Page 105 - Materials Chemistry, Second Edition

3.2 Energy Analysis 89

−1
allocated to the loaded goods, the specific energy consumption (in (l fuel tkm )or
−1
(MJ tkm )) decreases with increasing degree utilisation (real load/maximal load
capacity) (seeexercise in this chapter).
The degree of utilisation is thus of major importance for the calculation of the
environmental loads per person kilometre and per ton kilometre: A fully loaded
passenger car or truck will be more favourable per person or per ton than a partly
loaded one, despite larger fuel consumption per vehicle and kilometre. As the
specific degree of utilisation for the transport of persons or goods cannot easily be
determined, averages are often used.
Even if for most cases no complete data are available for modelling the transporta-
tion processes, the transportation distances and vehicles should be determined as
specifically as possible in order to select meaningful generic data records. In case
generic data is resorted to for environmental loads of the means of transport, which
are the basis for calculations related to passenger kilometre or tonne-kilometre,
their acquisition date must be considered: fuel (or electricity) consumption has
decreased over the past years as also emissions, as a result of slow but intensified
change of legislation. 71)
Not all transportation means depend on motion (railways, motor vehicles, ships,
air planes, etc.); they can also be based on tubing systems (pipelines) whose energy
requirements and maintenance must be obtained and related to the transported
mass/volume/energy. If such data are present in good quality, the conversion to a
fU is straightforward.
Here, transportation is discussed under the aspect of ‘energy’; without any ques-
tion, energy and the correlated resource consumption represent a major problem
in environmental politics. In addition, as in the case of electricity production, the
emissions of harmful gases and particles have to be considered as output. These
data are necessary for the determination of several impact categories and indicators
(see Chapter 4). In particular these are (the most important emissions are in
parentheses):
• climate change (CO ,CH ,N O, Freon substitutes),
2 4 2
• formation of photo oxidants (volatile organic compounds/VOCs, CO, NO ),
x
• terrestrial eutrophication (NO ),
x
• acidification (NO ,SO )and
x 2
• human toxicity (VOC, NO , fine dust, PAH).
x
Road traffic in particular substantially contributes to these emissions. However,
shipping traffic also contributes essentially to emissions of sulphur dioxide by
the use of fuel oil (bunker oil).The Federal Environmental Agency (UBA, Berlin
and Dessau) points out that the SO -load in ports is predominantly due to open
2
sea vessels (e.g. Hamburg 80%). The same is valid for offshore regions and the
North Sea.
Tanker accidents imply severe regional loads but can, only with difficulty, be
attributed to a specific product group (see also Section 4.5.5.1).

71) Institut f¨ ur Energie- und Umweltforschung Heidelberg, 2006.