Page 315 - Materials Chemistry, Second Edition

4.6 Illustration of the Phase Impact Assessment by Practical Example 299

Table 4.21 ROE: crude oil equivalence factors for fossil sources of energy according to UBA
a
Berlin .
Raw materials in deposits Static range Heat value, H ROE
u i
−1
(a) (MJ kg )or(MJ Nm −3 )
Crude oil 42 42.622 1
Natural gas 60 31.736 0.5212 b
Hard coal 160 29.809 0.1836
Brown coal 200 8.303 0.0409

a The static ranges of hard and brown coal used by the UBA significantly deviate from recent values
(Table 4.7). The former UBA values (UBA, 1995) probably referred to Germany while the values in
Table 4.7 were calculated from worldwide reserves and production figures. The energy contents are
average values of unknown provenance and should only be used in the context of ROE calculation
according to UBA. Their exaggerated accuracy is probably due to conversions from the outdated unit
calorie (cal). The ROE values are rounded; on the other hand not all decimal digits are consistent.
b The ROE for natural gas of the UBA table quoted refers to the heat value in MJ m −3
−3
(31 736 MJ Nm ). 31 736 MJ m −3 divided by 60 a results in an ROE of 0.529 (not 0.5212) related to
volume. With a natural gas density of 0.78 kg m −3 a heat value of 40.69 MJ kg −1 results plus an ROE of
0.678 referred to mass. The use of the value of 46.1 MJ kg −1 in accordance with Table 3.5 for natural
gas results in an ROE referred to mass for a static range of 60 a of 0.77. In the practical example (see
also Section 4.6) an ROE referred to mass for natural gas of 0.6202 was used.

The ROEs (ROE: R¨ oh¨ ol¨ aquivalenzfaktor) considered by UBA are defined accord-
ing to Equation 4.33 and listed in Table 4.21. Crude oil is assigned to one.

NCV
ROE = i (4.33)
i static range (a)
i

ROE : crude oil equivalence factor of fossil resource i
i
−1
NCV : Net calorific value of resource i (MJ kg ).
i
Deviating from Table 4.21 a ROE for natural gas of 0.6202 is used in the sample
study (see Table 4.22).

Table 4.22 Fossil resources consumption (ROE): raw oil equivalents/fU.
Fossil resources Inventory result Characterisation factor Impact indicator
(see Table 3.13) (kg) factor in kg raw oil equivalent/kg value
Brown coal 5.48 0.0409 0.22 kg ROE
Natural gas 8.03 0.6202 4.98 kg ROE
Oil 12.22 1 12.22 kg ROE
Hard coal 1.27 0.1836 0.23 kg ROE
Sum ROE: crude oil equivalence value 17.66 kg ROE