Grantee Research Project Results
2011 Progress Report: Emissions of gas-phase low-volatility organic compounds (LVOCs) from mobile sources
EPA Grant Number: R834560Title: Emissions of gas-phase low-volatility organic compounds (LVOCs) from mobile sources
Investigators: Kroll, Jesse H. , Cross, Eben
Institution: Massachusetts Institute of Technology
EPA Project Officer: Chung, Serena
Project Period: April 1, 2010 through March 31, 2013 (Extended to March 31, 2014)
Project Period Covered by this Report: April 1, 2011 through March 31,2012
Project Amount: $249,937
RFA: Novel Approaches to Improving Air Pollution Emissions Information (2009) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air
Objective:
The objective of the proposed work is to improve emission inventories of gas-phase low-volatility organic compounds (LVOCs) from mobile sources, providing inputs to microphysical/chemical modules important for air quality predictions. Present inventories of LVOCs are limited to total mass, or concentrations of only a few species, with little information about the chemistry or volatility of the total emissions.
Progress Summary:
In Year 2, we made substantial progress towards meeting the goals of this project. After having demonstrated the measurement of LVOCs using our new instrument (in Year 1), we have focused on the application of this technique. We carried out a second laboratory intensive at MIT's Sloan Automotive Laboratory for the measurement of LVOCs in diesel exhaust. Emissions of LVOCs (as well of particulate matter) were quantified and characterized as a function of engine load/power, engine speed, fuel type, and use of a diesel particulate filter. Analysis of this dataset is ongoing, but LVOC emissions are found to decrease with increasing engine load, a trend consistent with VOC emissions and opposite that of particulate matter. Analysis of the volatility-resolved mass spectra indicate that the LVOCs shift to lower vapor pressures and higher molecular weights as engine power increases, consistent with a shift from gas-phase to particulate emissions. The observation of transients (temporary changes in emissions immediately following shifts in engine conditions) suggests their importance in average emissions and underscores the importance of time-resolved analytical techniques for accurately characterizing real-world (on-road) emissions. In addition to the diesel exhaust experiments, this year we carried out field measurements of mobile source emissions. LVOC emissions from aircraft were measured as part of the AAFEX-2 campaign, and were found to be a substantial fraction (>20%) of total organic carbon emitted.
Future Activities:
A major focus of Year 3 is the mass spectrometric analysis of the three datasets collected so far as part of this project (two engine laboratory experiments, in Year 1 and Year 2, and the field measurements). We plan to determine all volatility-resolved parameters from the data, including total LVOC mass, elemental composition of the LVOCs (especially O/C and H/C), and aromatic/aliphatic character. These will be organized as a function of engine power, engine speed and use of the diesel particulate filter, allowing for the quantification of emission factors (and transients) for a range of conditions. We also plan to carry out one more experimental intensive in the engine laboratory in order to expand the parameter space of those previous experiments still further. The goal is to examine emissions from a different engine type and use a wider range of emissions control technology.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
| Other project views: | All 13 publications | 4 publications in selected types | All 4 journal articles |
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Cross ES, Sappok A, Fortner EC, Hunter JF, Jayne JT, Brooks WA, Onasch TB, Wong VW, Trimborn A, Worsnop DR, Kroll JH. Real-time measurements of engine-out trace elements: application of a novel soot particle aerosol mass spectrometer for emissions characterization. Journal of Engineering for Gas Turbines and Power 2012;134(7):072801 (10 pp.). |
R834560 (2011) R834560 (2012) R834560 (Final) |
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Supplemental Keywords:
atmosphere, PAHs, measurement methods, transportationProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.