Energy corner

Seed oil of Jatropha curcas for fuel
ATI activities on biofuel
Energy crops for liquid fuels, Indian initiative
New process of ethanol production
Liquid fuels for road transportation from biomass
Biodiesel market in the United States
Latin American Technical Cooperation Network on Dendroenergy
Household Energy Donor Organizations Network (HEDON)
Fuel-efficient stoves


Jatropha curcas or jatropha is a large shrub or tree native to the American tropics, but commonly found and utilized throughout most of the tropical and subtropical regions of the world. Several properties of the plant, such as its hardiness, rapid growth, easy propagation, and wide-ranging usefulness, have resulted in the spread of jatropha far beyond its original distribution. Most parts of the plant are utilized locally for their medicinal properties and it is often grown in house gardens for this very purpose. Jatropha produces a latex and inedible seed that is known to have toxic and purgative properties. The latex, oil, twigs, wood and leaves are all reportedly used externally for healing wounds, to stop bleeding, and to treat rheumatism and skin diseases. As an internal medicine, the plant's purgative or vomit-inducing property (particularly exhibited when the seed or oil is ingested) is also commonly exploited. The seed of jatropha yields, up to 50 percent by weight, a slow drying oil (known as "curcas oil") which is utilized as an industrial raw material and for manufacturing on a smaller scale. Curcas oil has historically (and currently) been used in the manufacture of candles and, particularly, soap.

Curcas oil's physical and chemical properties give it potential as a petroleum-substituting fuel. Research on this oil was first initiated during the Second World War to study its use as a liquid, renewable fuel substitute for diesel oil. In recent years, research has continued to assess the oil's application as a fuel substitute. As a crop, jatropha represents a renewable resource with a high energy content and oil yield. The economic feasibility of this technology has yet to be proved but, in the context of a rural community being able to produce energy for its own use, great potential exists. Seed harvesting, oil extraction and processing can be accomplished in a decentralized, rural environment providing opportunities for business cooperatives and small entrepreneurs. Production of a renewable energy source on a local scale can lead to self-sufficiency or a decrease in dependence on fuels such as diesel, kerosene, wood, etc. Despite the opportunities associated with curcas oil production as a fuel it is not viable when compared with global production costs for fossil fuels. However, viewing curcas oil production in the context of its other uses and benefits may result in economic feasibility under appropriate circumstances.

Jatropha compares well with other vegetable oils and, more important, with diesel fuel itself in terms of fuel rating per kilogram or hectare of oil produced. It should be noted that oils from other species of the genus Jatropha exceed curcas oil's energy content and, in some cases, even that of diesel fuel. This is important when considering the potential of crossbreeding for the improvement of jatropha as a fuel crop.

Figure 19

The greatest differences between curcas oil and No. 2 diesel oil occur in viscosity, solidifying point, flash point, carbon residue and sulphur content. The high viscosity of curcas oil contributes to the formation of carbon deposits in the engines, incomplete fuel combustion (particularly under low loads), and results in a reduction in the life of an engine. The higher solidifying point of curcas oil limits usage in cooler climates and the higher flash point leads to ignition problems. The carbon residue value and sulphur content in curcas oil have resulted in hydrocarbon and carbon monoxide emissions which exceed those of diesel oil under certain conditions, but sulphur emissions remain negligible when compared with diesel.

Polymerization is a serious engine problem encountered with curcas oil. This problem can be avoided simply through the addition of an antioxidant to the oil, frequent changes of the engine oil, or through hydrogenation of the oil.

Technically, the easiest method to overcome engine problems involves blending curcas oil with diesel. Problems with viscosity, sticking and gumming are usually avoided or significantly reduced through blending, although generally only 10-20 percent of crude vegetable oil can be blended with diesel to obtain reasonable results.

Further processing also solves many engine problems. Removal of the triglycerides through a chemical process called "transesterification" helps to lower the oil's viscosity. (Source: Jatropha curcas: a multipurpose species for problematic sites. World Bank Land Resources Series No. 1.)

For more information, please contact Norman Jones, Senior Forestry Specialist, AGRNR, World Bank, 1818 H St, NW, Washington, DC 20433, USA. Fax: +1 202 5221142.


Jatropha curcas, known as purging nut, is found in a semi-wild condition in the vicinity of villages in many tropical countries.

Oil from its seeds is used as an illuminant since it burns without emitting smoke; it can also be used as a lubricant for making soaps and candles. The seed cake contains toxic principles but is rich in nitrogen and phosphorus and can be used as manure.

All parts of the plant exude a sticky, astringent latex that dries to a reddish-brown brittle substance resembling shellac; it stains linen and can be used as marking ink. The bark contains tannin; it also contains wax, resins, saponins, reducing sugar and traces of a volatile oil.

Tender twigs of the plant are used for cleaning teeth; the juice relieves toothache and strengthens gums.

The leaf juice is used as an external application for piles and is applied for inflammation of the tongue in babies. A decoction of leaves and root is given for diarrhoea. The root bark is used in external application for sores. A decoction of the bark is given for rheumatism and leprosy. (Source: MFP News, Vol. 4, No. 3, January-March 1994.)


Appropriate Technology International is involved in developing and utilizing jatropha oil as a substitute for diesel fuel. Related studies are mainly centred in West African countries.

For more information, please contact Eric L. Hyman, Programme Economist, Appropriate Technology International, 1828 L St, NW, Suite 1000, Washington, DC 20036, USA. Fax: +1 202 2934598.


The scientists of the Indian Institute of Petroleum (IIP), Dehra Dun, started working on the development of energy crops for liquid fuels in 1979 in collaboration with the National Botanical Research Institute (NBRI), Lucknow, under the sponsorship of the Department of Science and Technology (DST) and later the Department of Non-Conventional Energy Sources. After screening about 480 latex-producing indigenous plants and 74 resinous plants, 54 common widely spread and easily cultivable plants were chosen for further studies.

The work on breeding and cultivation of hydrocarbon-yielding plants at NBRI is progressing. Extensive research regarding economics and other aspects is needed before commercial plantations can be promoted. (Extracted from: MFP News, Vol. 4, No. 2, June 1994.)


A number of developing countries produce ethanol as a petrol substitute, but the current production methods leave much to be desired. At Imperial College, London, United Kingdom, genetically engineered bacteria have been developed to facilitate the production of ethanol from various sources such as corn cobs and straw. These new bacteria, Bacillus stearothermophilus, have two advantageous characteristics that commonly used yeast lacks. They are also able to convert plant sugars, the so-called hemicelluloses, into ethanol. Since hemicelluloses accounts for one-third of the weight of a plant, this new method results in less waste.

Moreover, the bacteria are able to generate sufficient heat to keep the fermenter warm enough to vaporize the ethanol produced. It can easily be drawn out of the vessel by vacuum and then condensed. This is an advantage compared with the yeast method, which has to break off the process, extract the ethanol from the yeast cells and purify it. (Source: New Scientist, 2 April 1994.)


A new process is being experimented to convert biomass materials into reformulated gasoline components using heat and catalysis as well as biological conversion.

The primary product of this thermochemical process is the Ethyl Tertiary Buthil Ether (ETBE) which is suitable for substituting MTBE in reformulated gasoline for road transportation. ETBE is prepared using bioethanol derived from different kinds of biomass, while MTBE is a petrochemical derivative.

The Non-Wood Products and Energy Branch of FAO has already initiated some research activities for ETBE production in collaboration with the Forest Research Institute of Malaysia (FRIM) and with the technical assistance of British Petroleum (BP). These are giving promising results. The project's aim is to promote the production of ETBE from ethanol derived from oil-palm trunks.

Given the importance of the subject for member countries, the FAO Non-Wood Products and Energy Branch is now preparing a document on "New liquid fuels from wood". The envisaged target audience for the document are heads of energy, forestry and agriculture services and their staff in member countries who are advising and preparing policies, programmes and projects in this area of work.

For more information, please contact M.A. Trossero, Senior Forestry Officer, Non-Wood Products and Energy Branch, FAO, Rome. Fax: +39 6 52255618.


Palaeolithic man early learned to use firewood, and early man soon learned the utility of candlenuts (e.g. Chrysobalanus, Dialyanthera, Dipteryx, Elaeis, Licania and Virola, among tropical American genera). Modern humans, worried about the dietetic consequences of saturated fats in palm oils, are nonetheless looking at palm oils (and other oilseeds) as possible alternatives to petroleum. Properly managed fuelwood farms and oilseed farms could sustainably fuel certain tropical developing economies. Some optimists have suggested that two billion hectares of tropical land producing 25 barrels of palm oil per hectare renewably could satisfy the world's fuel needs. Babašu palm, from tropical America, and nipa, from tropical Asian brackish swamps, could also be fuel sources when the petroleum runs out. Nipa is estimated to give renewably up to 90 barrels of ethanol per hectare, three times as much as sugar cane. (Source: Duke, J.A. 1993. Tropical botanical extractives. In Caderno de Farmacia, Vol. 9, No. 1, p. 7-16.)


United States farmers have collaborated, working through an organization called the National Biodiesel Board, on creating a market for a cleaner burning fuel. The National Biodiesel Board, which promotes and researches soy-based biodiesel, is funded by the United Soybean Board through the national soybean checkoff. In a 20-percent blend with petroleum diesel, biodiesel significantly reduces emissions of particulate matter, carbon monoxide and total hydrocarbons, and it does not require the expensive infrastructure changes of other technologies.

Nevertheless, only 2 percent of the mass transit industry had heard of biodiesel in 1992. Consequently, the National Biodiesel Board and transit industry operators worked together to judge the fuel's merits first hand.

In only a few months, enough fuel was distributed to log 3.5 million road miles (approximately 5.5 million km) with biodiesel blends. To date, diesel engine users have driven nearly 8 million miles (almost 13 million km) with biodiesel - without uncovering a single biodiesel-related performance problem.

The programme dramatically increased awareness of biodiesel. A survey completed in September 1994 shows that 40 percent of transit managers are more receptive to using biodiesel than they were a year ago, and 20 percent rank biodiesel as their number one alternative fuel option. The only alternative fuel earning a higher ranking was compressed natural gas, which has a larger budget and a head start in the market.

Figure 20

Transit operators who have tried biodiesel were impressed with its performance and, realizing that petroleum may not be an option for transits in regulated regions, more than half of the transit managers report that they would consider buying biodiesel even at 30 to 40 cents more per gallon than petroleum diesel. (Source: Johannes, K. US Biodiesel markets gain momentum. In Vogel and Nout Industrieanlagenbau, Newsletter No. 2,1994.)


The following statement by President Clinton of the United States was released on 30 June 1994.

"I would like to commend the Environmental Protection Agency for its decision to make renewable fuels a major ingredient in reformulated gasoline under requirements of the Clean Air Act. Today, we are making good on a long-standing commitment to a cleaner environment and a stronger economy. This decision offers tremendous potential to provide the United States with thousands of new jobs for the future.

The use of reformulated gasoline will help to improve the quality of the air in the nation's dirtiest cities. Furthermore, a greater use of ethanol and its derivatives could help to reduce greenhouse gas emissions.

I especially support the use of ETBE, a fuel derived from ethanol, because of its special environmental promise.

Relying on renewable fuels also presents a major opportunity to farmers and other members of rural communities to get to work helping America. The rule could boost demand for corn by 250 million bushels a year.

Again, I commend EPA on this important decision to use renewable fuels to help achieve the objectives of the Clean Air Act. I believe our economy and our environment can go hand in hand. This policy is good for our environment, our public health and our nation's farmers - and that's good for America."


The Latin American Technical Cooperation Network on Dendroenergy, sponsored by the FAO Regional Office for Latin America and the Caribbean, was established in Buenos Aires, Argentina, in October 1984.

Today the network is composed of 16 countries: Argentina, Bolivia, Brazil, Costa Rica, Cuba, Chile, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Peru, the Dominican Republic and Uruguay.

The main aim of this network is to exchange experience, information and data among interested institutions involved in wood energy activities.

Since establishment, its activities have been focused on the preparation of technical documents, training and education activities, study tours, exchange of experts, and organization of meetings. Under the auspices of the network, a Regional Seminar on Optimized Wood Energy Systems was held in Tegucigalpa, Honduras, from 18 to 22 October 1993.

The proceedings of this seminar are available on request from Torsten Frisk, Regional Forestry Officer, Regional Office for Latin America and the Caribbean, RLAC, Ave. Santa Maria, 6700, Santiago, Chile. Fax: +56 2 6961121; or from M.A. Trossero, Senior Forestry Officer, Non-Wood Products and Energy Branch, Forest Products Division, FAO, Rome, Italy. Fax: +39 6 52255618.


HEDON is an informal consultative forum consisting of representatives of donor agencies concerned with aspects of the provision and use of household energy in the South. While these agencies approach the issue of household energy from different perspectives, HEDON is a reflection of their common goal: the improvement of social, economic and environmental conditions in developing countries through the promotion of local, national, regional and international initiatives in the household energy sector.

FAO hosted the Fifth HEDON meeting on "Household Energy and Agenda 21 of UNCED" on 26 and 27 September 1994, in Rome. The meeting identified the main concerns and areas of action of Agenda 21 which have relevance to household energy in order to develop a common strategy for action. The meeting also proposed an international Expert Consultation on Household Energy to be held in mid-1996. FAO will be responsible for the organization of the meeting with the close support of HEDON members. The Sixth meeting of HEDON will be held in Lund, Sweden in mid-1995.

For more information, please contact M.A. Trossero, Senior Forestry Officer, Non-Wood Products and Energy Branch, FAO, Rome, Italy. Fax: + 39 6 52255618.


Washington-based ATl's activities in Senegal on fuel-efficient, ceramic-lined stoves for household use under its programme to promote productivity increasing technological innovations have had successful results. By burning less charcoal, over 12000 Diambar stove-using households are each saving US$103 annually on energy costs, in addition to reducing charcoal consumption and, as a result, saving forests.

Figure 21

For more information, please contact Appropriate Technology International, 1828 L St, NW, Suite 1000, Washington, DC 20036, USA. Fax: +1 202 2934598.

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