Life Cycle Analyses (LCA) are used to compare biofuels to fossil fuels. These analyses are made according to the ISO 14040-43 standards, which using a defined unit compare mass and
energy balances for two or more comparison objects.
In Spain, the Spanish government Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, CIEMAT, has performed two LCA's in order to compare ethanol and ethanol mixtures with unleaded gasoline and biodiesel and biodiesel mixtures with fuel-oil according to these standards. Both LCA's conclude that biofuels require less primary energy than fossil fuels to be processed and that CO2 emissions are lower when using biofuels instead of fossil fuels.
However, these LCA's have been strongly criticized for several reasons. This report presents a new LCA model which allows the comparison of biofuels and fossil fuels based on the maximisation and optimisation of production resources avoiding the disadvantages of the traditional LCA model based on the ISO 14040-43 standards.
