Sunday, November 28, 2010
One of the biggest complaints about growing crops for biodiesel or fuel is that they take away from arable land needed to grow crops for food. However, there are numerous places in tropical and desert zones where the soil is for all practical purposes infertile and unsuitable for growing food crops. This is where Jatropha curcas steps into the picture. This tropical tree is tolerant of very poor soils, gravels, sand and salinity, producing large amounts of oil suitable for biodiesel, while serving to reclaim and improve the poor soil in which it was planted. It also offers the attraction of producing cash renewable energy crops in a short time frame, with a long perennial life span and the promise of socio-economic development opportunities in developing countries. The point this part 1 article wishes to make is that investing in tropical trees is not limited to just lumber profits. Part 2 will be a list of some of the numerous and profitable benefits of growing Jatropha curcas in tropical and semi-tropical locations.
Jatropha curcas grows as a small tree reaching heights of 6 meters or 20 feet. While the tree is known to live for up to 100 years, its productive span for oil production is considered to be between 30 to 40 years. As mentioned it is resistant to aridity, but starts to thrive with as little as 250 mm or 10 inches of annual rainfall. The more rain, the larger the oil crop will be. The oil seeds are encased in an outer fruit that makes excellent fertilizer rich in nitrogen, phosphorus and potassium. Fruit production starts within 9 months of planting, but best yields start to occur in the 2nd or 3rd year after planting. The yield is amazing: measured on a per hectare basis (2.47 acres) the plantation owner can anticipate average yields of 5000 kilos (5 metric tons) of oil seeds, rendering on average 1,650 kg (1.65 metric tons) of oil and 3,200 kg (3.2 metric tons) of compostable fertilizer. The tree can be propagated both by seed and by cuttings, and the plantation looks for good branching or ramification, as that increases seed yield.
Depending on rainfall, the seeds will render between 27 to 40% oil that can be easily processed to produce biodiesel for standard diesel engines. The oil cannot be used for human consumption, because the oil and the fruits are highly poisonous, containing both HCN (Hydrogen cyanide or Prussic acid) and toxalbumin curcin, a compound similar to Ricin. However, this is not a bad thing, because it makes Jatropha curcas trees resistant to all sorts of pests and fungi. The said compounds are also a very valuable precursor for pharmaceutical and polymer production. Jatropha curcas is a social tree and can be planted with other trees and plants, in which case it will act like a natural repellent, protecting its neighbours. Seed extraction is low tech, requiring the use of a nut shelling machine or mill and then the use of an oil press, providing employment to local people. Some combustion engines can be modified to use the oil directly, or the oil can be transesterified into biodiesel, which is also a simple and relatively cheap process.
At Amazonia Reforestation we are planting Jatropha curcas as part of our 2011 cultivation schedule. The idea is to make our entire operation energy independent (tractors, trucks, generators) using renewable energy, while creating economic opportunities for local workers. Doing this also fits in with our CO2 Tropical Trees program, as renewable energies like biodiesel and wood pellets can be considered carbon neutral, especially when processed on site.The carbon released is equal to the carbon absorbed by these amazing tropical trees and their oil seeds.