Some Comments on Air Quality Nitrogen Oxide

Transcription

1 Introduction Air quality Conclusions. Contribution to the workshop 14/1/25 Some Comments on Air Quality Nitrogen Oxide Udo Lambrecht Institute for Energy and Environmental Research Heidelberg 1

2 Introduction Introduction Air quality Conclusions. The atmospheric concentration of CO and Benzene in Germany is already below future air quality standards. Like in other countries: The concentration of nitrogen dioxide and PM1 exceeds air quality standards at several measurement sites especially near busy streets. This calls for a reduction of motor vehicle emissions. Buses contribute an average 1%, locally even more, to total urban NO x -emissions of road transport in Germany. Thus captive fleets should contribute to emission reductions. The formation of both pollutants [PM1 and NO 2 ] is complex and a reduction strategy requires a detailed analysis. Problems of emission reduction strategies will be exemplified for nitrogen oxides. 2

3 Air quality in Germany Emissions in urban areas NOx (kt/year) - urban areas Other PC Diesel PC Gasoline Heavy Duty Light Duty Bus Decreasing nitrogen oxide emissions: about 3% in Germany Share of heavy duty vehicles is continuously increasing Share of buses is constantly about 1% in German urban traffic 1 5 Busses Not many data available on taxis and other captive fleets Huge differences between cities and regions Source: TREMOD calculations [Version Nov. 23] 3

4 Air quality in Germany road side measurements NO 2 25 Air quality - NOx - urban areas road side measurements NRW NO Nitrogen oxide concentrations at busy streets in Germany have decreased by 5% since 199 annual mean NO 2 ug/m NO Nitrogen oxides are composed of nitrogen monoxide (NO) and nitrogen dioxide (NO 2 ), which exist in a chemical balance NO pollution has been decreasing considerably NO is relatively harmless for human health NO 2 pollution on the other hand has not been decreasing 4

5 Air quality in Germany road side NO Air quality - NO 2 - road side Near bus-stop Air quality limits have been exceeded in 23 in 1 (from 16) federal states Increasing NO 2 concentrations in recent years at many sites Annual mean ug/m limit 21 Berlin - Straße NRW - Straße Stuttgart-Mitte Str. Karlsruhe - Straße Possible causes: 5 Meteorological and chemical environment conditions Higher shares of NO 2 in combustion exhaust (e.g. caused by oxidation catalysts and CRT systems for diesel vehicles) This has to be taken into account for pollution reduction strategies

6 Air quality in Germany Emission city buses urban areas NOx (kt/a) - bus fleet Germany EURO 5 EURO 4 EURO 3 EURO 2 EURO 1 before EURO Source: TREMOD calculations [Version Nov. 23] Emissions are decreasing due to the replacement of old buses with new buses The contribution of pre EURO 3 buses to NO x emissions is currently about 8% The contribution of pre EURO 2 buses to NO x emissions is currently about 4% Fleet composition varies considerably between different cities. Example: 6 Berlin: 1 out of 13 buses equipped with CRT (> 75%) Germany: 8 out of 25 (3%)

7 Air quality in Germany Emission City Busses NO NOx emissions of city busses (urban) NO NO2 The use of CRT systems leads to an increase in direct NO 2 emissions of busses This considerably increase could be one reason for increasing local NO 2 concentration at several German cities Euro 2 Euro 2 CRT Euro 3 Euro 3 CRT Data: IFEU assumptions based on several sources 7

8 Air quality in Germany Emission Passenger Cars NO 2,8,7,6,5,4 NOx emissions of Passenger Cars (urban) NO NO2 The introduction of oxidation catalysts (passenger cars diesel) also led to higher direct NO 2 -emissions Considering the high increase of diesel cars in Germany, this also could be one reason for increasing NO 2 concentrations,3,2,1, Euro 1 no cat. Euro 2 Euro 3 oxidation cat. oxidation cat. PC Diesel Euro 2 3-way cat. PC Gasoline Euro 3 3-way cat. Data: IFEU assumptions based on several sources 8

9 Conclusions Introduction Air quality Conclusions. A reduction of road traffic and thus also of captive fleet emissions is necessary, because air quality limits are still exceeded. The formation of PM and nitrogen oxides is complex and a projection as well as the monitoring of reduction measures difficult. Besides the reduction of PM, the reduction of nitrogen oxides has to be the focus of future strategies in Germany and Europe in order to comply with future air quality standards. The influence of CRT-systems and Oxidation-catalysts on direct NO 2 -emissions has to be considered. In many air quality models input data are only NO X -emissions of transport. 9