1.A.3.c - Railways

Last updated on 16 Oct 2015 06:19 (cf. Authors)

Short description

In category 1.A.3.c - Railways the emissions from German railways are reported.

NFR-Code Name of Category Method AD EF Key Category for (by1)
1.A.3.c Railways T1, T2 NS, M CS, D, M no key category

Germany's railway sector is undergoing a long-term modernisation process, aimed at making electricity the main energy source for rail transports. Use of electricity, instead of diesel fuel, to power locomotives has been continually increased, and electricity now provides 80% of all railway traction power. Railways' power stations for generation of traction current are allocated to the stationary component of the energy sector (1.A.1.a) and are not included in the further description that follows here. In energy input for trains of German Railways (Deutsche Bahn AG), diesel fuel is the only energy source that plays a significant role apart from electric power.

Method

Activity Data

Basically, total inland deliveries of diesel oil are available from the National Energy Balances (NEBs) (AGEB, 2014) [1]. This data is based upon sales data of the Association of the German Petroleum Industry (MWV) [2]. As a recent revision of MWV data on diesel oil sales for the years 2005 to 2009 has not yet been adopted to the respective NEBs, this original MWV data has been used for this five years.

Data on the consumption of biodiesel in railways is provided in the NEBs as well, from 2004 onward. But as the NEBs do not provide a solid time series regarding most recent years, the data used for the inventory is estimated based on the prescribed shares of biodiesel to be added to diesel oil.

Small quantities of solid fuels are used for historical steam engines vehicles operated mostly for tourism and exhibition purposes. Official fuel delivery data are available for lignite, through 2002, and for hard coal, through 2000, from the NEBs. In order to complete these time series, a study was carried out in 2012 by Probst & Consorten. During this study, questionaires were provided to any known operator of historical steam engines in Germany. Here, due to limited data archiving, nearly complete data could only be gained for years as of 2005.
For earlier years, in order to achieve a solid time series, conservative gap filling was applied.

Table 1: Overview of data sources for domestic fuel sales to railway operators
Fuel data source / quality of activity data
Diesel oil 1990-2004: NEB lines 74 and 61: 'Schienenverkehr' / 2005-2009: MWV annual report, table: 'Sektoraler Verbrauch von Dieselkraftstoff' / from 2010: NEB line 61
Biodiesel calculated from official blending rates
Hard coal 1990-1994: NEB lines 74 / 1995-2004: interpolated data / ab 2005-2010: original data from study / from 2011: forward projection
Hard coal coke 1990-1997: NEB lines 74 and 61 / 1998-2004: interpolated data / ab 2005-2010: original data from study / from 2011: forward projection
Raw lignite from 1990: NEB lines 74 and 61
Lignite briquettes from 1990: NEB lines 74 and 61
Table 2: Annual liquid fuels consumption in German railways, in [TJ]
1990 1995 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Diesel Oil 38,458 31,054 25,410 23,530 22,041 21,611 20,372 18,142 17,101 16,730 16,389 14,336 14,626 14,730 13,514 13,088
Biodiesel 0 0 0 0 0 0 175 397 498 747 810 987 949 966 882 758
Liquids TOTAL 38,458 31,054 25,410 23,530 22,041 21,611 20,547 18,539 17,599 17,477 17,199 15,324 15,575 15,696 14,396 13,846

For use of solid fuels, the time series resulting fom the different sources are as follows:

Table 3: Annual solid fuels consumption in German railways, in [TJ]
1990 1995 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Lignite Briquettes NE NE 431.00 216.00 19.00 0.00 NE NE NE NE NE NE NE NE NE NE
Raw Lignite NE NE NE NE NE NE NE NE NE NE NE NE NE NE NE NE
Hard Coal 576.00 250.00 250.00 250.00 250.00 250.00 250.00 255.00 262.00 255.00 300.00 321.00 314.00 325.00 325.00 325.00
Hard Coal Coke NE 86 1.33 0.94 0.94 0.78 0.79 0.79 0.71 0.71 0.71 0.71 0.79 0.75 0.75 0.75
Solids TOTAL 576.00 336.00 682.33 466.94 269.94 250.78 250.79 255.79 262.71 255.71 300.71 321.71 314.79 325.75 325.75 325.75

italic: projected data only

Use of other fuels – such as vegetable oils or gas – in private narrow-gauge railway vehicles has not been included to date and may still be considered negligible.

Emission factors

The (implied) emission factors used here are of very different quality:
For main pollutants, carbon monoxide and particulate matter from the combustion of diesel fuels, annual tier2 IEF computed within the TREMOD model are used , representing the development of German railway fleet, fuel quality and mitigation technologies. (ifeu, 2014a) [4]. On the other hand, constant default values from (EMEP/EEA 2013a and b) [5], [6] are used for all reported POPs and heavy metals.

Regarding emissions from solid fuels used in historic steam engines, all emission factors displayed below have been adopted from small-scale stationary combustion.

Table 4: (I)EF values used for 2013 estimates
Main Pollutants Particulate Matter Heavy Metals Persistent Organis Pollutants
NEC Other PM2.5 ≤ PM10 ≤ TSP Main HM Other HM Polycyclic Aromatic Hydrocarbons Dioxins & Furans
Pollutant NH3 NMVOC NOx SO2 CO PM2.5 PM10 TSP Pb Cd Hg As Cr Cu Ni Se Zn B[a]P B[b]F B[k]F I[…]P ∑PAH 1-4 PCDD/F HCB PCBs
kg/TJ kg/TJ g/TJ mg/TJ g I-Teq mg/TJ
Diesel oil1 0.542 61.62 1,0042 0.373 1292 20.22 20.24 20.24 1.215 0.236 0.125 0.0025 1.166 406 1.636 0.236 236 6986 1.1646 8005 1835 2.8467 2.098 NE NE
Hard coal9 4 15 120 650 500 NE NE 700 NE NE NE NE NE NE NE NE NE NE NE NE NE NE NE NE NE
Hard coal coke9 4 0.5 120 500 1,000 NE NE 700 NE NE NE NE NE NE NE NE NE NE NE NE NE NE NE NE NE
Lignite9 4 15 120 500 500 NE NE 700 NE NE NE NE NE NE NE NE NE NE NE NE NE NE NE NE NE
Lignite briquettes9 4 15 120 120 500 NE NE 700 NE NE NE NE NE NE NE NE NE 34,500 IE in ∑PAH 90,000 30 NE NE

1 due to lack of better information: similar EF are applied for fossil diesel oil and biodiesel
2 annual country-specific value from (ifeu, 2014a) [3]
3 country-specific value from (ifeu, 2014a) [3]
4 EF(PM2.5) also applied for PM10 and TSP (assumption: > 99% of TSP from diesel oil combustion consists of PM2.5)
5 tier1 default from EMEP/EEA GB 2013, chapter 1.A.3.b i-iv - Road transport: exhaust emissions: tier1 value for diesel vehicles [5]
6 tier1 default from EMEP/EEA GB 2013, chapter 1.A.3.c - Railways [6]
7 sum of tier1 default value applied for B[a]P, B[b]F, B[k]F, and I[1,2,3-c,d]P
8 tier1 value derived from (Rentz et al., 2008) [7]
9 value derived from stationary combustion

Discussion of emission trends

NFR 1.A.3.c is no key source.

Basically, for all unregulated pollutants, emission trends directly follow the trend in over-all fuel consumption.

Here, as emission factors for solid fuels tend to be much higher than those for diesel oil, emission trends are disproportionately effected by the amount of solid fuels used.
Therefore, for the main pollutants, carbon monoxide, particulate matter and PAHs, emission trends show remarkable jumps especially after 1995 that result from the significantly higher amounts of solid fuels were used:

Here, this dominating impact of emissions from solid fuels is particularly significant for total suspended particles (TSP). In contrast, as no PM2.5 and PM10 emissions are calculated from solid fule use, these trends are only reflecting the consumption of diesel oil.

Due to fuel-sulphur legislation, the trend of sulphur dioxide emissions follows not only the trend in fuel consumption but also reflects the impact of fuel-quality legislation.

Regarding heavy metals, as there are emission factors applied for diesel oil only at the moment, the specific emission trends reflect the trend of diesel oil consumption:

Recalculations

Activity data: Given the revised NEB 2012, both the activity data fo diesel oil and the annual amounts of blended biodiesel were revised accordingly within TREMOD.

Table 5: Revised consumption data from final NEB 2012, in [TJ]
Diesel oil Biodiesel
Submission 2015 13,514 882
Submission 2014 14,117 922
absolute change -603 -39
relative change -4.27% -4.26%

Furthermore, the fragmantary data for solid fuels sold to operators of historical steam engines available from the National Energy Balance have been completed based on information from a study carried out in 2012. (see description of AD above)

Emission factors: Due to the routine revision of the TREMOD model [3], tier2 emission factors for 2013 changed in accordance to a revised composition of this year's haul engine fleet.

Table 6: Revised (I)EFs 2013 for emissions from diesel fuels
NH3 NMVOC NOx CO PM
Submission 2015 0.54 60.7 1,006 128.4 20.47
Submission 2014 0.40 58.9 998 125.9 19.99
absolute change +0.14 +1.9 +8 +2.50 +0.48
relative change +34% +3.15% +0.83% +1.96% +2.40%

Furthermore, the reporting of ∑PAH 1-4 from diesel use has been revised and the NEs for Pb, Hg, As have been replaced by tier1-EF provided for diesel use in road transport from [7].

Table 7: Newly implemented tier1 EFs for emissions from diesel fuels
Pb Hg As B[b]F B[k]F I[…]P
[g/TJ] [mg/TJ]
Submission 2015 1.21 0.12 0.002 1,164 801 184
Submission 2014 NE NE NE NE NE NE

Furthermore, the reporting of ∑PAH 1-4 from diesel use has been revised and the NEs for Pb, Hg, As have been replaced by tier1-EF provided for diesel use in road transport from [7].

Table 8: Revised summatory EF for PAH 1-4, in [mg/TJ]
PAH 1-4
Submission 2015 2,847
Submission 2014 930
absolute change +1,917
relative change +206%

Emissions: Given the broad revisions and further changes described for AD and (I)EF above, all emission data have been recalculated but cannot be displayed here in full detail.

Due to the broad changes in the NFR structure, no sector- and pollutant-specific information on the impacts on emission estimates are provided in chapter 8.1 - Recalculations with this submission.

Uncertainties

Uncertainty estimates for activity data of mobile sources derive from research project FKZ 360 16 023: "Ermittlung der Unsicherheiten der mit den Modellen TREMOD und TREMOD-MM berechneten Luftschadstoffemissionen des landgebundenen Verkehrs in Deutschland" by (ifeu & INFRAS 2009) [8]. - For detailled information, please refer to the project's final report here (German version only!)

Planned improvements

Besides the routine revision of the TREMOD model, a revision of the reporting of heavy metals and POPs from the consumption of soild fuels is planned based upon information from stationary combustion.

FAQs

Why are similar EF applied for estimating exhaust heavy metal emissions from both fossil and biofuels?

The EF provided in [5] represent summatory values for (i) the fuel's and (ii) the lubricant's heavy-metal content as well as (iii) engine wear. Here, there might be no heavy metals contained in the biofuels. But since the specific shares of (i), (ii) and (iii) cannot be separated, and since the contributions of lubricant and engine wear might be dominant, the same emission factors are applied to biodiesel.


Bibliography
1. AGEB, 2014: Arbeitsgemeinschaft Energiebilanzen (Hrsg.): Energiebilanz für die Bundesrepublik Deutschland; URL: http://www.ag-energiebilanzen.de/7-0-Bilanzen-1990-2012.html, (Aufruf: 21.11.2014), Köln, Berlin.
2. MWV, 2014: Mineralölwirtschaftsverband (MWV, Association of the German Petroleum Industry): MWV Jahresbericht Mineralöl-Zahlen 2013 - URL: http://www.mwv.de/upload/Publikationen/dateien/MWV_Jahresbericht_2013-Titelbild_mittel_5nWqRqG29p86sH5.pdf, (Aufruf: 10.02.2015), Berlin.
3. Probst & Consorten, 2012: Recherche des jährlichen Kohleeinsatzes in historischen Schienenfahrzeugen seit 1990 ('Inquiry of annual coal use in historic railway vehicles since 1990') - Study carried out for UBA; FKZ 363 01 392; not yet published
4. ifeu, 2014a: Knörr, W. et al., IFEU - Institut für Energie- und Umweltforschung Heidelberg gGmbH: Fortschreibung des Daten- und Rechenmodells: Energieverbrauch und Schadstoffemissionen des motorisierten Verkehrs in Deutschland 1960-2030, sowie TREMOD 5.4, im Auftrag des Umweltbundesamtes, Berlin.
5. EMEP/EEA, 2013b: EMEP/EEA air pollutant emission inventory guidebook – 2013; Chapter 1.A.3.b.i, 1.A.3.b.ii, 1.A.3.b.iii, 1.A.3.b.iv - Road transport - http://www.eea.europa.eu/publications/emep-eea-guidebook-2013/part-b-sectoral-guidance-chapters/1-energy/1-a-combustion/1-a-3-b-road-transport
6. EMEP/EEA, 2013a: EMEP/EEA air pollutant emission inventory guidebook – 2013; Chapter 1.A.3.c Railways - http://www.eea.europa.eu/publications/emep-eea-guidebook-2013/part-b-sectoral-guidance-chapters/1-energy/1-a-combustion/1-a-3-c-railways
7. Rentz et al., 2008: Nationaler Durchführungsplan unter dem Stockholmer Abkommen zu persistenten organischen Schadstoffen (POPs), im Auftrag des Umweltbundesamtes, FKZ 205 67 444, UBA Texte | 01/2008, January 2008 - URL: http://www.umweltbundesamt.de/en/publikationen/nationaler-durchfuehrungsplan-unter-stockholmer
8. ifeu & INFRAS, 2009: IFEU – Institut für Energie- und Umweltforschung Heidelberg gGmbH und INFRAS Zürich: Ermittlung der Unsicherheiten der mit den Modellen TREMOD und TREMOD-MM berechneten Luftschadstoffemissionen des landgebundenen Verkehrs in Deutschland, FKZ 360 16 023, Heidelberg & Zürich.
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