Date of Completion


Document Type

Honors College Thesis


Civil & Environmental Engineering

Thesis Type

Honors College

First Advisor

Britt A. Holmén


biodiesel, FTIR, MSAT, light-duty, emissions modeling


Biodiesel fuel use is more widespread, but existing studies of its effect on air toxic emissions, especially from light-duty diesel (LDD) engines, are insufficient for understanding the air quality effects of biodiesel use. This study applies steady-state and transient cycle data on air toxics and criteria pollutant exhaust emissions from a LDD engine running on biodiesel fuel blends (B0, B10, B20, B50, B100) to develop models for pollutant emission rates. Using second-by-second FTIR data on formaldehyde, CO, CO2, NO, and NO2 emissions from waste vegetable oil and soybean biodiesel blends, statistical analyses examined how engine operating conditions, biodiesel fuel content, and biodiesel feedstock affected steady-state emissions. Transient cycle emissions data were used to develop multivariate regression models for each pollutant based on measurable engine parameters (percent engine load, engine speed, exhaust temperature) and biodiesel content. Log-linear models of CO2 and NO predicted emission rates very well, while transient emissions of NO2, formaldehyde, and CO were modeled only moderately well. Modeling high concentrations in the two species formed by incomplete combustion, formaldehyde and CO, proved especially challenging, suggesting the need for additional variables or separate models for different modes of engine operation.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.