Jatropha curcas
Jatropha curcas is a species of flowering plant in the spurge family, Euphorbiaceae, that is native to the American tropics: Mexico, the Caribbean and Central and South America. It has been spread to tropical and subtropical regions around the world, becoming naturalized or invasive in many areas. The specific epithet, "curcas", was first used by Portuguese doc Garcia de Orta more than 400 years ago. Common names in English include physic nut, Barbados nut, poison nut, bubble bush or purging nut. In parts of Africa and areas in Asia such as India it is often known as "castor oil plant" or "hedge castor oil plant", but it is not the same as the castor oil plant, Ricinus communis.
Jatropha curcas is a semi-evergreen shrub or small tree, reaching a height of or more. It is resistant to a high degree of aridity, allowing it to grow in deserts. It contains phorbol esters, which are considered toxic. However, edible varieties native to Mexico also exist, known by the local population as piñón manso, xuta, chutacurcaste, among others. J. curcas also contains compounds such as trypsin inhibitors, phytate, saponins and a type of lectin known as curcin.
The seeds contain 27–40% oil that can be processed to produce a high-quality biodiesel fuel, usable in a standard diesel engine. The oil is a strong laxative. Edible varieties, as those developed by selection by ethnic Mexican natives in Veracruz, can be used for animal feed and food.
Description
- Leaves: The leaves have significant variability in their morphology. In general, the leaves are green to pale green, alternate to subopposite, and three- to five-lobed with a spiral phyllotaxis.
- Flowers: male and female flowers are produced on the same inflorescence, averaging 20 male flowers to each female flower, or 10 male flowers to each female flower. The inflorescence can be formed in the leaf axil. Plants occasionally present hermaphroditic flowers.
- Fruits : fruits are produced in winter, or there may be several crops during the year if soil moisture is good and temperatures are sufficiently high. Most fruit production is concentrated from midsummer to late fall with variations in production peaks where some plants have two or three harvests and some produce continuously through the season.
- Seeds: the seeds are mature when the capsule changes from green to yellow. The seeds contain around 20% saturated fatty acids and 80% unsaturated fatty acids, and they yield 25–40% oil by weight. In addition, the seeds contain other chemical compounds, such as saccharose, raffinose, stachyose, glucose, fructose, galactose, and protein. The oil is largely made up of oleic and linoleic acids. Furthermore, the plant also contains curcasin, arachidic, myristic, palmitic, and stearic acids and curcin.
- Genome: the whole genome was sequenced by Kazusa DNA Research Institute, Chiba Japan in October 2010.
Propagation
Cultivation
Cultivation is uncomplicated. Jatropha curcas grows in tropical and subtropical regions. The plant can grow in wastelands and grows on almost any terrain, even on gravelly, sandy and saline soils. It can thrive in poor and stony soils, although new research suggests that the plant's ability to adapt to these poor soils is not as extensive as had been previously stated. Complete germination is achieved within 9 days. Adding manure during the germination has negative effects during that phase, but is favorable if applied after germination is achieved. It can be propagated by cuttings, which yields faster results than multiplication by seeds.The flowers only develop terminally, so a good ramification produces the greatest amount of fruits. The plants are self-compatible. Another productivity factor is the ratio between female and male flowers within an inflorescence, more female flowers mean more fruits. Jatropha curcas thrives on a mere of rain a year, and only during its first two years does it need to be watered in the closing days of the dry season. Ploughing and planting are not needed regularly, as this shrub has a life expectancy of approximately forty years. The use of pesticides is not necessary, due to the pesticidal and fungicidal properties of the plant. It is used in rural Bengal for dhobi itch.
While Jatropha curcas starts yielding from 9–12 months time, the best yields are obtained only after 2–3 years time. The seed production is around 3.5 tons per hectare. If planted in hedges, the reported productivity of Jatropha is from 0.8 to 1.0 kg of seed per meter of live fence.
Processing
Seed extraction and processing generally needs specialized facilities.Oil content varies from 28% to 30% and 80% extraction, one hectare of plantation will give 400 to 600 litres of oil if the soil is average.
The oily seeds are processed into oil, which may be used directly to fuel combustion engines or may be subjected to transesterification to produce biodiesel. Jatropha oil is not suitable for human consumption, as it induces strong vomiting and diarrhea.
Biofuel
When jatropha seeds are crushed, the resulting jatropha oil can be processed to produce a high-quality biofuel or biodiesel that can be used in a standard diesel car or further processed into jet fuel, while the residue can also be used as biomass feedstock to power electricity plants, or used as fertilizer. The cake can also be used as feed in digesters and gasifiers to produce biogas.Image:Sedari Menanam Hingga Memetik.jpg|thumb|"From planting to picking. Treat your jatropha plant as well as possible to make the yield as large as possible!"
There are several forms of biofuel, often manufactured using sedimentation, centrifugation, and filtration. The fats and oils are turned into esters while separating the glycerin. At the end of the process, the glycerin settles and the biofuel floats. The process through which the glycerin is separated from the biodiesel is known as transesterification. Glycerin is another by-product from Jatropha oil processing that can add value to the crop. Transesterification is a simple chemical reaction that neutralizes the free fatty acids present in any fatty substances in Jatropha. A chemical exchange takes place between the alkoxy groups of an ester compound by an alcohol. Usually, methanol and ethanol are used for the purpose. The reaction occurs by the presence of a catalyst, usually sodium hydroxide or caustic soda and potassium hydroxide, which forms fatty esters, commonly known as biodiesel. It takes approximately 10% of methyl alcohol by weight of the fatty substance to start the transesterification process.
Estimates of Jatropha seed yield vary widely, due to a lack of research data, the genetic diversity of the crop, the range of environments in which it is grown, and Jatrophas perennial life cycle. Seed yields under cultivation can range from 1,500 to 2,000 kilograms per hectare, corresponding to extractable oil yields of 540 to 680 litres per hectare. In 2009 Time magazine cited the potential for as much as 1,600 gallons of diesel fuel per acre per year. The plant may yield more than four times as much fuel per hectare as soybean, and more than ten times that of maize, but at the same time it requires five times as much water per unit of energy produced as does corn. A hectare of jatropha has been claimed to produce 1,892 litres of fuel. However, as it has not yet been domesticated or improved by plant breeders, yields are variable.
Jatropha can also be intercropped with other cash crops such as coffee, sugar, fruits and vegetables.
However, despite its abundance and use as an oil and reclamation plant, none of the Jatropha species has been properly domesticated and, as a result, its productivity is variable, and the long-term impact of its large-scale use on soil quality and the environment is unknown.
In 2008 researchers at Daimler Chrysler Research explored the use of jatropha oil for automotive use, concluding that although jatropha oil as fuel "has not yet reached optimal quality,... it already fulfills the EU norm for biodiesel quality". Archer Daniels Midland Company, Bayer CropScience and Daimler AG have a joint project to develop jatropha as a biofuel. Three Mercedes cars powered by Jatropha diesel have already put some 30,000 kilometres behind them. The project is supported by DaimlerChrysler and by the German Association for Investment and Development.
Jet fuel
Aviation fuels may be more widely replaced by biofuels such as jatropha oil than fuels for other forms of transportation. There are fewer planes than cars or trucks and far fewer jet fueling stations to convert than gas stations. To fulfil the yearly demand for aviation fuel, based on demand in 2008, an area of farmland twice the size of France would need to be planted with jatropha, based on average yields of mature plantations on reasonably good, irrigated land.On December 30, 2008, Air New Zealand flew the first successful test flight from Auckland with a Boeing 747 running one of its four Rolls-Royce engines on a 50:50 blend of jatropha oil and jet A-1 fuel. In the same press release, Air New Zealand announced plans to use the new fuel for 10% of its needs by 2013. At the time of this test, jatropha oil was much cheaper than crude oil, costing an estimated $43 a barrel or about one-third of the June 4, 2008 closing price of $122.30 for a barrel of crude oil.
On January 7, 2009 Continental Airlines successfully completed a test flight from Houston, Texas using a 50/50 mixture of algae/jatropha-oil-derived biofuel and Jet A in one of the two CFM56 engines of a Boeing 737-800 Next Generation jet. The two-hour test flight could mark another promising step for the airline industry to find cheaper and more environmentally friendly alternatives to fossil fuel.
On April 1, 2011 Interjet completed the first Mexican aviation biofuels test flight on an Airbus A320. The fuel was a 70:30 traditional jet fuel biojet blend produced from Jatropha oil provided by three Mexican producers, Global Energías Renovables, Bencafser S.A. and Energy JH S.A. Honeywell's UOP processed the oil into Bio-SPK. Global Energías Renovables operates the largest Jatropha farm in the Americas.
On October 28, 2011 Air China completed the first successful demonstration flight by a Chinese airline that used jatropha-based biofuel. The mixture was a 50:50 mix of conventional jet fuel blended with jatropha oil from China National Petroleum Corp. The 747-400 powered one of its four engines on the fuel mixture during the 1-hour flight around Beijing airport.
On August 27, 2018 SpiceJet completed the first successful test flight by an Indian airline which used jatropha based biofuel. The ratio of conventional jet fuel to jatropha oil was 25:75.