140 / 188
138
A specific conversion factor
g
is used to transfer the energy consumption into the
emission. All calculations can be done for the well-to-wheel or tank-to-wheel separately.
In Table 6.3, the conversion factors are summarised.
Table 6.3 Conversion factors for well-to-wheel (calculation according to [4])
Energy source
MJ/kg
MJ/l
kg CO
2
e/kg kg CO
2
e/l
Diesel
51.3
42.7
3.9
3.24
Kerosene
52.5
42.0
3.88
3.1
Heavy fuel oil
44.1
42.7
3.41
3.31
MJ/kWh
kg CO
2
e/kWh
Electricity Germany 9.7
0.583
Natural gas
4.1
0.242
Example 5:
A plane transports different goods from Hamburg to Leipzig. From there, the
transport to the final distribution is done by a single truck. The truck needs 50 l of
diesel; the plane needs 6,000 l of kerosene. The energy consumption and the total
emissions are in this case in Table 6.4.
Table 6.4 Energy consumption and emission
Consumption
F
Conversion factor
e
/
g
Standardised consumption
Truck 50 l
42.7 MJ/l
2,135 MJ
Plane
6,000 l
42.0 MJ/l
25,200 MJ
Total
27,335 MJ
Emission
Truck 50 l
3.24 kg CO
2
e/l
162 kg
Plane
6,000 l
3.1 kg CO
2
e/l
18,600 kg
Total
18,762 kg
The total emission of the plane is by far higher than for the transport by truck.
The energy consumption
F
in equation (6.6) and equation (6.7) can be calculated
with the payload capacity
W
, the transport distance
D
and the specific energy
consumption
E
in l, kg or kWh per t km or TEU-km:
F
=
W
x
D
x
E
(6.8)
It is common that goods are transported by standardised container. An intermodal
way of transportation is in this case possible. The container itself and its weight have to
be considered in the calculation. The volume of a container is given in TEU (Twenty
Equivalent Units). One TEU is 20 feet long. A truck in Europe can carry up to two TEU.
Average values for the total weight for the transport of containers are given in Table 6.5.