Project Director

Thomas, Tricia

Department Examiner

Jones, Frank; Sutton, William; Sompayrac, Joanie


Dept. of Civil and Chemical Engineering


University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)


GREET was used to calculate energy consumption and pollutants emitted from specific fuel/vehicle types when given a specific set of parameters. In this case, the parameters were the type of fuel mix from TVA, the selected vehicle year of 2015, the vehicle weight specified in the heavy-duty vehicle range, and type of simulation technique, which was the Hammersely Sequence Sampling. These inputs, along with seventeen fuel/vehicles mixes, specific pollutants, and cost considerations, were used to investigate the environmental impact of the transition from petrol diesel to natural gas in the municipal fleets of Chattanooga, Tennessee. The energy consumption included coal, petroleum, natural gas, and other power generating sources like electricity and biomass/bio-diesel. The pollutants investigated included greenhouse gases (GHGs), carbon monoxide (CO), nitrous oxides (NOx), sulfur oxides (SOx), and particulate matter (PM2.5). The pollutant of particular importance to the city of Chattanooga is PM2.5 since the city is designated a Nonattainment Area by the EPA and is looking to be redesignated as a Maintenance Area. Natural gas vehicles emitted the lowest amount of GHGs, NOx , and PM2.5, only receiving competition from the standard electric vehicle with slightly lower emissions. Overall, Well-topump emissions were the lowest for vehicles that used pure natural gas. To summarize, compressed natural gas seems like the best option for a fuel because it is cheap, fueling the vehicle is easy, there is an unlimited hold time for the fuel, GHG and PM2.5 emissions are lower, compressed natural gas prices fluctuate less in the current market, and the engine for the vehicle is quieter, especially when compared to diesel trucks.


B. S.; An honors thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Bachelor of Science.




Natural gas vehicles -- Tennessee -- Chattanooga; Motor vehicle fleets -- Chattanooga -- Tennessee -- Fuel consumption


GREET; Fuel; Municipal


Chemical Engineering

Document Type



v, 38 leaves




Under copyright.