|hydrogen fuel cell by matthewvenn, on Flickr|
Hydrogen is the lightest and most abundant element on the planet. It has the potential to maintain the energy security of the planet without affecting the climate. Now a days hydrogen gas is used in the space craft propulsion. They are not yet industrialized or used in passenger vehicles because of its explosive nature and storage issues.
We know that hydrogen (H2), when react with oxygen (O2) it form water (H2O). This reaction is exothermic,that is heat energy will liberate in the oxidation reaction of hydrogen. Also hydrogen combustion in the atmosphere may yield small amounts of Nitrogen Oxides.
There are several direct and indirect methods to harness the energy in the hydrogen. Even though those methods are almost environment friendly, the extraction or production processes of hydrogen may affect the environment, and it requires more energy than it can be retrieved from the gas as a fuel. Here in this article we are going to discuss about different methods of harnessing energy from hydrogen, advantages and disadvantages of hydrogen as a fuel.
Methods of harnessing energy from hydrogen
1. Fuel cells
A fuel cell is a device used to convert chemical energy of a fuel to useful form through chemical reactions. There are different types of fuel cells. But the most common fuel for fuel cell is hydrogen. As name indicates there is no similarities between fuel cells and batteries. It need constant supply of fuel and oxygen to get continuous power output. The first crude fuel cell is developed by William Grove,a Welsh Physicist in 1839. A fuel cell consists of an anode,cathode and and an electrolyte. An article describing fuel cell in detail coming soon!
2. Direct combustion
The oxidation reaction between hydrogen and oxygen is exothermic. A large amount of heat energy will liberate suddenly as a result of this reaction. So direct combustion of hydrogen and oxygen can be conducted inside a cylinder piston arrangement. This technique is same as how a reciprocating petrol or diesel engine works.
Nuclear fusion reaction is another method to extract energy from hydrogen. Sun is the largest nuclear fusion reaction, where it produces large amount of heat energy by nuclear fusion of hydrogen nuclei into helium. 620 million metric tons of hydrogen get fused in the core of the Sun in each second.
Advantages of Hydrogen
1. Abundantly available
Hydrogen fuel is readily available in the earth surface. But to access the the hydrogen some work is needed.
2. Hydrogen fuel is Green
The first two methods of power generation from hydrogen are green. They do not causes any harmful emissions. The byproduct of hydrogen burning is pure water. In NASA's space ships astronauts were used this as clean drinking water.
3. Environment friendly
Hydrogen do not offer any risk to the environment when burned. So they are ideal for use in number of ways. Also hydrogen gas is nontoxic. While running it produces zero emissions.
4. Higher fuel efficiency
Hydrogen fuel has very high fuel efficiency and power than other traditional energy sources. Thrust generated per kilogram of hydrogen is very large. Or it has best and highest energy to weight ratio of all fuels. That's why they can be used as a fuel in rockets.
5. Very low ignition energy
The energy needed to ignite hydrogen gas is very less compared to other fuels.
Disadvantages of Hydrogen
It need time and work to extract hydrogen from other elements. The cost of the time and work is very large. So until technology advances enough to simplify hydrogen extraction process, hydrogen energy will continue to be too expensive.
2. Difficulty in storage and transportation
Hydrogen fuel is hard to store and transport.
3. Hydrogen is dangerous
Uncontrolled burning of hydrogen may leads to super explosion. We know the power of hydrogen fusion bomb from the incident in Japan.
4. It need extra power to extract hydrogen
Separating hydrogen from Oxygen need extra power source.
There are continues research and developments in this field. The liquefaction imposes a large energy loss, due to cooling down the gas to nearly -252.882 degree Celsius To over come this difficulty there are several suggestions from various research groups.