3.I - Agricultural: Other

Short description

NFR-Code Name of Category Method AD EF State of reporting
3.I Agriculture other
consisting of / including source categories
3.I Storage of digestate from energy crops T2 (NH3, NOx) Q, PS CS (NH3, NOx)
NOx NMVOC SO2 NH3 PM2.5 PM10 TSP BC CO Pb Cd Hg Diox PAH HCB
Key Category: -/- - - -/- - - - - - - - - - - -

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T = key source by Trend L = key source by Level

Methods
D Default
RA Reference Approach
T1 Tier 1 / Simple Methodology *
T2 Tier 2*
T3 Tier 3 / Detailed Methodology *
C CORINAIR
CS Country Specific
M Model
* as described in the EMEP/CORINAIR Emission Inventory Guidebook - 2007, in the group specific chapters.
AD - Data Source for Activity Data
NS National Statistics
RS Regional Statistics
IS International Statistics
PS Plant Specific data
AS Associations, business organisations
Q specific questionnaires, surveys
EF - Emission Factors
D Default (EMEP Guidebook)
C Confidential
CS Country Specific
PS Plant Specific data


Country specifics

In 2020, NH3 emissions from category 3.I (agriculture other) derived up to 0.6 % from total agricultural emissions, which is equal to ~ 3.1 kt NH3 . NOx emissions from category 3.I contribute 0.16 % (~ 0.17 kt) to the total agricultural emissions. All these emissions originate from the storage of digestate from energy crops (for details on anaerobic digestion of energy crops see Vos et al. 2022, Chapter 10 1). The emissions resulting from the application of energy crop digestates as organic fertilizer are dealt with under 3.D.a.2.c.

Activity Data

Time series of activity data have been provided by KTBL (Kuratorium für Technik und Bauwesen in der Landwirtschaft / Association for Technology and Structures in Agriculture). From these data the amount of N in energy crops fed into anaerobic digestion was calculated.

Table 1: N amount in energy crops fed into anaerobic digestion

N amount in energy crops in Gg N
1990 1995 2000 2005 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
0.1 0.7 5.6 47.6 172.0 214.5 234.9 284.1 297.3 308.8 307.1 302.1 297.6 297.8 297.8

Table 2: Distribution of gastight storage and storage in open tank of energy crop digestates

Distribution of gastight storage and non-gastight storage, in %
1990 1995 2000 2005 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
gastight 0.0 4.7 9.4 15.8 42.2 47.5 59.4 61.9 63.9 64.6 64.8 64.5 64.8 65.5 65.5
non-gastight 100.0 95.3 90.6 84.2 57.8 52.5 40.6 38.1 36.1 35.4 35.2 35.5 35.2 34.5 34.5

Methodology

The calculation of emissions from storage of digestate from energy crops considers two different types of storage, i.e. gastight storage and open tank. The frequencies of these storage types are also provided by KTBL (see Table 2). There are no emissions of NH3 and NO from gastight storage of digestate. Hence the total emissions from the storage of digestate are calculated by multiplying the amount of N in the digestate leaving the fermenter with the relative frequency of open tanks and the emission factor for open tank. The amount of N in the digestate leaving the fermenter is identical to the N amount in energy crops fed into anaerobic digestion (see Table 1) because N losses from pre-storage are negligible and there are no N losses from fermenter (see Vos et al. 2022, Chapter 10.2.1.).

Emission factors

As no specific emission factor is known for the storage of digestion residues in open tanks, the NH3 emission factor for storage of cattle slurry with crust in open tanks was adopted (0.045 kg NH3 -N per kg TAN). This choice of emission factor is based on the fact that energy crops are, in general, co-fermented with animal manures (i. e. mostly slurry) and that a natural crust forms on the liquid digestates due to the relatively high dry matter content of the energy crops. The TAN content after the digestion process is 0.56 kg TAN per kg N. The NO emission factor for storage of digestion residues in open tanks was set to 0.0005 kg NO-N per kg N. Table 3 shows the resulting implied emission factors for NH3 -N and NO-N. NOx emissions are related to NO-N emissions by the ratio of 46/14. This relationship also holds for NO-N and NOx emission factors.

Table 3: IEF for NH3 -N and NO-N emissions from storage of digested energy crops

1990 1995 2000 2005 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
IEF in kg NH3-N per kg N in digested energy crops
0.0252 0.0240 0.0228 0.0212 0.0146 0.0132 0.0102 0.0096 0.0091 0.0089 0.0089 0.0089 0.0089 0.0087 0.0087
IEF in kg NO-N per kg N in digested energy crops 
0.00050 0.00048 0.00045 0.00042 0.00029 0.00026 0.00020 0.00019 0.00018 0.00018 0.00018 0.00018 0.00018 0.00017 0.00017

Trend discussion for Key Sources

NH3 and NOx from storage of anaerobically digested energy crops are no key source.

Recalculations

All time series of the emission inventory have completely been recalculated since 1990. Table REC-1 shows the effects of recalculations on NH3 and NOx emissions from storage of anaerobically digested energy crops. Differences to last year’s submission occur only in 2019 and are due to the update of activity data (see main page of the agricultural sector, Chapter 5 - NFR 3 - Agriculture (OVERVIEW), recalculation reason No 16). For further details on recalculations see Vos et al. (2022), Chapter 3.5.2.

Table REC-1: Comparison of NH3 and NOx emissions of the submissions (SUB) 2021 and 2022

NH3 / NOx emissions in Gg
SUB 1990 1995 2000 2005 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
NH3 2022 0.0015 0.0190 0.1563 1.2267 3.0426 3.4504 2.9206 3.3062 3.2814 3.3428 3.3004 3.2741 3.2013 3.1419 3.1419
NH3 2021 0.0015 0.0190 0.1563 1.2267 3.0426 3.4504 2.9206 3.3062 3.2814 3.3428 3.3004 3.2741 3.2013 3.2013
NOx 2022 0.0001 0.0010 0.0084 0.0659 0.1634 0.1852 0.1568 0.1775 0.1762 0.1795 0.1772 0.1758 0.1719 0.1687 0.1687
NOx 2021 0.0001 0.0010 0.0084 0.0659 0.1634 0.1852 0.1568 0.1775 0.1762 0.1795 0.1772 0.1758 0.1719 0.1719

For pollutant-specific information on recalculated emission estimates for Base Year and 2019, please see the pollutant specific recalculation tables following chapter 8.1 - Recalculations.

Uncertainty

Details are described in chapter 1.7.

1)
Vos C, Rösemann C, Haenel H-D, Dämmgen U, Döring U, Wulf S, Eurich-Menden B, Freibauer A, Döhler H, Schreiner C, Osterburg B, Fuß R (2022) Calculations of gaseous and particulate emissions from German agriculture 1990 – 2020 : Report on methods and data (RMD) Submission 2022. Braunschweig: Johann Heinrich von Thünen-Institut, 452 p, Thünen Rep 91, DOI:10.3220/REP1646725833000. https://www.thuenen.de/de/ak/arbeitsbereiche/emissionsinventare/