Abstract: Exhaust hydrocarbon speciation provides novel insight into the complex mixing, ignition and combustion processes of advanced combustion and aftertreatment strategies being developed to reduce the consumption of conventional fuels, enable and improve combustion of alternative fuels and reduce tailpipe emissions. A methodology for sampling and analyzing volatile and semi-volatile hydrocarbons ranging from C1-C30 from fuels, undiluted exhaust gas and particulate matter has been developed in the UM speciation laboratory.

Research Accomplishments:
The UM hydrocarbon speciation laboratory is being used or has provided novel perspective and greater insight in the following internal combustion studies:

1. Effect of alternative fuels and fuel properties on low temperature premixed diesel combustion
2. Low temperature premixed diesel combustion and diesel oxidation catalysts
   • Han, M., Assanis, D. N., Bohac, S. V., 2009, “Sources of Hydrocarbon Emissions from Low-temperature Premixed Compression Ignition Combustion from a Common Rail Direct Injection Diesel Engine,” Combustion Science and Technology, 181, pp. 496-517.
   • Han, M., Assanis, D. N., Bohac, S. V., 2008, “Characterization of Heat-up Diesel Oxidation Catalysts through Gas Flow Reactor and In-situ Engine Testing,” Proc. IMechE Part D – Journal of Automobile Engineering, 222(9), pp. 1705-1716.
   • Han, M., Assanis, D. N., Bohac, S. V., 2008, “Comparison of HC Species from Diesel Combustion Modes and Characterization of a Heat-up DOC Formulation,” International Journal of Automotive Technology, 9(4), pp. 405-413.
   • Han, M., Assanis, D. N., Jacobs, T. J., Bohac, S. V., 2008, “Method and Detailed Analysis of Individual Hydrocarbon Species from Diesel Combustion Modes and Diesel Oxidation Catalyst,” (Initially presented as ASME ICEF2007-1632 in 2007) Journal of Engineering for Gas Turbines and Power, 130(4), pp. 042803-1 to 042803-10.
   • Bohac, S. V., Han, M., Jacobs, T. J., López, A. J., Assanis, D. N., Szymkowicz, P., 2006, “Speciated Hydrocarbon Emissions from an Automotive Diesel Engine and DOC Utilizing Conventional and PCI Combustion,” SAE Paper 2006-01-0201, SAE Transactions – Journal of Fuels and Lubricants, 115.
   • Knafl, A., Han, M., Bohac, S. V., Assanis, D. N., 2007, “Comparison of Diesel Oxidation Catalyst Performance on an Engine and Gas Flow Reactor,” SAE Paper 2007-01-0231.
3. Behavior of laser induced fluorescence tracers in fuel systems of direct injection spark ignited engines
• Zhang, R., Bohac, S. V., Sick, V., 2006, “Stability of Isooctane Mixtures with 3-Pentanone or Biacetyl as Fluorescence Tracers in Combustion Experiments,” Exp. in Fluids, 40, pp. 161-163.
4. Reduction of start-up hydrocarbon emissions from gasoline engines using modified exhaust valve timing
   • Bohac, S. V., Assanis, D. N., Holmes, H., 2004, “Speciated Hydrocarbon Emissions and the Associated Local Ozone Production from an Automotive Gasoline Engine,” Int. J. Engine Res., 5(1), pp. 53-70.