• September 19th, 2018
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Bio-Fuels for the Future

With crude oil prices unlikely to decrease from an all-time high of about US$100 per barrel, Namibia joins the race to find sustainable alternatives. New Era's Catherine Sasman reports WINDHOEK Imagine spending N$10 on fuel to cover a distance of about 600 kilometers. This is what Michael Linke did some weeks back with his diesel truck. It is not a conventional diesel truck, however. In October, he converted the truck to be able to use waste vegetable oil in tandem with diesel. The consideration for the conversion was not only to cut costs with petroleum prices that shot up last year. As the managing director of the Bicycling Empowerment Network Namibia (BEN Namibia), Linke is particularly concerned about sustainable transport to mitigate the effects of carbon dioxide on global warming. "The burning of vegetable oil does not produce sulfur and heavy metal emissions; in bigger cities diesel emissions cause more deaths than road accidents," said Linke, from his backyard in Windhoek where he showed New Era how the vegetable oil-run engine works. "The equipment is pretty simple; it is available technology that could be produced locally within five to 10 years," said Linke. The conversion system consisting of three components comes from a USA company Greasecar, and is valued from US$900 to US$1 200. A standard diesel fuel filter and two valves enable alternating between diesel and vegetable oil. A switch is attached close to the steering wheel to alternate the fueling of the engine. He also fitted an extra 50-liter tank at the back of the truck for the vegetable oil, while the diesel tank is still in place. Linke gets his supplies of waste vegetable oils from Wimpies, Nandos and the Gourmet Restaurant that use huge amounts of oil in their cooking. Because the waste oil, which is not suitable for human consumption, has food particles like chicken or chips, Linke uses a cloth to filter the oil. This process separates water, food particles and hydrogenated oils from the vegetable oil that will be used as fuel. "It is a very simple method of cleaning the oil. One can even do the pre-filtering with an old pair of jeans that have become fibrous. One should be careful that there is no bacterial contamination of the oil." A drawback is that vegetable oil does not heat up as fast as diesel. The energy density of the vegetable oil is about five to ten percent less than diesel. Because it takes longer to heat up, said Linke, it becomes more viable to run the engine on diesel, and only about 20 percent of vegetable oil, when driving in town. Before switching over to the use of waste vegetable oil, Linke was running his truck on bio-diesel, which he produced from oil extracted from the jatropha curcas plant, which he planted in his backyard. Vegetable and bio-diesel fuel can, however, only be used on diesel engines. Diesel cars use injectors, while petrol cars burn fuels. The search for alternative fuels, and bio-fuels, is gaining momentum here in Namibia, said Dean of the School of Natural Resources and Tourism with the Polytechnic of Namibia, Lameck Mwewa, primarily because of the exorbitant price of crude oil, concerns over global warming. Another consideration is that the production of bio-fuels locally is seen as a means to fight poverty. And the demand for energy is growing. When populations and living standards rise, the demand for modern energy increases as well. Today, global wealth is 30 times bigger than what it was at the turn of the twentieth century and the world population has quadrupled. As a result, global energy demand has grown more than ten-fold. This trend is likely to continue. Interest is particularly growing in the perennial oil nut bearing jatropha tree, which is viewed as the most feasible plant for dry-land cultivation for the extraction of bio-oil. The plant was often used for snakebites, as an insect repellent and for constipation. The jatropha tree originates from South America, but was brought to the southern African region by Portuguese explorers. The seeds of the plant grow on low fertility soils in low and high rainfall areas; it has a small gestation period, and can be harvested in non-rainy seasons. The size of the plant is also convenient for collection of seeds. It produces seeds with a high oil-content (30 to 40 percent) after two to five years, depending on soil fertility and rainfall. According to Mwewa, the plant can yield one liter of oil from three kilogrammes of the nuts, and harvesting can be done over a 50-year period. The oil from the jatropha plant can be transformed into bio-diesel fuel - which is produced from the reaction of vegetable oil with alcohol in the presence of a catalyst to yield mono-alkyl esters and glycerine, which is then removed - through an etherification process. What makes it more popular amongst protagonists of bio-fuels is because of its toxicity, it is not for human consumption, and therefore not in competition with food crops. Threats to food security are recognised as the primary drawback of large-scale bio-fuels development. Bio-ethanol (which is alcohol produced by fermenting and then distilling sugars), for example, is produced from carbohydrate-rich plants like sugarcane, maize, beet, cassava, wheat and sorghum. In Brazil, staple food prices have soared over recent years because of the rush to produce energy crops. Another advantage of jatropha - or other plant fuels - is that it is carbon dioxide "neutral". This means that carbon dioxide emissions are "sucked in" by plant production, unlike fossil fuels. Moreover, said Mwewa, the jatropha crop alleviates soil degradation, desertification and deforestation. One criticism is that the jatropha plant is invasive, thus shouldering out indigenous plants. Mwawe contests this view. Through his travels he found huge amounts of jatropha trees in the marshes of the Congo, in Zambia, even in certain parts of Namibia. "But the plant does not spread," he insists. Bio-diesel also reduces all forms of air pollution. Pure bio-diesel can reduce the cancer risks by 94 percent. B20 (which means 20 percent bio-diesel and 80 percent petroleum) reduces the risks of air pollution by 27 percent. Because there is no sulfur in bio-diesel, it will not contribute to sulfur dioxide emissions or poison exhaust catalysts. The Agronomic Board, which did a study on the 'national bio-oil energy roadmap' for the country in 2006, said the jatropha is suited to smallholders of land, as well as large-scale farming. The Agronomic Board envisaged that approximately 63 000 hectares of jatropha would be planted in Namibia by 2013, the first phase towards 2030. This would translate into an industry that would contribute an additional N$189 million in Gross Domestic Product (GDP) to the economy. Based on 2005 prices, this would contribute 0.5 percent to GDP. Namibia's liquid fuel consumption in 2005 was about 870 million liters, which is about two percent of fuel consumption in southern Africa. Of this, 52 percent was diesel and 44 percent petrol consumption. The remainder liquid fuels used were paraffin, heavy fuel oil and jet fuel. "If we can substitute just 10 percent of all the fuel imports with local plant oils, the country can save a lot of foreign exchange," said Mwewa. According to the Agronomic Board, the options for bio-fuel crops are confined to the northeastern part of the country, where there are large tracks of land available. For a biofuel industry, it said, constraints are the competition for land, the problem of proper security of tenure mostly in communal areas, and the risk of further land degradation. Although the interest for the production of bio-fuels are increasing with many applications for land gone to the Ministry of Lands for this purpose, the Agribank of Namibia has not yet granted any loans to applicants particularly interested in this line of production, said Regan Mwazi. Farmer in the maize triangle, Peter Zensi, said the development of a bio-fuel industry amongst the farming community is also very poor, despite the existence of three projects in the communal areas of the Kavango. "To earn carbon credits, a farmer has to have a leasehold, and the Ministry of Lands is not prepared to give a leasehold," said Zensi. It is also not yet clear what the yields per hectare would be. Another factor impeding the development of bio-fuel production in commercial farming areas, said Zensi, is the obligatory minimum wages of N$2.20 per hour, and the provision in the new Labour Act that workers have to be registered with the employer even if such worker only works for one day. This would make harvesting less economical, he said. Loffi von Lansberg, who farms on Shadikongoro east of Rundu, has taken the plunge and planted 18 000 jatropha trees on 15 hectares a year ago. Von Lansber said he expects to harvest this year. He previously planted sunflowers, and yielded two tons of vegetable oil per hectare in the first year. Last year, the yield was eight tons per hectare. But with the increase in prices of pure sunflower oil, the production has become too expensive. He anticipates to use the oil extracted from jatropha for use on the farm, which uses about 100 000 liters of diesel per year. Mwewa also said that it would only be financially viable to use bio-fuels if the crude oil price remains above the US$50 per barrel. "But we need to unlock the energy potential of bio-fuels; it is linked to all aspects of development," said Mwewa.
2008-02-01 00:00:00 10 years ago
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