Emissions from Wild Land Fires, Diesel Engines and Other Combustion Sources
- Author(s): Dixit, Poornima
- Advisor(s): Cocker, David
- et al.
The overall goal of this research was an in depth investigation of emissions from a number of sources, with emphasis on two under-explored areas. One study delved into the characterization of emissions from wildland fires an increasingly important source due to climate change, and the other undertook a deeper examination of the in-use emissions from heavy duty trucks operating in the port regions of Southern California.
An in-depth characterization of emissions from lab scale wildland fires was carried out, including: polyaromatic hydrocarbons (PAHs), levoglucosan, anions and cations, elemental and organic carbon. The unique aspect of this research was the comparison of data from two independent measurement methods; one method used real-time analytical methods and the other collected a sample over time and was analyzed off-line with reference methods. A side-by-side comparison of the two approaches showed significant differences and inaccuracies for many of the analyses by the Aerosol Mass Spectrometer. Further analysis enabled transformation of real time analysis to useful data.
Usually marine ports have the highest emissions in a region as many of the sources have weak emission standards. In this research the emissions of criteria and toxic pollutants were measured from the engines in heavy duty trucks representative of those operating in the port regions. An important finding was the emissions measured during real world drive cycles more accurately represented the emission characteristics for the vehicles than the certification cycle or values determined from in-use compliance testing. Further, emissions from NOx control technologies were important to understand as emissions were multiple times higher for near port activities as compared with regional activity. High emissions reduction benefits from the SCR were observed but largely depended on catalyst temperature. Another important analysis completed during this thesis was the emissions factors from yard tractors in the port region for a period of over ten years. Both case studies provide additional insight into the emissions from port sources.