Airborne Measurements of the Atmospheric Emissions from a Fuel Ethanol Refinery

Thursday, 18 December 2014: 1:55 PM
Joost A De Gouw1,2, Stuart A McKeen1,2, Kenneth Aikin1,2, Charles A Brock1, Steven S Brown3, Jessica Gilman1,2, Martin Graus4, Thomas F Hanisco5, John S Holloway1,2, Brian M Lerner1,2, Jennifer Kaiser6, Frank N Keutsch6, Jin Liao1,2, Milos Z Markovic7, Ann M Middlebrook1, Kyung-Eun Min1,2, J A Neuman1,2, John B Nowak8, Jeff Peischl1,2, Ilana B Pollack1,2, James M Roberts1, Thomas B Ryerson1, Michael Trainer1, Patrick R Veres1,2, Carsten Warneke1,2, Andre Welti9 and Glenn M Wolfe Jr5, (1)NOAA Earth System Research Lab, Boulder, CO, United States, (2)Cooperative Institute for Research in Environmental Sciences, Boulder, CO, United States, (3)NOAA Earth System Research Lab, Chemical Sciences Division, Boulder, CO, United States, (4)Universität Innsbruck, Institut für Meteorologie und Geophysik, Innsbruck, Austria, (5)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (6)University of Wisconsin Madison, Madison, WI, United States, (7)Environment Canada Toronto, Toronto, ON, Canada, (8)Aerodyne Research Inc., Billerica, MA, United States, (9)ETH Swiss Federal Institute of Technology Zurich, Zurich, Switzerland
Ethanol made from corn now constitutes approximately 10% of the fuel used in gasoline vehicles in the United States. The ethanol is produced in over 200 fuel ethanol refineries across the country. In this work, we report measurements of the atmospheric emissions from the third largest fuel ethanol refinery in the U.S. located in Decatur, Illinois. Measurements were made from the NOAA WP-3D research aircraft during the NOAA Southeast Nexus (SENEX) campaign in the summer of 2013, which was part of the larger Southeast Atmosphere Study (SAS). Emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) agreed with reported emissions in the 2011 National Emissions Inventory (NEI-2011). In contrast, emissions of several volatile organic compounds (VOCs) including ethanol, formaldehyde and acetaldehyde, were underestimated by an order of magnitude in the NEI-2011. By combining data from the NEI-2011 and fuel ethanol production numbers from the Renewable Fuels Association, we calculate emission intensities for SO2, NOx and VOCs, defined as the emissions per volume of fuel produced. These emission intensities can be readily compared to fuel-based emission factors from gasoline vehicles and the relative contributions made by fuel refining and fuel use to overall emissions will be quantified. Emission intensities of SO2 and NOx are particularly high for those fuel ethanol refineries that use coal as an energy source, including the plant in Decatur studied in this work. Finally, by comparing the measurements at different distances downwind, chemical transformation of the emissions could be observed, including the formation of new particles, peroxyacyl nitrates, ozone and sulfate aerosol.