Chemical and biological characterization of exhaust emissions from two bioethanol fuels containing different diesel ignition improvers

摘要

The report describes the results of an investigation on the potential environmental and health impacts of exhaust emissions from ethanol fuel containing two different diesel ignition improvers. Emission from these two ethanol fuels were compared with respect to their contents of regulated and unregulated exhaust components, affinity of binding the dioxin receptor and mutagenicity of compounds associated with particles and the semi-volatile phase, risk estimates of exhaust components judged to be carcinogenic. Emissions from fuel B contained smaller amounts of CO, particles, ethylene and total particle-associated PAH, but higher amounts of butadiene, than did emissions from fuel A. With respect to the other components measured, the fuels were approximately the same. In general, the emissions give similar responses in the biological tests, with, perhaps, a tendency to lower values of S9-dependent mutagenicity for fuel B. From the point of view of cancer risk, these two ignition improvers are, within the limits of uncertainty, approximately equivalent. The somewhat higher emission of butadiene from fuel B may be balanced by the lower amounts of particles and ethylene emitted from this fuel. 38 refs, 37 figs, 12 tabs