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Rachel Elias

Biodiesel Structure Property Correlations for Cold Weather Applications

Departments: Chemical Engineering and Environmental Science (Lafayette College)
Advisor: Lindsay Soh (Lafayette College)

Biodiesel consists of mono alkyl esters of long chain fatty acids derived from a renewable lipid feedstock, for use in compression ignition (diesel) engines. Biodiesel offers advantages including low toxicity, lubricity, optimal flash point, low sulfur content, lower exhaust content, and biodegradability. While there are several advantages to using biodiesel, some potential technical hindrances are associated with the fuel properties, including its functionality in cold weather climates. This research aims to study select properties of biodiesel blends. It also incorporates the use of the possible biodiesel co-product, triacetin, as a potential cold flow enhancer; triacetin is also of interest because it is miscible in biodiesel and could avoid the added cost of glycerol removal from the biodiesel product.

Blends were binary mixtures comprising of differing ratios of three saturated and two unsaturated fatty and methyl esters (FAME). Shorter chain length and higher degree of unsaturation in FAME compounds tend to yield optimal cold flow properties. Several predetermined blends were run with 0%, 10%, and 20% triacetin by weight in order to determine the relationship between FAME structure, triacetin concentration, and cold weather performance. Differential scanning calorimetry (DSC) was used to determine the cloud point, melting temperatures, and the heat released during a phase transition. Analysis of DSC curves and corresponding data indicates that triacetin lowers cloud point to different extents, depending on blend constituents. With some blends, triacetin added in concentrations above 10% does not have significant potential to further depress cloud point.

About Rachel Elias:
Rachel is a sophomore at Lafayette College, pursuing a double major in Chemical Engineering and Environmental Science with a concentration in Energy Resources. Since this past summer, she has worked under Professor Lindsay Soh and Professor Michael Senra, studying the optimization of cold flow properties as they apply to biodiesel. Outside of her research, Rachel is also the current Vice President of the Society of Environmental Engineers and Scientists at Lafayette.