Chapter 9: Natural Gas Distribution System
We learned in Chapter 8 that natural gas is
a fossil fuel. It is a gaseous molecule that's made up of two atoms -
one carbon atom combined with four hydrogen atom. It's chemical formula
is CH4. The picture on the right is a model of what the molecule could
look like.
Don't confuse natural gas with "gasoline," which we call "gas" for
short. Like oil, natural gas is found under ground and under the ocean
floor. Wells are drilled to tap into natural gas reservoirs just like
drilling for oil. Once a drill has hit an area that contains natural
gas, it can be brought to the surface through pipes.
The natural gas has to get from the wells to us. To do that, there is a
huge network of pipelines that brings natural gas from the gas fields to
us. Some of these pipes are two feet wide.
Natural gas is sent in larger pipelines to power plants to make electricity or to
factories because they use lots of gas. Bakeries use natural gas to heat ovens to
bake bread, pies, pastries and cookies. Other businesses use natural gas for heating
their buildings or heating water.
From larger pipelines, the gas goes through smaller and smaller pipes to your
neighborhood.
In businesses and in your home, the natural gas must first pass through
a meter, which measures the amount of fuel going into the building. A
gas company worker reads the meter and the company will charge you for
the amount of natural gas you used.
In some homes, natural gas is used for cooking, heating water and heating the
house in a furnace.
In rural areas, where there are no natural gas pipelines, propane (another form of
gas that's often made when oil is refined) or bottled gas is used instead of natural
gas. Propane is also called LPG, or liquefied petroleum gas, is made up of methane
and a mixture with other gases like butane.
Propane turns to a liquid when it is placed under slight pressure. For regular natural
gas to turn into a liquid, it has to be made very, very cold.
Cars and trucks can also use natural gas as a transportation fuel, but they must carry
special cylinder-like tanks to hold the fuel.
When natural gas is burned to make heat or burned in a car's engine, it burns very
cleanly. When you combine natural gas with oxygen (the process of combustion), you
produce carbon dioxide and water vapor; plus the energy that's released in heat and light.
Some impurities are contained in all natural gas. These include sulphur
and butane and other chemicals. When burned, those impurities can
create air pollution. The amount of pollution from natural gas is less
than burning a more "complex" fuel like gasoline. Natural gas-powered
cars are more than 90 percent cleaner than a gasoline-powered car.
That's why many people feel natural gas would be a good fuel for cars because it
burns cleanly.