Hi,
I'm doing some research on whether aluminium is suited to producing hydrogen which would then be used in a fuel cell to power a car. I want to know the energy potential of 1 kg of aluminium.
The reaction to evlove hydrogen from aluminium is given by:
1. 2Al + 3H20 --> 2Al(OH)3 + 3H2 -199.6kcal
The hydrogen is then passed through a fuel cell. The net reaction is:
2. 2H2 + O2 --> 2H2O
Gibbs Free Energy = ΔG = ΔH - TΔS = -285.83 kJ + 48.7 kJ = -237.1 kJ /mole H2
Molar mass Al = 26.981g --> (1000g/26.981g)= 37moles. From equation 1, 37moles Al gives 55.6moles H2. From Equation 2, 55.6moles H2 has the electrical energy potential of (55.6*237.1kj)= 13MJ. The fuel cell is 55% efficient. So that gives a grand total of 7MJ useful energy per kg Aluminium.
Can someone kindly look over these calculations?
Thanks,
Eamon