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Hydrogen Fuel Cells

posted Oct 18, 2011 00:31:44 by izack.beaudry
Hydrogen Fuel Cell Car Technology

The quest for a pollution-free energy source has been the goal of the auto industry almost since its beginning. Its pursuit has become more grave in recent decades with the environment showing signs of irreversible damage from fossil fuels and the fear that this resource is running out. Fuel cells in one form or another have been in existence for over 160 years and are now the focus of aggressive research and development. Today, fuel cell powered vehicles are projected to go into production for personal use by the end of the decade. Many environmental and economic forces are actively involved in bringing this to fruition. The oil industry, the automobile industry, and other giant corporations have more than a casual interest in seeing the fuel cell become the leading energy source for the future.
Fuel Cell Concept Toyota Fine-S

The public is already being primed for the day when the first production models are shipped to showrooms. To make intelligent decisions about this technology, a better grasp of its application will be helpful. The science behind the product gives some clues about how this technology will be implemented, and what problems lie ahead. There are a number of critical hurdles that must be overcome before fuel cells provide a viable solution for the impending transportation crisis.
Fuel Cell Benefits

Fuel efficiencies of between 30% and 90% can be achieved by converting fuel directly into electrical energy.
Fossil fuel combustion leads to byproducts that are known to damage the environment. In fuel cell systems using hydrogen as the fuel, the only byproducts of the electrochemical reaction are electricity, heat, and water.
Extracting fossil fuels from the earth comes with its own set of environmental hazards, not found in the process associated with generating fuel cell hydrogen. The environmental impact of fuel cell technology is pleasingly miniscule.
A fuel cell's simplicity of design, with no moving parts, offers the benefits of quiet operation and reliability.
Hydrogen can be produced a number of ways domestically, relieving the stress of overseas petrochemical dependence.

Fuel Cell Risks

The gamble of mass-market acceptance rides on allaying concerns of reliability, longevity, availability and cost of fuel. The cost of fuel cell technology needs to be low enough to spur acceptance.
The infrastructure for the delivery and storage of fuel cell fuels does not currently exist. To create convenient and affordable fueling stations, the public will rely on the oil and gas industries to introduce them.
For yet unforeseen reasons, fuel cell technology may not be suitable for automotive applications. Hybrid technology is currently gaining popularity and will potentially slow the enthusiasm and requisite research on fuel cell technology.
Platinum is an important component in the fuel cell electrochemical reaction. It is also a scarce earth resource that could be prone to shortages.

The Physics behind the Hydrogen Fuel Cell

Fuel cells can be looked at as a type of battery which generates but does not store electrical energy. In the common alkaline battery, electricity is created through an electrochemical reaction, whose ingredients are eventually exhausted. In a fuel cell, electricity is created by a different set of reactants, and the two ingredients that cause the reaction, hydrogen and oxygen, can be replenished. The byproducts of the process are pure water and heat. Shuttle astronauts rely on fuel cell technology to power their life-support systems and other critical functions.
Fuel Cell - How It Works

A simple fuel cell is composed of two electrodes, an anode and a cathode. These are sandwiched onto an proton exchange membrane (PEM) which permits the transfer of protons from the anode to the cathode. The reaction occurs when hydrogen is introduced onto the surface of the anode and its protons and electrons separate. The electrons travel along the circuit while the protons unite with oxygen to form water. The byproducts of the electrochemical reaction, water and heat, can be recycled to improve the efficiency of the system. 35% to 90% efficiencies can be achieved depending on whether the waste heat is utilized.

Hydrogen flows into the fuel cell on the anode side.
Platinum catalyst facilitates the separation of the hydrogen gas into electrons and protons (hydrogen ions) in a proton exchange membrane or PEM fuel cell.
Protons travel through the PEM to the cathode, where the catalyst helps the protons bond to oxygen to produce water.
The electrons, to which the membrane is impermeable, flow through a circuit containing a motor or other device which consumes the power generated by the cell.
As long as the device is supplied with hydrogen and oxygen, the electrochemical reaction proceeds and the electrical current flows.

Fuel Cell - Promise of Renewable and Clean Energy

Only the future will tell whether the use of fuel cell technology will live up to its potential as a clean and viable energy source. Oil companies have a jump start on implementing the technology with an infrastructure similar to that necessary to generate, store, and dispense hydrogen. Auto manufacturers seem to be, at least in the present, jumping on the hybrid vehicle band wagon. Both technologies hold considerable promise.
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