Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/1/2005
Publication Date: 2/1/2005
Citation: Kenar, J.A., Knothe, G.H., Dunn, R.O., Ryann, III, T.W., Matheaus, A. 2005. Physical properties of oleochemical carbonates. Journal of the American Oil Chemists' Society. 82(3):201-205. Interpretive Summary: In the interest of making bio-based compounds for use as additives in commercial products such as lubricants and fuel additives, the physical and fuel properties of several fatty compounds (materials derived from vegetable oil feedstocks) containing a carbonate group were investigated. The properties include: low-temperature properties, viscosity, lubricity, cetane number, and surface tension. This work provides fundamental information about these compounds which is not currently available. The basic knowledge gained from this research has clear importance for the potential applications of the compounds studied. The development of new industrial products derived from vegetable oils, a renewable resource, not only benefits farmers in the United States, but also reduces our dependence on petroleum-based resources.
Technical Abstract: Carbonates are a class of compounds that have recently found increasing interest in commercial applications due to their physical properties and relatively straightforward synthesis. In this work, physical and fuel properties of five straight-chain C17-39 and three branched C17-33 oleochemical carbonates were investigated. These properties include cetane number (CN), low-temperature properties, (kinematic) viscosity, lubricity, and surface tension. The carbonates studied had cetane numbers ranging from 47-107 and depend on chain length and branching. For the same number of carbons, the cetane numbers of carbonates are lower than those of fatty acid alkyl esters due to interruption of the CH2 chain by the carbonate moiety. Kinematic viscosities at 40 deg C ranged from 4.9-22.6 mm²/s while melting points ranged from +3 to below -50 deg C depending upon the carbonate structure. High frequency reciprocating rig (HFRR) testing showed the neat carbonates to have acceptable lubricity that improved as chain length increased. Finally, the carbonate's ability to influence cold flow properties in biodiesel (methyl soyate) and lubricity in low-lubricity ultra-low sulfur diesel (ULSD) were examined. The carbonates studied did not significantly affect cold flow or lubricity properties at concentrations up to 10,000 ppm (1 wt %). The properties of the carbonates resemble those of fatty alkyl esters with similar trends resulting from compound structure.