What is Natural Gas?
Natural gas is generally considered a nonrenewable fossil
fuel. There are renewable sources of natural gas
discussed later in this info sheet. Natural gas is called
a fossil fuel because most scientists believe that
natural gas was formed from the remains of tiny sea
animals and plants that died 200-400 million years ago.
When these tiny sea animals and plants died, they sank to
the bottom of the oceans where they were buried by layers
of sand and silt. Over the years, the layers of sand and
silt became thousands of feet of thick, subjection the
energy-rich plant and animal remains to enormous
pressure. Most scientists believe that the pressure,
combined with the heat of the earth, changed this organic
mixture into petroleum and natural gas. Eventually,
concentrations of natural gas became trapped in the rock
layers much like a wet sponge traps water. Raw natural
gas is a mixture of different gases. Its main ingredient
is methane, a natural compound that is formed whenever
plant and animal matter decays. By itself, methane is
odorless, colorless, and tasteless. As a safety measure,
natural gas companies add a chemical odorant called
mercaptan (it smells like rotten eggs) so escaping gas
can be detected. Natural gas should not be confused with
gasoline, which is made from petroleum.
History of Natural Gas
The ancient peoples of Greece, Persia, and India
discovered natural gas many centuries ago. The people
were mystified by the burning springs created when
lightning ignited natural gas seeping from cracks in the
ground. They sometimes built temples around these eternal
flames so the could worship the fire.
About 2,500 years ago, the Chinese recognized that
natural gas could be put to work. The Chinese piped the
gas from shallow wells and burned it under large pans to
evaporate seawater for salt. Natural gas was first used
in America to illuminate the streets of Baltimore in
1816. Soon after, in 1821, William Hart dug the first
successful American natural gas well in Fredonia, New
York. His well was 27 feet deep, quite shallow compared
to today's wells. The Fredonia Gas Light Company opened
its doors in 1858 as the nation's first natural gas
company. By 1900, natural gas had been discovered in 17
states. In the past 40 years, the use of natural gas has
grown. Today, natural gas accounts for about 23 percent
of the energy we use.
Producing Natural Gas
Natural gas can be hard to find since it can be trapped
in porous rocks deep underground. Scientists use many
methods to find natural gas deposits. They may look at
surface rocks to find clues about underground formations.
The may set off small explosions or drop heavy weights on
the surface and record the sound waves as they bounce
back from the rock layers underground. They also may
measure the gravitational pull of rock masses deep within
the earth. If test results are promising, the scientists
may recommend drilling to find the natural gas deposits.
Natural gas wells average 6,100 feet deep and can cost a
hundred dollars per foot to drill, so it's important to
choose sites carefully.
Only about 48 percent of the exploratory wells produce
gas. The others come up dry. The odds are better fro
developmental wells-wells drilled on know gas fields. On
average, 85 percent of the developmental wells yield gas.
Natural gas can be found in pockets by itself or in
petroleum deposits.
After natural gas comes out of the ground, it goes to a
processing plant where it is cleaned of impurities and
separated into its various components. Approximately 90
percent of natural gas is composed of methane, but it
also contains other gases such as propane and butane.
Natural gas may also come from several other sources. One
source is the methane gas found in coal beds. Until
recently, coal bed gas was just considered a safety
hazard to miners, but now it is a valuable source of
natural gas. Another source of natural gas is the gas
produced in landfills. Landfill gas is considered a
renewable source of natural gas since it comes from
decaying garbage. The gas from coal beds and landfills
accounts for six percent of the total gas supply
today-that could double by the year 2010.
The gas recovered from landfills is usually burned on the
landfill site to generate electricity for the facility
itself. Today, natural gas is produced in 32 states,
though just three states-Texas, Louisiana, and
Oklahoma-produce 60 percent of the country's natural gas.
Altogether, the United States produces about 25 percent
of the world's natural gas each year.
Transporting and Storing Natural Gas
How does natural gas get to you? Usually by pipeline.
More than one million miles of underground pipelines link
natural gas fields to major cities across the United
States. Natural gas is sometimes transported thousands of
miles by pipeline to its final destination.
A machine called a compressor increases the pressure of
the gas, forcing the gas to move along the pipelines.
Compressor stations, which are spaced about 50 to 100
miles apart, move along this subterranean highway is
temporarily stored in huge underground reservoirs. The
underground reservoirs are typically filled in the summer
so there will be enough natural gas during the winter
heating season. Eventually, the gas reaches the city gate
of a local gas utility. The pressure is reduced and an
odorant is added so leaking gas can be detected. Local
gas companies use smaller pipes to carry gas the last few
miles to homes and businesses. A gas meter measures the
volume of gas a consumer uses.
Natural Gas Use
Just about everyone in the United States uses natural
gas. Natural gas ranks number three in energy use, right
after petroleum and coal. About 23 percent of the energy
we use in the United States comes from natural gas.
Industry is the biggest consumer of natural gas, using it
mainly to manufacture goods. Industry also uses natural
gas as an ingredient in fertilizer, photographic film,
ink, glue, paint, plastics, laundry detergent, and insect
repellents. Synthetic rubber and man-made fibers like
nylon also could not be made without the chemicals
derived from natural gas.
Residences-people's homes-are the second biggest users of
natural gas. Six in ten homes use natural gas for
heating. Many homes also use gas water heaters, stoves,
and clothes dryers. Like residence, commercial use of
natural gas is mostly for heating-including stores,
offices, schools, churches, and hospitals. Natural gas is
also used to make electricity. Many people in the energy
industry believe natural gas will play a bigger role in
electricity production as the demand for electricity
increases in the future.
Natural gas power plants are cleaner than coal plants,
and can be brought on-line very quickly. Natural gas
plants produce electricity about 20 percent more
efficiently than new coal plants, and produce it will
fewer emissions. In 1998, natural gas produced 15 percent
of the electricity in the United States. To a lesser
degree, natural gas is becoming popular as a
transportation fuel. Natural gas can be used in any
vehicle with a regular internal combustion engine,
although the vehicle must be outfitted with a special
carburetor and fuel tank. Natural gas burns cleaner than
gasoline, costs less, and has a higher-octane (power
boosting) rating. In 1998, nearly 100,000 vehicles ran on
natural gas in the United States.
Natural Gas Reserves
People in the energy industry use two special terms when
they talk about how much natural gas there is-resources
and reserves. Natural gas resources include all the
deposits of gas that are still in the ground waiting to
be tapped. Natural gas reserves are only those gas
deposits that scientists know, or strongly believe, can
be recovered given today's prices and drilling
technology. In other words, when scientists estimate the
amount of known gas reserves, they do not include gas
deposits that may be discovered in the future or gas
deposits that are not economical to produce given today's
prices.
Think of reserves this way. If it cost you $10 to
manufacture a toy that you could sell for $8, would you
make the toy? Of course not. You would lose $2 on every
toy. The United States has large reserves of natural gas.
Most reserves are in the Gulf of Mexico and in the
following states: Texas, Louisiana, Oklahoma, New Mexico,
Wyoming, Kansas, and Alaska. If we continue to use
natural gas at the same rate as we use it today, the
United States has about a 50-year supply of natural gas,
though another 200 years of additional gas supplies could
be produced if people are willing to pay more for the gas
they use.
Natural Gas Prices
Since 1985, the market has set natural gas prices. The
federal government sets the price of transportation for
natural gas that crosses state lines. State public
utility commissions will continue to regulate natural gas
utility companies-just as they regulate electric
utilities. These commissions regulate how much utilities
may charge their customers, and they monitor the
utilities' policies.
So how much does it cost to hear your home with natural
gas? Compared to other energy sources, natural gas is a
good buy. Heating with natural gas is cheaper than any
other major heating source. It is nearly four times
cheaper than electricity when you use resistance heat and
is 25 percent less expensive than electric heat pumps.
However, this has changes dramatically of the past six
months with the gas shortages.
Natural Gas and the Environment
All the fossil fuels-coal, petroleum, and natural
gas-release pollutants into the atmosphere when burned.
The good news is that natural gas is the most
environmentally friendly fossil fuel. Burning natural gas
produces less sulfur, carbon, and nitrogen than burning
other fossil fuels. Natural gas also emits little ash
particulate into the air when it is burned. Like all
fossil fuels, burning natural gas produces carbon
dioxide, a greenhouse gas. Many scientists believe that
increasing levels of carbon dioxide in the atmosphere
caused in large part by fossil fuel use could have
long-term affects on global climate.
In 1997, the United States and many other industrialized
countries agreed upon a plan to reduce emissions of
greenhouse gases. This treaty, called the Kyoto Protocol,
has been signed by the United States, but not approved by
the Senate. Most experts doubt that it will be approved
in its present form, because it exempts emerging
countries such as China, which will soon surpass the
United States as the top emitter of greenhouse gases.
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