689f Identification of Metals Found In Biofuel Lipids Using Inductively Coupled Plasma/mass Spectrometry

Tracy J. Benson¹, Dr. Rafael Hernandez², Todd French¹, William E. Holmes³, and Ashli Brown⁴. (1) Chemical Engineering, Mississippi State University, Mississippi State, MS 39759, (2) Dave C. Swalm School of Chemical Engineering, Mississippi State University, Box 9595, Mississippi State, MS 39762, (3) Mississippi State Chemical Laboratory, Mississippi State University, Box 9595, Mississippi State University, MS 39762, (4) Biochemistry and Molecular Biology, Mississippi State University, Dorman Hall, Mississippi State, MS 39762

Recent research has identified the use of lipids as feedstocks for the production of green fuels via heterogeneous catalytic cracking. These green fuels, which are comprised of the same types of compounds found in petroleum-based fuels, could be produced from a wide variety of plant, animal, and microbial lipid sources and could replace significant amounts of petroleum fuels. The lipids are comprised mainly of free fatty acids, acylglycerols, and phospholipids and contain trace levels of metals either from growth media or from extraction processes. High phosphorus levels are expected due to the phospholipid content of extracted oils.

The metals, lithium, sodium, magnesium, phosphorus, potassium, calcium, strontium, and barium, have been identified as poisons to the heterogeneous solid catalysts used in catalytic cracking processes. A catalyst poison is defined by any agent that lowers the effectiveness of the solid substrates. This can include coke, water, and metals. Literature has shown that the above stated metals can hinder catalytic activities and even alter product distributions. Therefore, clean-up strategies must be employed to remove metals from the lipid feedstocks before catalytic cracking.

This paper will demonstrate the utility of using Inductively Coupled Plasma/Mass Spectrometry (ICP/MS) as an analytical tool for inorganic analysis of catalyst poisoning agents. In this study, lipids produced and extracted from oleaginous yeasts have been examined using ICP/MS to identify and quantitate these metals and other potentially catalyst poisoning metals. Metals analysis was performed on the bulk lipid, which included both neutral and polar lipids, separated fractions of the bulk lipid material, and the growth media. First, a full mass spectral scan was used to characterize a wide range of metals. Then, specific metals were quantitated based upon their respective dominate mass ions. An assessment has been made on the quantity of the uptake of metals from the growth media to the extracted lipids. Results from this work will be used to develop clean-up strategies for lipids before catalytic processing.