Модуль 3 - Passive Voice, особенности (1096807), страница 6
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But the main deposits of fossil fuels are from the Carboniferous Period.As the trees and plants died, they sank to the bottom of the swamps of oceans. They formed layersof a spongy material called peat. Over many hundreds of years, the peat was covered by sand andclay and other minerals, which turned into a type of rock called sedimentary.More and more rock piled on top of more rock, and it weighed more and more. It began to pressdown on the peat.
The peat was squeezed and squeezed until the water came out of it and iteventually, over millions of years, it turned into coal, oil or petroleum, and natural gas.CoalCoal is a hard, black colored rock-like substance. It is made up of carbon, hydrogen, oxygen,nitrogen and varying amounts of sulphur. There are three main types of coal – anthracite,bituminous and lignite.
Anthracite coal is the hardest and has more carbon, which gives it a higherenergy content. Lignite is the softest and is low in carbon but high in hydrogen and oxygen content.Bituminous is in between. Today, the precursor to coal—peat—is still found in many countries andis also used as an energy source.The earliest known use of coal was in China. Coal from the Fu-shun mine in northeastern Chinamay have been used to smelt copper as early as 3,000 years ago. The Chinese thought coal was astone that could burn.Coal is found in many of the lower 48 states of U.S. and throughout the rest of the world.
Coal ismined out of the ground using various methods. Some coal mines are dug by sinking vertical orhorizontal shafts deep under ground, and coal miners travel by elevators or trains deep under groundto dig the coal. Other coal is mined in strip mines where huge steam shovels strip away the toplayers above the coal. The layers are then restored after the coal is taken away.The coal is then shipped by train and boats and even in pipelines. In pipelines, the coal is ground upand mixed with water to make what's called a slurry. This is then pumped many miles throughpipelines.
At the other end, the coal is used to fuel power plants and other factories.Oil or PetroleumOil is another fossil fuel. It was also formed more than 300 million years ago. Some scientists saythat tiny diatoms are the source of oil. Diatoms are sea creatures the size of a pin head. They do onething just like plants; they can convert sunlight directly into stored energy.In the graphic on the left, as the diatoms died they fell to the sea floor (1). Here they were buriedunder sediment and other rock (2). The rock squeezed the diatoms and the energy in their bodiescould not escape. The carbon eventually turned into oil under great pressure and heat.
As the earthchanged and moved and folded, pockets where oil and natural gas can be found were formed (3).Oil has been used for more than 5,000-6,000 years. The ancient Sumerians, Assyrians andBabylonians used crude oil and asphalt ("pitch") collected from large seeps at Tuttul (modern-dayHit) on the Euphrates River. A seep is a place on the ground where the oil leaks up from belowground.
The ancient Egyptians, used liquid oil as a medicine for wounds, and oil has been used inlamps to provide light.The Dead Sea, near the modern Country of Israel, used to be called Lake Asphaltites. The wordasphalt was derived is from that term because of the lumps of gooey petroleum that were washed upon the lake shores from underwater seeps.In North America, Native Americans used blankets to skim oil off the surface of streams and lakes.They used oil as medicine and to make canoes water-proof. During the Revolutionary War, NativeAmericans taught George Washington's troops how to treat frostbite with oil.As our country grew, the demand for oil continued to increase as a fuel for lamps. Petroleum oilbegan to replace whale oil in lamps because the price for whale oil was very high. During this time,most petroleum oil came from distilling coal into a liquid or by skimming it off of lakes – just as theNative Americans did.Then on August 27, 1859, Edwin L.
Drake (the man standing on the right in the black and whitepicture to the right), struck liquid oil at his well near Titusville, Pennsylvania. He found oil underground and a way that could pump it to the surface. The well pumped the oil into barrels made outof wood. This method of drilling for oil is still being used today all over the world in areas where oilcan be found below the surface.Oil and natural gas are found under ground between folds of rock and in areas of rock that areporous and contain the oils within the rock itself. The folds of rock were formed as the earth shiftsand moves.
It's similar to how a small, throw carpet will bunch up in places on the floor.To find oil and natural gas, companies drill through the earth to the deposits deep below the surface.The oil and natural gas are then pumped from below the ground by oil rigs (like in the picture).They then usually travel through pipelines or by ship.Oil is found in 18 of the 58 counties in California. Kern County, the County where Bakersfield isfound, is one of the largest oil production places in the country.
But we only get one-half of our oilfrom California wells. The rest comes from Alaska, and an increasing amount comes from othercountries. In the entire U.S., more than 50 percent of all the oil we use comes from outside thecountry... most of it from the Middle East.Oil is brought to California by large tanker ships. The petroleum or crude oil must be changed orrefined into other products before it can be used.RefineriesOil is stored in large tanks until it is sent to various places to be used. At oil refineries, crude oil issplit into various types of products by heating the thick black oil.Oil is made into many different products – fertilizers for farms, the clothes you wear, the toothbrushyou use, the plastic bottle that holds your milk, the plastic pen that you write with.
They all camefrom oil. There are thousands of other products that come from oil. Almost all plastic comesoriginally from oil. Can you think of some other things made from oil?The products include gasoline, diesel fuel, aviation or jet fuel, home heating oil, oil for ships and oilto burn in power plants to make electricity. Here's what a barrel of crude oil can make.In California, 74 percent of our oil is used for transportation – cars, planes, trucks, buses andmotorcycles.Natural GasSometime between 6,000 to 2,000 years BCE (Before the Common Era), the first discoveries ofnatural gas seeps were made in Iran.
Many early writers described the natural petroleum seeps in theMiddle East, especially in the Baku region of what is now Azerbaijan. The gas seeps, probably firstignited by lightning, provided the fuel for the "eternal fires" of the fire-worshiping religion of theancient Persians.Natural gas is lighter than air. Natural gas is mostly made up of a gas called methane. Methane is asimple chemical compound that is made up of carbon and hydrogen atoms.
It's chemical formula isCH4 – one atom of carbon along with four atoms hydrogen. This gas is highly flammable.Natural gas is usually found near petroleum underground. It is pumped from below ground andtravels in pipelines to storage areas. The next chapter looks at that pipeline system.Natural gas usually has no odor and you can't see it. Before it is sent to the pipelines and storagetanks, it is mixed with a chemical that gives a strong odor. The odor smells almost like rotten eggs.The odor makes it easy to smell if there is a leak.Energy Safety Note!If you smell that rotten egg smell in your house, tell your folks and get out of the housequickly. Don't turn on any lights or other electrical devices.
A spark from a light switch canignite the gas very easily. Go to a neighbor's house and call 9-1-1 for emergency help.Saving Fossil FuelsFossil fuels take millions of years to make. We are using up the fuels that were made more than 300million years ago before the time of the dinosaurs. Once they are gone they are gone.So, it's best to not waste fossil fuels. They are not renewable; they can't really be made again. Wecan save fossil fuels by conserving energy.2.
Natural Gas Distribution SystemWe learned earlier that natural gas is a fossil fuel. It is a gaseous molecule that's made up of twoatoms – one carbon atom combined with four hydrogen atom. It's chemical formula is CH4. Thepicture 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 isfound under ground and under the ocean floor. Wells are drilled to tap into natural gas reservoirsjust like drilling for oil. Once a drill has hit an area that contains natural gas, it can be brought to thesurface through pipes.The natural gas has to get from the wells to us. To do that, there is a huge network of pipelines thatbrings natural gas from the gas fields to us.
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