Fossil FuelsFossil Fuels

Under what type of conditions did Under what type of conditions did coal form millions of years ago?coal form millions of years ago?

Do you remember the stages in Do you remember the stages in the formation of coal?the formation of coal?

The finished productsThe finished products

How are they used?How are they used?

Coal is Coal is crushed to a crushed to a fine dust and fine dust and burned.burned.

Oil and gas Oil and gas can be burned can be burned directly. directly.

How does it make electricity?How does it make electricity?

1.1. Burn fuelBurn fuel

2.2. Heat water to make steamHeat water to make steam

3.3. Steam turns turbinesSteam turns turbines

4.4. Turbines turn generatorsTurbines turn generators

5.5. Generators produce a stream of Generators produce a stream of electrons: ELECTRICITY!!!electrons: ELECTRICITY!!!

What happens to the steam?What happens to the steam?

The steam that has passed The steam that has passed through the power station's through the power station's turbines has to be cooled, to turbines has to be cooled, to condense it back into water condense it back into water before it can be pumped round before it can be pumped round again. This is what happens in the again. This is what happens in the huge "cooling towers" seen at huge "cooling towers" seen at power stations.power stations.

Cooling TowersCooling Towers

Alternative way of coolingAlternative way of cooling

Some power Some power stations are built on stations are built on the coast, so they the coast, so they can use sea water can use sea water to cool the steam to cool the steam instead. However, instead. However, this warms the sea this warms the sea and can affect the and can affect the environment environment

Three major coal producing areas Three major coal producing areas in the United Statesin the United States

Millions of Short Tons Amount produced in millions of short tons

2006

What are the advantages of using What are the advantages of using Coal?Coal?

It is cheapIt is cheap

There is lots of it (enough for hundreds of There is lots of it (enough for hundreds of years)years)

Can produce large amounts of electricity Can produce large amounts of electricity all in one locationall in one location

It is easily and safely transportedIt is easily and safely transported

Supplies are readily available and localSupplies are readily available and local

Little need to rely on outside sourcesLittle need to rely on outside sources

What are the disadvantages of What are the disadvantages of coal?coal?

Severe land disturbance occurs when Severe land disturbance occurs when mining for itmining for it

High carbon and sulfur dioxide emissions High carbon and sulfur dioxide emissions

Contributes to acid rain which affects Contributes to acid rain which affects waterwayswaterways

Releases radioactive particles and toxic Releases radioactive particles and toxic mercury into the airmercury into the air

Threat to human healthThreat to human health

What is crude oil?What is crude oil?

Crude oil (petroleum) is a thick liquid Crude oil (petroleum) is a thick liquid containing hydrocarbons that we extract from containing hydrocarbons that we extract from underground deposits and separate into underground deposits and separate into products such as gasoline, heating oil and products such as gasoline, heating oil and asphalt.asphalt. Only 35-50% can be economically recovered Only 35-50% can be economically recovered

from a deposit.(by conventional pumping)from a deposit.(by conventional pumping) About 10-25% more can be recovered from About 10-25% more can be recovered from

expensive secondary extraction techniques. expensive secondary extraction techniques. (involves injecting steam into well)(involves injecting steam into well)

This lowers the net energy yield.This lowers the net energy yield.

How does oil form?How does oil form?

What are reserves?What are reserves?

Estimated reservesEstimated reserves are educated guesses are educated guesses about how much oil or natural gas is left about how much oil or natural gas is left and where it may be found.and where it may be found.

Proven reservesProven reserves are exact amounts of oil are exact amounts of oil that can be economically obtained from a that can be economically obtained from a field. Proven reserves are determined only field. Proven reserves are determined only after drilling.after drilling.

So where do we find oil today?So where do we find oil today?

Shale formations in the U.S.Shale formations in the U.S.

Core Case Study: Core Case Study: How Long Will the Oil Party Last? How Long Will the Oil Party Last?

We have three We have three options:options: Use or waste less oil.Use or waste less oil. Use something else.Use something else. Continue to utilize Continue to utilize

shale-oil and other shale-oil and other “unconventional” oil “unconventional” oil sources and sources and technologiestechnologies

Figure 16-1Figure 16-1

OILOILRefining crude oil:Refining crude oil: Based on boiling Based on boiling

points, components points, components are removed at are removed at various layers in a various layers in a giant distillation giant distillation column.column.

The most volatile The most volatile components with components with the lowest boiling the lowest boiling points are removed points are removed at the top.at the top.

Figure 16-5Figure 16-5

OILOIL

Twelve OPEC (Organization of Petroleum Twelve OPEC (Organization of Petroleum Exporting Countries) have 78% of the Exporting Countries) have 78% of the worldworld’’s proven oil reserves and most of s proven oil reserves and most of the worldthe world’’s unproven reserves.s unproven reserves.

After global production peaks and begins a After global production peaks and begins a slow decline, oil prices will rise and could slow decline, oil prices will rise and could threaten the economies of countries that threaten the economies of countries that have not shifted to new energy have not shifted to new energy alternatives.alternatives.

So what is up with the oil prices?So what is up with the oil prices?There’s too much supplyThere’s too much supply..

“ “ Continued growth in U.S. shale production Continued growth in U.S. shale production and increase in non-OPEC countries oil and increase in non-OPEC countries oil exports have led to excess capacity,” says exports have led to excess capacity,” says Fortune magazineFortune magazine

And too little demandAnd too little demand..

““At the same time, demand for oil in places At the same time, demand for oil in places like Europe, Asia, and the US began like Europe, Asia, and the US began tapering off, thanks to weakening tapering off, thanks to weakening economies and new efficiency measures”economies and new efficiency measures”

Prudhoe Bay on Alaska’s North Slope is the Prudhoe Bay on Alaska’s North Slope is the highest yielding oil field in the United States, highest yielding oil field in the United States,

typically producing approximately 400,000 barrels typically producing approximately 400,000 barrels per day.per day.

Keystone PipelineKeystone PipelineThe basics are easy enough: The proposed The basics are easy enough: The proposed pipeline would carry 830,000 barrels of oil pipeline would carry 830,000 barrels of oil per day from Canada's oil sands down to per day from Canada's oil sands down to Nebraska. Supporters argue that building it Nebraska. Supporters argue that building it will create jobs and bolster the flow of crude will create jobs and bolster the flow of crude from a friendly neighbor. Opponents say all from a friendly neighbor. Opponents say all that extra fossil fuel will exacerbate global that extra fossil fuel will exacerbate global warming. The Obama administration, which warming. The Obama administration, which has final say over the project, has wavered has final say over the project, has wavered on a decision.on a decision.

Drilling on the Arctic National Drilling on the Arctic National Wildlife Refuge: The big debateWildlife Refuge: The big debateThe controversy The controversy over oil drilling in over oil drilling in ANWR continues ANWR continues with no resolution with no resolution in sight. So, what in sight. So, what are public opinions are public opinions on drilling? It on drilling? It depends on whom depends on whom you ask:you ask:

Many Alaskans favor ANWR oil drilling as it would Many Alaskans favor ANWR oil drilling as it would strengthen the Alaskan economy and provide jobs.strengthen the Alaskan economy and provide jobs.

The Inupiat Eskimos are open to drilling, so long The Inupiat Eskimos are open to drilling, so long as it can be done in an environmentally safe as it can be done in an environmentally safe manner and they have say into the process and manner and they have say into the process and revenues.revenues.

The Gwich'in Indians are opposed to drilling in The Gwich'in Indians are opposed to drilling in ANWR.ANWR.

During July 2008's high gas prices, the Pew During July 2008's high gas prices, the Pew Center found that the U.S. public increasingly Center found that the U.S. public increasingly favored opening ANWR to drilling -- 53 percent favored opening ANWR to drilling -- 53 percent favored it, 43 percent opposed it and 7 percent favored it, 43 percent opposed it and 7 percent were undecided [source: were undecided [source: Pew Center].Pew Center].

Fig. 16-7, p. 363

Trade-OffsConventional Oil

Advantages Disadvantages

Ample supply for 42–93 years Need to find

substitutes within 50 years

Low cost (with huge subsidies)

Artificially low price encourages waste and discourages search for alternatives

High net energy yield

Easily transported within and between countries

Air pollution when burnedLow land use

Releases CO2 when burned

Technology is well developed

Efficient distribution system Moderate water

pollution

Transporting oil is usually safe, but Transporting oil is usually safe, but accidents do happen!!!accidents do happen!!!

BP oil spill in Gulf of MexicoBP oil spill in Gulf of Mexico

Which spill was worse?Which spill was worse?

You decide!!!!!!!!!!!

Heavy Oils from Oil Sand and Oil Heavy Oils from Oil Sand and Oil Shale: Will Sticky Black Gold Save Shale: Will Sticky Black Gold Save

Us?Us?Heavy and tarlike oils from oil sand and oil Heavy and tarlike oils from oil sand and oil shale could supplement conventional oil, but shale could supplement conventional oil, but there are environmental problems.there are environmental problems. High sulfur content.High sulfur content. Extracting and processing produces:Extracting and processing produces:

Toxic sludgeToxic sludge

Uses and contaminates larges volumes of waterUses and contaminates larges volumes of water

Requires large inputs of natural gas which reduces net Requires large inputs of natural gas which reduces net energy yield.energy yield.

Oil ShalesOil Shales

Oil shales Oil shales contain a solid contain a solid combustible combustible mixture of mixture of hydrocarbons hydrocarbons called called kerogenkerogen..

Figure 16-9Figure 16-9

Natural GasNatural Gas

Natural Gas is the Natural Gas is the fastest growing fastest growing fossil fuel in use fossil fuel in use today and today and comprises 25% of comprises 25% of global commercial global commercial energy energy consumption.consumption.

FormationFormation

Natural Gas consists primarily of methane, Natural Gas consists primarily of methane, CHCH4 4 and typically includes varying and typically includes varying

amounts of other volatile hydrocarbons.amounts of other volatile hydrocarbons.

The main type of natural gas is called The main type of natural gas is called thermogenic because it results from thermogenic because it results from compression and heat deep underground.compression and heat deep underground.

Fig. 16-2, p. 357

Oil and natural gasOil and natural gasFloating oil drilling

platform Oil storage CoalCoalContour strip miningOil drilling

platform on legs

Geothermal Geothermal energyenergy

Hot water storageOil well

Pipeline Geothermal power plant

Gas well Valves Mined coal

Pump Area strip mining Drilling

tower

Pipeline

Impervious rock

Underground coal mineNatural gasWaterOil

Water is heated and brought up as dry

steam or wet steamWater

Coal seam Hot rock

Water penetrates

down through the rock

Magma

ExtractionExtraction

Most gas extracted commercially is Most gas extracted commercially is thermogenic and is found above deposits thermogenic and is found above deposits of crude oil or seams of coal.of crude oil or seams of coal.

Many of the most accessible reserves Many of the most accessible reserves have been tapped by wells and used have been tapped by wells and used already.already.

““FrackingFracking”” fuels environmental fuels environmental debatedebate

http://www.cbsnews.com/video/watch/?id=6836255n&tag=related;photovideo

Fracturing Fracturing

Fracturing techniquesFracturing techniques

One popular method is to pump One popular method is to pump salt water under high pressure salt water under high pressure into the rocks to crack them. into the rocks to crack them. Sand or small glass beads are Sand or small glass beads are inserted to hold the cracks open inserted to hold the cracks open once the water is withdrawn.once the water is withdrawn.

NATURAL GASNATURAL GAS

Russia and Iran have almost half of the Russia and Iran have almost half of the worldworld’’s reserves of conventional gas, and s reserves of conventional gas, and global reserves should last 62-125 years.global reserves should last 62-125 years.

Natural gas is versatile and clean-burning Natural gas is versatile and clean-burning fuel, but it releases the greenhouse gases fuel, but it releases the greenhouse gases carbon dioxide (when burned) and carbon dioxide (when burned) and methane (from leaks) into the troposphere.methane (from leaks) into the troposphere.

Fig. 16-11, p. 368

Trade-Offs

Conventional Natural Gas

Advantages Disadvantages

Ample supplies (125 years) Nonrenewable resource

High net energy yieldReleases CO2 when burnedLow cost (with huge

subsidies)

Methane (a greenhouse gas) can leak from pipelines

Lower CO2 emissions than other fossil fuels

Difficult to transfer from one country to another

Moderate environmental impact Shipped across ocean as

highly explosive LNG

Easily transported by pipeline

Sometimes burned off and wasted at wells because of low price

Low land use

Good fuel for fuel cells and gas turbines

Requires pipelines

Less air pollution than other fossil fuels