Related Experiment Video
Updated: Jun 21, 2026

Ultrasonic-Assisted Preparation of Biodiesel Products from Vegetable Oils
Published on: April 19, 2024
A comparison of used cooking oils: a very heterogeneous feedstock for biodiesel
Gerhard Knothe1, Kevin R Steidley
1National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, 1815 N. University St., Peoria, IL 61604, USA. gerhard.knothe@ars.usda.gov
Abstract:
Used cooking or frying oils are of increasing interest as inexpensive feedstock for biodiesel production. In this work, used frying oils obtained from 16 local restaurants were investigated regarding their fatty acid profile vs. the fatty acid profile of the oil or fat prior to use. The fatty acid profiles were analyzed by gas chromatography and proton nuclear magnetic resonance spectroscopy. Besides the fatty acid profile, the acid value and dynamic viscosity of the samples were determined. Dynamic viscosity was determined because of non-Newtonian behavior of some samples. The results indicate that oils and fats experience various degrees of increase in saturation during cooking/frying use, with the magnitude of these changes varying from sample to sample, i.e., a high degree of randomness of composition is found in used frying oil samples. Properties of the samples that were investigated were acid value and viscosity which consistently increased with use, also in a random fashion. Multiple independent samples obtained from the same restaurants indicate that there is little consistency of used cooking oil obtained from the same source. These results are discussed with regards to the potential fuel properties of biodiesel derived from these used frying oils.
More Related Videos
09:10Experimental Protocol for Biodiesel Production with Isolation of Alkenones as Coproducts from Commercial Isochrysis Algal Biomass
Published on: June 24, 2016
11:33Laboratory Production of Biofuels and Biochemicals from a Rapeseed Oil through Catalytic Cracking Conversion
Published on: September 2, 2016
Related Concept Videos
Biofuels
Microbial Bioremediation of Hydrocarbons
Biosynthesis of Lipids
Overview of Fatty Acid Metabolism
Fatty acids are catabolized in a process called beta-oxidation, which takes place in the matrix of the mitochondria and converts their fatty acid chains into two-carbon units of acetyl groups. The acetyl...
Combustion Energy: A Measure of Stability in Alkanes and Cycloalkanes
Alkanes undergo combustion in the presence of excess oxygen and high-temperature conditions to give carbon dioxide and water. A combustion reaction is the energy source in natural gas, liquified petroleum gas (LPG), fuel oil, gasoline, diesel fuel, and...