NATURAL GAS
NATURAL GAS
In many parts of the world large quantities of what is
called natural gas is found in association with petroleum. The gas flows to the
surface of earth through natural outlets (say spring ) form gas deposits. It is
also found dissolved in natural petroleum and is given out when the oil comes
to the oil comes to the surface. Some wells produce nothing else but gas.
The gas
emerging from gas fields is a mixture of mostly methane with small amounts of
ethane, propane and butane, nitrogen and carbon dioxide. The composition of
typical sample of natural gas is:
CH4
C2H6,C3H8,C4H
10 CO2 N2
95.0%
3.6% 0.48% 1.92%
The proportion of ingredients of the varies with
source, C2-C4 Gases are present to the extent of 20% in
the petroleum field gases.
In early days, natural gas was considered a hazard in
the petroleum industry as it formed explosive mixtures with air, and was taken
away from the source and burnt. The production and utilization of the gas dates
to the beginning of the 20th century in USA. It was not before 1950
that USSR and other countries did so. In India the gas industry is in infancy
and it is largely derived from the cracking units of petroleum refineries and
the gas fields at Cambay (Gujrat ). As compared to 172 million cu mt of gas
produced in 1961, India produced 1,424 million cu mt in 1970. In petroleum countries like USA
and USSR the gas is stored in
large steel reservoirs and distribute
through a system a system of pipe line as fuel for domestic stoves or
for boilers. Liquefied natural gas is now being transported from north Africa
to France and great Britain by tankers.
In Britain the ‘col gas’ supply for North Africa to domestic use has almost replaced by the
‘oil gas’ supply.
A liquid
mixture of propane can be butane can be obtained from natural gas or refinery
gasses at room temperature under a pressure of 3-5 atmospheres. This is stored
and distributed in 40-100liter capacity steel cylinders which can be directly
connected domestics gas stoves. The fuel gasses themselves are Odourless but to
warm against leakage a very small amount of foul smelling substance is added.
In India, the ‘bottled gas’ is being gas made available for domestic
consumption in large towns under the trade names ‘Indane’ and ‘Burshane’.
The use of liquid gas in this way obviates the need for gas pipes, which would
be both costly and cumbersome.
In USA and USSR natural gas serves as staring material
for making useful ‘Petro-Chemicals’.
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