Volume 7, Issue 4 (April 2010)
CO2-Neutral Fuels and Lubricants Based on Second Generation Oils such as Jatropha
For the production of raw materials, the generation of energy and for their mobility, the industrialized countries strongly depend on the import of fossil resources. Second generation resources, such as Jatropha, grow on arid soils and produce non-edible oils. Thus, their cultivation does not compete with food production for farmland. Oils of such plants are therefore suggested as sustainable, CO2-neutral and regenerative alternatives to fossil fuels and lubricants. The present work establishes one of the first functional profiles of second generation oils with properties relevant for the use as fuel or lubricants in order to validate the potential for substituting fossil resources. It concentrates on the characterization of oil gained from the Jatropha Curcas plant to be used as fuel and lubricant. Properties were determined such as pour point, flash point, lubricity of diesel-like fuel in high frequency reciprocating rig, high-temperature/high-shear viscosity, and viscosities as function of temperature, extreme pressure behavior, oxidation resistance as well as its toxicity and bio-degradability. These properties are compared to those of currently used plant oils and fossil oils. The fatty acid chain length distribution of Jatropha oil was determined and found to be close to that of palm oil. This qualifies Jatropha oil as a substitute, thus releasing the pressure on the prices of food based oils. First tribological characterizations were carried out and are presented here, showing impressive performance of the as pressed filtered pure Jatropha plant oil. In oil dilution tests carried out on piston-ring/cylinder-liner test rigs, the performance of oils processed from plants such as Jatropha are compared to ester-based, polyalkylene glycol based, and hydrocarbon-based oils. Finally, functional properties of Jatropha were compared to further possible second generation bio-oils and aspects of availability and costs are discussed.