Production de biocarburant et biogaz en Inde avec le Pongamia pinnata.
Résumé: One Seed, Many Products
As people around the world are rediscovering, vegetable oils can be used to supplement or even replace traditional petroleum fuels.
Though its raw oil can be used in stationary generators, pongamia oil, like all vegetable oils, needs additional processing known as transesterification to be used to power motorized vehicles. This involves heating unrefined oil and agitating it with a catalyst for a few hours to separate the pure vegetable oil from other constituents, such as glycerol. This transforms 90 percent of the dark-brown unrefined oil into a light-yellow liquid that can properly be called biodiesel.
The glycerol in the remaining 10 percent has wide range of applications, including use in cosmetics and pharmaceuticals.
In fact, almost every step in the life cycle of pongamia seeds results in a safe and useful product.
Once the oil has been extracted from the seeds, the remaining seedcake can be mixed with water and placed in an airtight environment where it ferments, producing a flammable gas and a slurry, which is a safe and highly effective organic fertilizer.
The gas can be compressed and stored in small tanks for use as cooking fuel. (Biogas burns far cleaner than wood or cow dung, the traditional cooking fuels, and so causes fewer respiratory disorders.) Widespread use of gas for cooking could also help curb the rampant deforestation common to areas where wood is used as a primary fuel.
The seedcake has other uses as well. The toxic compounds that make pongamia seeds repellent to grazing livestock can be extracted to create a potent natural pesticide. And once these toxins are removed, the seedcake makes a cattle feed that is rich in amino acids.