Future in a Fuel Cell

In the age of climate change, everyone is keen to help promote an alternative future for automotive transportation. The Oil Age may soon be over, and the time of cheap oil has definitely come to a close. Innovation demands a new source of power for humanity’s cars and trucks. Biodiesel, ethanol, solar electric, compressed air and even steam powered systems are being rushed into development as the world consumes 85 million barrels of crude oil everyday. Fuel Ghoul believes that mankind’s next energy source will be wonderfully simple and infinitely practical, totally green and one hundred percent renewable.

Hydrogen fuel cells might form half of the solution – extracting the hydrogen (to power the fuel cells) is the other half of the equation.

When Fuel Ghoul asks scientists 'What is the perfect automotive energy source?’ they inevitably answer, ‘hydrogen’. And when Fuel Ghoul asks them how they would turn that element into energy they simply reply ‘fuel cells’, even though the science isn’t one hundred percent obvious yet, and the process of securing the hydrogen has yet to become cost effective.

Today, fuel cells are often mentioned in the news. Some say hydrogen fuel cells will be the most widely used. Others say methanol or ethanol would be more appropriate for the transportation sector. And there are even some visionaries who believe mankind will be refining gasoline for a long time yet, and that fossil fuels will only be eclipsed by the dawn of fusion power.

With an eye on the future, Fuel Ghoul took the time to read up on fuel cells. These handy devices are designed similar to batteries except they don’t store energy – they convert the chemical energy of the input material directly into electricity. The principle of the fuel cell was developed by William Grove in 1839.

What is a hydrogen fuel cell?


A fuel cell is an electrochemical device that combines hydrogen and oxygen to produce electricity, with water and heat as its by-product. As long as fuel is supplied, the fuel cell will continue to generate power. Various types of fuel cells exist, but the one automakers are primarily focusing on for fuel cell cars is one that relies on a proton-exchange membrane, or PEM.

A simple hydrogen fuel cell consists of two conductors (an anode and a cathode) separated by an ionic conductor – an electrolyte (eg, a salt solution). Hydrogen is pumped to the anode, and oxygen to the cathode. Hydrogen reacts with charged particles (ions) in the electrolyte, producing water and electrons. The electrons leave the fuel cell along wires; this is the DC electricity generated by the cell.

The electrons return to the fuel cell cathode where they combine with oxygen and water to form ions which replace those consumed at the anode. And so the cycle continues, with hydrogen and oxygen being turned into water while generating electricity.

Fuel cells in space

One hydrogen fuel cell can generate up to 1.2 volts of DC electricity. Individual cells can be wired together to produce greater voltages or higher current. The space shuttle has 96 individual cells arranged in three stacks. When hydrogen and oxygen are pumped into the shuttle's fuel cells, they generate 28 volts of direct current as well as heat and water. The heat is put to good use, vaporizing the liquid fuels before they reach the fuel cells. Water flows into storage containers for drinking and other uses.

Fuel Cells: Chapter Two



Today, hydrogen and oxygen are commonly used as the fuel and oxidant. The electrodes are made of porous carbon plates which are laced with a catalyst (a substance that accelerates chemical reactions). The electrolyte is usually potassium hydroxide. At the anode, the hydrogen gas combines with hydroxide ions to produce water vapor. This reaction results in some left over electrons. These excess electrons are forced out of the anode and produce DC electric current. At the cathode, oxygen and water plus returning electrons from the circuit form hydroxide ions which are again recycled back to the anode. The basic core of the fuel cell consisting of the manifolds, anode, cathode and electrolyte is generally called the stack.

There are three types of fuel cells that appear to be the most promising. The Solid Oxide Fuel Cell or SOFC is the most likely contender for both large and small electric power plants. The Direct Alcohol Fuel Cell or DAFC appears to be the most promising as a battery replacement for portable applications such as cellular phones and laptop computers. The Alkaline Fuel Cell AFC has been used in space applications where hydrogen and oxygen are available.

Its easy to see why scientists love fuel cells – they have a lot of obvious advantages. Firstly, fuel cells produce almost no emissions at the tailpipe (securing the hydrogen could be messy though) and secondly the technology is safe and reliable, modular, lightweight and quiet. Fuel Cells really are tomorrow’s perfect power plants.

Fresh ideas about alternative fuel, climate change and planet Earth's new energy diet.


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