Page 62 - Materials Chemistry, Second Edition

48 N. E. Korres

scope of the LCA. General impact categories are human health, biotic natural
environment, natural resource depletion, abiotic environment, and man-made
biotic and abiotic environment (Korres 2013). These impacts are operationalized
by specific impacts such as global warming, ozone depletion, acidification or
eutrophication, ecotoxicity, land use, and habitat loss (Korres 2013). In the
characterization phase, the impacts are analyzed, quantified, and calculated,
requiring scientific knowledge about load–response relationships. For that purpose,
the inventory data need to be analyzed by modeling approaches, like the use of
equivalency factors (e.g., ozone depletion potential) or toxicological data. The last
phase (interpretation) reports the results in a comprehensible way and evaluates the
opportunities to reduce the environmental impact of the product or service under
examination according to the goal and scope of the study. As a basis for a decision-
making process, the results of the LCA can be used for improvements and support
evidences for other environmental concepts, tools, and systems such as ecola-
beling, environmental management system (Fawer 2001). In contrast to other
environmental management tools, which tend to focus on specific life stages of a
product or process, LCA analyzes the entire life cycle, looking up and down the
supply chain, from raw material extraction to final disposal. A simplified biofuel
pathway is shown in Fig. 7 where system boundaries, inventory analysis (data for
inputs), and impact assessment (environmental effects) are clearly shown.
More particularly, the feedstock production phase (left part) which includes
crop production and husbandry management along with processing of the feed-
stock (middle part) and some of the important markets (right part) into which
biofuels and their coproducts are traded. Examples of bioethanol production co-
products include animal feed from corn ethanol or bagasse, from sugarcane eth-
anol, which can be used for the production of heat or electricity though its

Fig. 7 A simplified biofuel pathway in which inputs and related environmental effects are
depicted (dotted lines represent pathways irrelevant to this chapter) (based on Kammen et al.
2007)