This work explores near-term approaches for improving the low-temperature properties of triglyceride oil-derived fuels for direct-injection compression-ignition (diesel) engines. Methyl esters from transesterified soybean oil were evaluated as a neat fuel and in blends with petroleum middle distil~ates. Winterization showed that the cloud point (CP) of methyl soyate may be reduced to -I 6~ Twelve cold-flow additives marketed for distillates were tested by standard petroleum methodologies, including CP, pour point (PP), kinematic viscosity, cold filter plugging point (CFPP), and low-temperature flow test (LTFT). Results showed that additive treatment significantly improves the PP of distillate/methyl ester blends; however, additives do not greatly affect CP or viscosity. Both CFPP and LTFT were nearly linear functions of CP, a result that compares well with earlier studies with untreated distillate/methyl ester blends. In particular, additives proved capable of reducing LTFT of neat methyl esters by 5-6~ This work supports earlier research on the low-temperature properties; that is, approaches for improving the cold flow of methyl ester-based diesel fuels should continue to focus on reducing CP. JAOCS 73, 1719-1728 (]996).

No abstract

Several novel fatty diesters with bulky moieties were synthesized by esterification of mono-or bifunctional fatty acids or with mono-or bifunctional alcohols using p-toluenesulfonic acid as catalyst. They were characterized by 1 H and 13 C nuclear magnetic resonance as well as positive chemical ionization (PCI) mass spectrometry. The PCI mass spectra of the resulting diol diesters and diacid diesters are discussed and compared. The compounds were investigated as potential additives for improving the cold flow properties of vegetable oil esters used as biodiesel. FIG. 2. Cleavages in methane positive chemical ionization mass spectrometry of (A) diacid diesters and (B) diol diesters.