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United States Department of Agriculture

Agricultural Research Service

Title: Kinetics of Biodiesel Oxidation by Non-Isothermal Pressurized-Differential Scanning Calorimetry

Author
item Dunn, Robert

Submitted to: World Oleochemical Conference
Publication Type: Abstract Only
Publication Acceptance Date: February 10, 2005
Publication Date: April 10, 2005
Citation: Dunn, R.O. 2005. Kinetics of biodiesel oxidation by non-isothermal pressurized-differential scanning calorimetry [abstract]. World Oleochemical Conference. p. 19.

Technical Abstract: Biodiesel, an alternative diesel fuel derived from transesterification of vegetable oils or animal fats, is composed of saturated and unsaturated long-chain fatty acid alkyl esters. During long-term storage, oxidation caused by contact with air (autoxidation) presents a legitimate concern with respect to monitoring and maintaining fuel quality. Extensive oxidative degradation of unsaturated alkyl esters can compromise fuel quality by increasing kinematic viscosity, acid value or peroxide value. This study is an investigation of the oxidation reaction applied to biodiesel (methyl soyate) under pressure (2000 kPa) to increase the molar concentration of oxygen for reaction. Non-isothermal pressurized-differential scanning calorimetry (P-DSC) heating scans were conducted on methyl soyate with ramp rates varying from 1 to 20ºC/min. Static and dynamic mode P-DSC results were treated by Ozawa-Flynn-Wall (OFW) analysis to infer activation energy and pre-exponential factor associated with Arrhenius kinetics. This work shows the kinetic parameters of biodiesel oxidation obtained from non-isothermal P-DSC analyses may be employed to determine relative resistance to oxidation at any temperature.

Last Modified: 10/1/2014
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