The idea of hydrogen economy is to utilize locally available and renewable energy sources, such as wind, solar and biomass to produce hydrogen gas. Hydrogen can then be used in fuel cells to produce electricity without producing pollution; replacing gasoline and petroleum with hydrogen would decrease the consumption of petroleum and also reduce the carbon-dioxide emissions.
BUT.. is it realistic to think that inexpensive, pollution-free hydrogen energy will be the fuel of the future?
First of all hydrogen is not at all a primary source of energy. It is always chemically bound in organic compounds or water. We require some other source like fossil fuel, nuclear reactors, hydroelectric dams, geothermal wells, wind turbines or solar panels to break the chemical bonds and hence produce free hydrogen. So basically hydrogen economy is incomplete without a primary energy source.
Well we can use electrical energy too for electrolysis of water (direct current + water = hydrogen + oxygen). But this process is highly inefficient. Only 45% of the initial energy is captured in this process.
Then there are numerous other problems attached to Hydrogen. Storing hydrogen is perhaps the greatest hurdle. Compressed hydrogen gas is the only viable approach. Carbon-fiber tanks can hold hydrogen at 10,000 psi. However, thee tanks hold only one-eighth the energy of a gasoline tank of equal size.
Moreover, compressed gas at 10,000 psi can be extremely dangerous. The energy released by the sudden rupture of a 10,000 psi tank holding 6 kg of hydrogen is equivalent to 50 sticks of dynamite!!
Even liquid hydrogen ( at -250 °C) has only one-fourth of the energy per unit volume of gasoline.
To add to the problems, hydrogen is odorless and invisible and has a wide range of flammability.
So, how realistic is the vision of the Hydrogen economy ?? And when will it occur ?? I guess some fundamental breakthroughs are necessary to make hydrogen economy a reality but one more thing.. Is Hydrogen economy the right goal ??
CHEW ON THIS TOO: - Recent Developments
Recently I came across an article - “Hydrogen Balls: a safe fuel of future”. This was about hydrogen powered cars. Thought of mentioning it here.
Hydrogen gas is stored in small balls – “ping pong” balls to overcome the risk of fire and explosion. Lass Stenmark, Uppsala University says, “By storing the gas in round, spherical form, it can withstand twice the pressure that a cylindrical form can. If the car crashes and tank breaks, the hydrogen-filled balls would just spread out and roll away, and the gas from any broken balls would just simply seep out and disappear into the atmosphere without causing harm”
Sounds simple and exciting, lets wait and see the application part !!
By Associate Writer - Nidhi Garg