TY - JOUR
T1 - A mass transfer model for VOC emission from silage
AU - Hafner, Sasha D.
AU - Montes, Felipe
AU - Rotz, C. Alan
N1 - Funding Information:
Funding for this work was provided by the National Milk Producers Federation . Appendix
PY - 2012/7
Y1 - 2012/7
N2 - Silage has been shown to be an important source of emissions of volatile organic compounds (VOCs), which contribute to the formation of ground-level ozone. Measurements have shown that environmental conditions and silage properties strongly influence emission rates, making it difficult to assess the contribution of silage in VOC emission inventories. In this work, we present an analytical convection-diffusion-dispersion model for predicting emission of VOCs from silage. It was necessary to incorporate empirical relationships from wind tunnel trials for the response of mass transfer parameters to surface air velocity and silage porosity. The resulting model was able to accurately predict the effect of temperature on ethanol emission in wind tunnel trials, but it over-predicted alcohol and aldehyde emission measured using a mass balance approach from corn silage samples outdoors and within barns. Mass balance results confirmed that emission is related to gas-phase porosity, but the response to air speed was not clear, which was contrary to wind tunnel results. Mass balance results indicate that alcohol emission from loose silage on farms may approach 50% of the initial mass over six hours, while relative losses of acetaldehyde will be greater.
AB - Silage has been shown to be an important source of emissions of volatile organic compounds (VOCs), which contribute to the formation of ground-level ozone. Measurements have shown that environmental conditions and silage properties strongly influence emission rates, making it difficult to assess the contribution of silage in VOC emission inventories. In this work, we present an analytical convection-diffusion-dispersion model for predicting emission of VOCs from silage. It was necessary to incorporate empirical relationships from wind tunnel trials for the response of mass transfer parameters to surface air velocity and silage porosity. The resulting model was able to accurately predict the effect of temperature on ethanol emission in wind tunnel trials, but it over-predicted alcohol and aldehyde emission measured using a mass balance approach from corn silage samples outdoors and within barns. Mass balance results confirmed that emission is related to gas-phase porosity, but the response to air speed was not clear, which was contrary to wind tunnel results. Mass balance results indicate that alcohol emission from loose silage on farms may approach 50% of the initial mass over six hours, while relative losses of acetaldehyde will be greater.
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U2 - 10.1016/j.atmosenv.2012.03.005
DO - 10.1016/j.atmosenv.2012.03.005
M3 - Article
AN - SCOPUS:84860524769
SN - 1352-2310
VL - 54
SP - 134
EP - 140
JO - Atmospheric Environment
JF - Atmospheric Environment
ER -