Mercurial Essays

Free Essays & Assignment Examples

Hydrogen (1101 words)

HydrogenHydrogen in it’s liquid form has been used in space vehicles for years.

Hydrogen has a high combustion energy per pound relative to any other fuel,
meaning hydrogen is more efficient on a weight basis than fuels currently used in
air or ground transportation. Hydrogen is the universe’s most abundant element.

Most of that hydrogen though, is tied up in chemical bonds. Hydrogen can exist in
either a gaseous form or a liquid form. Hydrogen is The liquid form is usually used
for storage while the gaseous form is used as a heat transfer, and also as a cooling
agent in nuclear power plants. The name hydrogen is Greek for water former.

Hydrogen was once called ?inflammable air? by a British scientist names Joseph
Priestly . French chemist Antoine Laurent Lavoisier then renamed it to today’s
name, hydrogen.

Hydrogen can be produced in many ways. Electrolysis is a common way
hydrogen is produced. Electric current is passed through water which releases the
elements it is made of. These elements are hydrogen and oxygen. Today’s
efficiency of this method is about 65 percent, however 80-85 percent are possible
with more research. Another method of producing hydrogen is through chemical
means. It is a scientific fact that every metal that is less noble than hydrogen will
displace hydrogen from water . Common materials used in this reaction is sodium
or potassium . Sodium plus water will produce hydrogen , NaOH, and heat . Other
reactions include the ?producer? reaction that was discovered in 1800 . It involves
combining heat, carbon, and water. It then yields hydrogen and carbon monoxide .

Bacteria can also be a hydrogen producer. Bacteria and other microorganisms may
release hydrogen in the process of creating heavier hydrocarbons or oxygen for
assimilation . A process known as Photoconversion or photosynthesis involves
light combining with water, which produces hydrogen and oxygen .

Hydrogen can be stored in a variety of ways. Compressed gas storage and
transportation has been widely used for more than 100 years. Common materials
for storage canisters are mild steel, aluminum, and composites. Storage pressure
for hydrogen ranges from 3,000 to 10,000 P.S.I . Cooling hydrogen to below the
boiling point of -252.7? C allows storage as a cryogenic liquid without the need for
pressurization . Cryogenic storage of hydrogen allows regular commercial
shipment by truck and rail. Many commercial processes such as glass
manufacturing, brazing, heat treating, and semiconductor manufacturing are served
by deliveries of liquid hydrogen. Liquid hydrogen has also facilitated the U.S.

space exploration program. If liquid hydrogen is suddenly subjected to a vacuum it
will evaporate with a subsequent cooling of the liquid mass will cause the
temperature to fall to below the freezing point of -259? C and solid hydrogen will
be produced . This mixture of liquid and solid hydrogen is called ?slush? and
provides more dense storage of hydrogen than liquid hydrogen. Hydrogen can also
be stored in metal hydrides . Hydrogen is pumped into the interaom spaces of a
granular metal. When the hydrogen needs to be released the metal is heated. This
system is reliable and compact, but is very expensive.

The energy from hydrogen can be harnessed in many ways. One method of
doing this is using a fuel cell. A fuel cell is a device that converts chemical energy
directly into electricity via a modified oxidation process . The process also
produces heat, water, and carbon dioxide. By-products such as nitrous oxide and
sulfur are eliminated because of the low reaction temperatures of 200? – 500? C.

Fuel cells create electricity more efficient than mechanical systems because a fuel
cell has no moving parts. The absence of moving parts allows them to run quietly.

Fuel cells operate in reverse of electrolysis. In a fuel cell hydrogen and oxygen
stream pass through porous metal plates separated in an electrolyte bath. The
plates have a single connection to each other which is outside the electrolyte bath.

The oxygen molecules are combined with the hydrogen modules which creates
heat and water. The heat is then captured and turned into electricity.

The first fuel cell was constructed by Sir William Groves in 1839 . He
used platinum electrodes and sulfuric acid as the electrolytbath . A significant
amount of research was done in the 1920’s in Germany which laid the groundwork
for today’s fuel cells. One of the most important accomplishments in the history of
fuel cells was the accomplishments of Francis T. Bacon. He developed the Bacon
Cell. The Bacon Cell substitutes potassium hydroxide for the regular acid which
was corrosive on the electrodes . The Bacon Cell was selected by NASA to be
used in the Apollo missions and the space shuttles as the primary electrical fuel
source. Fuel cells are manufactured throughout the world, including in South
Windsor, Connecticut. International Fuel Cells, a subsidiary of United
Technologies, is the world’s largest manufacturer of fuel cells. This company
produced the Bacon Cell, that went into space.

Today’s gasoline engines can be fairly easily converted to run on hydrogen.

The biggest cost involvement is in purchasing the tank, however in some cities
they can be leased or rented. Engines can also be made to run on hydrogen
initially. These would be more effective since they were built to take advantage of
the fast-burn and far-lean combustion characteristics of hydrogen. Many auto
makers including BMW and Mazda have already made prototype hydrogen cars, to
hit the market around the year 2000 . When hydrogen pumps are developed and
placed at gas stations, hydrogen will only cost about 75 cents a gallon, compared
to the high prices of gasoline . There are still other uses for hydrogen. It is
currently being used in stationary turbines and aircraft engines. In 1980 a propeller
plane was fitted to run on hydrogen in an air show.

As the public notices the advantages of hydrogen, it popularity will
increase. Hydrogen is a clean and efficient fuel but it can be dangerous at times.

Hydrogen is both flammable and buoyant. It is more flammable than gasoline or
natural gas, but it dissipates more rapidly of either of these two fuels in a spill.

Like all gases hydrogen should be used in a ventilated area.

Since 1766 hydrogen has been a part of the world. First appearing as
?inflammable air? and then hydrogen. Hydrogen is a flexible material in that it can
be harnessed many ways and be utilized in many ways. In fact if the US beings to
use solar hydrogen California, Arizona, and other sunny states would be richer
than Saudi Arabia . Hydrogen will be the key source of energy for the future. As
of today hydrogen is the safest and most economical way to move energy across
the ocean . In fact, if we being to use hydrogen on a large-scale basis we would
actually reverse the greenhouse effect. The switch to hydrogen will make the
world a better place to live. The hydrogen market will cut pollution, provide
cheaper transportation, and create more jobs. If safe power is the question,
hydrogen is the answer.