2 Life cycle assessment
2.1 Molasses-based ethanol fuel case study and functional
unit
Sugar cane, the essential raw material for sugar industry in
Thailand, is found abundantly in the central region
accounting for the highest percentage of the national sugar
cane production (OAE 2004). Relevant information on
sugar/molasses production and ethanol conversion was
obtained from a typical sugar mill and ethanol distillery in
Thailand, respectively.
In this study, the functional unit (FU) chosen to compare
E10 and conventional gasoline (CG) is 1 L gasoline
equivalent consumed by a new passenger car to travel a
specific distance. PTT Research and Technology Institute,
Thailand has conducted tests for cars running on gasoline
and gasohol E10 (Tantithumpoosit 2004). The test results
based on Toyota 1.6 L/2000 were used in this study. The
car running on E10 gets fewer kilometres per litre than on
CG: 13.31 versus 13.46 (PTT 2006). Fuel economy
comparison reveals that 1 L of E10 is equal to 0.989 L of
CG. The relative performance of new vehicles, which has
been acknowledged in various other studies (Brekke 2005;
Fu et al. 2003; Macedo et al. 2004), is that 1 L of low
ethanol blends is equal to 1 L of gasoline. This analysis,
therefore, presents a conservative assignation of environmental
loads to ethanol in the form of E10.