Seminar

Abstract

Over the last two decades, various legislations in the United States have targeted a reduction of the emissions of air pollutants to improve the air quality in cities, and a reduction of the country’s dependence on (imported) petroleum. As one result the U.S. has become the world's largest producer of fuel ethanol. In the U.S. fuel ethanol is largely produced from corn grain in conventional starch-based fermentation. In 2010 more than 50 billion liters of fuel ethanol were produced (EIA, 2011) consuming about 40% of the total annual corn harvest, which was grown on 357,000 square km of agricultural land (NASS, 2011). The Renewable Fuel Mandate caps the starch based fuel ethanol production (corn based) and incentivizes the fuel ethanol production from cellulosic feedstock such as wood chips but also grassy plants like switchgrass or miscanthus. Plants produce numerous organic compounds in their metabolism, some of which are volatile and can escape into the atmosphere. Volatile organic compounds (VOCs) in the atmosphere are photo-oxidized and have the potential to enhance ozone production in polluted air and contribute to the organic aerosol fraction. In order to assess the atmospheric impact of the cultivation of fuel ethanol crops, emission data from the various plant species are needed to drive the emission models. In this seminar data from several lab studies and field experiments on the VOC exchange between biofuel crops and the atmosphere will be presented and the results will be discussed.