Fuel Cell as an Alternative Energy Source Report

Introduction

A fuel cell can be defined as an electrochemical device that uses chemical energy to produce electric power. This process is in the presence of an electrolyte and result into minimal emissions. For the fuel cell to operate continuously the reactants must flow into the cell, and the products out of the cell and the electrolyte must remain within the cell (John & Shahed, 2002).

Although the fuel cell generate power much like the batteries they are different in that they consume reactants from external source which must be replenished while the battery store electric energy chemically (John & Shahed, 2002).

Fuel cell processes

Through the process of catalysis, fuel cell works to separate the reactant fuel components into protons and electrons and hence converting the electrons into electrical energy when they pass through the circuit. The catalyst comprise of platinum metal or alloy. Through another process the electrons are forced back in thus combining with the protons to produce a waste water and carbon dioxide.

An ordinary fuel cell produces a voltage of a bout 0.6V to 0.7 V of related load (Galen, 2001). To attain a desired amount of energy the fuel cells can be arranged either in series or parallel circuits. Whereas series circuit yield more amount of energy, the parallel arrangement allows a stronger current to be drawn – fuel set back (Galen, 2001).

In the beginning the use of fuel cell was constrained to short distances but due to economic growth and the have a low cost, carbon dioxide free transport system accelerated the need for fuel cell (Brain, 2003).

All cell have both positively and negatively charged electrodes and an electrolyte sandwiched between them, they can achieve an efficiency of 40 to 70 percent and thus making them much ore efficient than the internal combustion engines. Although high efficiency means more power being drawn from the cell, the more the power drawn the less the life span of the fuel cell (Brandsher, 2002).

The various types of fuel cells include:

1. Phosphoric Acid- this is commonly used commercially and generates electricity at efficiency of 40 percent and above.
2. Proton Exchange Membrane-it is most used in passenger car applications and operates in relatively low temperature and high power density.
3. Molten Carbonate- this allows for h9igh con version of fuel – to – electricity and can utilize coal based fuels.
4. Solid Oxide- this is mostly used in places that require high power application. It has an efficiency of 60 percent power generation.
5. Alkaline- although it can reach a 70 percent power generating efficiency it is considered expensive for transport application and it’s only used for space programmes.
6. Direct Methanol- the cell extract hydrogen from methanol and can reach an efficiency of 40 percent in low temperatures.
7. Regenerative- this fuel cell separates water into Hydrogen and Oxygen while utilizing solar energy (Brandsher, 2002).

Because impurities causes catalyst poisoning in low temperature fuel cells, Proton Exchange, Direct Methanol and phosphoric acid fuel cell, platinum catalyst is widely. Due to this high hydrogen purity or higher catalytic densities are required. In high temperature fuel cells, molten carbonate, alkaline, and solid oxide, a cheaper material is used such as nickel or nickel oxide. These cells do not suffer from catalytic poisoning and thus they do not need high hydrogen purity to operate. This gives them an advantage over the low temperature fuel cells (John & Shahed, 2002).

Over the years air pollution has posed a major threat to citizens in the industrialized world. The exposure to particulate of ozone, carbon dioxide and air borne toxic chemicals has posed a greater threat to their health. But the danger caused by air pollution is not only to the human but also the environment in general, vegetation has dried up, ice caps have melted and deserts have increased in both size and heat intensity and all this have been attributed to air pollution (Bradsher, 2002).

In order to reduce global warming and improve the quality of air in the world, a more improved and suitable system that minimizes the emission of green house gases and particularly carbon dioxide by 80 percent should be developed. This has been seen in the use of fuel cell whose by-products are mainly water, oxygen and heat and l very minimal amounts of carbon dioxide as compared to gasoline which produces carbon dioxide, sort and lead when used in vehicles (Galen, 2001).

One of the environmentally positive sides, fuel cell emits very minimal air pollutants and this exempts them from air pollution requirement permits thus saving thousands of dollars annually. The use of fuel cell has drawn the attention of both the policy makers and the environmentalist, this is due to the fact that the use fuel cell have helped in achieving both energy and environmental goals, for instant reducing the emission of carbon dioxide by 80 percent. In areas where there is lots of smog in the air the fuel cell vehicles offer a 98 – 100 cleaner thus having a major air quality benefit to these areas. This reduces chances of contracting respiratory diseases in these areas (John & Shahed, 2002).

The uses of fuel cell have also helped in reducing the alarming impact caused by global warming. This is achieved through the fact that the fuel cell help in reducing the emission of heat trapping gases by 80-100 percent. When Natural gases are used, fuel cell help reduce the emission of the heat trapping gases by 60- 70 percent (Galen, 2001).

Conclusion

Even in fuel cell, electricity generation pollution may occur from plants generating electricity required to produce hydrogen which is used as a power source, for instant, when coal or natural gas is used more pollution will occur. Thus to attain a pollution free state the electricity must be generated from a pollution free system which may include; solar, biomass wind energy or other clean sources. Thus one should adopt a holistic point of view where one should make sure that the hydrogen being used for electrolysis comes from a clean source of energy. This ensures that the pollution is minimized (Bradsher, 2002).

Work cited

1. John, Bockric & Shahed, Khan. Surface Electrochemistry, A Molecular Level Approach, 2002.
2. Bradsher, K.High.,SUVS- The World Most Dangerous Vehicles & How They Got That Way. New York, Perseus Books Group, 2002.
3. Brain, Marshall, Marshall Brain’s More on How Stuff Work. New York, Wiley, 2003.
4. Galen R, Frysinger., A Hydrocarbon- Air Fuel Cell Using an Acid Electrolyte, 2001.