Cetane numbers for various esters of the saturated fatty acids from C8 to C18 have been determined according to ASTM D‐613. For the methyl esters the cetane numbers were found to increase in a non‐linear relationship with the chain length of the fatty acid. Cetane numbers of esters in which the fatty acid is kept constant while the alcohol esterified is altered also increased with the molecular weight of the ester. However, increases in the molecular weight of the fatty acid portion of the ester produce greater increases in cetane number than the same change in molecular weight in the alcohol portion of the ester. Except for the esters of octanoic acid, all of the esters tested had cetane numbers above the value of 40, which is specified as the minimum cetane number for commercial diesel fuel.

Cetane indexes have been calculated for the esters of the individual saturated fatty acids in the Cs-C24 range plus palmitoleic, oleic, linoleic, and linolenic acids. Two methods were used for these calculations: ASTM 976 and a method involving simultaneous equations relating the experimentally determined cetane numbers for several transesterified oils and the fatty acid compositions of the oils. Cetane indexes calculated according to ASTM 976 produced values which were too low for ester mixtures high in saturated acids and low in polyunsaturated acids, and were somewhat high for ester mixtures high in polyunsaturated acids. When cetane indexes calculated according to the simultaneous equation method were applied to the fatty acid mixtures, the agreement with those experimentally determined was approximately the error of determination of the cetane number.

The effect of increasing concentrations of lysolecithin (1-palmitoyl-sn-glycerol-3-phosphorylcholine) on the gel ~ liquid crystal thermal transition of lecithin (1,2-dipalmitoyl-sn-glycerol-3-phosphorylcholine) in the aqueous phase was studied by differential scanning calorimetry (DSC). Lysolecithin showed an endothermic transition at 3.4°C whereas the transition of the lecithin occurred at 42 ° C. No phase separation could be observed calorimetricaUy at lysolecithin concentrations up to 60 mol%. Freeze etch electron microscopy showed that mixtures containing as much as 50 mol% lysolecithin exist in a lamellar phase. The lysolecithin was found to cause an initial slight increase in the enthalpy of transition followed by a gradual decrease. The enthalpy increased again at very high lysolecithin concentrations. The lysolecithin also caused a non-linear decrease in the temperature at which the lecithin transition took place.Cholesterol was found to decrease the enthalpy of transition of the lysolecithin, eliminating it at a concentration of 50 mol%. Cholesterol caused an increase in the temperature at which the lysolecithin transition took place.

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Methyl esters of commercial grades of lauric, myristic, palmitic, stearic, linoleic and linolenic acids, as well as ethyl and butyl esters of oleic acid, were burned in a diesel engine to determine their efficiencies as fuels. Triolein and some common vegetable oils were burned as comparison fuels and No. 2 diesel fuel was used as a control. The fuels were tested in a single‐cylinder direct‐injection engine running at rated speed and load in short‐term, performance engine tests. Specific fuel consumption and thermal efficiencies of the engine burning these fuels were then determined. Among the methyl esters of the saturated acids, thermal efficiency was inversely related to chain length of the fatty acid. Introduction of a double bond resulted in increased efficiency. Further increases in unsaturation had negligible effects on thermal efficiencies. Ethyl oleate had the highest thermal efficiency and butyl oleate had the lowest thermal efficiency of any of the ester fuels tested. Most of the ester fuels produced higher thermal efficiencies than did No. 2 diesel fuel. Triolein produced the lowest specific fuel consumption of the triglyceride fuels and peanut oil produced the lowest specific fuel consumption of the vegetable oils. The data suggest that ethyl esters of monounsaturated or short‐chain fatty acids should make good alternative fuels and that they should be further evaluated in longterm engine tests.