Page 311 - Materials Chemistry, Second Edition

4.6 Illustration of the Phase Impact Assessment by Practical Example 295

Table 4.17 Global warming potential of substances considered in the context of
this project.

Greenhouse gas (GWP ) (CO -equivalents)
i 100
2
Carbon dioxide (CO ) 1
2
Methane (CH ) a 25.75
4
Methane (CH ), regenerative 23
4
Dinitrogenmonoxide (N O) 296
2
Tetrachloromethane 1 800
Tetrafluoromethane 5 700
Hexafluoroethane 11 900
a
In Houghton et al. (2001) indirect impacts like oxidation from CH to CO are not included in
4 2
the GWP values. For methane from fossil sources the GWP value increases if formed (fossil)
CO is considered.
2
Houghton et al. (2001).
The contribution to the greenhouse effect is the sum of the products of
released quantities of the individual greenhouse-relevant pollutants (m )and
i
their respective GWP (GWP ) according to the following formula:
i
GWP = ∑ (m × GWP )
i
i
i
4.6.1.2 Photo-Oxidant Formation (Photo Smog or Summer Smog Potential)
The gases and their POCPs, which could be procured in the context of this
LCA are listed in Table 4.18.
Table 4.18 Ozone formation potential of substances considered in the context of this
project.

Noxious gas POCP (ethene equivalents)
i
Ethene 1
Propene 1.123
Methane 0.006
Hexane 0.482
Formaldehyde 0.52
Ethanol 0.399
Aldehydes (average) 0.443
Benzene 0.22
Toluene 0.637
Xylene 1.1
Ethylbenzene 0.73
Hydrocarbons
NMVOC from diesel releases 0.7
NMVOC (average) 0.416
VOC (average) 0.377
CML (1992), Guin´ ee et al. (2002) and Kl̈ opffer (1995).