4 ms·

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 di

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.

biomcgary 3y ago
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 3y ago
  > and a large off-the shelf propane tank for cloudy days (or weeks!) Months. I have a residential sized propane tank for gas and backup power that only gets refilled once a year at most. Worst case scenario I can go off grid for two to three months in the summer on a generator (tested frequently) and this is a pretty standard size for exurban houses in California.
  - meragrin_ 3y ago
    > I have a residential sized propane tank for gas Could you elaborate on that? I imagine most people do not have any concept of that. Are you talking basketball, person, tiny car, SUV, or something else in terms of size? I'm imagining something between tiny car and SUV.
    - compumike 3y ago
      https://www.amerigas.com/about-propane/propane-tank-sizes https://www.amerigas.com/about-propane/propane-tank-sizes I've most commonly seen the 120 gallon size at homes that use it for a water heater.
sbierwagen 3y ago
Propane fuel cells have been around for a while: https://www.wattfuelcell.com/portable-power/watt-imperium/ https://www.wattfuelcell.com/portable-power/watt-imperium/
- Const-me 3y ago
  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 3y ago

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 3y ago
> and a large off-the shelf propane tank for cloudy days (or weeks!) Months. I have a residential sized propane tank for gas and backup power that only gets refilled once a year at most. Worst case scenario I can go off grid for two to three months in the summer on a generator (tested frequently) and this is a pretty standard size for exurban houses in California.
- meragrin_ 3y ago
  > I have a residential sized propane tank for gas Could you elaborate on that? I imagine most people do not have any concept of that. Are you talking basketball, person, tiny car, SUV, or something else in terms of size? I'm imagining something between tiny car and SUV.
  - compumike 3y ago
    https://www.amerigas.com/about-propane/propane-tank-sizes https://www.amerigas.com/about-propane/propane-tank-sizes I've most commonly seen the 120 gallon size at homes that use it for a water heater.

sbierwagen 3y ago

Propane fuel cells have been around for a while: https://www.wattfuelcell.com/portable-power/watt-imperium/ https://www.wattfuelcell.com/portable-power/watt-imperium/

Const-me 3y ago
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.