/sci/ - Science & Math

just how much denser is subcooled propane?
That will be on the other side of gasoline, yeah?

>>15265317
I went to a forum at EAA a year or two ago presented by a NASA employee that addressed the viability of hydrogen-electric fuel cells for aviation which inadvertently proved quite convincingly that combusting hydrogen is a fool's errand. There is literally absolutely zero possible reason to ever use hydrogen combustion for aircraft propulsion; owing to both the extremely low energy density per unit volume of hydrogen even in cryogenic liquid form (huge tanks for not much fuel), as well as the possibility of >>15265929 e.g. the Sabatier Process since liquid methane is:
1) easier to store/transport - much higher boiling point means less insulation is needed making for lighter tanks and higher fuel mass-fractions
2) much easier to build lightweight tanks for (again the higher boiling point making for also significantly cheaper tanks)
3) much higher energy density by volume, and when considering energy density per unit mass *when the tank mass is also included* CH4 is not that far behind H2 in terms of specific (read: gravimetric) energy
4) much more economically efficient (CH4 is currently one tenth the $/BTU of H2) due to a much larger industrial base for producing/transporting/handling and using methane (i.e. natural gas, comes from the ground) vs hydrogen (comes from oil and hydrocarbon refining, and most of that is from natural gas refining)
5) Methane fueled aircraft would also not be any worse for the environment, since as I stated hydrogen is produced almost exclusively by refining other petrochemicals; in other words all current hydrogen fuels are 'dirty' environmentally and are only even viable at all because they're a byproduct of fossil fuel use.