Hydrogen as an Alternative Fuel

Hydrogen as an Alternative Fuel

What is Hydrogen?

The simplest and lightest fuel is hydrogen gas (H2). Hydrogen is in a

gaseous state at atmospheric pressure and ambient temperatures.

Hydrogen is being explored for use in combustion engines and fuel cell

electric vehicles. On a volumetric basis, the energy density of

hydrogen is very low under ambient conditions. This presents greater

transportation and storage hurdles than for liquid fuels. Storage

systems being developed include compressed hydrogen, liquid hydrogen,

and physical or chemical bonding between hydrogen and a storage

material (for example, metal hydrides).The ability to create hydrogen

from a variety of resources and its clean-burning properties make it a

desirable alternative fuel.

Hydrogen's physical and chemical properties make it a good candidate

for a fuel. At normal atmospheric conditions, hydrogen is a colorless

and odorless gas. It is stable and coexists harmlessly with free

oxygen until an input of energy drives the exothermic reaction that

forms water. Fuel cells also may use hydrogen as a fuel. A fuel cell

is an electrochemical engine that converts the chemical energy

contained in the hydrogen molecule into electrical energy. Hydrogen

can react with oxygen to produce electricity in a fuel cell.

Hydrogen is the lightest element occurring in nature and contains a

large amount of energy in its chemical bond. Because of its low

density, liquid hydrogen weighs less than petroleum-based fuels. The

density of gaseous hydrogen is 0.0899 grams per liter (g/l). (Air is

1.4 times as dense.) Liquid hydrogen boils at -252.77 degrees Celsius,

and it has a dens...

... middle of paper ...

...e compared to liquid fuels like gasoline or

ethanol. Hydrogen can also be cooled to produce liquid hydrogen, but

it is costly.

Hydrogen's clean burning characteristics may, one day, make it a

popular transportation fuel. For now, the problem of how to store

enough hydrogen on a vehicle for a reasonable range, and its high

cost, compared to gasoline, are critical barriers to widespread

commercial use.

Nearly all hydrogen currently is made from natural gas. For that

reason, hydrogen usually costs more than natural gas.

Hydrogen fueled vehicles

There have only been a small number of prototype hydrogen vehicles

made. Most of these have been experimental vehicles made by car

manufacturers. Nearly all of these prototype cars were equipped with

internal combustion engines, similar to ones that run on gasoline.