The Problem with Hydrogen as a Fuel
If energy levels are reduced by a global reduction in the allowed use of fossil fuels then will the use of Hydrogen as a fuel provide an alternative sustainable fuel up to 2050.
This analysis gives an ongoing framework to test that question.
Hydrogen does not occur naturally on Earth. It has to be synthesized.
This analysis uses water.
Per unit yield for Hydrogen From water by electrolysis
Molecular weight of Water H20 = 1 + 16 = 18 grams
Molecular weight of Hydrogen H = 1 x 2g = 2 grams
Molecular weight of Oxygen O = 16 = 16 grams
As percentages H = 2 / 18 = 11 %
O = 16 /18 = 89 %
So in 1 metric ton of water = 1000000 g
Likely H content = 110000 g
= 0.11 metric tons of hydrogen
At a calorific value of 1 ton of hydrogen = 39000 kwh/ton
Potential energy from H in 1 ton of water = 39000 x 0.11
= 4290 kwh per ton of water
= 4,290,000 wh per ton of water
Compares to
= 1,870,000 wh per ton of coal
= 11,666,000 wh per ton of crude oil
= 5,300,000 wh per ton of wood
= 3,084,000 wh per ton of
short rotation coppice
The Hydrogen production process also needs
Electricity from fossil fuels
Electrolysis anode, cathode, connections.
A controlled seal container for at least 1 ton of water
1 ton of Water
A controlled seal container for the Hydrogen Gas measuring approx.
1,341m x 1,341m x 1,341m = 2,411,494,821 m3
Energy converters to change the Hydrogen into electrical energy.
Electrical Energy Storage Batteries
To replace the same tonnage per year of crude petroleum the amount of hydrogen needed would have to be
84,060,000 bbl/day (2011 est.)
Source: CIA World Factbook
Allowing 42 gallons per barrel. Allowing 7.33 barrels per metric ton
84,060,000 x 42 / 7.33
481,653,478 tons of crude oil per day
175,803,519,470 tons of crude oil per year
2,050,923,858,137,020 kWh per year
So we would need
2,050,923,858,137,020 / 4290 kWh
478,070,829,403 tons of water to get the same energy equivalent of hydrogen
by electrolysis per year.
This amount of water needs an area of approximately 1m x 700,000m x 700,000m
This amount of Hydrogen would need a storage area of approximately 52,587,791,234 m3 of hydrogen a volume of approximately of 1m x 240,000m x 240,000m
Conclusion
Hydrogen is not a sustainable fuel at our current level of technology.
Ian K Whittaker
Website:
https://sites.google.com/site/architecturearticles
Email: iankwhittaker@gmail.com
31/10/2013
14/10/2020
441 words over 2 pages.