Hydrogen
Hydrogen 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 -252.7º
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 -259º 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 200º - 500º 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.