EGEE 401
Energy in a Changing World

Environment

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Combustion Engines

So, how does a gallon of gas move a car 20, 30, 40 or more miles? Put that way, it's really kind of amazing isn't it? To answer this question, let's take a look at the operation of internal combustion engines.

Reading Assignments

Visit How Car Engines Work and read through these sections: opening section, Internal Combustion and Basic Engine Parts.

Visit How Diesel Engines Work and read through these sections: Diesel Engines vs. Gasoline Engines, Diesel Fuel Injection and Diesel Fuel

The Environment

How do we estimate emissions from our fuel use? Exactly how does burning fuel generate emissions? Start with the brief, but extremely important, reading below.

Reading Assignment

Visit www.fueleconomy.gov and read How can a gallon of gasoline produce 20 pounds of carbon dioxide? (You'll need to click on "Learn more...")

The U.S Environmental Protection Agency explains how emissions are calculated for the combustion of petroleum products (Emission Facts: Average Carbon Dioxide Emissions Resulting from Gasoline and Diesel Fuel)—interesting reading. Based on IPCC guidelines, a procedure for estimating CO2 emissions is outlined below:

CO2 emissions from a gallon of gasoline = 2,421 grams x 0.99 x (44/12) = 8,788 grams = 8.8 kg/gallon = 19.4 pounds/gallon

CO2 emissions from a gallon of diesel = 2,778 grams x 0.99 x (44/12) = 10,084 grams = 10.1 kg/gallon = 22.2 pounds/gallon

Notice that to calculate the CO2 emissions from a gallon of fuel, the carbon emissions are multiplied by the ratio of the molecular weight of CO2 (m.w. 44) to the molecular weight of carbon (m.w.12): 44/12. (This should look familiar...prior reading!)

Reading Assignment

From the Environmental Protection Agency's read Fast Facts: U.S. Transportation Sector Greenhouse Gas Emissions 1990-2014 (June 2016) and scan all tables.