ARS | Publication request: Branched chain derivatives of alkyl oleates: tribological, rheological, oxidation, and low temperature properties

Submitted to: Fuel
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 12, 2008
Publication Date: February 4, 2008
Citation: Moser, B.R., Erhan, S.Z. 2008. Branched chain derivatives of alkyl oleates: tribological, rheological, oxidation, and low temperature properties. Fuel. 87:2253-2257.

Interpretive Summary: A series of previously prepared organic compounds was evaluated in this study with respect to low temperature performance, oxidation stability, lubricity, viscosity, and surface tension. Further evaluation of these materials at additive levels in soybean biodiesel was also accomplished. These are important properties for the development of additives for biodiesel, which suffers from relatively poor cold weather operability and oxidation stability in comparison to petrodiesel. The organic compounds evaluated in this study exhibit improved low temperature performance and oxidation stability when compared to soybean biodiesel. This research benefits the vegetable oil industry by helping to open markets for vegetable oil-based materials for use in biodiesel fuel, another vegetable oil product.

Technical Abstract: We report the evaluation of four previously prepared oleochemical alpha-hydroxy ethers (1-4) and soybean methyl esters (SME) against cloud point, pour point, oxidation stability, kinematic viscosity, specific gravity, lubricity, and surface tension. The ethers exhibit excellent cold flow behavior, oxidation stability, and lubricity. However, at low blend levels (0.5, 1.0, 2.0 wt%) in SME, 1-4 have minimal impact on cloud and pour points. The specific gravity and surface tension data of 1-4 are nearly identical to SME. Ethers 1-4 display increased viscosity when compared to SME, but are still within ASTM D 6751 specifications at low blend levels in SME. Conversely, ethers 3 and 4 at 2.0% in SME are out of specification for kinematic viscosity in EN 14214. Both SME and 1-4 exhibit excellent tribological behavior, as evidenced by HFRR wear scar data well below prescribed ASTM and CEN petrodiesel maximum specifications.