A fuel cell may be defined as a device that converts chemical energy from a fuel into electricity through a chemical reaction. The chemical reaction occurs in the presence of oxygen or an oxidizing agent.
Hydrogen fuel cells are cells that contain hydrogen as the fuel. Hydrogen fuel is a zero emission fuel that releases energy during combustion or through electrochemical reactions. Fuel cells and batteries produce an electric current through a chemical reaction, but a fuel cell will produce energy as long as there is fuel, thus never losing its charge.
Sourced from: Think Stock
Hydrogen is the simplest and most abundant element in the universe. Despite its abundance, hydrogen is rarely found in its pure form. Water is the chief source of hydrogen, hydrocarbons being the next in line in sources of hydrogen. Hydrogen can be extracted from its sources quite easily, in both renewable and non-renewable sources. Hydrogen fuel cells are one of the best option when switching over to sustainable energy systems.
Production of Hydrogen
Hydrogen can be obtained from its chief sources, hydrocarbons and water, by following the below mentioned methods. Hydrogen can also be obtained from organic enzymes.
Electrolysis of Water – when an electric current is passed through water, it dissociates into its elements oxygen and hydrogen. Hydrogen, being positive, can be attracted by a cathode and oxygen, being negative, by an anode. This method of producing hydrogen is being used at hydrogen refueling stations.
Reforming of Hydrocarbons – hydrocarbons such as methanol, ethanol, petroleum and natural gas are rich sources of hydrogen. The process of extracting hydrogen from hydrocarbons is called reforming.
Operation of a Hydrogen Fuel Cell
The basic construction of a hydrogen fuel cell consists of two electrodes, an electrolyte, a fuel (hydrogen) and a power supply. An electrolyte that separates the two electrodes is an ion conducting material which facilitates the free passage of ions. In a fuel cell, an oxidizing agent (or oxygen) is made to flow through a fuel (hydrogen). Hydrogen and oxygen combine to form water and generate heat. At the anode, hydrogen is stripped of its electron and its proton is made to pass through the electrolyte. The electron is made to pass through an external DC (direct current) circuit to power devices.
For enhanced power generation, a series of fuel cells may be used.
Advantages and Disadvantages of Hydrogen Fuel Cells
The advantages of using hydrogen fuel cells are listed below:
- Hydrogen is an abundant resource
- Fuel cells do not emit harmful emissions
- Hydrogen gas is non-toxic and does not produce any harmful byproducts
- High efficiency and powerful energy production
- Hydrogen fuel cells are highly fuel efficient
- Hydrogen is a renewable source of energy
However, there are some disadvantages of using hydrogen fuel cells, as mentioned below:
- Expensive to construct and maintain
- Storage of hydrogen gas is difficult
- Compressed hydrogen gas is highly flammable
Applications of Hydrogen Fuel Cells
Some of the applications of hydrogen cells are listed below:
- Used to fuel rockets (and can even provide water supply through pure H20 emissions)
- Used for powering residential areas
- Used to power cars and airplanes