Informatics Publishing Limited

Abstract

The energy crisis and shortage of fuel emanating from total dependence on mineral oil with resultant socioeconomic problems demand the need to explore the use of renewable energy as alternative. This study evaluates the physical properties Jatropha (Jatropha curcas) oil as alternative base oil for lubricant in auto engines.

A quantity of 32 kg dried base decorticated seeds of Jatropha was locally obtained. Volume of 4 litres of Jatropha oil was extracted from the seeds using existing hydraulic press machine, while its physical properties was determined through laboratory analytical procedure of American Society for Testing and Materials analytical standard 960-52 (ASTM,D960-52). The properties determined were: viscosity, density, flash point, pour point, melting point, refractive index, specific heat and thermal conductivity. Comparisons of the properties were also made with the standard lubricant (SAE 40 engine oil). The principles of flow theories were employed to develop heat generated equation in terms of temperature, density and viscosity of the oil and a computer program in C⁺⁺ language was thus written. Sensitivity analysis was performed on the effect of temperature change, (30 °C to 100 °C) on value of density and viscosity.

The physical properties of Jatropha oil are viscosity (162.8) cst, density (0.920) g/ml, flash point (113)°C, pour point (7.7)°C, melting point (4 to 5)°C, refractive index (1.435), specific heat (0.082) KJ/Kg/K and thermal conductivity (4.250) W/m°C. Comparative analysis showed that the values of viscosity, density, thermal conductivity and pour point for Jatropha oil were higher than the values of SAE 40 engine oil while specific heat, flash point and refractive index values of Jatropha oil were less than the values of SAE 40 engine oil. The result showed that the average values for density and viscosity of Jatropha oil were 890.75 Kgm^-3 and 0.1385 N.S/m². Sensitivity analysis showed that Jatropha oil has highest density and viscosity values at 30°C and lowest values at 100°C.

In conclusion, Jatropha oil is suitable as alternative to conventional lubricating oils in auto engines. This study provides baseline information for production of lubricating oils from Jatropha seeds.

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