FATTY-ACID METHYL-ESTERS AS DIESEL FUEL - ECONOMIC, ECOLOGICAL AND ENERGETIC IMPLICATIONS

Changes in the ''Common Agricultural Policy'' of the European Union have increased the rapeseed crops on ''set-aside'' lands remarkably. Rapeseed oils are transesterified with methanol to obtain fatty acid methyl esters. Blends of these esters with diesel oil are sold in petrol stations in different european countries like any other fuel. This informative article starts by reviewing basic characteristics of diesel fuel, and continues with an analysis of physical properties, chemical composition and present specifications for the rapeseed methyl esters. Subsequently several implications derived from the industrial development of this biofuel are discussed. These implications are economic (production, consumption, prices, subventions, tax exemptions), ecological (nearly zero emissions for whole cycle of carbon dioxide, other exhaust emissions from combustion, ecobalances), and energetic (complete evaluation of energy expenditure for production, energetic ratios).