Nitrogen Fertilizer-Induced N2o Emission Factors for Corn Ethanol Life-Cycle Analysis | AIChE

Nitrogen Fertilizer-Induced N2o Emission Factors for Corn Ethanol Life-Cycle Analysis


Kwon, H. - Presenter, Argonne National Laboratory
Xu, H., Argonne National Laboratory
Cai, H., Argonne National Laboratory
Xia, Y., University of Illinois
Wander, M., University of Illinois
In existing biofuel regulations such as the Renewable Fuel Standard, benefit of corn ethanol relative to petroleum fuels in terms of greenhouse gas emissions (GHG) is typically evaluated based on life-cycle carbon intensity. It is well recognized that N fertilizer-induced N2O emissions from corn production contributes significantly to ethanol carbon intensity. Typically, N2O emissions from N fertilizers applied are calculated by multiplying N rate with a N2O emission factor, which could be measured via field experiment or derived from a meta-analytic approach of published literature. Recently, there is a growing interest to capture spatial variations in N2O emissions and to understand management and environmental drivers.

The objectives of this study are to (1) update fertilizer-induced N2O emission factors using latest studies and (2) to assess impacts of spatial variability in emission factors on carbon intensity of corn ethanol. Existing N2O emission database used in GREET life-cycle model was built in 2012 and since, about 280 new papers on this topic were published according to Web of Science. We expand existing database through a meta-analysis of published literature regarding N2O emissions from corn-based farming systems in US. Literature review covers US-based studies published between 1990 and 2019 to update current N2O emission factor. Fertilizer management and environmental factors will also be evaluated. Findings obtained from the meta-analysis will be used to characterize the significance of N2O emissions in the overall GHG emissions profile of corn ethanol production in various US states.