Jatropha curcas

Jatropha curcas is a species of plant that has traditionally been viewed as a pest and a danger due to toxicity, but is now a potential alternative source of diesel. The seeds contain approximately 30% oil, 98% of which can be extracted using hexane as a solvent. However, hexane is a hydrocarbon, so the production of the biofuel is not completely sustainable. The ideal solution would be to find another solvent that is not a hydrocarbon and will still yield approximately the same percentage of oil.

Methods of extraction

The ripe fruits are plucked from the trees and the seeds are sun dried. The shells are then decorticated and either roasted for about 10 minutes or solar-heated for several hours. The breaking down of cells and the liquefaction of the oil due to the heat make easier and better extraction. There are three main ways that oil is extracted: mechanical extraction using screw presses such as The Sayari Expeller, The Bielenberg Ram Press, or the Komet Expeller, solvent extraction, with hexane for example, or a technique called soxhlet extraction.

Optical Density

Optical density is the measure of the transmission of electromagnetic waves through an optical medium for a given wavelength. It is, put simply, the ability of a material to absorb light. In an OD test, darker material has a higher density than lighter material. Density is usually expressed on a logarithmic scale of Optical Density (OD) units. Extra organic compounds in extracted oil increase optical density.

Basic Chemical Characteristics of Solvents