PI: Lisa D. Pfefferle, Yale University; Co-PI: Charles S. McEnally, Yale University Collaborator: Charles Mueller, Sandia National Laboratory Collaborator: William Cannella, Chevron Corporation
This research will develop surrogate fuels that can replicate the sooting characteristics of conventional and alternative diesel fuels. Surrogate fuels are mixtures with only a few chemical components that mimic the properties of real fuels that contain thousands of components. They are necessary to perform computational simulations of diesel engines because any detailed chemical kinetic mechanism that included all of the significant components in real fuels would be prohibitively large and render computations unfeasible. During the project sooting tendencies will be measured in laboratory burners for individual components representative of diesel fuels. This data will be used to develop quantitative relationships between fuel structure and soot production that can be used to estimate sooting tendencies of unmeasured chemical compounds and aid in the development of less sooting fuels. Sooting tendencies will also be measured for mixtures to develop and test rules for predicting the sooting tendencies of mixtures from those of their individual components. Then sooting tendencies will be measured for real diesel fuels and surrogate mixtures formulated to have the same sooting tendency. Finally, the surrogates will be tested in the laboratory burners and in actual diesel engines.
Emissions of carbonaceous soot particles from diesel engines into the atmosphere directly harm human health; therefore new engine designs and concepts that improve fuel efficiency are only viable if they do not increase soot emissions. Computer aided design tools are critical for optimizing engines to be simultaneously efficient and nonpolluting and this is not possible using real fuels due to the large number of fuel components. This research will develop recipes for simple fuel mixtures that mimic soot formation in engines yet can be easily computed. In addition, the structure property relationships we develop will be broadly useful for scientists building surrogates for yet to be developed fuels.
