Extracting & Quantifying the Organic Composition of Biodiesel Exhaust Particulate Matter
Conference Year
January 2019
Abstract
Biodiesel is a renewable transportation and heating fuel that is typically thought of as “cleaner” than petroleum diesel, but that is not necessarily the case when it is combusted. The combustion of biodiesel can produce harmful organic compounds, such as polycyclic aromatic hydrocarbons (PAH’s) and n-alkanes. This research focuses more on quantifying PAH’s, rather than n-alkanes, because they are more mutagenic and carcinogenic. These compounds are not regulated in terms of tailpipe emission standards, and there is little quantitative data on PAH chemical speciation in particulate matter (PM) from biodiesel fuel combustion. To study the exhaust PM, different blends of biodiesel and petroleum-diesel fuels combusted in a VW light-duty diesel engine and tailpipe emissions samples were collected using 47 mm Fiber Film filters. The PM on the filters is extracted using Dicholormethane:Hexane solvents, sonication and analyte concentration by nitrogen gas blowdown. Sample extracts are analyzed using Gas Chromatography-Mass Spectrometry (GCMS) with a method that is set up to quantify 16 PAH’s and 14 even C12-C40 n-alkanes. Developing this method involved using a PAH-specific GC column-Zebron ZB-PAH 30 meter with a 0.25 mm internal diameter-and a temperature ramp program that allows the target analytes to elute in separate peaks. Two different filter punch sizes have been tested, 1/8 – inch and 1/4 – inch, in spiked chemical extractions where a known mass and concentration of a compound is added to the filter punch. The current extraction method uses two 1/4 – inch punches of filter in each vial improved GCMS detection limits in the biodiesel PM filter samples. Data analysis involves using the peak area response from the chromatogram to calculate percent recovery. Though a known mass is spiked, theoretically the percent recovery should be around 100%, but due to the volatile nature of certain compounds, their abundance can be significantly reduced or lost completely during the extraction process. Work is ongoing to improve the percent recovery of spiked filter extractions before extracting and quantifying real world samples that contain unknown compounds with varying masses and concentrations.
Primary Faculty Mentor Name
Britt Holmen
Status
Undergraduate
Student College
College of Engineering and Mathematical Sciences
Program/Major
Environmental Engineering
Primary Research Category
Engineering & Physical Sciences
Secondary Research Category
Food & Environment Studies
Extracting & Quantifying the Organic Composition of Biodiesel Exhaust Particulate Matter
Biodiesel is a renewable transportation and heating fuel that is typically thought of as “cleaner” than petroleum diesel, but that is not necessarily the case when it is combusted. The combustion of biodiesel can produce harmful organic compounds, such as polycyclic aromatic hydrocarbons (PAH’s) and n-alkanes. This research focuses more on quantifying PAH’s, rather than n-alkanes, because they are more mutagenic and carcinogenic. These compounds are not regulated in terms of tailpipe emission standards, and there is little quantitative data on PAH chemical speciation in particulate matter (PM) from biodiesel fuel combustion. To study the exhaust PM, different blends of biodiesel and petroleum-diesel fuels combusted in a VW light-duty diesel engine and tailpipe emissions samples were collected using 47 mm Fiber Film filters. The PM on the filters is extracted using Dicholormethane:Hexane solvents, sonication and analyte concentration by nitrogen gas blowdown. Sample extracts are analyzed using Gas Chromatography-Mass Spectrometry (GCMS) with a method that is set up to quantify 16 PAH’s and 14 even C12-C40 n-alkanes. Developing this method involved using a PAH-specific GC column-Zebron ZB-PAH 30 meter with a 0.25 mm internal diameter-and a temperature ramp program that allows the target analytes to elute in separate peaks. Two different filter punch sizes have been tested, 1/8 – inch and 1/4 – inch, in spiked chemical extractions where a known mass and concentration of a compound is added to the filter punch. The current extraction method uses two 1/4 – inch punches of filter in each vial improved GCMS detection limits in the biodiesel PM filter samples. Data analysis involves using the peak area response from the chromatogram to calculate percent recovery. Though a known mass is spiked, theoretically the percent recovery should be around 100%, but due to the volatile nature of certain compounds, their abundance can be significantly reduced or lost completely during the extraction process. Work is ongoing to improve the percent recovery of spiked filter extractions before extracting and quantifying real world samples that contain unknown compounds with varying masses and concentrations.