Jojoba (pronounced ho-HO-baa) is a desert plant which has been cultivated for decades in southwest America and Northwest Mexico, throughout South America, and in the Middle East. Usually jojoba oil winds up in shampoo or cosmetics or is used as an industrial lubricant. But Mohamed Selim and his colleagues at the United Arab Emirates University and the Helwan University report in the journal Renewable Energy, vol. 28 that jojoba oil can fuel your car—in fact more quietly, with fewer emissions and with less corrosion to your engine than diesel. Mr. Selim's team modified natural jojoba oil with a little methanol and catalyst to form a methyl ester, which is a typical processing procedure for manufacturing biodiesel. They tested this fuel at engine speeds of 1000 to 2000 revolutions per minute and found that it produced better power and torque performance than diesel. The fuel has all the advantages which are typical of "neat biodiesel" (biodiesel which is not blended with petroleum). It is completely sulfur free so it produces no sulfur oxides and is less corrosive to engine parts. It also has a lower carbon ratio, so carbon monoxide, carbon dioxide and particulate emissions are also lower. Also, the properties of the jojoba fuel make it safer for transport and handling, and also reduce the engine noise. Mr. Selim suggests this is because the combustion gases expanded more slowly, taking slightly longer to reach maximum pressure in the cylinder.
You've probably already figured out the down side on this one: it is unlikely that enough jojoba plants can be grown to meet the world's demand. But it is an attractive regional solution. Jojoba can be grown in saline soils and even deserts, which favors growing the large quantities of the shrubs necessary. Farmers in Egypt have started growing jojoba specifically to use the nut oil as fuel. [by ©C. Lepisto, 2005]