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Nonrenewable EnergyFossil Fuels

“Our civilization runs by burning the remains of humble creatures who inhabited the Earth hundreds of millions of years before the first humans…”

- Carl Sagan

Dynamic processes within the earth and on its surface produce the mineral resources on which we depend

Mineral resources are nonrenewable Produced and renewed over millions of years

mostly by the earth’s rock cycle

14-1 What Are the Earth’s Major Geological Processes/Mineral Resources?

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During the carboniferous period, lasting from about 350-300 million years ago, much of the Earth was ideal for plant growth. The overall climate

was warm. Glaciersretreated.

Much of the landmass was nearthe equator.

The Carboniferous Period

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The dominant plants during this time were fern-like trees.

The trees evolved a new carbon-based chemical compound called lignin. This formed the basis of their bark.No bacteria , fungus,

or insect had yet evolved the ability to decompose lignin.

The forests, with few limiting factors, grew massive and numerous.

Plants of the Carboniferous Age. Meyers Konversationslexikon, 1885-1890.

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The surplus of photosynthesis drove oxygen levels up, reaching concentrations in the atmosphere near 35%.

Arthropods, which breathe through their exoskeletons, were no longer size-restricted by available oxygen.

Model of a Meganisoptera, a giant dragonfly.

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A short, intense ice age eventually led to the demise of these forests.

Nearly 50 million years of accumulated plant matter (lignin) became buried under swamps.As the plant material was exposed to greater

amounts of pressure and heat, it became coal.

Fig. 15-11, p. 383

Increasing moisture content Increasing heat and carbon content

Peat (not a coal)

Lignite (brown coal)

Bituminous (soft coal)

Anthracite (hard coal)

Heat Heat Heat

Pressure Pressure Pressure

Partially decayed plant matter in swamps and bogs; low heat content

Low heat content; low sulfur content; limited supplies in most areas

Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content

Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas

Stepped Art

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Today, the countries with the greatest coal deposits line up with the locations of largest carboniferous swamps – North America, Northern Europe, and Asia.

Fig. 15-15, p. 385

TRADE-OFFSCoal

Advantages DisadvantagesSevere land disturbance, air pollution, and water pollution

Ample supplies (225–900 years)

High net energy yield Severe threat to human health when burnedEnvironmental costs not included in market price

Low cost

Large government subsidies

Well-developed technology High CO2 emissions

when produced and burned

Air pollution can be reduced with improved technology

Radioactive particle and toxic mercury emissions

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Coal was first widely used in China. Europeans were astonished at its ability to

produce heat, as written by Marco Polo:

Applications of Coal

“Throughout the whole province of Cathay are a kind of black stones cut from the mountains in veins, which burn like logs.

They maintain the fire better than wood. If you put them on in the evening they will preserve it the whole night, and it will be found burning in the morning.”

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The demand for coal increased tremendously during the industrial revolution of the late 19th century as the steam engine was developed.

Today, it is almost exclusively used for electricity generation.

Midwest Generation Power Plant, Waukegan, Illinois.

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Today, the largest coal-fired power plant in the world is the Taichung Power Plant, located in Taiwan.

The plant uses a total of nearly 15 million tons of coal per year.One open hopper

train car holds 100-125 tons of coal.

A coal train will have 100-125 cars.

Taichung uses over1,100 train loads of coal per year, just over 3 per day.

Science: Coal-Burning Power Plant

Extracting, Processing, Using Nonrenewable Mineral and Energy Resources

Shallow deposits of coal can be removed by surface mining.This process requires the removal of all

vegetation and topsoil before the deposit can be accessed.

Open-pit mining is where large holes are dug into the earth and the minerals removed.

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Coal Extraction

Ffos-y-fran Land Reclamation Scheme, Wales, U.K.

Natural Capital Degradation: Open-Pit Mine in Western Australia

Strip mining actuallycarves away horizontal beds of coal deposit close to the surface.

Mountaintop removal isa method that uses machines and explosives to expose seams of coal underneath entire mountain tops.

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Natural Capital Degradation: Contour Strip Mining Used in Hilly or Mountainous Region

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The cumulative effects of mountaintop removal can be seen from satellite, as shown in this NASA Earth Observatory slideshow of the Hobet Mine in West Virginia.

Natural Capital Degradation: Mountaintop Coal Mining in West Virginia, U.S.

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Subsurface, or underground mining, removes coal through deep tunnels and shafts.

Most of the removal is done by machine and conveyor belt.

The mining machines generate high amounts of explosive coal dust.

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Coal dust can build up in the lungs over long periods of time, causing Black Lung disease.

Normal lung tissue.

Mild case of Black Lung disease.

Severe case of Black Lung disease.

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Once the coal is extracted, its potential energy converted to electricity in a power plant.The coal is pulverized into

a powder, then blown into the boiler.

The heat from the boiler converts water into steam.

Pressure from the steam causes a giant set of turbine blades to spin.

The shaft of the turbine is connected to a generator, where magnets spin within wire coils to generate electricity.

Coal-Generated Electricity

Coal is about 90% carbon, 4% hydrogen, and 3% oxygen, and about 1% sulfur. This is similar to the chemical

composition of plants.When coal is burned for fuel,

it combines with oxygen in air to form several air pollutants, including:Carbon dioxide, CO2Sulfur dioxide, SO2Nitrogen oxides, NOxFine black particles of

carbon (soot)25

Coal

Pleasant Prairie Power Plant, Wisconsin.Source: www.kevinpalmer.com

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Burning coal also produces a great deal of leftover ash.The ash contains toxins and heavy metals

including arsenic, cadmium, chromium, lead, mercury, and radioactive radium.

The ash is usually mixedwith water, to minimize dust, then pumped into a temporary storage pond.Eventually, 70-80% of

this ash is disposed of in landfills. The rest is used in concrete, asphalt, and other applications.

Power plant and coal ash ponds, Asheville, North Carolina.

We Can Convert Coal into Gaseous and Liquid Fuels

Conversion of solid coal toSynthetic natural gas (SNG) by coal

gasificationMethanol or synthetic gasoline by coal

liquefaction

Are there benefits to using these synthetic fuels?

Fig. 15-16, p. 386

TRADE-OFFS

Synthetic fuels

Advantages DisadvantagesLarge potential supply

Low to moderate net energy yield

Higher cost than coal

Vehicle fuelRequires mining 50% more coal

Environmental costs not included in market price

Moderate cost High environmental impact

Large government subsidies

High water useLower air pollution than coal when burned Higher CO2 emissions

than coal

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Like coal, most of the oil on Earth was formed millions of years ago.

Certain warm shallow seas, such as the Gulf of Mexico and Tethys Sea, were so ideal for life that organic material was formed faster than it could decompose.Large masses of organic

material became buried at the sea bottom, were heated and pressurized, forming oil.

Oil

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The present day distribution of oil lines up with these ancient shallow seas.Majority of oil reserves are in Middle Eastern

countries.

Worldwide Oil Exports

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In elemental composition, oil is similar to coal.Mostly carbon,

but also hydrogen, nitrogen, oxygen and sulfur.

As a liquid, oil can be distilled (separated) into other fuels such as gasoline, kerosene, and diesel fuel.

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As a liquid, oil can be pumped directly out of the ground. This eliminates the need for mining.

A long drill is used to bore deep into the Earth to reach the deposit.

The hole is lined with a steel pipe and cement.

The top is outfitted with collection pipes and valves.

Oil Extraction

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The ease of transporting oil has enabled drilling at very remote locations.

At its peak, Alaska accounted for about 25% of the U.S. oil production. It is transported to the southern ports of the

state through the Alaska Oil Pipeline.

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As a liquid, oil can also escape more easily, forming an oil spill.

Oil spills are devastating to marine life. Penetrates through the fur and feathers of

animals, reducing their ability to fly, float, and insulate themselves.

Benthic organisms, living at the bottom of the sea, can be suffocated.

Entire populations of krill and plankton can be wiped out.

Exxon Valdez oil spill, 1987.

Oil ReservesOf the fossil fuels, oil has

been the most quickly depleted.

Peak oil is defined as the point at which known all known oil reserves have been tapped and production will begin declining in the following years.The United States reached

its peak production in the 1970s.

The estimated date of worldwide peak oil is unknown.

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Natural Gas

Natural gas is actually a mixtures of gases.50-90% methane.Smaller amounts of propane and butane.

As a gas, it is the most difficult fossil fuel to transport.

A supply of natural gas exists above most oil wells, however, if no pipelines are nearby, it will often simply be burned off.

Fig. 15-10, p. 382

TRADE-OFFS

Conventional Natural Gas

Advantages DisadvantagesAmple supplies Nonrenewable

resourceHigh net energy yield

Releases CO2 when burnedLow cost

Gas turbine Government subsidiesLess air pollution than other fossil fuels

Environmental costs not included in market priceLower CO2 emissions

than other fossil fuels Methane (a greenhouse gas) can leak from pipelinesEasily transported by

pipelineDifficult to transfer from one country to another

Low land use

Good fuel for fuel cells, gas turbines, and motor vehicles

Can be shipped across ocean only as highly explosive LNG

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One of the biggest advantages in natural gas is the relatively small amount of pollution produced by burning it.The only two waste products are carbon dioxide

and water vapor.

Hydraulic FracturingHydraulic fracturing, or “fracking”, is a

controversial technique used to extract natural gas from rock formations (such as shale) that are not very permeable.

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Fracturing has become an increasingly populartool for extracting natural gas, especially with the discovery of the methane-rich Marcellus Shale.

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First, a mixture of water and other chemicals is pumped into a narrow hole drilled into the rock formation.

The pressure created from this fluid causes the rock formation to crack.

Sand is injected afterwards to fill the cracks, because it is more permeable and allows the methane to seep out.

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There are two big issues that make hydraulic fracturing controversial.Millions of gallons of

water are needed to “frack” the well.

The water that returns back to the surface, called flowback water, is contaminated with minerals, fracturing fluid chemicals, and natural gas itself.

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Water trucking containers, Dimock, Pennsylvania.

The disposal of flowback water has been a major source of contamination.

Due to an exemption given to gas drillers in a 2006 law, they do not have to disclose the full list of chemicals injected into a well.These chemicals include carcinogens and

endocrine disruptors.

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Water collected from a well in rural Bradford County, Pennsylvania.

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Energy ConsumptionFossil Fuels currently

provide about 85% of all commercial energy in the world.Other renewable

sources (wind, solar, hydroelectric) make up 7% of commercial power.

Nuclear power makes up 8% of commercial power.

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The richest 20 countries consume nearly 80% of natural gas, 65% of oil, and 50% of coal production annually.On average, each person in

the U.S. and Canada uses more than 300 GJ of energy annually.

In the poorest countries of the world, each person generally consumes less than one GJ annually.

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The environmental and human costs of extracting fossil fuels ultimately lies with those who use them the most.

CO2 Emissions Per Unit of Electrical Energy Produced for Energy Sources

Solutions: Sustainable Use of Nonrenewable Minerals

Fig. 14-25, p. 367

Sludge

Pharmaceutical plant Local farmers

SludgeGreenhouses

Waste heat

Waste heat

Waste heat

Waste heat Fish farming

Surplus natural gas

Electric power plantOil refinery

Fly ashSurplus sulfur Surplus

natural gas

Waste calcium sulfate

Waste heat

Cement manufacturer

Sulfuric acid producer

Wallboard factory Area homes