It
is a known fact that a gas plant is known in accordance with its final
output. So we have oxygen gas plant producing oxygen, nitrogen gas plant
producing nitrogen, acetylene gas plant producing acetylene and so on. This
implies that the gases available are the main raw materials used in gas
plants, without which the existence of a gas plant has no meaning.
Accordingly the manufacturers and suppliers are involved in the production
of certain gases which are useful in various industrial and commercial,
including residential applications. There are different types of gases on
the basis of which a plant is installed. We give below the description of
certain gases:
Oxygen (O2)
The most common element found in nature is oxygen. One of the major five
elements required to sustain life is oxygen. A tasteless, odorless and
colorless gas, oxygen is essential to life, it is essential for respiration
of even plants and animals. It reacts very strongly in the presence of
other chemical substances. By weight, oxygen makes up the following:
- 89% of the Earth's water
- 62% of the human body
- 46% of the Earth's crust (in the form of silicates, oxides, etc.)
- 21% of the air we breathe
Nitrogen (N2)
Mainly found in the atmosphere, nitrogen gas makes up 78% of the earth's
air, by volume. In 1772 nitrogen was discovered by chemist and physician
Daniel Rutherford who showed when oxygen and carbon dioxide are removed from
air, the residual gas, that is nitrogen, would not support combustion or
living organisms. Nitrogen is a neutral and colorless gas. From an
exhaustible source in our atmosphere, including the Earth's crust in the
form of niter, nitrates, in organic form and also in mineral form, nitrogen
gas can be obtained by liquefaction and fractional distillation. It is found
in all living systems as component of the makeup of biological compounds.
Argon (Ar)
About 0.9% argon exists in the atmosphere. It is a neutral and colorless
gas and does not exist in nature other than in the air. It is a highly
useful gas though it cannot sustain life. Argon is soluble in water in the
same amount as oxygen gas and is 2.5 times more soluble in water than
nitrogen gas. Argon gas is used in metals and manufacturing industry, iron
and steel industry, laboratories and semi conductor industry.
Hydrogen (H2)
Hydrogen is only found in the atmosphere at trace levels. But this gas is
found in abundant quantities in hydrocarbons (petroleum and petroleum
by-products). It is also found in ordinary water. Hydrogen constitutes the
lightest fraction of the H2O molecule in water. The gas is highly flammable.
A colorless and a very light gas, hydrogen cannot sustain life and reacts
easily with other chemical substances.
Carbon Dioxide (CO2)
This gas is formed from the combination of two elements: oxygen and carbon.
Carbon dioxide is produced from the fermentation of liquids, the combustion
of hydrocarbons and the breathing of humans and animals. Found in small
quantities in the atmosphere, it is mixed by plants which in turn produce
oxygen. With a slightly irritating odor, carbon dioxide cannot sustain life.
It is colorless and heavier than air. It forms carbon dioxide snow when it
freezes at -78.5 degree C. In an aqueous solution it forms carbonic acid. In
its solid state, CO
2 is commonly called dry ice, which is widely used in the
food and beverage industry.
Biogas
Biogas is that type of gas formed by the anaerobic fermentation of
biological materials. The main constituents of biogas are methane and carbon
dioxide. Considerable amount of biogas is produced by sludge digestion in
the tanks of sewage treatment plants, which can be referred to as sewage
gas. The anaerobic fermentation of organic residues and agricultural waste
and garbage tips produce biogas, referred to as landfill gas. With no net
carbon dioxide emissions, biomass is a good source of energy to be used as a
fuel and can help in reducing the use of fossil fuels. This in turn can help
to reduce the greenhouse effect.
Acetylene (C2H2)
This is not an air gas. This gas is a synthesis gas usually produced from
the reaction of calcium carbide with water. In the 19th century, acetylene
was burnt in "acetylene lamps" to light mining tunnels and homes.
Acetylene is a gaseous hydrocarbon. It has a strong garlic odor. The gas is
colorless, unstable, highly combustible. Acetylene produces a very hot flame
when combined with oxygen. Acetylene is used in machine/metal construction
for cutting and welding (with oxygen). It is also used in the glass industry
for lubrication of bottle production molds.
Krypton (Kr), Neon (Ne) and Xenon (Xe)
These gases are known as "rare" gases. They are so called because
all the three gases account for one thousandth of the air which surround us.
These gases are colorless and tasteless and cannot sustain life. They are
inert gases which do not react. These gases can only be combined with other
chemical substances with great difficulty. This extreme inertness quality in
these gases makes them very valuable for certain applications.
Gaseous Hydrocarbons (CnHm)
The basic characteristic of hydrocarbon gases is that they contain both
carbon atoms and hydrogen atoms. The carbon atoms give the flame its hot
color when burnt and the hydrogen atoms are particularly combustible. The
most well-known gaseous hydrocarbons are as follows:
- Acetylene (C2H2): The decomposition
of calcium carbide in water produce acetylene.
- Methane (CH4): It is main component of natural
gas and is also known as "marsh gas" or "pit gas".
- Ethane (C2H6): This is a petroleum
gas. It is used as a fuel.
- Ethylene (C2H4): This is a petroleum
gas. It is used to produce many synthetic products like plastics.
- Propane (C3H8): It is a common
petroleum fuel gas. Propane gas is often delivered to domestic storage
tanks.
- Butane (C4H10): This is also a
petroleum fuel gas. This gas can easily be liquefied. It is sold in
low-pressure cylinders sometimes.
Ozone (03)
This gas is formed by the combination of three oxygen atoms. With a strong
and irritating odor, it is a very unstable gas. This gas is corrosive, very
toxic. It is also a strong oxidant. It is therefore absolutely unsuitable
to sustain life. This gas is produced by generating high-power electrical
discharges in the air or in oxygen. Ozone gas is found in the upper layers
of the atmosphere. The gas serves as a shield which protects the earth from
the sun's ultraviolet radiation. The gas is used to sterilize water, bleach
textiles, neutralize odors, paper, and in certain chemical manufacturing
processes.
Types
of Gases
