no longer becomes issue, then we can
         | certainly do it. But until then, it is a major stumbling block.
         | 
         | The other problem is that if all you want is something more
         | "practical" than hydrogen, you will stop at methane. Same basic
         | idea as this, but you only need the Sabatier process. And we
         | already have many facilities capable of dealing with methane.
         | So we do not necessarily need to go further. But if you insist
         | on long carbon chains, why stop at C3? Keep going until you
         | reach C8, or even C12-20, at which point you have the
         | equivalent of gasoline or diesel. Basically, get to the point
         | where you have a liquid at room temperature, and it will be
         | even more practical than propane.
        
         | avar wrote:
         | "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 wrote:
           | You'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.
        
             | rocqua wrote:
             | We will need all the electrification we can get for
             | electric cars and heat pumps. offloading some of that to
             | other energy sources, using pre-existing infrastructure,
             | would be amazing!
        
             | mschuster91 wrote:
             | You 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 wrote:
               | I'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 wrote:
               | It replaces equivalent 8% of CO2 from fossil fuels that
               | would be burned otherwise.
        
               | yetihehe wrote:
               | Cement is absorbing some of that CO2 back when it's
               | curing. Some of CO2 is emitted by processing (crushing
               | and heating), that part could be eliminated by renewable
               | fuels, some is inherent in making cement (releasing CO2
               | from limestone) but most of that part is absorbed back
               | during curing. There are also carbon-negative
               | alternatives in works[0]. That propane from cement could
               | be used for synthesis of other materials instead of oil
               | (not used yet because it's not needed only because we
               | have cheaper oil) instead of being burned.
               | 
               | [0] https://www.theguardian.com/environment/2008/dec/31/c
               | ement-c...
        
           | goodpoint wrote:
           | Patio heaters should be illegal.
        
           | pjc50 wrote:
           | Patio heaters: for when the planet isn't warming fast enough
           | and you want to pump heat directly into the atmosphere.
        
             | PaulDavisThe1st wrote:
             | That's good.
             | 
             | But also a bit misleading. Pumping heat into the atmosphere
             | isn't really at the heart of climate change - adding
             | insulation to the atmosphere is. It probably isn't great to
             | pump heat into it either, but the mechanisms for radiative
             | loss of that extra heat are (were) pretty good, and it
             | would take a gigantic amount of heat (more than we've
             | produced by burning fossil fuels) to shift the energy level
             | in the atmosphere by much over longer time frames. However,
             | effectively adding another blanket to the atmosphere is far
             | more impactful. Last credible estimate I saw was the
             | atmosphere now contains about an extra 8 peta-watts
             | compared to pre-industrial times, and almost all of that
             | comes from a reduction in "radiative forcing" (loss of heat
             | to space, essentially) rather than additional heat
             | generation.
        
               | pjc50 wrote:
               | This is true, but it's also explaining a joke. The real
               | point is that patio heaters are necessarily very
               | inefficient because they're operating in an uninsulated
               | space that's open to the elements - almost all the heat
               | will be immediately lost to the atmosphere. Heat lamps
               | are better, but really patio heaters are used by people
               | trying to cosplay an outdoor culture at a latitude or
               | season that doesn't support it, and they should put some
               | warmer clothes on or go inside.
        
               | PaulDavisThe1st wrote:
               | Your final observation _might_ be true of parts of the
               | USA. But go to Berlin in winter, or anywhere in northern
               | Europe really, where  "it's cold" and "being outside" are
               | not considered oppositional. Take a winter walk down a
               | Berlin street with outdoor restaurant seating, and see
               | people sitting under blankets, with warm coats on, and
               | hats ... enjoying dinner ... _and_ patio heaters.
               | 
               | They are not cosplaying at anything. It's just how it is.
        
               | lxgr wrote:
               | Patio heaters (at least the gas-powered kind) are
               | prohibited in most German cities. Berlin has only
               | temporarily allowed during Covid, as far as I know.
               | 
               | > It's just how it is.
               | 
               | It's a fairly new trend, and as mentioned above, one
               | that's probably already over. Germany has had outdoor
               | Christmas markets for much longer than patio heaters have
               | existed.
        
               | PaulDavisThe1st wrote:
               | I lived in Berlin in 2008/2009. They must have been
               | banned since then, because they were very common at that
               | time.
               | 
               | And yes, the christmas market version of being outside is
               | obviously much older, but in my experience (also,
               | Heidelberg in 1986) was less sitting around and more
               | moving around outside (or in heated tents).
        
               | SoftTalker wrote:
               | Yes, the amount of heat added to the atmosphere by human
               | activities is negligible compared to what we receive
               | every day from the sun.
               | 
               | It's the heat that is retained that is the problem.
        
         | rocqua wrote:
         | > Are there use cases where we must burn propane because we
         | can't replace that process with electricity?
         | 
         | I think this might slot in everwhere we currently plan to use
         | hydrogen, with the added benefit of larger storage.
         | 
         | Here in Europe we have massive natural gas storage facilities
         | so we can buy gas during summer to use for heating in winter.
         | We will need something similar but renewable. If we can fill
         | that storage with green propane, that would be amazing. It
         | would mean we can keep our heating infrastructure. And we have
         | an amazing use for the solar over-production in summer.
         | 
         | Honestly tho, this sounds to good to be true.
        
           | konschubert wrote:
           | it's probably still more efficient to burn the gas in power
           | plants and use heat pumps for heating.
           | 
           | Also saves us from maintaining a residential gas network.
        
             | wokkel wrote:
             | Maybe, but if everyone starts using heat pumps we have a
             | problem in getting enough copper in the ground everywhere
             | on time. So even if it's temporary (20 years or so) this is
             | still a great solution.
        
               | teruakohatu wrote:
               | > Maybe, but if everyone starts using heat pumps we have
               | a problem in getting enough copper in the ground
               | everywhere on time.
               | 
               | In New Zealand everyone uses heatpumps and there is no
               | problem with everyone running them. Heatpumps don't use a
               | huge amount of power even on cold days. If the grid can
               | handle everyone cooking dinner at 6pm, it can handle
               | heatpumps running throughout the day keeping the house
               | warm.
               | 
               | Fast electric car charging on the other hand draws a lot
               | of current.
        
               | apexalpha wrote:
               | The copper is mostly already in the ground. At least in
               | the Netherlands it is.
               | 
               | Apparently decades ago some absolute madman genius
               | decided that we should put down 5 copper cables to every
               | house and building for 3-phase power, even though they
               | only needed one phase for the coming decades.
               | 
               | You know. _just in case_.
        
             | j-a-a-p wrote:
             | At energy level a heat pump never made sense, it merits are
             | with the fossil fuel transition.
             | 
             | Example, a gas furnace runs at 100% efficiency (103% I
             | believe). Heat pump at 300%. Gas to electricity to home
             | goes at 30%. End to end they both perform at 100%. So on
             | efficiency perspective the gas furnace equals the heat pump
             | - but at a much lower cost.
             | 
             | Retaining the gas network saves us from the massive
             | investments needed in the electricity network.
        
               | CorrectHorseBat wrote:
               | A gas furnace isn't 100% either (103% is impossible, they
               | lie about what 100% means), and gas to electric can go up
               | to 60%. Heat pumps can also go over 300%, so it's
               | definitely possible for a heat pump to beat a gas
               | furnace.
        
               | j-a-a-p wrote:
               | About the gas furnaces, their efficiency exceeds 100%
               | because of water vapour condensation. It happens both in
               | the furnace and in the plastic exhaust pipe that
               | exchanges heat with the outside air inflow. Gas comes in,
               | liquid goes out and your law of thermodynamics is
               | preserved. AFAIK the majority of housing is using this.
               | 
               | It would surprise me if gas turbines exceed 40% on
               | average, and then the electricity still needs to be
               | distributed. New turbines, probably particularly when
               | using propane could do much better indeed.
               | 
               | My heat pumps all advertise a SCOP of around 5 for
               | heating, and I guess the domestic hot water it would be
               | 2.5 (don't have that, using solar for that myself). And
               | there is a lot the installers can and will screw up, just
               | read some user forums on this. And which consumer
               | actually checks the real COP? So large numbers of heat
               | pumps will perform far from optimal without somebody
               | noticing. The 'screw up surface' of gas furnaces is much
               | smaller. For example, ground heat sources rarely get
               | replenished in summer (not mandatory for residential in
               | my country).
        
               | konschubert wrote:
               | This calculus changes if you consider that on most winter
               | days, a big part of the electricity will come from wind
               | instead of synthetic gas.
        
               | j-a-a-p wrote:
               | No, your point was on using propane gas to produce
               | electricity for heating. If your consider/complicate the
               | equation with other energy sources (coal, wind, ...) the
               | outcome is more random.
               | 
               | Heat pumps do not make sense unless the energy transition
               | into the equation (wind and solar indeed). But also then,
               | there are major shortcomings with wind/solar currently
               | not yet fixed. For example, my home produces appr. 12 MWh
               | solar energy per year and the heat pumps use a similar
               | amount. Nice balance, but too bad the is a gap of six
               | months between the two.
        
             | rocqua wrote:
             | Yes, heat pumps are more efficient. But they require lots
             | more infrastructure.
             | 
             | Not only is that going to be expensive and thus impopular.
             | It will also be a delayed transition, and use up an
             | incredible amount of resources.
             | 
             | Not that we should do this instead of heat-pumps. We can do
             | both. Heat-pumps in new houses and if possible when
             | replacing old furnaces.
             | 
             | For all the existing stuff, this could be a great stop-gap.
        
               | konschubert wrote:
               | I don't disagree
        
           | worldsayshi wrote:
           | > this sounds to good to be true.
           | 
           | This post seems to have gotten a lukewarm reception. People
           | are maybe extra sceptical after the lk99 dud.
        
         | garyclarke27 wrote:
         | CO2 concentration in atmosphere is .04% not .4% But Yes is too
         | low as a source for this process.
        
           | rocqua wrote:
           | Estimates I found (in one article, I linked it somewhere
           | else) put the energy usage of CO2 capture from ambient air at
           | about 2800kwh per ton of CO2, someone else calculated one ton
           | of CO2 would produce 376kg of propane. Which is about 5254
           | kwh. So it would be a significant hit to efficiency, changing
           | it from about 90% to 60%. But that doesn't bring the
           | efficiency to stupidly low levels.
        
           | nonethewiser wrote:
           | So lets pump more CO2 into the atmosphere.
        
           | gcanyon wrote:
           | > .04%, not .4%
           | 
           | Give it time, we're working on it...
        
             | zaroth wrote:
             | > _Concentrations of CO2 in the atmosphere were as high as
             | 4,000 ppm during the Cambrian period about 500 million
             | years ago, and as low as 180 ppm during the Quaternary
             | glaciation of the last two million years._
             | 
             | So a range of 0.018% to 0.4% over the last 500 million
             | years. We're currently at ~420ppm, and human impact is
             | estimated to have been about +140ppm since the 1700s where
             | we had been at 280ppm for the ~10,000 years prior.
             | 
             | If the planet ever hit 0.4% again it would be due to
             | natural not anthropogenic reasons.
        
         | mschuster91 wrote:
         | > Are there use cases where we must burn propane because we
         | can't replace that process with electricity?
         | 
         | Yes. Ships, for one - no way you can power an oceangoing large
         | ship with batteries for the entire trip, but doable with LPG
         | (which is essentially a propane/butane mix). Assuming that
         | further technology (chemical or biotech) gets developed to
         | combine it to form larger hydrocarbons, it can also be used as
         | a precursor for airflight synthfuel.
        
           | semi-extrinsic wrote:
           | Liquid hydrogen or ammonia are both very much feasible and
           | carbon-free.
           | 
           | Both Yanmar and Kawasaki are developing large marine four-
           | stroke piston engines for hydrogen, with 2025 as launch date.
           | 
           | Ammonia-fuelled piston engines are easy, their only problem
           | is idling due to the poor combustion properties of ammonia,
           | which you can solve in the pragmatic way by using a little
           | hydrocarbons during idle - combined with power from shore
           | during docking, that still gets you >95% emission reductions.
        
             | bawolff wrote:
             | If the carbo is being extracted from the atmosphere, does
             | it really matter it gets rereleased? It would still be net-
             | zero.
        
               | rocqua wrote:
               | Might be better of extracting the carbon and just storing
               | it, rather than releasing it again.
               | 
               | Net-zero is nice, but extraction and storage is net-
               | negative.
        
               | regularfry wrote:
               | By the time any of this hits a reasonable scale we'll be
               | past a reasonable CO2 level in the atmosphere. The best
               | thing to do may well be to use it as plastic feedstock
               | and just chuck it into landfill.
        
             | Slava_Propanei wrote:
             | [dead]
        
             | MagnumOpus wrote:
             | Hydrogen has the problem with thick-walled heavy fuel tanks
             | - problematic for both cars and planes.
             | 
             | Ammonia to my knowledge has a problem of both potential
             | toxicity (both if gas escapes in refuelling and NOx
             | emissions after burning) and needing enriched pure oxygen
             | rather than running with atmospheric air.
             | 
             | Propane or other hydrocarbons look superior to both of
             | these to me.
        
               | Qwertious wrote:
               | Hydrogen has problems, but at the end of the day it's
               | viable and are the best option for planes/ships _if_ we
               | don 't find anything better. On ships fairly easily, on
               | planes with a fair bit of re-engineering. Local pollution
               | aside, renewable hydrocarbons would be a better option,
               | _if_ they 're viable at all.
        
               | Retric wrote:
               | Green hydrogen is still horrifically expensive, wind
               | powered cargo ships are currently more valuable though
               | not actually viable without a massive carbon tax.
               | Batteries can provide enough power for ships electrical
               | systems. There's some niche fully battery powered boats
               | which work fine for trips up to a few hundred miles.
               | 
               | A full EV transition would also free up quite a lot of
               | biofuels. Not enough on its own, but still significant.
        
               | walnutclosefarm wrote:
               | If the efficiency of propane production (from atmospheric
               | CO2) can be made even close to that for hydrogen from
               | hydrolysis, then the systems benefits of propane over
               | compressed and/or liquid hydrogen will blow liquid
               | hydrogen out of the water. Hydrogen is an awful fuel.
               | It's only real advantage is the potential for being
               | carbon neutral, and the fact that it doesn't create
               | noxious air pollution when used in a fuel cell. It's
               | claimed advantage of energy density is at best a wash in
               | most applications - higher density by mass, but much
               | lower by volume. But everything to do with hydrogen as a
               | fuel system is hard, complicated, and expensive, compared
               | to the alternatives.
        
               | SoftTalker wrote:
               | Storing propane is much easier than storing hydrogen. It
               | liquifes at reasonable pressure so it can be stored as a
               | liquid in uninsulated, relatively lightweight tanks (the
               | tank under your BBQ grill is an example).
               | 
               | Hydrogen leaks out of almost everything, embrittles
               | steel, is hard to store as a liquid and needs very high
               | pressures to store a meaningful amount as a gas.
        
           | speedgoose wrote:
           | One ship could always go nuclear, or use wind.
        
             | pfdietz wrote:
             | A fuel-powered ship can ramp output up and down as needed,
             | since the per-power costs of the powerplant aren't that
             | high.
             | 
             | Nuclear power plants are much more expensive, and require a
             | much higher (and more expensive) level of labor. These
             | fixed costs are not reduced when full power is not needed.
        
             | mschuster91 wrote:
             | Wind doesn't work with container ships, the sails are in
             | the way of the cargo cranes at port. Might be an
             | interesting idea for passenger ships though, but even
             | there... there are ports which have a height limit (e.g.
             | Hamburg) because ships need to pass below bridges.
             | 
             | Nuclear in civilian hands is an absolute no-go for
             | proliferation / terrorism concerns.
        
               | lucidguppy wrote:
               | Someone should tell theses guys about wind power.
               | 
               | https://www.cnn.com/2023/08/22/travel/wind-powered-cargo-
               | shi...
        
               | sandos wrote:
               | Yep, and those smartly can fold down! Also used for
               | storms I assume.
        
               | ch4s3 wrote:
               | Those only provide about 30% of the ships power.
        
               | dv_dt wrote:
               | Well there are cranes at the port, make the sails
               | detachable and dismount them to load.
        
               | smileysteve wrote:
               | 2 proposed solutions for wind are
               | 
               | 1. Kites attached by cable (deployed, high altitude for
               | consistent winds)
               | 
               | 2. Magnus effect cylindrical turbines that rise out of
               | the ship.
        
             | BoxOfRain wrote:
             | Civilian nuclear-powered cargo ships have actually been
             | tried in the past, a large issue was that a lot of ports
             | refused them entry if I remember correctly.
        
               | codersfocus wrote:
               | There could be nuclear "tanker" ships that recharge
               | electric battery ships on their routes.
        
               | pydry wrote:
               | There's also the minor issue that they are, like most
               | forms of nuclear power, hellishly expensive.
               | 
               | Several have been built and people have generally gone
               | "huh, thats cool but it's way too expensive".
               | 
               | Thats the main reason why theres currently only 1 in the
               | whole world.
        
               | SoftTalker wrote:
               | They are expensive because they don't externalize their
               | environmental costs upon the rest of the world.
        
               | pfdietz wrote:
               | The environmental costs of renewables (other than
               | biomass) are minor.
        
               | eesmith wrote:
               | I don't that that's the major issue. At least, the
               | Wikipedia entry for the NS Savannah only mentions being
               | excluded from Australia, New Zealand and Japan.
               | 
               | https://en.wikipedia.org/wiki/Nuclear_marine_propulsion#C
               | ivi... comments the major issue is the costs of
               | specialized infrastructure, and points out how research
               | about a modern design concluded "further maturity of
               | nuclear technology and the development and harmonisation
               | of the regulatory framework would be necessary before the
               | concept would be viable."
        
               | boilerupnc wrote:
               | Nice picts and walkthrough [0] of the NS Savannah, "the
               | world's first, and only, nuclear-powered cruise ship. The
               | Savannah is the only nuclear-powered merchant ship the
               | U.S. ever built, and the only nuclear vessel in the world
               | designed with passengers in mind."
               | 
               | [0] https://www.npr.org/2023/06/23/1182973358/step-
               | aboard-the-nu...
        
             | noir_lord wrote:
             | Russia tried that for nuclear, it wasnt a success.
             | 
             | Though that was because it was badly mismanaged and the
             | technology wasn't there yet.
        
         | aqme28 wrote:
         | > Are there use cases where we must burn propane because we
         | can't replace that process with electricity?
         | 
         | That's not relevant in the short term. There are so many things
         | using propane right now and it's a lot easier send them
         | "renewable propane" than to entirely retrofit them to be
         | electric.
        
           | bertil wrote:
           | Not if it's a lot more expensive.
        
             | fodkodrasz wrote:
             | You can run ICE cars on LPG (propane + butane, would
             | probably work on pure propane as well), with minor (<1000$)
             | modification in the fuel injection system and fitting a
             | proper tank.
             | 
             | This could make millions of older cars cleaner, also in the
             | developing world. LPG is already cleaner, would benefit the
             | developing world, and ICE engines can be produced without
             | needing exotic materials, can be recycled 100% by smelting,
             | are a proven, well known, durable technology, unlike
             | lithium batteries (which are also proven, but recycling and
             | exotic materials are problematic), and are and will be a
             | popular technology in the developing world for a long time.
             | 
             | Also it would allow for cheaper and cleaner cars in the
             | developed world, where not everybody can afford the
             | electric dream many here are living.
             | 
             | It would also be somewhat suitable for long haul and heavy
             | machinery, but most likely in a hybrid drivertrain setup.
             | 
             | Also it would solve the big issue of the German home
             | heating and industry: how to stove away the sun and wind
             | from the summer to the winter, when in the windless dark
             | days nowadays coal is burnt, as battery of hydro storage
             | cannot be scaled beyond a few days capacity at extremes.
             | 
             | There is already built, or cheap technology to gas powered
             | solutions, no need to transition to new technology hastily.
             | This would give runway to the green transition, as it could
             | be net zero carbon footprint solution with less disturbance
             | to the existing solutions.
        
               | bertil wrote:
               | Yeah, but that solution means your gallon of gas, or its
               | propane equivalent, costs 45$.
        
               | nnevod wrote:
               | Electricity is way cheaper at the poont of generation
               | than for residential consumer.
               | 
               | IIRC, solar now gets to about 3$ per Mwth, so purely
               | energy cost would be about 0.33$ per kg of propane if
               | 100Mj of input energy per kg of propane stands for that
               | electrolyser plus stated 13Mj for Co2 capture for 1 kg of
               | propane. So, the cost is not negligible, but could be
               | competetive even now, and solar is likely to get cheaper.
        
               | orthecreedence wrote:
               | How are you arriving at this number?
        
               | WirelessGigabit wrote:
               | What about cooling? As engines get smaller they quite
               | often will dump in extra fuel under load to ensure the
               | cylinder doesn't melt.
               | 
               | E85 does that even better, as the cost of being less
               | dense. But it cools so much better you can run higher
               | boost.
               | 
               | What about LPG?
               | 
               | And if we want LPG to be something we still have to deal
               | with legislation, like in many countries you can't park
               | in an underground garage with LPG.
        
               | SoftTalker wrote:
               | > in many countries you can't park in an underground
               | garage with LPG
               | 
               | I'm not sure why parking with LPG is a problem but
               | parking with 10-20 gallons of gasoline is not?
        
               | jaclaz wrote:
               | LPG is a gas, and it is heavier than air.
               | 
               | In case of a leak there is a risk in case of a not-
               | ventilated enough underground garage it is possible that
               | the gas accumulates in the lower parts before it can be
               | sensed/sniffed, and a mix of just 2.1% with air is
               | already at risk of explosion if a spark is generated.
               | 
               | Security norms changed in the EU around 2001, the norm is
               | the ECE/ONU 67-01 (though different countries may have
               | implemented differently in the local Law) and LPG powered
               | cars conforming to that standard are allowed (generally)
               | to be parked in underground garages BUT only on the first
               | underground floor and only if the garage is conforming to
               | some (earlier) ventilation standards.
               | 
               | AFAIK cases of explosions/fires related to LPG car tanks
               | are extremely rare (thanks also to the added safety
               | measures mandated by ECE/ONU 67-01), whilst
               | fires/explosions originated by domestic LPG use, while
               | not common, are more common than what they should be (the
               | tanks in themselves are generally safe, but the - often
               | underground - pipings often are not).
        
               | fodkodrasz wrote:
               | I'm not a mechanical engineer, but for one I have driven
               | my father's LPG-converted car, and the cylinder didn't
               | melt so far, so I think this is already more-or-less
               | under control. Many car vendors in the EU (especially
               | south and east) offered LPG-petrol bi-fuel powered cars
               | out of the box. (I know of Dacia and Fiat for sure, and
               | according to my brother LPG converted hybrid Priuses are
               | popular in Poland for insanely cheap operations by cab
               | drivers for example).
               | 
               | For engines getting smaller: the LPG operation of petrol
               | engines provides lower power output (and lower torque),
               | so an uptick in LPG powered (dual fuel?) cars would
               | probably mandate slightly different engines sensible
               | (bigger ones), the market would surely adapt to it.
               | 
               | E85 would also be fine if it wouldn't be manufactured
               | from intensively farmed monocultural agricultural
               | products, which make it totally non-sustainable and non-
               | renewable factoring in the sustainability problems of
               | industrial agriculture (soil erosion, carbon depletion of
               | soil, death of soil microbiome, groundwater depletion,
               | etc)
               | 
               | The parking ban for LPG in closed garages is a real
               | problem, I have faced it myself. Though it is
               | justifiable, but then it would also be justified for the
               | BEVs as there were cases already where (heat from) a
               | battery fire compromised the structural integrity parking
               | complexes, so it is a manageable risk probably, and
               | probably mostly legislative.
        
               | ed_balls wrote:
               | > will dump in extra fuel under load to ensure the
               | cylinder doesn't melt
               | 
               | They dump extra fuel to prevent knock. It's hard to melt
               | cylinders.
               | 
               | > can't park in an underground garage with LPG
               | 
               | And yet people park. I haven't heard about an accident in
               | the last 5 years. Maybe it could be managed by an extra
               | detector?
               | 
               | LPG engines could be excellent generators (back ups or
               | range extenders for cars and trucks). The emit less
               | particulate matter and NOx.
        
               | coderenegade wrote:
               | This. There's no way the global car fleet is switching
               | over to electric any time soon. Globally there are around
               | 1.2 billion cars, with 65 million or so sold each year,
               | which puts us at 15-20 years for the fleet to be replaced
               | if every single car sold from today were electric.
               | 
               | Like it or not, internal combustion cars have many
               | advantages, a big one being that they can run on
               | different fuels. Converting to green LPG or (my pick)
               | methanol will have to happen if we're serious about
               | reducing transport emissions, because it's the only
               | immediate non-cost-prohibitive option.
        
           | hannob wrote:
           | > There are so many things using propane right now and it's a
           | lot easier send them "renewable propane" than to entirely
           | retrofit them to be electric.
           | 
           | I see statements like this every now and then, and I really
           | wonder where that comes from, because that is not at all
           | obvious, and most likely in most cases wrong.
           | 
           | If you imagine that "renewable propane" is something that you
           | can just get, then it may appear easier to use your existing
           | devices. But it's not. It's something that is not produced at
           | any meaningful scale anywhere. There are no industrial
           | processes to do so yet. You're talking about creating a whole
           | new industry using technologies that don't exist yet, and by
           | the way, a new industry that needs massive amounts of
           | renewable energy. A lot more of that renewable energy
           | compared to direct electrification. Nothing about that is
           | easy.
        
             | aqme28 wrote:
             | What? This is a thread about a new technology that is a
             | proposed commercializable "renewable propane" generator.
             | 
             | This whole conversation is a hypothetical. Restricting the
             | discussion to only existing technology makes no sense.
        
               | hannob wrote:
               | I haven't said you can't discuss them, I was pushing back
               | against the idea that this is easy.
        
             | orthecreedence wrote:
             | > It's something that is not produced at any meaningful
             | scale anywhere. There are no industrial processes to do so
             | yet.
             | 
             | As opposed to...replacing every single ICE with an all-
             | electric equivalent. I think scaled up renewable propane
             | would be a much cheaper cost overall than rebuilding every
             | single vehicle in existence.
        
               | hannob wrote:
               | > I think scaled up renewable propane would be a much
               | cheaper cost overall than rebuilding every single vehicle
               | in existence.
               | 
               | I don't think you have any realistic idea about the
               | energy costs of synthetic hydrocarbons. We're talking
               | about something in the range of 5x the amount of energy
               | you need. Think 5x the number of wind turbines and solar
               | panels, and then reconsider if you still imagine that is
               | a cheap solution.
        
               | [deleted]
        
         | emptybits wrote:
         | > Are there use cases where we must burn propane because we
         | can't replace that process with electricity?
         | 
         | "Must", no. But hundreds millions of cars and trucks on the
         | road right now can be converted to propane. It's relatively
         | easy and well understood and you keep your same motor and
         | drivetrain.
         | 
         | Converting existing cars and trucks to electric is so intensive
         | it's almost unthinkable ... cost, energy input, waste, etc.
        
           | bertil wrote:
           | That process relies on DAC, plus electrolysing H2 and that
           | conversion processes, which means the propane would have to
           | be at the equivalent of 15-45$ per gallon. What is less
           | affordable?
        
             | bluGill wrote:
             | The current iteration does. Research often brings costs
             | down, though there is no guarantee.
        
       | jokoon wrote:
       | 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.
        
         | red_admiral wrote:
         | The answer to this kind of claim is in the book "The Wizard and
         | the Prophet", which was reviewed on ACX/SSC here [1].
         | 
         | To summarise the review: there are two approaches to solving
         | humanity's big problems, from food production (mostly solved)
         | to climate change. The Prophet approach is to go around saying
         | "we must live within our means!" and "technology bad!", and the
         | Wizard approach is to seek techological solutions. And as the
         | reviewer writes:
         | 
         | > Though Mann insists from the start that the book is not meant
         | to advocate for or condemn either side, it was initially
         | difficult for me to read it as anything but two-and-three-
         | quarters cheers for Wizardry.
         | 
         | It turns out that Prophets tend to be misanthropes at best, and
         | racists at worst. William Vogt, Mann's archetypal Prophet,
         | founded (according to Mann) much of modern-day environmentalism
         | but also (according to the review, which I personally trust)
         | called people in India "backward populations" who "breed with
         | the irresponsibility of codfish". Says the reviewer:
         | 
         | > _Which_ people deserved to live in harmony with nature in the
         | ensuing pastoral utopia and which would be relegated to the
         | dustbin of history was not an exercise they left to the reader.
         | 
         | (Meanwhile Norman Borlaug, the Wizard, was busy producing a
         | Green Revolution that ended up raising rice yields in India
         | from 2 to 6 tons/hectare and lowered rice costs from $550 to
         | $200 a ton, according to the Wiki page.)
         | 
         | [1] https://astralcodexten.substack.com/p/your-book-review-
         | the-w...
        
         | bawolff wrote:
         | Sometimes i think one of the biggest hurdles to
         | environmentalism is greens insisting on wishful, return to
         | edan, thinking instead of practical solution.
         | 
         | Convincing everyone in the world to do a massive cultural
         | change involving large standard of living decreases is not
         | happening except at the point of a literal gun. The world can't
         | afford to wait for impractical solutions.
        
           | pjerem wrote:
           | No, it's more a narrative issue than anything else.
           | 
           | Nobody says we should go back to Stone Age but we should
           | unleash our narratives of what is a nice future.
           | 
           | Living in a world where everyone is eating healthy local
           | food, where you live longer because it's safe to use your
           | bicycle and hard to use the car. Living in a world where you
           | can walk everyday because there are trees to give you their
           | shadows. Living in a world where work is meaningful. For me
           | that's a bright future.
           | 
           | Nobody says we have to abandon all of our technological and
           | cultural advances but that we have to prefer some over
           | others.
           | 
           | Like my grandfather said, plant 2 trees when you build your
           | home and you'll never need air conditioning. His idea wasn't
           | that you should ban A/C but rather that you can use it way
           | more efficiently just by adding some shadow.
           | 
           | That's the world we must live in now : consuming energy is ok
           | but not if it is a countermeasure to our own stupid
           | decisions.
           | 
           | It's the same with cars. Ok they are nice sometimes. But they
           | are stupid if we use them to go in a far office with the same
           | computer you have at home.
           | 
           | We don't need to go back to Stone Age but we need to dream of
           | a future where we don't use the energy for stupid things. And
           | this implies being able to see what is stupid and who have
           | interest in keeping a given stupid thing, stupid.
        
             | bawolff wrote:
             | > Living in a world where everyone is eating healthy local
             | food, where you live longer because it's safe to use your
             | bicycle and hard to use the car. Living in a world where
             | you can walk everyday because there are trees to give you
             | their shadows. Living in a world where work is meaningful.
             | For me that's a bright future.
             | 
             | That sounds nice and all (although as a canadian, too much
             | heat due to lack of shade is definitely not the issue
             | around here ;) ). I'd even go as far as to say that those
             | types of life style changes have an important part to play.
             | However, even if implemented to the fullest extent
             | possible, i don't really think it solves the greenhouse gas
             | problem by itself or even comes close.
        
               | orthecreedence wrote:
               | > i don't really think it solves the greenhouse gas
               | problem by itself or even comes close.
               | 
               | Well, yeah...ok, everyone rides around on bikes. Someone
               | has to make the bike. Is it done by hand? How do you
               | scale that to 8B people? Or is it done by a scaled
               | industrial process, and if so, how do you power this?
               | 
               | The answer to these questions isn't to limit technology,
               | it's to _limit population_. The scale of our population
               | is the cause of all of these strange threshold-breaking
               | externalities we 're now facing. And you can't point at
               | the technology and say "SEE?! It's ruining everything!"
               | 
               | The technology is just a companion to our population.
               | Real primitivists should be arguing for drastically
               | reduced population (however that is achieved ethically),
               | not a reduction of technology.
        
             | sneak wrote:
             | > _Living in a world where everyone is eating healthy local
             | food, where you live longer because it's safe to use your
             | bicycle and hard to use the car. Living in a world where
             | you can walk everyday because there are trees to give you
             | their shadows._
             | 
             | As someone who dislikes physical movement or being
             | outdoors, this sounds terrible. Local food is often heavy
             | in ingredients I don't like or to which I am allergic, or
             | doesn't fulfill my nutritional needs and desires. This is
             | not the idea of an ideal world for many modern people.
             | 
             | I'd much rather we solve the issues related to being
             | sedentary with technology than we try to figure out how to
             | make everyone bike everywhere, which most people don't want
             | to do, even given the option. I don't wash my clothes by
             | hand and I'm not sure why bicycling is seen as some ideal
             | correspondingly. I'd take a 200 year perfect artificial
             | heart over safe bike lanes. I'd take better solar (to run
             | more AC and dehumidification) over more trees. I've
             | swallowed enough bugs whilst cycling for more than one
             | lifetime.
             | 
             | Your position, to me, is still just a yearning for
             | historical lifestyles that we abandoned en masse for good
             | reasons. Using energy on air conditioning and
             | transportation are perhaps the least stupid things one can
             | spend energy on - right alongside spending energy on
             | washing machines for your bedclothes and underwear, which
             | nobody seems to regard as some insanely wasteful luxury.
             | Why is energy for heating seen by europeans as OK when
             | energy for cooling is regarded as a senseless waste? It's
             | just cultural bias and tradition.
             | 
             | When the majority of humans live in space or on bodies
             | without an atmosphere, this whole "fresh air and trees"
             | meme will finally die, I hope.
        
               | Tade0 wrote:
               | > Why is energy for heating seen by europeans as OK when
               | energy for cooling is regarded as a senseless waste?
               | 
               | I'm not the type of person who would want everyone to
               | cycle - chiefly because four wheels > two everywhere and
               | everytime, but there's an argument to be made against
               | overusing AC, namely: you're just moving heat around and
               | producing some in the process, so the net effect is that
               | the area around you gets extra hot.
               | 
               | AC is a pretty blunt tool and there are ways of keeping
               | places cooler without it.
        
               | megaman821 wrote:
               | The heating vs cooling this always gets me. Living in
               | Arizona and cooling your home 30-40 degrees down with a
               | 50% carbon-free electricity mix and 3 or 4x COP is seen
               | as unsustainable, but living Illinois and heating your
               | home 50-60 degrees up by burning fossil fuels is fine.
        
           | tonyedgecombe wrote:
           | Expecting technology to solve all our problems is just as
           | wishful.
        
             | sneak wrote:
             | Everyone who made it out of childhood thanks to antibiotics
             | and vaccines should probably reject takes like this.
             | 
             | Technology has solved the vast majority of all of the major
             | problems of human beings throughout all of human
             | civilization. Agriculture is technology. Writing is
             | technology. Inks and paper are technology. Pharmaceuticals
             | are technology. Heart surgery is technology. The modern
             | industrial supply chain is technology. Transportation is
             | technology. Seatbelts and blood typing to enable blood
             | transfusions - technology.
             | 
             | It is theoretically possible that technology could solve
             | the problem of death itself.
             | 
             | To make claims to the contrary, which would be
             | extraordinary, something a great deal more substantial than
             | a handwavey dismissal is required.
        
               | rini17 wrote:
               | I don't think anyone is talking here about going without
               | antibiotics or modern agriculture. More like curbing
               | excess production of concrete (making construction more
               | sustainable) and metals (reducing automobilism and other
               | wasteful means of transport).
        
               | tchaffee wrote:
               | The revolutions or sometimes evolutions resulting in
               | democrat nations with regulated market based economies
               | are what allowed the rapid pace of innovating you are
               | praising. Those revolutions were radical social changes.
        
               | goodpoint wrote:
               | Nothing in your post rebukes the claim made by the
               | parent.
        
               | mdiesel wrote:
               | Sure, we now survive childhood based on vaccines, but
               | remember that there was a time between the disease
               | appearing and the vaccine being developed, and in that
               | time we used simpler methods to try survive.
               | 
               | The issue is not what the world will be like in 200 years
               | when the climate crisis is solved, it's how we get there.
               | Tech takes decades to research, design, and develop; we
               | need ways to limit the damage that can be implemented in
               | years to limit the effects we'll see in our lifetimes. I
               | agree tech will be the end solution, but continuing to
               | burn at current rates while we wait for that is going to
               | cause, or already is causing, massive problems.
        
               | tticvs wrote:
               | > Sure, we now survive childhood based on vaccines, but
               | remember that there was a time between the disease
               | appearing and the vaccine being developed, and in that
               | time we used simpler methods to try survive.
               | 
               | 50% of children died before their 5th birthday
        
             | reacharavindh wrote:
             | IMO, we need both - people screaming out loud to reduce
             | consumption and rooting for truly green technologies that
             | create a revolution. While some silent practical warriors
             | change the status quo one kg of CO2 at a time until those
             | revolutionary changes kick in.
             | 
             | I think no sensible person would protest a more sustainable
             | solution than the current fossil burning tech even if it is
             | not 100% renewable.
        
               | mschuster91 wrote:
               | > IMO, we need both - people screaming out loud to reduce
               | consumption and rooting for truly green technologies that
               | create a revolution.
               | 
               | Nuclear fusion for energy generation purposes has been
               | promised for, what, 60 years now? Hoping for that to
               | eventually succeed will only lead to one thing: it won't
               | work out and whoops, suddenly humanity is out of options
               | because everyone had refused to change in the hope for a
               | miracle.
               | 
               | It is more sensible to prepare for the worst case now.
        
               | bawolff wrote:
               | Fortunately nuclear fisson technology has been here for a
               | while and solves most of the immediate problems we have.
               | 
               | Too bad we barely used it.
        
               | Tade0 wrote:
               | We barely used it because it's a textbook case of
               | overpromising and underdelivering.
               | 
               | A nuclear project on average has a probability of going
               | over time and budget somewhere between an IT project and
               | organizing the Olympics.
               | 
               | These are not great odds, especially that renewables are
               | on the other end of the same scale.
        
               | reacharavindh wrote:
               | It is one of those things that genuinely polarizes
               | people's opinion. On the one-hand you have a solution
               | that used carefully could simply replace fossil fuels for
               | a large set of use cases. On the other hand, as little as
               | it may be, their wastes are an undealt problem that is
               | only wish washed away. Ironically, it also needs one of
               | those revolutionary discoveries before it is truly safe.
        
           | mschuster91 wrote:
           | > Convincing everyone in the world to do a massive cultural
           | change involving large standard of living decreases is not
           | happening except at the point of a literal gun.
           | 
           | ...or when you have millions of people on the Western borders
           | fleeing from climate change and its side effects (we're
           | already seeing just how cruel politicans behave towards the
           | relatively small amount of people at the borders currently -
           | imagine how the situation will look like with just 10x as
           | many!), or entire of _our_ states being devastated by
           | wildfires, hurricanes or tornadoes. Probably it 's going to
           | take the latter until politicians wake up, when the situation
           | is undeniable even to the hardest MAGAts and other deniers.
           | 
           | The key thing is: humanity is using more resources (no matter
           | if you're talking about food, drinkable water or fuel) than
           | nature can regenerate, each year. We are currently digging
           | into reserves that took (in case of groundwater) sometimes
           | many millennia to create.
           | 
           | > The world can't afford to wait for impractical solutions.
           | 
           | It can't afford doing nothing, because continuing as-is
           | without managing sensible degrowth may work out for our
           | generations, but the ones born after 2010? They're fucked.
        
         | hackerlight wrote:
         | Even if I believed degrowth was a good solution (I mostly
         | don't), I would still hope for the success of these
         | technologies as a backup plan.
        
         | tticvs wrote:
         | If 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 wrote:
           | Energy policy based on being "nice" will never have
           | significant longevity.
        
             | reacharavindh wrote:
             | We(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.
        
             | [deleted]
        
             | tchaffee wrote:
             | Except 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 wrote:
               | Would 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.
        
         | colechristensen wrote:
         | >What's really needed is culture change on growth and
         | consumption.
         | 
         | It is not.
         | 
         | At no point in the history of human civilization has growth
         | been static. It will not ever be. It will and should be
         | exponential. Figure out how to make that happen or go join one
         | of the religious groups that stop using new technology.
         | 
         | We want, need, and benefit from growth.
         | 
         | Our energy source just needs to change, and is changing. Plenty
         | of earthbound solar and nuclear to satisfy our growth for a
         | good while. There isn't enough fossil fuel around anyway if we
         | wanted to keep growing with it.
         | 
         | By the time we need it we can produce plenty of energy in
         | space. Think square miles of solar arrays in solar orbits
         | fixing energy into whatever passes for a future battery while
         | also colocating with asteroid smelting and refining facilities.
        
           | pkdpic wrote:
           | > There isn't enough fossil fuel around anyway if we wanted
           | to keep growing with it
           | 
           | I in all seriousness love this angle and find it super
           | refreshing, the puny amount of oil on this tiny planet isn't
           | enough to satisfy human ambition. We should own the stars.
        
             | tsimionescu wrote:
             | Very little oil among the stars, though... Very little
             | sunlight or wind on route either.
        
               | AnthonyMouse wrote:
               | Fair amount of hydrogen. Get fusion working and you don't
               | need much.
        
           | hutzlibu wrote:
           | > There isn't enough fossil fuel around anyway if we wanted
           | to keep growing with it
           | 
           | There is plenty of coal left and you can make oil out of it,
           | so we could burn fossil fuels for centuries to come if we
           | don't mind the side effects .. otherwise agree.
        
           | goodpoint wrote:
           | > At no point in the history of human civilization has growth
           | been static
           | 
           | Indeed countless civilizations collapsed once they depleted
           | natural resources.
        
           | jokoon wrote:
           | > At no point in the history of human civilization has growth
           | been static.
           | 
           | So? "The limits to growth" was published in the 70, you
           | should try to educate yourself on finiteness of earth.
           | 
           | Good luck with your space dreams. Smells like the Elysium
           | movie.
        
           | RetroTechie wrote:
           | > At no point in the history of human civilization has growth
           | been static.
           | 
           | Generally: correct. _So far_.
           | 
           | > It will not ever be.
           | 
           | Yes, it will. This will be forced by 2 factors:
           | 
           | a) The Earth we live on is essentially a closed system. Yes @
           | some point we might be able to mine asteroids, use
           | extraterrestrial energy sources, move people off-planet etc.
           | But this depends on technology to make this feasible. Until
           | such technology appears, we're stuck on this rock. And thus,
           | have to make do with what _this rock_ provides. Which is a
           | lot, but finite.
           | 
           | b) The laws of physics (those related to energy, in
           | particular).
           | 
           | The "eternal growth" is a classical economist's view. Which
           | (sadly) is very pervasive.
           | 
           | Historically, population growth, raw materials consumption,
           | energy use, and technological progress have been tightly
           | coupled.
           | 
           | But this coupling _will_ be loosened.
           | 
           | Technology will probably keep progressing ..somehow.
           | 
           | Energy use _might_ increase if eg. we can get nuclear fusion
           | to work. Even that is not 100% a given, btw (apart from the
           | timescale). How energy is generated will be very different
           | 30..50y from now.
           | 
           | But raw material consumption can NOT keep increasing. There
           | is finite amounts of [insert material here] on this planet.
           | Never mind agri stuff like phosphor, pollution, or the amount
           | of CO2 we can release 'safely'. And it's not feasible to
           | recover 100% of any reserve.
           | 
           | Same with population. Earth is already too crowded. Would you
           | want continued growth until entire Earth surface is covered
           | with humans? Stacked 50 humans high?
           | 
           | No? Then population growth _will_ stop. Not to mention that
           | population growth eats any gains made elsewhere (10% more raw
           | materials, 10% more energy, 10% more food, followed by 10%
           | more people = back to square 1 despite the gains).
           | 
           | Historically this wasn't a problem because those limits
           | weren't hit (well... they were, locally, which caused past
           | civilizations to collapse). But we are hitting those limits
           | now - globally.
           | 
           | It's this decoupling of growth factors that's a hard pill for
           | people to swallow. Especially economists & politicians.
           | 
           | But don't worry! The laws of physics are very reliable.
        
             | colechristensen wrote:
             | > @ some point we might be able to mine asteroids
             | 
             | Essentially, we can do this now. There is no real
             | technological barrier and several organizations are
             | actively developing solutions. We're at over a billion
             | dollars invested. Go read a report on the status of things
             | [1]. This isn't far off science fiction but something
             | practical folks are throwing money after.
             | 
             | 1. https://www.mordorintelligence.com/industry-
             | reports/space-mi...
        
           | tonyedgecombe wrote:
           | >At no point in the history of human civilization has growth
           | been static.
           | 
           | From the 1200s to 1600s England went through a period of zero
           | or extremely low growth.
        
             | pjc50 wrote:
             | Mostly due to the plague killing some massive fraction of
             | the population in the 1300s?
        
           | tchaffee wrote:
           | > At no point in the history of human civilization has growth
           | been static.
           | 
           | This is a bold and hard to believe claim. Weren't the Dark
           | Ages in fact a reversal? Can you provide a source for your
           | claim?
        
         | jskrablin wrote:
         | I really fail to understand how you can push "light technology"
         | while using a modern computer connected to the Internet - both
         | are very very far away from being light in terms of technology
         | involved. In fact the technology making both run is incredibly
         | complex/sophisticated with a high environmental impact
         | resulting from production, assembly and shipping of components
         | required to make it work.
         | 
         | Wanna go light? Ditch your computer, phone and most of
         | electronic/digital devices you use every day (for a start, then
         | follow up with car and basically anything that depends on
         | "heavy technology" to exist and run). But that is probably not
         | the lifestyle you're imagining ATM.
        
           | jokoon wrote:
           | you're attacking the messenger, not the message
           | 
           | im using a low performance computer, and computer have enough
           | power to do things.
           | 
           | it's about the ressources spent to make a computer.
        
       | api wrote:
       | 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.
        
       | Animats wrote:
       | Whatever happened to a similar announcement from Stanford in
       | 2019?[1]
       | 
       | [1] https://news.stanford.edu/2019/10/17/new-catalyst-helps-
       | turn...
        
         | tuetnsuppe wrote:
         | 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.
        
       | murkt wrote:
       | > 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 wrote:
         | 1-ethyl-3-methylimidazolium is a fairly simple molecule and
         | already used in industry.
        
       | Derbasti wrote:
       | 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?
        
         | rocqua wrote:
         | It'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.
        
           | XorNot wrote:
           | This 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.
        
             | malfist wrote:
             | Only if you use energy from fossil fuels to do the
             | conversion. Earth's energy isn't a zero sum game, we have
             | plenty of decarbonized energy sources.
        
             | rocqua wrote:
             | I meant to do the CO2 capture at gas furnaces in homes.
             | Because the electric power available for heating is ofte
             | limited, but might still be sufficient to gather CO2 from
             | the exhaust of the furnace.
             | 
             | It'll cost energy, but it is a cheap source of CO2 for this
             | electrolysis.
        
               | XorNot wrote:
               | To convert CO2 back to propane you have to put in every
               | bit of energy released when burning it and then some.
               | 
               | So again, it wouldn't work because as you note: the
               | electric power available is less than the gas.
        
           | modo_mario wrote:
           | >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.
        
       | londons_explore wrote:
       | 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)
        
         | murkt wrote:
         | Reversed electrolyzer would be called a fuel cell then? What
         | are their typical efficiencies?
        
           | londons_explore wrote:
           | Yep. Fuel cell efficiency varies widely, but the efficiency
           | of the reverse process is a good guide - typically efficiency
           | is fairly symmetrical.
        
         | fodkodrasz wrote:
         | Gas 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!
        
           | rjmunro wrote:
           | I wonder if you can have the same plant act as both a propane
           | producer at times of extra power available on the grid, but
           | also generate electricity when there is a shortage. Then the
           | power density and exotic materials are irrelevant as the
           | plant already exists.
           | 
           | You'd use the plant mainly to make propane, just run it
           | backwards when electricity prices were the highest.
        
           | londons_explore wrote:
           | At 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.
        
             | galangalalgol wrote:
             | Propane fuel cells already exist, and are in use for remote
             | power. The problem with using them for cars is that they
             | operate at high temperature, so you spend a lot of battery
             | warming the cell for steady state, but most trips are short
             | so you would be there before it got to temp. Might make
             | sense as a phev sort of thing where you punch in a trip and
             | it decides to warm it up or not. You'd always leave enough
             | battery to warm the cell while driving so you never get
             | stuck.
        
               | cduzz wrote:
               | Several tesla superchargers near where I live have fuel
               | cell setups, presumably to shave peak loads for the rare
               | cases that the charging stations are all in use and all
               | charging at peak rates.
        
               | londons_explore wrote:
               | I suspect they have batteries rather than fuel cells?
               | 
               | Tesla is known to colocate them for exactly the reasons
               | you say - also to shift load to cheaper hours of the day
               | and to get paid by the grid for balancing services.
        
               | sp332 wrote:
               | I think the current ones don't use generators, but that
               | one time they used a gas generator to charge Teslas,
               | called it a "battery swap station", and got a bunch of
               | money from California that was supposed to go to zero-
               | emissions car projects. I doubt they'll ever live that
               | down.
        
               | londons_explore wrote:
               | High temperature isn't a problem for cars. It's simple
               | enough to have a small fuel cell which can be heated up
               | quickly, which in turn can provide the energy required to
               | heat up a larger cell if needed. A small battery can
               | drive you a few miles while that process is happening.
               | The small fuel cell could then recharge the battery while
               | parked if most journeys are only a couple of miles,
               | avoiding the energy cost of heating the large cell except
               | for extended journeys.
        
               | galangalalgol wrote:
               | Not sure why no one has done it? Not carbon neutral I
               | guess, but paired with this and solar power it would be.
               | Batteries are already so good is probably part of it too.
               | But adding about 25% travel time on long drives is
               | annoying.
        
               | infinityio wrote:
               | Up until this point I'd imagine there was no significant
               | advantage to creating propane vehicles unless they could
               | be made significantly more efficient than petrol or
               | diesel (which I'm guessing is not known to be the case)
               | 
               | by comparison, this discovery _could_ make it a green-vs-
               | brown fuel debate, at which point it would be much more
               | valuable to invest in for vehicles
        
               | galangalalgol wrote:
               | Propane combustion vehicles are common, and I'd guess a
               | fuel cell would extract roughly 30% extra energy from the
               | same fuel. They typically have battery efficiencies.
        
             | fodkodrasz wrote:
             | Did they? Are they capable to be scaled to 100 MW scales
             | with MTBF of years already?
        
         | legulere wrote:
         | Shouldn't the chemical reaction be: 4 H2O + 3 CO2 <=> C3H8 + 5
         | O2
        
           | londons_explore wrote:
           | The reaction described in the paper doesn't have spare oxygen
           | on either side, presumably because oxygen has a habit of
           | destroying catalysts and being explosive when mixed with
           | hydrocarbons. Instead hydrogen is required.
        
             | bertil wrote:
             | So you would need to have two separate electrolyzing
             | processes, one that isolates H2 and one that runs this
             | operation? How much energy would have to go into the first
             | one?
             | 
             | I'm asking because a lot of the demand for hydrocarbon that
             | I see mentioned is for processes that have more efficient,
             | non-hydrocarbon equivalents.
        
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