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Tracy J. Benson,
tjb5@msstate.edu1, Rafael Hernandez1, W. Todd
French1, Mark G. White1, Earl G. Alley,
earl@ra.msstate.edu2, and William E. Holmes,
wholmes@ra.msstate.edu2. (1) Dave C. Swalm School of
Chemical Engineering, Mississippi State University, P.O. Box 9595,
Mississippi State, MS 39762, (2) State Chemical Laboratory,
Mississippi State University, P.O. Box 9572, Mississippi State, MS
39762
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| Although the growing demand for renewable fuels has
led to an increase in annual production of biodiesel from 0.5 to 75
million gallons, biodiesel production is mainly limited to plant oils
such as soybean and canola and gives off glycerol as an unwanted
byproduct. Therefore, a new biofuel is needed that can utilize a wider
variety of lipids without producing unwanted byproducts. Municipal
sewage sludge and oleaginous yeasts are just two lipid sources that
could be used to produce green diesel. These lipids (e.g., glycolipids,
phospholipids, sphingolipids) can be cracked with superacids to produce
diesel range organics that are usable in compression ignition engines.
In this study, oleic acid, a major fatty acid component of many
potential lipid feedstocks, was reacted at 0°C using triflic acid as the
protonating catalyst. Analytical determinations using NMR, FTIR, and
GC/MS identified a mixture of C9-C14, C16,
and C18 free fatty acids. This is indicative of γ cracking
analogous found in heterogeneous catalysis of petroleum fuels. Both
straight and branch chain isomers are formed for many of the
carbon-lengths. Furthermore, decarboxylation to form diesel range
organics can be achieved using high-temperature, transition metal
catalytic reactions. |