How to Extract Oil from JATROPHA for Bio-diesel Fuel
Then what is this JATROPHA Bio-Diesel Fuel, and how does it look like?
Jatropha curcas is a small oleaginous fruit bearing tree from the Euphorbiaceae family that thrives in warm weather and can grow in barren soil (i.e. even in the desert). The oil found in its seeds can be converted into a high quality diesel fuel.
Since it’s inedible, it does not compete with food crops. Furthermore its ability to withstand periods of drought, naturally repel pests, and grow in subprime soil makes it a great candidate for combating soil erosion and providing energy independence to a number of third world countries.
Jatropha also boasts a large rainfall tolerance, surviving in conditions between 250 and 3000 mm of rainfall per year.
Jatropha does have its limitations, being susceptible to frost damage. This restricts Jatropha to what industry experts call the Jatropha Belt, a region spanning 30 N latitude to 35 S latitude
How to Extract Oil from JATROPHA
After harvesting the fruits and removing the seeds, it is necessary to extract the oil for use as feedstock in biodiesel production. The average seed is approximately 30-40 weight % oil. The seeds need to be dried in an oven at 105 C or dried under the sun for three weeks. Oil extraction can be accomplished mechanically or chemically.
The traditional mechanical approach involves pressing the oil out of the seeds in a screw press. Seeds are fed into a hopper and subjected to intense frictional and shear forces by a rotating screw.
Engine driven presses can extract anywhere from 75 – 80% on a single pass and as high as 89-91% if precooked and subjected to two passes.
The chemical approach uses a solvent to chemically leech the oil from ground seed kernels. The ideal solvent will have high oil solubility and a low boiling point. Upon multiple passes of a chemical solvent in a commercial distillation tower it is possible to boil off the solvent and concentrate nearly all of the oil present in the ground kernels in the bottoms product of the tower.
This method is only feasible for large scale production schemes due to the cost of maintaining and running a distillation tower.
How to Leverage the leftover Seed Cake
Regardless which process is used for oil extraction, a significant amount of seed cake is left behind. While most biomass waste cakes can be used as feedstock for farm animals, the same phorobol esters present within the Jatropha plant that make the crop resistant to pests also make it mildly toxic to mammals.
Fortunately, the seed cake is 100% biodegradable and shares many of the desirable elements found in commercial fertilizers, making it an excellent source of nutrients for the Jatropha trees back at the plantation. Nutritional value of Jatropha seed cake is comparable to chicken manure.
P.S. Thanks for reading this far! If you found value in this, we’d really appreciate it if you recommend this post (by clicking the share buttons) so other people can learn!