Study of Biodiesel Purification Methods pp. 151-176
Authors: (M. Berrios, J.A. Siles, M.A. Martín, A. Martín, Departamento de Química Inorgánica e Ingeniería Química, Universidad de Córdoba, Campus Universitario de Rabanales, Córdoba, Spain)
Abstract: Renewable fuels have now come to play an important role in meeting the world‘s energy requirements. Due to the economic, environmental and supply problems derived from the use of fossil fuel, liquid biofuels are a growing and interesting complement to petroleum-based fuel. Biodiesel, which consists of long-chain fatty acid methyl esters (FAME) obtained from renewable lipids such as those in vegetable oils or animal fat can be used as both an alternative fuel and an additive for petroleum diesel. After transesterification reaction, the obtained biodiesel must be purified before being used as diesel fuel in compliance with the EN 14214 Standard. The main disadvantages of using biodiesel are the high cost of the raw material and the need to purify the product, resulting in a very expensive final product in comparison to petrol-diesel. The first drawback to using biodiesel could be overcome by employing a cheap raw material such as used cooking oils or by using microalgae oils. On the other hand, improving product purification is one of the aims of this chapter with a view to fulfilling EN 14214 specifications.
Because FAME cannot be classified as biodiesel until the EN 14214 Standard specifications are met, the purification stage is essential. Depending on the raw material (used cooking oils, crude vegetable oils or refined vegetable oils) and the catalyst used, the purification stage will be more or less difficult. The purity level of the biodiesel has a strong effect on fuel properties and on engine life.