Are hydrogen fuel cells a viable alternative to gasoline?

1 Answer
Jun 22, 2018

? see below


Hydrogen is the gas that give the best combustion at all, both as energy produced and (by far) the least harmuful for enviromental impact:
#H_2 + O_2 = 2 H_O# + Energy
also if , having the combustion in air, hence with nitrogen, you can have very little amount of #NO_x#:
#N_2 + O_2 = 2 NO#

On the other side we have some difficulties:
1) You cannot find free Hydrogen in nature nd you must obtain it from:
a) water with the same reaction you use to obtain energy, in truth, a bit bigger for problem of efficiency
b) from Coal , methane or oil:
#C+ 2H_2O = CO_2 + 2H_2#
#CH_4 + O_2 = CO_2 + 2H_2# this reaction is more complex but i give you only the final result
c) from Methanol
#CH_3OH = CO + 2H_2# but you must obtain methanol and must dispose of CO
The enviromental problem is only schift to an other side till we will obtain all the Hydrogen by renovable energy

2) Hydrogen is a gas till -250°C (!) and you can stock it only at very hight pressure:
1 only kg of Hydrogen at 200 atm has a volume of
#V= n xx R xx T/P = 50 mol xx 0,082 (L xx atm)/ (mol xx K ) xx (300K)/(200 atm) =6,15 L#
3) Hydrogen is a very little molecule and it need specially tanks to stock it.
4) Hydrogen is the most pericolous element for infiammability and explosiveness.

in spite of this difficulties, Toyota is commercializing car with fuel cells. At the moment only few car.

Nowadays, I think that for Bus and Tir that make great distance is still better Diesel engines(more robust), for city is better use electric or methane fuel, for mixed routes GPL, methane or gasoline.

But tecnology must go on and only with impruving this new systems we could safe environment