How Can We Reduce Air Pollution from Automobiles?

     Module written by Howard Drossman, Wayne Tikkanen, and Sandra Laursen

    Session 1: How Does an Automobile Pollute?
    Analyzing Issues of Automobile Fuels and Air Pollution

      Exploration 1A: What is Gasoline?
      Properties of Automobile Fuels

        Virtual field trip to a gas station

      Exploration 1B: How Does Gasoline Affect Air Quality?
      Air Pollutants and Regulations

      • "Gasoline and Air Quality," Chapter 2 in Chevron Motor Gasoline Technical Review (http://www.chevron.com/prodserv/fuels/bulletin/motorgas). Read just Chapter 2 online or download the entire manual in pdf format. Save a tree, don't print the whole thing!
      • What is reformulated gasoline? Includes a clear distinction betweeen RFG and wintertime oxygenates (http://www.epa.gov/otaq/rfgnew.htm)
      • How does a catalytic converter work? (http://www.howstuffworks.com/catalytic-converter.htm)

      Exploration 1C: What Is Oxygenated Gasoline?
      Mass Percentage Requirements

      • Where in the US is reformulated gasoline required by the EPA?
        Summer Reformulated Gasoline program (http://www.epa.gov/otaq/rfgmap.jpg)
        Winter Oxygenated Fuels program (http://www.epa.gov/otaq/regs/fuels/oxy-area.pdf
      • "Oxygenated Gasoline", Chapter 4 in Chevron Motor Gasoline Technical Review (http://www.chevron.com/prodserv/fuels/bulletin/motorgas). Read just Chapter 4 online or download the entire manual in pdf format. Save a tree, don't print the whole thing!
      • EPA links on oxygenated fuels (http://www.epa.gov/otaq/rfg.htm)

      Exploration 1D: Who Is For and Against Oxygenates in Gasoline?
      Critical Reading

      • EPA's overview of the issue of leaking underground gas storage tanks and water contamination by MTBE. Includes a good collection of links to other resources. (http://www.epa.gov/swerust1/mtbe)
      • Reformulated Gasoline fact sheet from the EPA (http://www.epa.gov/region02/faq/refgas.htm)
      • "Gas Additive May Not Ease Pollution." An AP wire story by H. Josef Hebert (http://www.anomalous-images.com/news/news442.html)
      • "Health and Environmental Assessment of MTBE," State of California, (http://tsrtp.ucdavis.edu/mtberpt/Homepage.html)
      • "Governor of California sues EPA" (http://www.arb.ca.gov/fuels/gasoline/oxy/wav/lawsuit.pdf)

    Session 2: How Does the Fuel-Air Mixture Affect Air Pollution?
    Stoichiometry and Gas Laws

      Figure 2-1. Vehicle Inspection Report

        View online (544 K jpg) or download file (464K pct or 904 K tif)

      Exploration 2A: What is the Ideal Fuel-Air Mixture?
      Stoichiometry of Fuel-Air Reactions

      Exploration 2B: What Happens When Fuel and Air are Not Mixed in Stoichiometric Amounts?
      Limiting Reagents

      • Listen to "America is Smoking" radio excerpt from Car Talk at
        http://cartalk.cars.com/Radio/Back-Tracks/Audio/RA/ctm200104.ram (Requires Real-Player).
      • The Car Guys diagnose some car problems related to nonstoichiometric fuel-air mixture:
        Shirley's car flunks the smog test (http://cartalk.cars.com/Columns/Archive/1997/January/05.html)
        Robert's catalytic converter is overheating (http://cartalk.cars.com/Columns/Archive/1999/July/03.html)
        Richard's spark plugs are sooty (http://cartalk.cars.com/Columns/Archive/1995/August/04.html)
        Emily's car gives off black, smelly smoke (http://cartalk.cars.com/Columns/Archive/1993/February/07.html)
        David's car keeps stalling out (http://cartalk.cars.com/Columns/Archive/1992/August/11.html)

      Exploration 2C: How Do Changes in the Fuel-Air Mixture Affect Air Pollution?
      Constructing a Stoichiometric Model

    Session 3: How Does Combustion Move a Car?
    Thermodynamics of Auto Engines

      Exploration 3A: How Much Heat is Released upon Fuel Combustion?
      Calorimetry Experiment

      Exploration 3B: How Do Chemical Bond Energies Affect the Heat Obtained from Automobile Fuels?
      Bond Enthalpies

      Exploration 3C: How Much Heat is Produced From Combustion of Automobile Fuel?
      Hess' Law and Standard Enthalpies

        The National Institute of Standards and Technology maintains an excellent database of chemical data, including thermochemical data for many compounds and reactions. Follow the screen instructions at http://webbook.nist.gov to search for the desired data.

      • Oxygenated gasoline and fuel economy from Chevron (http://www.chevron.com/prodserv/fuels/bulletin/oxy-fuel)
      • Effect of RFG on fuel economy from the EPA (http://www.epa.gov/otaq/rfgecon.htm)

      Exploration 3D: How Does an Automobile Engine Convert Heat to Work?
      Heat, Work, and the First Law

      • How does an automobile engine work? See an animated demonstration at http://www.howstuffworks.com/engine.htm
      • Check the fuel economy, pollution rating, and greenhouse gas emissions for your car at the Fuel Economy web site for the US Department of Energy and US Environmental Protection Agency (http://www.fueleconomy.gov)
      • Engine specifications for new and older cars (http://www.cars.com). Enter your model and look at "performance" for engine inforomation and "specifications" for curb weight.
      • The Carfolio web site is slower to use but has specifications for many older cars and some less common makes and models (http://www.carfolio.com/specifications)
      • Autoshop 101 - Toyota's Automotive Training Resource Site with detailed information for people studying to be auto mechanics (http://www.autoshop101.com)

      Exploration 3E: How Efficient is an Automobile Engine?
      Thermodynamic Efficiency and Heat Capacity

    Session 4: How Does Engine Temperature Affect Air Pollution?
    Chemical Equilibrium

      Exploration 4A: How Much NO2 is in the Air I'm Breathing?
      Laboratory Analysis of NO2

      • EPA has a collection of links to state and regional data and maps on air quality from current monitoring stations. Use the "Where I live" link at http://www.epa.gov/airnow/where/ to find a state or regional page that is close to you.
      • State and regional sites that are fairly comprehensive include
        South Coast Air Quality Management District for the Los Angeles, CA, region (http://www.aqmd.gov/)
        Texas Natural Resource Conservation Commission Air and Water Monitoring site (http://www.tnrcc.state.tx.us/air/monops)
        Colorado Department of Public Health Air Quality Index Reporting System (http://apcd.state.co.us/psi/)
        California Air Resources Board recent and historical pollution data (http://www.arb.ca.gov/aqd/aqd.htm)

      Exploration 4B: Can We Model the Amounts of CO and NOx Produced in Auto Engines?
      Equilibrium Constants

      Exploration 4C: Are NOx and CO Formed in the Air We Breathe?
      Entropy and Gibbs Free Energy

      Exploration 4D: How Does a Hot Engine Affect CO and NOx Production?
      Temperature Dependence of Equilibrium

      Exploration 4E: How Do Pressure and Concentration Affect CO Removal?
      Le Chatelier's Principle

      • Learn how a catalytic converter removes CO and NOx from auto exhaust at
        http://www.howstuffworks.com/catalytic-converter.htm

      Exploration 4F: What is the NOx Concentration in an Engine?
      Equilibrium Concentrations

      Exploration 4G: Are Reactions in Real Engines in Equilibrium?
      Free Energy and the Reaction Quotient

    Session 5: How Does Fuel Volatility Affect Air Pollution?
    Phase Transitions of Fuel Compounds

      Exploration 5A: How Well Does Fuel Mix with Water?
      Intermolecular Forces and Mixing

      • Fuel testing for the presence of water in gasoline used for aviation from the Experimental Aircraft Assocation (http://www.eaa.org/education/fuel/oxygenated.html)
      • EPA "Frequently Asked Questions" about Movement and Disposition of MTBE in the Environment (http://www.epa.gov/mtbe/water.htm#movement)

      Exploration 5B: What Determines Fuel Volatility?
      Vapor Pressure and Phase Changes

    Session 6: Should We Run Our Cars on Oxygenated Gasoline?
    Culminating Activities

      • EPA Office of Transportation and Air Quality information on a variety of programs including reformulated gasoline and others (http://www.epa.gov/otaq/)
      • EPA Blue Ribbon Panel on the Use of MTBE and other Oxygenates (http://www.epa.gov/oms/consumer/fuels/oxypanel/blueribb.htm)
      • California has long led the nation in studying and managing air quality, including requiring new fuel formulations to minimize specific types of emissions. California takes a contrary view to the US EPA about the role of oxygenates. In summer 2001, the state sued the EPA over EPA's denial of California's request to be released from EPA requirements and independently set its own requirements for gasoline reformulation. The California Air Resources Board maintains an informative site about this controversy and other issues (http://www.arb.ca.gov/fuels/gasoline/gasoline.htm)
      • Oxygenated Fuels Association, an industry group (http://www.cleanfuels.net)
      • How's the air pollution where you live? Pollution Locator for Criteria Air Pollutants, map and county-by-county data from the EPA, gathered in this locator tool by the Environmental Defense Fund (http://www.scorecard.org/env-releases/cap/).


    Copyright © 2004 by the trustees of Beloit College and the Regents of the University of California. This Module has been developed under the direction of the ChemLinks Coalition, headed by Beloit College, and the ModularChem Consortium, headed by the University of California at Berkeley. This material is based upon work supported by the National Science Foundation grants No. DUE-9455918 and DUE-9455924. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation, Beloit College, or the Regents of the University of California.

    Published through exclusive license with W. W. Norton.
    How Can We Reduce Air Pollution from Automobiles? ISBN 0-393-92438-6


    Air Pollution from Automobiles | ChemConnections