54
biofuels leads to GHG emissions, to a greater or lesser extent. In other words, there
is a trade-off between the carbon dioxide reductions when biofuels are used instead
of fossil fuels and the GHGs that are generated in the production of biofuels.
A quantitative evaluation with life cycle assessment (LCA) is necessary for a
judgment of this trade-off. The environmental loading of a biofuel can be evaluated
from the beginning to the end use in LCA. The net effect may be evaluated by calculating increases and reductions in GHGs throughout the life cycle.
LCA is a tool originally devised for the chemistry industry. Their salient features
are combining and quantitatively evaluating environmental loads associated with
the manufacture of a product, from the acquisition of raw materials to disposal.
LCA is useful in design for environment and employed for sustainable consumption
and consumption of products with low environmental loading. The environmental
loading associated with creating and disposing of these products may not be immediately apparent. This hidden environmental loading is estimated by LCA and is
referred to as embodied environmental loading. Terms such as embodied energy and
embodied CO 2 are used when evaluating the environmental aspects of products. The
prime example of application of LCA for the public is carbon footprint, a figure
focusing on carbon dioxide.
The basic phases of LCA are shown in Fig. 6.1. The environmental loads include
energy consumption and emissions of a wide range of substances such as GHGs, air
pollutants, water pollutants, or heavy metals. First, the goals and scope of an analysis are specified. In this phase, the scope is suitably determined with consideration
to the purpose for using LCA, and the environmental loads to be analyzed are specified. Next, an all-encompassing inventory of emissions relating to the selected environmental loads is created. In the impact assessment phase, these environmental
loads undergo a comprehensive evaluation. The environmental loading is ascertained, and processes are improved by interpretation phases.
Previous researches on LCA of biofuels have been controversial and produced
diverse reports. In some reports, biofuels were found to be beneficial for the environment, and in other reports, they were found to be ineffective or even damaging.
Reasons for the contradictions among these results include the questions of which
environmental loads were considered and which biofuels were considered. Another
issue is that environmental loading differs between different geographic regions.
Goal and scope
definition
Inventory analysis
Impact assessment
Interpretation
Fig. 6.1 Basic scheme of
life cycle assessment
K. Hanaki and J. Portugal-Pereira
biofuels leads to GHG emissions, to a greater or lesser extent. In other words, there
is a trade-off between the carbon dioxide reductions when biofuels are used instead
of fossil fuels and the GHGs that are generated in the production of biofuels.
A quantitative evaluation with life cycle assessment (LCA) is necessary for a
judgment of this trade-off. The environmental loading of a biofuel can be evaluated
from the beginning to the end use in LCA. The net effect may be evaluated by calculating increases and reductions in GHGs throughout the life cycle.
LCA is a tool originally devised for the chemistry industry. Their salient features
are combining and quantitatively evaluating environmental loads associated with
the manufacture of a product, from the acquisition of raw materials to disposal.
LCA is useful in design for environment and employed for sustainable consumption
and consumption of products with low environmental loading. The environmental
loading associated with creating and disposing of these products may not be immediately apparent. This hidden environmental loading is estimated by LCA and is
referred to as embodied environmental loading. Terms such as embodied energy and
embodied CO 2 are used when evaluating the environmental aspects of products. The
prime example of application of LCA for the public is carbon footprint, a figure
focusing on carbon dioxide.
The basic phases of LCA are shown in Fig. 6.1. The environmental loads include
energy consumption and emissions of a wide range of substances such as GHGs, air
pollutants, water pollutants, or heavy metals. First, the goals and scope of an analysis are specified. In this phase, the scope is suitably determined with consideration
to the purpose for using LCA, and the environmental loads to be analyzed are specified. Next, an all-encompassing inventory of emissions relating to the selected environmental loads is created. In the impact assessment phase, these environmental
loads undergo a comprehensive evaluation. The environmental loading is ascertained, and processes are improved by interpretation phases.
Previous researches on LCA of biofuels have been controversial and produced
diverse reports. In some reports, biofuels were found to be beneficial for the environment, and in other reports, they were found to be ineffective or even damaging.
Reasons for the contradictions among these results include the questions of which
environmental loads were considered and which biofuels were considered. Another
issue is that environmental loading differs between different geographic regions.
Goal and scope
definition
Inventory analysis
Impact assessment
Interpretation
Fig. 6.1 Basic scheme of
life cycle assessment
K. Hanaki and J. Portugal-Pereira