What Is Natural Gas and History of Use
Natural gas is generally
considered a nonrenewable fossil fuel. (There are some renewable sources
of natural gas; we'll discuss these later.) 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 thick, subjecting 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 household 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 (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
The ancient peoples of
Greece, Persia, and India discovered natural gas many centuries ago. The people
were mystified by the burning springs created when natural gas seeping from cracks
in the ground was ignited by lightning. They sometimes built temples
around these eternal flames so they 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 sea
water 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 dramatically.
Today, natural gas accounts for about a quarter 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. They 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 6,000 feet deep and can cost more than $75
per foot to drill, so it's important to choose sites carefully. On average, 27
out of every 100 exploratory wells produce gas. The others come up
"dry." (The odds are better f or developmental wells-wells
drilled on known gas fields. On average, 80 out of every 100 developmental
wells yield gas.) Natural gas can be found in pockets by itself or in petroleum
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 small amounts of
other gases such as propane and butane.
Natural gas may also come
from several other sources. One source is the gas found in coalbeds. Until recently,
coalbed 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
coalbeds and landfills accounts for three percent of the total gas supply
today, yet their contribution could double by the year 2010.
Today natural gas is
produced in 32 states, though just three states--Texas, Louisiana, and
Oklahoma-produce 61 percent of the country's natural gas. Altogether, the
United States produces nearly 22 percent of the world's natural gas each year.
In 1994 the United States imported 12 percent of its natural gas from other
countries-mostly from Mexico and Canada.
Storing Natural Gas
How does natural gas get
to you, the consumer? 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 the gas along the
pipelines at about 15 miles per hour.
Some gas moved 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. Here, 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.
Who Uses Natural Gas and How Much?
Just about everyone in
the United States uses natural gas. Natural gas ranks number three in energy
use, right after petroleum and coal. Twenty-three 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 are people's
homes. Residences 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
commercial use of natural gas is mostly for heating. Commercial use includes
stores, offices, schools, churches, and hospitals.
Natural gas is also used
to make electricity. Just as the heat energy in coal is used to make
electricity, so can the heat energy in natural gas. 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. Why? Because natural gas
power plants are cheaper and cleaner than coal plants. Natural gas plants
produce electricity about 20 percent more efficiently than new coal plants, and
they produce it with far fewer air-polluting emissions.
To a lesser degree,
natural gas is making inroads 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 is
cleaner burning than gasoline, costs less, and has a, higher octane (power
boosting) rating. Today more than 30,000 cars, trucks, and buses run 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. (You can think of reserves this
way. if it cost you $10 to manufacture a box of yoyos that you could sell for
$8, would you make the yoyos? Of course not! You would lose $2 on every box.)
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.
New Ways to Use and
Produce Natural Gas
Because natural gas is
cleaner than coal or petroleum, scientists are researching new ways to use and
Many scientists are
interested in using natural gas to generate electricity. Engineers have already
developed ways to use coal/petroleum and natural gas together to generate
electricity, but a device called a fuel cell can use natural gas alone. A fuel
cell is similar to a battery. It uses a chemical process rather than combustion
(burning) to convert the energy of a fuel into electricity. The chemical
process is much more energy-efficient than combustion and it emits no
air pollutants. Unfortunately, the technology to generate electricity from fuel
cells must be improved if it is to be commercially successful.
Scientists are also
researching new ways to obtain natural (methane) gas from biomass--a fuel
source derived from plant and animal wastes. Methane gas is naturally produced
whenever organic matter decays. Today we can drill shallow wells into landfills
to recover the methane gas. Landfills are already required to collect methane
gas as a safety measure. Typically, landfills collect the gas and bum it to get
rid of it. But the gas can be put to work. Last year over four billion cubic
feet of landfill methane gas was used for heating and electricity production.
There are other ways to
convert biomass into natural gas. One method converts aquatic plants, such as
sea kelp, into methane gas. In the future, huge kelp farms could also produce
renewable gas energy.
Liquid Natural Gas
development has been the conversion of natural gas into a liquid state. In its
liquid state, natural gas is called LNG, or liquid natural gas.
LNG is made by cooling
natural gas to a temperature of minus 260 degrees F. At that temperature,
natural gas becomes a liquid and its volume is reduced 615 times. (A car
reduced 615 times would fit on your thumbnail.) Liquid natural gas is easier to
store than the gaseous form since it takes up much less space. LNG is also
easier to transport. People can put LNG in special tanks and transport it on
trucks or ships. Today more than 100 LNG storage facilities are operating in
the United States.
Natural Gas Prices and the Environment
Since 1985, natural gas
prices have been set by the market. 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'
So how much does it costs
to heat your home with natural gas? Compared to other energy sources, natural
gas is a good buy. Heating your home with natural gas is cheaper than any other
major heating source. It is more than four times less expensive than
electricity when you use resistance heat. It is 25 percent less expensive than
electricity when you use a heat pump.
Natural Gas and the
All the fossil fuels
coal, petroleum, and natural gas-release pollutants into the atmosphere when
burned to provide the energy we need. The list of pollutants they release reads
like a chemical cornucopia-carbon monoxides, reactive hydrocarbons, nitrogen
oxides, sulfur oxides, and solid particulates (ash or soot).
The good news is that
natural gas is the most environmentally friendly fossil fuel. It is cleaner
burning than coal or petroleum because it contains less carbon than its fossil
fuel cousins. Natural gas also has less sulfur and nitrogen compounds, and it
emits less ash particulates into the air when it is burned than coal or