Crude oil or liquid petroleum, is a fossil fuel that is refined into many different energy products (e.g., gasoline, diesel fuel, jet fuel, heating oil). Oil forms underground in rock such as shale, which is rich in organic materials. After the oil forms, it migrates upward into porous reservoir rock such as sandstone or limestone, where it can become trapped by an overlying impermeable cap rock. Wells are drilled into these oil reservoirs to remove the gas and oil. Over 70 percent of oil fields are found near tectonic plate boundaries, because the conditions there are conducive to oil formation.

Oil recovery can involve more than one stage. The primary stage involves pumping oil from reservoirs under the normal reservoir pressure. About 25 percent of the oil in a reservoir can be removed during this stage. The secondary recovery stage involves injecting hot water into the reservoir around the well. This water forces the remaining oil toward the area of the well from which it can be recovered.

Sometimes a tertiary method of recovery is used in order to remove as much oil as possible. This involves pumping steam, carbon dioxide gas or nitrogen gas into the reservoir to force the remaining oil toward the well. Tertiary recovery is very expensive and can cost up to half of the value of oil removed. Carbon dioxide used in this method remains sequestered in the deep reservoir, thus mitigating its potential greenhouse effect on the atmosphere. The refining process required to convert crude oil into useable hydrocarbon compounds involves boiling the crude and separating the gases in a process known as fractional distillation. Besides its use as a source of energy, oil also provides base material for plastics, provides asphalt for roads and is a source of industrial chemicals.

Over 50 percent of the world's oil is found in the Middle East; sizeable additional reserves occur in North America. Most known oil reserves are already being exploited, and oil is being used at a rate that exceeds the rate of discovery of new sources.

If the consumption rate continues to increase and no significant new sources are found, oil supplies may be exhausted in another 30 years or so.

Despite its limited supply, oil is a relatively inexpensive fuel source. It is a preferred fuel source over coal. An equivalent amount of oil produces more kilowatts of energy than coal. It also burns cleaner, producing about 50 percent less sulfur dioxide.

Oil, however, does cause environmental problems. The burning of oil releases atmospheric pollutants such as sulfur dioxide, nitrogen oxides, carbon dioxide and carbon monoxide. These gases are smog-precursors that pollute the air and greenhouse gases that contribute to global warming. Another environmental issue associated with the use of oil is the impact of oil drilling. Substantial oil reserves lie under the ocean. Oil spill accidents involving drilling platforms kill marine organisms and birds.

Some reserves such as those in northern Alaska occur in wilderness areas. The building of roads, structures and pipelines to support oil recovery operations can severely impact the wildlife in those natural areas.

Lesson 64: Animation: Oil Recovery, contains instruction and demonstration on oil recovery. To begin the animation, click here.

You will need to download Macromedia Flash Player to view this lesson.

Materials:

• Internet access
• Online NewsHour In-depth Coverage of Alternative Fuels which includes:
  • Online NewsHour Report "Ethanol: Questions Loom"
  • Evaluating Alternative Fuels Worksheet (Printer-friendly PDF)
  Background:
  
  Americans love their cars. Most Americans use gasoline-powered cars to commute, run errands, take family vacations, and get places they want to go. Americans consume 25 percent of the world's oil each year, but the country only provides 2-3 percent of the world's oil resources, according to the U.S. Department of Energy. As demand for oil grows, car manufacturers and scientists have been looking for alternatives fuels to reduce cost, dependence on international sources of oil, and the amount of greenhouse gases that contribute to global warming.

  Today's typical car releases "greenhouse gases." Ozone, Nitrogen Oxides, and carbon monoxide are pollutants that come from motorized vehicles when fuel is burned up in internal combustion engines to produce energy to move the car forward. People have been using this type of engine for over 100 years.

  Gasoline is an aliphatic hydrocarbon, which means it is made up of molecules composed of hydrogen and carbon arranged in chains. Gasoline is made from crude oil. The crude oil pumped out of the ground is called petroleum.

  Many new cars have been designed to use alternative fuels to run the engine. Alternative fuels for vehicles are any materials or substances that can be used as a fuel, other than conventional fossil fuels (oil and natural gas). The alternative fuels discussed here today include Ethanol (E85), natural gas (CNG), electric, hydrogen, and biodiesel.

  Ethanol is an alcohol produced from feed corn that is used to fuel internal combustion engines, either alone or in combination with other fuels. When alcohol fuel (ethanol) is mixed into gasoline, the result is labeled with an 'E' followed by the percentage of Ethanol. E10 is commonly found throughout the southern United States and E85 refers to an 85 percent ethanol fuel. To be considered an alternative fuel vehicle (for tax incentives), the car or truck must be able to operate on up to 85 percent ethanol.

  Compressed Natural Gas (CNG) is high-pressure compressed natural gas, mainly composed of methane that is used to fuel normal combustion engines instead of gasoline. Gasoline cars can be retrofitted to compressed natural gas and become natural gas vehicles (NGVs) that use both gasoline and compressed natural gas.

  Electric vehicles run on the chemical energy of batteries. Electric vehicles produce no emissions while being driven. The electrical energy to power the motors comes from battery packs. Battery powered cars have primarily used lead-acid batteries and NiMH batteries.

  Hydrogen fuel cells produce electricity through a chemical reaction between hydrogen and oxygen and produce no harmful emissions. In hydrogen fuel cell vehicles, hydrogen is stored as a pressurized gas in the car's fuel tanks. The electricity feeds a storage battery that energizes the vehicle's electric motor.

  Biodiesel is a processed fuel derived from biological sources (such as vegetable oils), which can be used in diesel-engine vehicles. Biodiesel is biodegradable and largely non-toxic. Most cars need to be modified to run on 100 percent biodiesel, but nearly all diesel engine cars can run on a blend of biodiesel without modifications.

  Using the interactive, you can find additional information about the above fuels (click on more info. under each fuel) and you will learn about cost and carbon dioxide emissions of using the various alternative fuels. When discussing the different fuels, keep in mind the accessibility and availability of the different fuels according to different lifestyles, i.e., how far away is the nearest hydrogen pump? Or where will the biodiesel come from? Also keep in mind the constraints of different types of fuels, i.e., if you want to go on a long trip in an electric vehicle, where will you recharge the car?
   

  Procedure:
  
  Guiding the Lesson:

  For Homework and background to the topic, have the students watch the NewsHour Report, "Ethanol Boom Aids Farmers, but Stirs Environmental Concerns" , which is available as streaming video or a written transcript and/or have students read the Online NewsHour Reports, "Case Study: Switch to Unleaded Gas" and "Ethanol: Questions Loom".

  People have been using gasoline engines for over 100 years; why is it a problem now? Guide students to discuss the impact of increasing numbers of motor vehicles over time on air quality, oil resources, public health, and the economy (personal/family finances).

  Students should keep in mind that carbon dioxide, a known greenhouse gas, is emitted from conventional gasoline vehicles; too much carbon dioxide in the atmosphere contributes to global warming. The human activity that has the largest impact on climate change is driving a vehicle. For each gallon of gasoline burned, 20 pounds of carbon dioxide is released into the atmosphere.

  Every million gallons of gasoline consumed by vehicles releases about 10,000 U.S. tons of carbon dioxide into the atmosphere. The population of the United States uses approximately 420 million gallons of gasoline per day. So, just from gasoline, the United States releases over 8 billion pounds of carbon dioxide into the atmosphere per day, according to the Department of Energy, Alternative Fuels Data Center (AFDC).

  Researchers and car manufacturers have looked into the problems associated with conventional gasoline-burning cars and have been developing vehicles that use alternative fuels. Advise students that good shoppers research what is out there before they purchase items, especially big-ticket items like cars. Good sellers know what is out there so they can make comparisons to win over their buyers.

  Today the students are going to go shopping for different types of cars. They are going to examine several issues: What does it mean to be environmentally friendly in terms of vehicles? What are some vehicles that they have heard of that might be considered green because they use alternative fuels, and why? How would the seller of an automobile use these different pieces of information to sell his particular car? What are the characteristics of a green vehicle if they were going to buy one? For instance, how much gas it uses (mpg), the cost of fuel, how much air pollution it puts out. What does it mean to be fuel-efficient?

  Because buying a car is a big decision, it is important to do "comparison shopping." Many magazines, books, and Web sites rate and compare vehicles. Use an overhead projector to familiarize the students with the Online NewsHour Interactive: "How Does Your Car Stack Up?" by comparing their family's car to other cars that use alternative fuels. Give short explanations of each of the fuels used in the cars on the Interactive.

  Student Activity:

  It is now time to buy and sell. Your students have looked at some alternative fuel options: biodiesel, ethanol, electricity (batteries), hydrogen and compressed natural gas.

  Divide the students into groups:

  Selling: Have the "seller" students sign up in groups of two to represent a category of alternative fuel to sell, including one group for conventional gasoline. Designate the groups by fuel type, not by car make and model. Encourage students to be scientific, creative, and persuasive in their arguments to the buyers about the cars available in their fuel type. Have students work on their pitches for homework, researching not only their type of fuel, but the others as well, so they can give compelling comparisons to their buyers. The sellers will need to be able to discuss each of the fuel types to be successful salespeople.

  Buying: Have the "buyer" students sign up in groups of two to represent a variety of different types of buyers. Buyers need to be very well educated before they choose a car. Give them a profile of their socio-economic backgrounds to guide them in their decision.
  
  Examples include but are not limited to the following. You are a:

  1. family of four that takes two vacations to the beach (that is 300 miles away by car) each year and commutes 250 miles per week from their home in the suburbs.
  2. married couple with one car, sharing it for commutes to two different jobs each, up to 400 miles per week, family income less than $50,000 per year.
  3. family of 3 with more than $100,000 income that lives in the city and uses public transportation to commute.
  4. single person who commutes 50 percent of the time about 100 miles per week, but likes to go hiking to the country on the weekends.
  5. family of 5 who lives in rural America with no commute, but most travel 40 miles each way to buy household items.
     
  Students can also come up with additional socioeconomic backgrounds or use their own family as a model.

  Use the rest of the class period for student groups to meet and design their pitches or decide what might be important to a particular buyer. For homework, have the students research the different kinds of fuels and how they meet their needs. They should be prepared to come in the next class ready for the alternative fuel sales event.

  Have the buyers meet with each of the seller groups for 5-10 minutes to hear their pitches and ask questions. Use the Alternative Fuels Worksheet (PDF) to record the pros and cons of each type of fuel. At the end of the class, the buyers should present to the group which car they decided to buy and why. This can be done as formally as needed and provide an opportunity to fulfill the state requirements for various types of speaking presentations.
  
  Post activity discussion:
  
  Have each buyer group share their decisions with the class. Discuss the socioeconomic, accessibility, financial, and environmental issues that were used to make decisions. There will be no right and wrong answers for automobile choices, as they depend on each person's needs, finances, and choices about the environment. Teachers may use additional class time to have the groups trade places and use different car makes and models.

  Additional Resources for Teachers:

  There are several Web sites that provide more information on the topic:

  http://www.pbs.org/now/shows/302/biodiesel.html

  http://www.fueleconomy.gov/feg/current.shtml

  http://www.epa.gov/otaq/consumer/fuels/altfuels/altfuels.htm

  http://www.socalgas.com/business/ngv/faq.shtml

  http://www.eere.energy.gov/afdc/

  http://www.cleanvehicle.org/technology/

  http://www.sciencedaily.com/news/matter_energy/alternative_fuels/

  http://www.energyquest.ca.gov/transportation/index.html

  http://www.popularmechanics.com/science/earth/2690341.html

  http://www.nrdc.org/air/energy/fensec.asp#note2

  National Standards

  Geography
  Standard 14: Understands how human actions modify the physical environment
  Standard 16: Understands the changes that occur in the meaning, use, distribution and importance of resources
  Standard 18: Understands global development and environmental issues

  Science
  Standard 13: Understands the scientific enterprise
  Earth and Space Sciences
  Standard 1: Understands atmospheric processes
  Life Sciences
  Standard 6: Understands relationships among organisms and their physical environment

  Mathematics
  Standard 3: Uses basic and advanced procedures while performing the processes of computation

  Language Arts
  Writing
  Standard 1: Uses the general skills and strategies of the writing process
  Standard 3: Uses grammatical and mechanical conventions in written composition
  Standard 4: Gathers and uses information for research purposes

  Reading
  Standard 5: Uses the general skills and strategies of the reading process
  Standard 7: Uses reading skills and strategies to understand and interpret a variety of informational texts

  Economics
  Standard 3: Understands the concept of prices and the interaction of supply and demand in a market economy
  Standard 5: Understands unemployment, income, and income distribution in a market economy

  Listening and Speaking
  Standard 8: Uses listening and speaking strategies for different purposes

  Technology
  Standard 3: Understands the relationships among science, technology, society, and the individual
  Standard 4: Understands the nature of technological design
  Standard 6: Understands the nature and uses of different forms of technology

  Working with Others
  Standard 1: Contributes to the overall effort of a group
  Standard 4: Displays effective interpersonal communication skills