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This work examines low-temperature properties of triglyceride-based alternate fuels for direct-injection compression-ignition engines. Methyl esters from transesterified soybean oil were studied as neat fuels and in blends with petroleum middle distillates (No. 1 or No. 2 diesel fuel). Admixed methyl esters composed of 5-30 vol% tallowate methyl esters in soyate methyl esters were also examined. Pour points, cloud points, and kinematic viscosities were measured; viscosities at cooler temperatures were studied to evaluate effects of sustained exposure. Low-temperature filterability studies were conducted in accordance with two standard methodologies. The North American standard was the low-temperature flow test (LTFT), and its European equivalent was the cold-filter plugging point (CFPP). With respect to cold-flow properties, blending methyl esters with middle distillates is limited to relatively low ester contents before the properties become preclusive. Under most conditions, cold41ow properties were not greatly affected by admixing the methyl esters with up to 30 vol% tallowate (before blending). Least squares analysis showed that both LTFT and CFPP of formulations containing at least 1 0 vol% methyl esters are linear functions of cloud point. In addition, statistical analysis of the LTFT data showed a strong 1:1 correlation between LTFT and CP. This result may prove crucial in efforts to improve low-temperature flow properties of alternate diesel fuels that contain methyl esters derived from triglycerides.JAOCS 72, 895-904 (1995).

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).

Resting cell suspensions of seven Nocardia species catalyzed the production of 10-hydroxystearic acid from oleic acid. Nocardia cholesterolicum N R R L 5767 gave a good yield with optimum conditions at pH 6.5 and 40 ° C. Yields exceeding 90% can be obtained within 6 h with 0.1 g cells (dry weight) and 178 mg oleic acid in 10 ml of 0.05 M sodium phosphate buffer (pH 6.5). In addition, minor amounts of 10-ketostearic acid were formed as a by-product. The reaction proceeded via hydration of the double bond as shown by labeling experiments with deuterium oxide and 180-labeled water. The system was specific for fatty acids with cis unsaturation at the 9 positon.

Cetane numbers (C#} for the homologous series of straight-chain, saturated n-alcohols, C5-C12 and C14, were determined according to ASTM D 613. Measured C# ranged from 18.2-80.8 and increased linearly with carbon number {CN). Regression analyses developed equations that related various physical properties or molecular characteristics of these alcohols to calculated C#. The degree of relationship between measured and calculated C# was expressed as R 2. The decreasing order of the precision with which these properties correlated with C# was: boiling point (bp) > melting point imp) > CN > heat of combustion {HG) > refractive index (UZ0v} > density (d). This ranking was based upon R 2 (0.99-0.96) and the Average % Error (2.8-7.2%). C# were also determined for straight-chain homologs of saturated methyl esters with CN of 6, 10, 12, 14, 16 and 18. C# ranged from 18.0-75.6 and increased eurvilinearly with CN. Equations were also developed that related physical properties of these esters to C#. The precision with which these properties correlated with C# was: bp > viscosity iV} > heat of vaporization {HV) > HG > CN > surface tension (ST) > mp > n20D> d. R 2 ranged from 0.99 for bp to 0.98 for d. Equations for the alcohols were linear or quadratic, while equations for the esters were linear, quadratic or cubic based upon statistical considerations that included a Student's t-test. With related physical properties and these equations, accurate predictions of C# can be made for saturated n-alcohols and methyl esters.

This study was prompted by the special interest in sugar crops, at a time of high petroleum prices and fuel shortages, as potential renewable resources which would supplement non‐renewable fossil resources. Four to six sweet sorghum [Sorghum bicolor (L.) Moench] cultivars were evaluated 4 yr for fermentable sugar production potential at eight locations in the continental USA and at one location in Hawaii. Latitudes represented ranged from 21 to 47° N with the average number of frost‐free days ranging from 120 to more than 350. Data were collected for biomass yield, percent lignin, percent cellulose, stalk sugar yields, and other agronomic characters. Total sugar yield for the continental USA ranged from 4 Mg ha‐1 to 10.7 Mg ha‐1 during 3 yr of the study and up to 12 Mg ha‐1 at the Hawaiian location. Accordingly, theoretical ethanol production in the continental USA ranged from 2129 L ha‐1 to 5696 L ha‐1. Results of the study demonstrated that sweet sorghum is far more widely adapted than was anticipated for a plant of tropical origin and certainly has the potential for providing a good source of fermentable carbohydrates across a wide geographic area.

Sixty‐two cultures from the Agricultural Research Service (ARS) Culture Collection and 10 cultures isolated from soil and water samples in Illinois were screened for their ability to convert agricultural oils to value‐added industrial chemicals. A new compound, 7,10‐dihydroxy‐8(E)‐octadecenoic acid (DOD), was produced from oleic acid at a yield of greater than 60% by bacterial strain PR3 which was isolated from a water sample in Morton, IL. To our knowledge, DOD has not been previously reported. The optimum time, pH and temperature for the production of DOD were 2 days, 7.0, and 30°C, respectively. The production of DOD is unique in that it involves hydroxylation at two positions and rearrangement of the double bond of the substrate molecule.