22-05-2012, 01:20 PM
AN INTRODUCTION TO FUEL CELLS AND HYDROGEN TECHNOLOGY
AN INTRODUCTION TO FUEL CELLS AND HYDROGEN TECHNOLOGY.docx (Size: 2.31 MB / Downloads: 43)
AN INTRODUCTION TO FUEL CELLS AND HYDROGEN TECHNOLOGY
Whereas the 19th Century was the century of the steam engine and the 20th Century was the century of the internal combustion engine, it is likely that the 21st Century will be the century of the fuel cell.
Full cells are now on the verge of being introduced commercially, revolutionizing the way we presently produce power. Fuel cells can use hydrogen as a fuel, offering the prospect of supplying the world with clean, sustainable electrical power.
WHAT IS A FUEL CELL?
A fuel cell by definition is an electrical cell, which unlike storage cells can be continuously fed ith a fuel so that the electrical power output is sustained indefinitely (Connihan, 1981). They onvert hydrogen, or hydrogen-containing fuels, directly into electrical energy plus heat through the electrochemical reaction of hydrogen and oxygen into water. The process is that of electrolysis in reverse.
Overall reaction: 2 H2(gas) + O2(gas) → 2 H2O + energy (Eq.1)
Because hydrogen and oxygen gases are electrochemically converted into water, fuel cells have many advantages over heat engines. These include: high efficiency, virtually silent operation nd, if hydrogen is the fuel, there are no pollutant emissions. If the hydrogen is produced from renewable energy sources, then the electrical power produced can be truly sustainable.
The two principle reactions in the burning of any hydrocarbon fuel are the formation of water and carbon dioxide. As the hydrogen content in a fuel increases, the formation of water ecomes more significant, resulting in proportionally lower emissions of carbondioxide (Fig. 1). As fuel use has developed through time, the percentage of hydrogen content in the fuels has increased. It seems a natural progression that the fuel of the future will be 100% hydrogen.