2 - History of Vegetable Oil-Based Diesel Fuels

Abstract

This chapter presents a history of vegetable oil-based diesel fuels. Vegetable oils and animal fats were investigated as diesel fuels well before the energy crises of the 1970s and early 1980s sparked renewed interest in alternative fuels. Palm oil was often considered as a source of diesel fuel in the “historic” studies, although the diversity of oils and fats as sources of diesel fuel, an important aspect again today, and striving for energy independence were reflected in other “historic” investigations. Most major European countries with African colonies—Belgium, France, Italy and the UK with Portugal apparently making an exception—at the time, had varying interest in vegetable oil fuels. Vegetable oils were also used as emergency fuels and for other purposes during World War II. The kinematic viscosity of vegetable oils is about an order of magnitude greater than that of conventional, petroleum-derived diesel fuel. High viscosity causes poor atomization of the fuel in the engine's combustion chambers and ultimately results in operational problems, such as engine deposits. As a result of the energy crises of the 1970's, vegetable oils were remembered as alternatives to petrodiesel fuel, with work commencing in countries such as Austria, Germany, South Africa, and the United States. The use of methyl esters of sunflower oil to reduce the viscosity of vegetable oil was reported at several technical conferences in 1980 by South African researchers and marked the beginning of the rediscovery and eventual commercialization of vegetable oil esters as biodiesel fuel.