Sustainability aspects of biofuels
Starch-
based crops must be first converted into sugars in the saccarification process, which requires
substantial volumes of enzymes to turn starch into sugars (Soetaert, W. 2008). The starchy
products represent only a small percentage of the total plant mass. Other plants' building
blocks like cellulose and lignin are currently not being used to make biofuels as there is not a
commercial viable production method for making ethanol form cellulosic biomass (FAO,
2008).
Biodiesel is based on the oil crops, such as rapeseed in Europe and soybean in the USA and
Brazil. In tropical regions, biodiesel feedstock can also be sourced from palm, coconut and
jatropha oils, but these are currently not major feedstock for biodiesel. Biodiesel is produced
by combining vegetable oil with an alcohol and a catalyst through a chemical process known
as transesterification (FAO, 2008).
Margit Tepner
k0848752
Figure 1
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