Page 245 - Materials Chemistry, Second Edition

L1644_C06.fm Page 218 Monday, October 20, 2003 12:06 PM

IP IP
RM PR1 PR2 PR3 Product

• Fate Analysis
SO 2 SO 2 SO 2
PM10 PM10 PM10 • Impact Factors
Cd Cd Cd • Final Weighting

Costs or Costs or Costs or
+ + = Total (Damage Profile)
Indicator Indicator Indicator
FIGURE 6.4 Determination of damage estimations by site-specific assessment (IP = inter-
mediate product, PR = process, RM = raw material). (Reprinted from J. Hazardous Mater.,
77, Sonnemann, G.W. et al., pp. 91–106, ©2000 with permission from Elsevier.)

Another approach to performing the environmental assessment of a functional unit
consists in analyzing the actual impacts of each process according to a site-specific
damage estimation concept (Figure 6.4). Consequently, the environmental loads of
each process are also accounted for, but the evaluation is carried out for each process
in its specific region. Each assessment contains the three consecutive procedures of
fate analysis, application of impact factors, and weighting across the impact categories.
The results of each process assessment can be summed up if they are expressed in
monetary units or by the same indicators. A damage profile is provided.
In order to express this different method in an algorithm based on the same
principles as introduced before, the eco-vector must be transformed into an eco-
technology matrix E . In this matrix, which is similar to the technology matrix
M
mentioned by Heijungs (1998), there are M columns for M linear processes, and N
rows for the N environmental loads as those for the eco-vector. The example has
three columns for the three processes and three rows for the three environmental
loads, SO , PM and Cd. (See Expression 6.2 for an illustration.) It is evident that
2
10
Process 1 Process 2 Process 3 Process ... Process m
SO2 SO2 SO2 SO2 SO2
PM10 PM10 PM10 PM10 PM10
e v1 = Cd e v2 = Cd e v3= Cd e v...= Cd e vm = Cd
X ... X ... X ... X ... X ...
X n X n X n X n X n

N environmental loads
SO2 1 SO2 2 SO2 3 SO2 ... SO2 m
PM10 1 PM10 2 PM10 3 PM10 ... PM10 m
E M =
Cd 3
Cd m
Cd ...
Cd 1
Cd 2
X ...,1 X ...,2 X ...,3 X ...,... X ...,m
X n,1 X n,2 X n,3 X n,... X n,m
M processes
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