Report - DCE - Nationalt Center for Miljø og Energi

Therefore, in order to represent the Danish fleet and to support average national
emission estimates, emission factors must be chosen which derive
from numerous emissions measurements, using a broad range of real world
driving patterns and a sufficient number of test vehicles. It is similar important
to have separate fuel consumption and emission data for cold-start
emission calculations and gasoline evaporation (hydrocarbons).
For heavy-duty vehicles (trucks and buses), the emission limits are given in
g pr kWh and the measurements are carried out for engines in a test bench,
using the EU ESC (European Stationary Cycle) and ETC (European Transient
Cycle) test cycles, depending on the Euro norm and exhaust gas aftertreatment
system installed. A description of the test cycles is given by Nørgaard
and Hansen, 2004). Measurement results in g pr kWh from emission
approval tests cannot be directly used for inventory work. Instead, emission
factors used for national estimates must be transformed into g pr km, and
derived from a sufficient number of measurements which represent the different
vehicle size classes, Euro engine levels and real world variations in
driving behaviour.
In terms of the sulphur content in the fuels used by road transportation vehicles,
the EU directive 2003/17/EF describes the fuel quality standards
agreed by the EU. In Denmark, the sulphur content in gasoline and diesel
was reduced to 10 ppm in 2005, by means of a fuel tax reduction for fuels
with 10 ppm sulphur contents.