Tracing Fuel Component Carbon in the Emissions from Diesel Engines
The addition of oxygenates to diesel fuel can reduce particulate emissions, but the underlying chemical pathways for the reductions are not well understood. While measurements of particulate matter (PM), unburned hydrocarbons (HC), and carbon monoxide (CO) are routine, determining the contribution of carbon atoms in the original fuel molecules to the formation of these undesired exhaust emissions has proven difficult. Renewable bio-derived fuels (ethanol or bio-diesel) containing a universal distribution of contemporary carbon are easily traced by accelerator mass spectrometry (AMS). These measurements provide general information about the emissions of bio-derived fuels. Another approach exploits synthetic organic chemistry to place {sup 14}C atoms in a specific bond position in a specific fuel molecule. The highly labeled fuel molecule is then diluted in {sup 14}C-free petroleum-derived stock to make a contemporary petroleum fuel suitable for tracing. The specific {sup 14}C atoms are then traced through the combustion event to determine whether they reside in PM, HC, CO, CO{sub 2}, or other emission products. This knowledge of how specific molecular structures produce certain emissions can be used to refine chemical-kinetic combustion models and to optimize fuel composition to reduce undesired emissions. Due to the high sensitivity of the technique and the lack of appreciable {sup 14}C in fossil fuels, fuels for AMS experiments can be labeled with modern levels of {sup 14}C and still produce a strong signal. Since the fuel is not radioactive, emission tests can be conducted in any conventional engine lab, dynamometer facility, or on the open road.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 15002020
- Report Number(s):
- UCRL-JC-149036; TRN: US200408%%40
- Resource Relation:
- Conference: 9th International Conference on Accelerator Mass Spectrometry, Nasgoya (JP), 09/09/2002--09/13/2002; Other Information: PBD: 14 Oct 2002
- Country of Publication:
- United States
- Language:
- English
Similar Records
Measuring the Effect of Fuel Structures and Blend Distribution on Diesel Emissions Using Isotope Tracing
Using Carbon-14 Isotope Tracing to Investigate Molecular Structure Effects of the Oxygenate Dibutyl Maleate on Soot Emissions from a DI Diesel Engine