Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: February 14, 2005
Publication Date: May 1, 2005
Citation: Hess, M.A., Haas, M.J., Foglia, T.A., Marmer, W.N. 2005. Additive treatment and its impact on nox emissions from biodiesel [abstract]. Annual Meeting and Expo of the American Oil Chemists' Society. p. 57-58. Technical Abstract: Biodiesel is a renewable, domestically produced fuel that has been shown to reduce particulate, hydrocarbon, and carbon monoxide emissions from diesel engines. Biodiesel produced from certain feedstocks, however, has been shown to cause an increase in nitrogen oxides (NOx), which is of particular concern in urban areas that are subject to strict environmental regulations. For example, when using a blend of 20% soy biodiesel in petrodiesel (B20) in a single cylinder direct injection Yanmar diesel engine, NOx emissions were elevated on average 6.1% when compared to petrodiesel. Two different tactics of lowering NOx emissions were investigated. The first was the addition of antioxidants to B20 to reduce prompt NOx formation. Several antioxidants were tested, and the addition of butylated hydroxyanisole at a concentration of 1000 ppm was shown to be successful at reducing NOx output to levels that were nearly comparable to those observed using petrodiesel. In another approach, attempts were made to modify the bulk modulus of compressibility of the biodiesel by various methods in order to reduce NOx levels. These methods included the addition of cyclohexyl esters or a commercially available anti-gelling additive. The cyclohexyl esters increased NOx formation by 4.2% over levels observed with B20 whereas the anti-gel additives had no effect on NOx emissions of the B20 fuel.