Page 46 - Materials Chemistry, Second Edition

32 E. I. Wiloso and R. Heijungs

bioenergy systems are now emerging. It is concluded that energy from biomass
has, by far, the largest water footprint compared with other energy sources (van der
Voet et al. 2010).
According to van Dam et al. (2010) in IPCC (2011), environmental impacts of
bioenergy systems can be distinguished by two classifications based on the cov-
erage of impacted areas. The first is global or regional in nature, including GHGs,
acidification, eutrophication, water availability, and air quality. The second is local
coverage, including soil quality, biodiversity, water availability, and air quality.
Other important classifications related to bioenergy systems are genetically
modified organisms and food security (replacement of staple crops and safe-
guarding local food security). Recent LCA studies typically include a wider scope
of impacts supported by sufficient databases and characterization models. Standard
life cycle impact assessment methods are available, namely ReCiPe, EDIP,
TRACI, LIME, and CML-IA. These methods include selected set of impact
categories.

4.2 Regionalized Impact Assessment

Regionalized impact assessment is important in bioenergy system as the boundary
also includes agricultural systems. Therefore, assessment criteria should reflect the
regional or local conditions of the specific bioenergy system under study. For truly
global impact categories like climate change and stratospheric ozone depletion,
this is not a problem since the impact is independent of where the emission occurs.
For the other impacts, however, they are often regional or even local in nature. In
this case, a global set of standard conditions can disregard large and unknown
variations in the actual exposure of the sensitive parts of the environment.
Sometimes, differences in sensitivities of the receiving environment can have a
stronger influence on the resulting impact than differences in inherent properties of
the substance (Potting and Hauschild 1997; Bare et al. 2003). In general, these
spatial differentiations relate to the characteristics of both the emitting source and
the receiving environment (Finnveden et al. 2009). LCA can address net changes
across large geographical areas, but it must also address how the impacts will be
experienced on local or regional scales. Accurate assessments must not only
capture spatial variation in appropriate scales (from global to farm level) but also
provide a process to aggregate spatial variability that can be applied on all geo-
graphical scales (McKone et al. 2011).
Several groups have worked on developing site-dependent characterization for
LCIA. Recently, methods supporting site-dependent characterization of a range of
non-global impact categories were published for processes in Europe, the USA,
and within some countries (Finnveden et al. 2009). There are some differences
between these data sets partly related to the different definitions of the charac-
terization factors (Seppälä et al. 2006). For example, the variation in acidification
impact can be as high as three orders of magnitude between different countries