Page 90 - Materials Chemistry, Second Edition

74 3 Life Cycle Inventory Analysis

and not product-related), can be applied for regional issues, for example, in waste
management, and as a tool in industrial ecology. 34) Contrary to LCA, no impact
assessment is usually conducted in MFA (that would correspond to an inventory
or LCI). There are, however, exceptions to this rule (MFA is not standardised),
for example, the study ‘poly(vinyl chloride) (PVC) in Sweden’, where an MFA
including system boundary = state border of Sweden was supplemented by an
impact assessment according to CML. 35)

3.2
Energy Analysis

3.2.1
Introduction
Energy analysis based on process chain analysis is, together with the material flow
analysis, one of the centrepieces of the inventory analysis. For this, three reasons
36)
are indicated by Boustead and Hancock :
1. Environmental problems are frequently coupled with energy supply and ‘energy
consumption’. 37)
2. The availability of resources (above all fossil resources like oil, natural gas
and, to a smaller degree, coal) is limited. This aspect has been dramatically
described in the report to the Club of Rome ‘Limits to Growth’. 38)
3. Energy prices rising on a long-term basis (energy as commodity) leads to
dependence on politically uncertain regions.
Despite the fact that today the task of LCA is substantially broader defined, energy
analysis has remained one of the central instruments of LCA. The most important
forms of energy which, according to the first principle of thermodynamics, can be
transformed into one another, are listed in Table 3.1.
If energy is regarded as commodity, there is a primary interest in the final
energy which is bought by customers (industry, private consumers, agriculture,
etc.). In LCA this definition of energy is only relevant as input: how much energy
is necessary for a specific unit process for the production of a defined amount of
output? However, for environmental assessments the primary energy expenditure
is of interest. Production and transport of energy carriers, efficiency of plants for

34) Baccini and Brunner, 1991; Ayres and Ayres, 1996; Baccini and Bader, 1996; Brunner and
Rechberger, 2004.
35) Tukker, Kleijn and van Oers, 1996.
36) Boustead and Hancock, 1979.
37) According to the first principle of thermodynamics, only energy conversions occur. This applies
for the physical notion of energy. Energy in different forms is, however, economically a
commodity which is traded to be used, and therefore the expression ‘energy consumption’ is
justifiable.
38) Meadows et al., 1973.