DANISH EMISSION INVENTORIES FOR ROAD TRANSPORT ...

8 Future improvements
Some improvements are envisaged in the future inventories mainly focusing
on road transport. These improvements relate to the distribution of total
mileage within vehicle categories and between road types, calculation of
modified type approval fuel economy values for passenger cars and estimation
of CO2 emissions from the consumption of lube oil and urea.
Based on data processing of new data for the year 2008 collected in the Danish
vehicle inspection and maintenance programme, new annual mileage
distributions per first registration year can be calculated for all vehicle types
except two-wheelers. Further, a revised split of total mileage between urban,
rural and highway driving conditions can be made for based on new traffic
count data from the Danish Road Directorate.
Also, modifications of type approval fuel economy values can be calculated
for passenger cars on the basis of new research performed by TU Graz, Infras
and Emisia (University of Thessaloniki). Input for these modified values
will be fuel type, engine capacity (cm 3 ), vehicle reference mass and type approval
fuel economy value (l per 100 km) for the individual vehicle. The calculation
parameters are a part of the fleet registry data underpinning the national
fleet data provided by DTU Transport. The modified type approval
values will have an impact on the adjusted fuel consumption factors described
in paragraph 4.3.
In the future inventories, CO2 emissions from lube oil consumption will be
estimated based on amount of lube oil consumed (kg) by Danish road
transport vehicles and CO2 emission factors for lube oil. Functions for the
lube oil consumption are already established as a part of the HM estimations
from lube oil in the Danish inventory. The CO2 emissions from urea usage
by SCR equipped diesel vehicles will be calculated based on the urea consumption
(l) and a CO2 emission factor for urea, as explained by Ntziachristos
(2011).
The methodologies for calculating CO2 from lube oil and urea are included
in the newest version of COPERT IV (v9.0) released in November 2011.
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