Dude, most of your energy table is wrong. Hydrocarbon fuels are a combination of efficient (hydrogen) and inefficient (carbon) so the net energy content of the fuel is equal to the mass * hydrogen energy * efficiency or, mass * hydrogen energy - inefficiency. When calculating the net energy content of a hydrocarbon fuel the inefficiency must be removed first or we will get the wrong answer. Methane is 25.13% hydrogen and 74.87% carbon so, 1 * 120 * 25.13% = 30.156 MJ/kg Gasoline is 13% hydrogen and 87% carbon so 1 * 120 - 87% = 15.6 MJ/kg 500 GJ = 500,000 MJ so 500,000 ÷ 120 = 4166.666 kg of hydrogen.
At the very top of your list It shows the heat value for 1 kg (1000 grams) of hydrogen at 120 MJ Every item on the list has the same mass, so every item on the list should have the same heat value, except every item actually has a different mass percentage of hydrogen and carbon. Methane contains 251.3 grams of hydrogen + 748.7 grams of carbon, so 251.3 * 0.120 = 30.156 MJ Gasoline contains 130 grams of hydrogen + 870 grams of carbon, so 130 * 0.120 = 15.6 MJ The Toyota Mirai holds 5.6 kg of hydrogen 5.6 * 120 = 672 MJ. To make gasoline we need to add 5.6 ÷ 0.13 − 5.6 = 37.4769 kg of carbon. If we add 37.4769 kg of carbon we get 43.07 kg of gasoline, but no additional energy. If we add 37.4769 kg of hydrogen we will run into bit of a problem!
Thank you!
Dude, most of your energy table is wrong. Hydrocarbon fuels are a combination of efficient (hydrogen) and inefficient (carbon) so the net energy content of the fuel is equal to the mass * hydrogen energy * efficiency or, mass * hydrogen energy - inefficiency. When calculating the net energy content of a hydrocarbon fuel the inefficiency must be removed first or we will get the wrong answer.
Methane is 25.13% hydrogen and 74.87% carbon so, 1 * 120 * 25.13% = 30.156 MJ/kg
Gasoline is 13% hydrogen and 87% carbon so 1 * 120 - 87% = 15.6 MJ/kg
500 GJ = 500,000 MJ so 500,000 ÷ 120 = 4166.666 kg of hydrogen.
We are talking about heat value of each fuel.
At the very top of your list It shows the heat value for 1 kg (1000 grams) of hydrogen at 120 MJ
Every item on the list has the same mass, so every item on the list should have the same heat value, except every item actually has a different mass percentage of hydrogen and carbon.
Methane contains 251.3 grams of hydrogen + 748.7 grams of carbon, so 251.3 * 0.120 = 30.156 MJ
Gasoline contains 130 grams of hydrogen + 870 grams of carbon, so 130 * 0.120 = 15.6 MJ
The Toyota Mirai holds 5.6 kg of hydrogen 5.6 * 120 = 672 MJ. To make gasoline we need to add 5.6 ÷ 0.13 − 5.6 = 37.4769 kg of carbon. If we add 37.4769 kg of carbon we get 43.07 kg of gasoline, but no additional energy. If we add 37.4769 kg of hydrogen we will run into bit of a problem!