Fossil fuels

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There are three major forms of fossil fuels: coal, oil and natural gas. All three were formed many hundreds of millions of years ago before the time of the dinosaurs - hence the name fossil fuels. The age they were formed is called the Carboniferous Period. It was part of the Paleozoic Era. "Carboniferous" gets its name from carbon, the basic element in coal and other fossil fuels.

The Carboniferous Period occurred from about 360 to 286 million years ago. At the time, the land was covered with swamps filled with huge trees, ferns and other large leafy plants. The water and seas were filled with algae - the green stuff that forms on a stagnant pool of water. Algae is actually millions of very small plants.

Some deposits of coal can be found during the time of the dinosaurs. For example, thin carbon layers can be found during the late Cretaceous Period (65 million years ago) - the time of Tyrannosaurus Rex. But the main deposits of fossil fuels are from the Carboniferous Period. For more about the various geologic eras, go to

As the trees and plants died, they sank to the bottom of the swamps of oceans. They formed layers of a spongy material called peat. Over many hundreds of years, the peat was covered by sand and clay and other minerals, which turned into a type of rock called sedimentary.

More and more rock was piled on top of more rock, and it weighed more and more. It began to press down on the peat. The peat was squeezed and squeezed until the water came out of it and it eventually, over millions of years, it turned into coal, oil or petroleum, and natural gas.

For questions 1-8, you are to choose the one best answer, (A), (B), (C) or (D), to each question

1. The word “they” in line 3 refers to

(A) dinosaurs

(B) fossil fuels

(C) basic elements

(D) Palezoic Era

2. The word “swamps” in line 7 could be best replaced by

(A) marshes

(B) fens

(C) moors

(D) pastures

3. The word “green stuff” in line 8 refers to

(A) trees

(B) ferns

(C) seas

(D) algae

4. Which title best expresses the ideas in this passage ?

(A) Three forms of fossil fuels

(B) Occurrences during the Carboniferious Period

(C) The origins of fossil fuels

(D) The conversion of buried trees and plants into fossil fuels

5. According to the passage, the first form of fossil fuels is called

(A) deposits

(B) peat

(C) sedimentary

(D) thin carbon layers

6. Do the following statements agree with the information given in the passage ?

Write your correct answers in boxes below by choosing

TRUE if the statement agrees with the information

FALSE if the statement contradicts the information

NOT GIVEN if there is no information on this

a. Coal, oil and natural gas existed before the time of the dinosaurs.

b. They were formed in the late Cretaceous Period.

c. The late Cretaceous Period was part of the Palezoic Era, too.

d. After being buried in the swamps for hundreds years, the peat was transformed into sedimentary.

e. Under intense pressure, water was pressed out of the peat which then turned into fossil fuels over millions of years.

f. Algae would develop into plants over millions of years.

g. The large majority of coal was found in the late Cretaceous Period.

8. The word “piled” in line 19 is closest in meaning to

(A) heaped

(B) collected

(C) flocked

(D) bunched

Oil is another fossil fuel. It was also formed more than 300 million years ago. Some scientists say that tiny diatoms are the source of oil. Diatoms are sea creatures the size of a Picture of oil formationpin head. They do one thing 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 buried under sediment and other rock (2). The rock squeezed the diatoms and the energy in their bodies could not escape. The carbon eventually turned into oil under great pressure and heat. As the earth changed 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 and Babylonians used crude oil and asphalt ("pitch") collected from large seeps at Tuttul (modern-day Hit) on the Euphrates River. A seep is a place on the ground where the oil leaks up from below ground. The ancient Egyptians, used liquid oil as a medicine for wounds, and oil has been used in lamps to provide light.

The Dead Sea, near the modern Country of Israel, used to be called Lake Asphaltites. The word asphalt was derived is from that term because of the lumps of gooey petroleum that were washed up on 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, Native Americans 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 oil began 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 the Native Americans did.

Then on August 27, 1859, Edwin L. Drake struck liquid oil at his well near Titusville, Pennsylvania. He found oil under ground and a way that could pump it to the surface. The well pumped the oil into barrels made out of wood. This method of drilling for oil is still being used today all over the world in areas where oil can be found below the surface.

Oil and natural gas are found under ground between folds of rock and in areas of rock that are porous and contain the oils within the rock itself. The folds of rock were formed as the earth shifts and 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. They then usually travel through pipelines or by ship.

For questions 9-14, you are to choose the one best answer, (A), (B), (C) or (D), to each question

9. The word “they” in line 3 refers to

(A) plants

(B) sea creatures

(C) fossil fuels

(D) diatoms

10. The word “wounds” in line 19 can be best replaced by

(A) injuries

(B) bruises

(C) griefs

(D) pains

11. It can be inferred from the passage that oil has been employed.

(A) since 1859

(B) since it was exploited by Edwin L. Drake.

(C) more than 5000-6000 years ago.

(D) since native American found whale oil expensive.

12. According to the passage, who used oil as medicine ?

(A) the ancient Assyrians

(B) the ancient Egyptians and Native Americans

(C) George Washington's troops

(D) Edwin L. Drake

13. How can Americans obtain oil before 1859 ?

(A) They followed the same way as Native American.

(B) They drilled for oil underground in folds of rock.

(C) They collect it from large seeps.

(D) They pump it to the surface using oil rigs.

14. Do the following statements agree with the information given in the passage ?

Write your correct answers in boxes below by choosing

TRUE if the statement agree with the information

FALSE if the statement contradicts the information

NOT GIVEN if there is no information on this

a. Diatoms can store energy like plants.

b. Some parts of diatoms were transformed into oil. (Review)

c. The ancient Babylonians used oil to make water-proof. (Review)

d. George Washington's troops did not know how to use oil.

e. Israeli people exploited oil from the Dead Sea.

f. It is earth shifts which led to formation of folds of rock.

g. Edwin L. Drake invented the way of drilling for oil and natural gas on August 27, 1859.

Biomass is matter usually thought of as garbage. Some of it is just stuff lying around -- dead trees, tree branches, yard clippings, left-over crops, wood chips, and bark and sawdust from lumber mills. It can even include used tires and livestock manure.

Your trash, paper products that can't be recycled into other paper products, and other household waste are normally sent to the dump. Your trash contains some types of biomass that can be reused. Recycling biomass for fuel and other uses cuts down on the need for "landfills" to hold garbage. This stuff nobody seems to want can be used to produce electricity, heat, compost material or fuels. Composting material is decayed plant or food products mixed together in a compost pile and spread to help plants grow.

How biomass works is very simple. The waste wood, tree branches and other scraps are gathered together in big trucks. The trucks bring the waste from factories and from farms to a biomass power plant. Here the biomass is dumped into huge hoppers. This is then fed into a furnace where it is burned. The heat is used to boil water in the boiler, and the energy in the steam is used to turn turbines and generators .

Biomass can also be tapped right at the landfill with burning waster products. When garbage decomposes, it gives off methane gas. Pipelines are put into the landfills and the methane gas can be collected. It is then used in power plants to make electricity. This type of biomass is called landfill gas. A similar thing can be done at animal feed lots. In places where lots of animals are raised, the animals - like cattle, cows and even chickens - produce manure. When manure decomposes, it also gives off methane gas similar to garbage. This gas can be burned right at the farm to make energy to run the farm.

Using biomass can help reduce global warming compared to a fossil fuel-powered plant. Plants use and store carbon dioxide (CO2) when they grow. CO2 stored in the plant is released when the plant material is burned or decays. By replanting the crops, the new plants can use the CO2 produced by the burned plants. So using biomass and replanting helps close the carbon dioxide cycle. However, if the crops are not replanted, then biomass can emit carbon dioxide that will contribute toward global warming.

So, the use of biomass can be environmentally friendly because the biomass is reduced, recycled and then reused. It is also a renewable resource because plants to make biomass can be grown over and over.

Today, new ways of using biomass are still being discovered. One way is to produce ethanol, a liquid alcohol fuel. Ethanol can be used in special types of cars that are made for using alcohol fuel instead of gasoline. The alcohol can also be combined with gasoline. This reduces our dependence on oil - a non-renewable fossil fuel.

For questions 15-18, you are to choose the one best answer, (A), (B), (C) or (D), to each question

15. The word “manure” in line 3 is closest in meaning to

(A) wastes

(B) dung

(C) composts

(D) faeces

16. The word “gives off” in line 19 can be best replaced by

(A) releases

(B) produces

(C) generates

(D) emits

17. According to the passage, which products are produced through the recycling of biomass ?

(A) carbon dioxide

(B) ethanol

(C) electricity, heat, compost material and fuels

(D) compost, methane and alcohol

18. What does “raise” in line means ?

(A) to grow

(B) to breed

(C) to feed

(D) to reproduce

19. Do the following statements agree with the information given in the passage ?

Write your correct answers in boxes below by choosing

TRUE if the statement agree with the information

FALSE if the statement contradicts the information

NOT GIVEN if there is no information on this

a. Compost can be used as fertilizers.

b. All household waste is difficult to recycle.

c. Landfills is areas where rubbish is dumped.

d. Production of ethanol from biomass produces carbon dioxide, contributing to global warming.

e. Landfill gas emited from landfills is a sourse of energy.

f. All cars can be powered by ethanol.

g. Ethanol-powerd cars are much cleaner than gasoline-powered cars in terms of emissions.

h. Crops should be replanted to reused biomass burnt, thereby restoring the carbon dioxide cycle.

i. When incubated, manure emits only a small portion of methane.

j. Alcohol can be blended with petrol to reduce the usage of sole oil.

Fossil fuels in our lives

For questions 20-21, you are to choose the one best answer, (A), (B), (C) or (D), to each question

20. The word “intimately” in line 1 could be best replaced by

(A) confidentially

(B) closely

(C) tightly

(D) deeply

21. According to the author's anticipation, what would happened if fertilizers were replaced with manure ?

(A) Manufacturers would fail to meet the world's demand in fertilizers.

(B) Food costs would increase subtanstially.

(C) Oil stocks would become depleted.

(D) They would harness renewable energy sources to produce fertilizers.

22. From what source would they rely on for production of plastic once oil was depleted ?

(A) biomass

(B) alternative materials

(C) lubricants

(D) whale oil

23. What makes calculating fossil fuel consumption for each person impossible ?

(A) It is impossible to collect enough data

(B) Calculation costs are extremely high.

(C) A great number of fossil fuel consumption is hidden in each consuming process

(D) There are up to 3 forms of fossil fuels, which makes calculation complicated.

24. Do the following statements agree with the information given in the passage ?

Write your correct answers in boxes below by choosing

TRUE if the statement agree with the information

FALSE if the statement contradicts the information

NOT GIVEN if there is no information on this

a. Consumption rate of fossil fuels is expected to rise increasingly in years to come.

b. The scarcity of fossil fuels may lead to wars to fight for these stuff in the future.

c. Transport fossil fuel usage is more important than consumption of fossil fuels in industrial manufacture.

d. It is easy to calculate direct usage of fossil fuels.

e. Fossil fuel shortages do not seem to destabilise the economy of society .

f. Once fossil fuels are scarce, whale oil would be widely used.

g. Each household in the US consumes over 8.2 barrels of oil, 0.7 tons of coal and 53 tcf of natural gas per year.

Fill in the gaps with given words provided in the boxes below. Note: some words may be used twice

Coal is a hard, black colored (1) substance. It is made up of carbon, hydrogen, oxygen, nitrogen and varying amounts of (2) . There are three main types of coal - anthracite, bituminous and lignite. (3) coal is the hardest and has more carbon, which gives it a higher energy content. (4) is the softest and is low in carbon but high in hydrogen and oxygen content.� Bituminous is in between. Today, the precursor to coal - (5) - is still found in many countries and is also used as an (6) .

The earliest known use of coal was in China. Coal from the Fu-shun mine in northeastern China may have been used to (7) copper as early as 3,000 years ago. The Chinese thought coal was a (8) that could burn.

Coal is found in many of the lower 48 states of U.S. and throughout the (9) of the world. Coal is mined out of the ground using various methods. Some coal mines are (10) by sinking vertical or horizontal shafts deep under ground, and coal miners travel by elevators or trains deep under ground to (11) the coal. Other coal is mined in strip mines where huge steam shovels strip away the top layers above the coal. The layers are then (12) after the coal is taken away.

The coal is then (13) by train and boats and even in (14) , the coal is ground up and mixed with water to make what's called (15) . This is then (16) many miles through pipelines. At the other end, the coal is used to fuel power plants and other factories.

Fill in the gaps with given words provided in the boxes below. Note: some words may be used twice

Geothermal Energy has been around for as long as the Earth has existed. "Geo" means earth, and "thermal" means heat. So, geothermal means earth-heat.Have you ever cut a boiled egg in half? The egg is similar to how the earth looks like inside. The yellow (1) of the egg is like the (2) of the earth. The white part is the mantle of the earth. And the thin shell of the egg, that would have surrounded the boiled egg if you didn't peel it (3) , is like the earth's crust.

Below the crust of the earth, the top layer of the mantle is a hot liquid rock called (4) . The crust of the earth (5) on this liquid magma mantle. When magma (6) through the surface of [Earth's crust]the earth in a (7) , it is called (8) .

For every 100 meters you go below (9) , the temperature of the rock increases about 3 degrees Celsius. Or for every 328 feet below (10) , the temperature increases 5.4 degrees Fahrenheit. So, if you went about 10,000 feet below ground, the temperature of the rock would be hot enough to boil water.

Deep under the surface, water sometimes makes its (11) close to the hot rock and turns into boiling hot water or into steam. The hot water can reach temperatures of more than 300 degrees Fahrenheit (148 degrees Celsius). This is hotter than boiling water (212 degrees F / 100 degrees C). It doesn't turn into (12) because it is not in contact with the air.When this hot water comes up through a (13) in the earth, we call it a hot spring, like Emerald Pool at Yellowstone National Park. Or, it sometimes explodes into the air as a geyser, like Old Faithful Geyser.

About 10,000 years ago, Paleo-Indians used hot springs in North American for cooking. Areas around hot springs were neutral (14). Warriors of fighting tribes would bathe together in peace. Every major hot spring in the United States can be (15) with Native American (16) . California hot springs, like at the Geysers in the Napa area, were important and sacred areas to tribes from that area.

In other places around the world, people used hot springs for rest and relaxation. The ancient Romans built (17) buildings to enjoy hot baths, and the Japanese have enjoyed natural hot springs for centuries.

Fill in the gaps with given words provided in the boxes below. Note: some words may be used twice.

Vietnam's (1) has expanded (2) in recent years, with its real gross domestic product (GDP) growing 7.7% in 2004 and 8.4% in 2005. Growth is forecast at 8.0% in 2006. Vietnam has had Normal Trade Relations status with the United States since (3) 2001, with 2002 marking the first time Vietnam shipped more (4) United States than to Japan. Despite (5) exports, Vietnam currently runs a slight trade (6) , but is (7) to begin having trade surpluses by 2007.

(8) of Vietnam's large (9) population relies heavily on non-commercial biomass energy sources such as wood, dung, and rice (10) . As a result, Vietnam's per (11) commercial energy consumption (12) among the lowest in Asia. The country's commercial energy consumption is predicted to rise in coming years, primarily due to increases in the use of natural gas.

Vietnam claims (13) of a portion of the potentially hydrocarbon-rich Spratly Islands, as do the Philippines, Brunei, Malaysia, China, and Taiwan. Vietnam, China, and the Philippines agreed in March 2005 to conduct a joint (14) survey for potential oil and natural gas (15) in a portion of the (16) area. Vietnam also (17) the Paracel Islands, which China first (18) in 1974.

It was a wet, chilly day in Washington DC in 1979 when a few scientists and engineers joined with government and college officials on the campus of Georgetown University to celebrate the completion of one of the world's most advanced coal combustors.

It was a small coal burner by today's standards, but large enough to provide heat and steam for much of the university campus. But the new boiler built beside the campus tennis courts was unlike most other boilers in the world.


A Fluidized Bed Boiler



In a fluidized bed boiler, upward blowing jets of air suspend burning coal, allowing it to mix with limestone that absorbs sulfur pollutants.

It was called a "fluidized bed boiler." In a typical coal boiler, coal would be crushed into very fine particles, blown into the boiler, and ignited to form a long, lazy flame. Or in other types of boilers, the burning coal would rest on grates. But in a "fluidized bed boiler," crushed coal particles float inside the boiler, suspended on upward-blowing jets of air. The red-hot mass of floating coal — called the "bed" — would bubble and tumble around like boiling lava inside a volcano. Scientists call this being "fluidized." That's how the name "fluidized bed boiler" came about.

Fluidized Bed Combustor

There are two major reasons for a "fluidized bed boiler" burn coal cleaner . One, the tumbling action allows limestone to be mixed in with the coal. Limestone is a sulfur sponge — it absorbs sulfur pollutants. As coal burns in a fluidized bed boiler, it releases sulfur. But just as rapidly, the limestone tumbling around beside the coal captures the sulfur. A chemical reaction occurs, and the sulfur gases are changed into a dry powder that can be removed from the boiler. (This dry powder — called calcium sulfate — can be processed into the wallboard we use for building walls inside our houses.)

The second reason a fluidized bed boiler burns cleaner is that it burns "cooler." Now, cooler in this sense is still pretty hot — about 1400 degrees F. But older coal boilers operate at temperatures nearly twice that (almost 3000 degrees F). NOx forms when a fuel burns hot enough to break apart nitrogen molecules in the air and cause the nitrogen atoms to join with oxygen atoms. But 1400 degrees isn't hot enough for that to happen, so very little NOx forms in a fluidized bed boiler.

The result is that a fluidized bed boiler can burn very dirty coal and remove 90% or more of the sulfur and nitrogen pollutants while the coal is burning. Fluidized bed boilers can also burn just about anything else — wood, ground-up railroad ties, even soggy coffee grounds.Today, fluidized bed boilers are operating or being built that are 10 to 20 times larger than the small unit built almost 20 years ago at Georgetown University. There are more than 300 of these boilers around this country and the world.

For questions 1-5, you are to choose the one best answer, (A), (B), (C) or (D), to each question

1. The word “rest” in line 9 is closest in meaning to

(A) stay

(B) lie down

(C) idle

(D) stand

2. The word “captures” in line 17 can be best replaced by

(A) catches

(B) absorbs

(C) holds

(D) suspends

3. The word “break apart” in line 24 is closest in meaning to

(A) separate

(B) detach

(C) cleave

(D) divide

4. It can be inferred from the passage that NOx can form at

(A) nearly 3000 degree F

(B) much lower than 3000 degree F

(C) higher than 1400 degree F

(D) just over 1400 degree F

5. Do the following statements agree with the information given in the passage ?

Write your correct answers in boxes below by choosing

TRUE if the statement agree with the information

FALSE if the statement contradicts the information

NOT GIVEN if there is no information on this

a. Fluidized bed boiler is still the world's most mordern coal combustors .

b. The boiler of this kind provides heat and steam for almost all campus of Georgetown university.

c. This boiler is partly similar to any other boilers in the world.

d. When burnt, the floating coal inside the boiler mimic movements of lava generated inside a volcano.

e. Limestone should be mixed with coal before addition of this mixture into the boiler.

f. The efficiency of this boiler is higher than other traditional types of boilers.

g. Fluidized bed boiler can operate at far lower temperature than older coal boilers.

h. This boiler emits much of NOx when operating.

i. NOx emitted, if any, is then absorbs by limestone inside the boiler.

Temperature can also be important in freeing oil from underground reservoirs. In some oil reservoirs -- in much of California, for example -- the oil is thicker and heavier. It hardly flows out of a jar, much less out of an oil reservoir. But if the oil is heated, it becomes thinner and more slippery. To heat heavy oil in a reservoir, oil companies boil water in huge pressure vessels on the surface and send the steam down wells. The steam works its way through the oil reservoir, heating the oil and making it easier to pump to the surface.

Another way to free trapped oil is to inject carbon dioxide. Some carbon dioxide exists naturally underground, and companies often pump it out of the ground, then back in to oil reservoirs to help produce more oil. Carbon dioxide is also given off when anything burns. Many power plants that produce our electricity burn coal, natural gas and other fuels. These plants produce large amounts of carbon dioxide as do factories. Even you produce carbon dioxide when you breathe. It would be very hard to capture the carbon dioxide of every breathing person, but it may be possible in the future to capture carbon dioxide from big power plants or factories. This carbon dioxide can be injected into an oil reservoir to mix with the oil, break it away from the underground rock, and push it toward oil wells.

Still another technique being studied uses microscopic organisms called "microbes." Even though some scientists jokingly call these tiny microbes "bugs," they really don't have heads or legs or bodies. Instead, they are more like bacteria — tiny, single-cell organisms that can grow and multiply inside the rocks deep within oil reservoirs.

How can microbes be used to produce more oil? Actually, several ways. Some microbes can feed on nutrients in a reservoir and release gas as part of their digestive process. The gas collects in the reservoir, like air inside a balloon, building up pressure that can force more oil droplets out of the rock pores and toward oil wells. To get microbes to grow and multiply fast enough, oil scientists are testing ways to inject nutrients, or food, for the microbes into a reservoir.

Microbes can also be used to block off portions of a reservoir. After many years of waterflooding, most of the water eventually finds the easiest path through the oil reservoir. Oil trapped in the rocks along that path is washed out of the reservoir, but oil in other parts of the reservoir may be left untouched. To send the water to other parts of the reservoir, scientists mix microbes, along with food for the microbes, into the waterflood. As the microbes move along with the water, they digest the food, grow and multiply. Eventually, enough microbes are created to block off the tiny passageways. Now, scientists can inject fresh water and send it to portions of the reservoir that haven't been swept clean by the earlier waterflood, and more oil can be produced.

For questions 1-4, you are to choose the one best answer, (A), (B), (C) or (D), to each question.

1. What is the author's main point ?

(A) Some methods of producing oil

(B) Temperature is important to releasing oil from oil reservoirs.

(C) Injection of carbon dioxide can help free trapped oil.

(D) How to extract oil from underground reservoirs.

2. The word “microbes” in the line 16 can be best replaced by

(A) microorganisms

(B) bugs

(C) bacteria

(D) single cells

3. The word “multiply” in line 19 means

(A) to develop

(B) to breed

(C) to divide

(D) to reproduce

4. Do the following statements agree with the information given in the passage ?

Write your correct answers in boxes below by choosing

TRUE if the statement agree with the information

FALSE if the statement contradicts the information

NOT GIVEN if there is no information on this

a. Heat can facilitate the pumping of oil to the surface.

b. Oil is thick and heavy, so it should be heat up before being pumped out of oil wells.

c. Carbon dioxide released from breath is collected to inject into oil reservoirs.

d. Big plants may serve as a source of carbon dioxide for exploitation of oil.

e. Microbes can grow well in oil reservoirs due to nitrients added.

f. An amount of carbon dioxide emitted from factories is higher than those produce from human respiratory system.

g. When mixed with food and water, microbes fail to grow well.

h. Injection of carbon dioxide is the most popular method of producing oils.

i. Carbon dioxide is trapped undergound until it is in need.

j. Not everything emits carbon dioxide when it burns.