3.I - Agricultural: Other

Short description

NFR-Code	Name of Category	Method	AD	EF
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:	-/-	-	-	-/-	-	-	-	-	-	-	-	-	-	-	-
Method(s) applied
D	Default
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/EEA Emission Inventory Guidebook - 2019, in category chapters.
(source for) Activity Data
NS	National Statistics
RS	Regional Statistics
IS	International Statistics
PS	Plant Specific
As	Associations, business organisations
Q	specific Questionnaires (or surveys)
M	Model / Modelled
C	Confidential
(source for) Emission Factors
D	Default (EMEP Guidebook)
CS	Country Specific
PS	Plant Specific
M	Model / Modelled
C	Confidential

Country specifics

In 2021, NH3 emissions from category 3.I (agriculture other) derived up to 0.7 % from total agricultural emissions, which is equal to ~ 3.2 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 Rösemann et al. 2023, Chapter 5.1 1) Rösemann C, Vos C, Haenel H-D, Dämmgen U, Döring U, Wulf S, Eurich-Menden B, Freibauer A, Döhler H, Steuer B, Osterburg B, Fuß R (2023) Calculations of gaseous and particulate emissions from German agriculture 1990 – 2021: Report on methods and data (RMD) Submission 2023. www.eminv-agriculture.de . 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	2021
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	304.2	304.2

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	2021
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	65.8	65.8
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	34.2	34.2

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 Rösemann et al. 2023, Chapter 5.1).

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	2021
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	0.0086	0.0086
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	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 2020 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 15). For further details on recalculations see Rösemann et al. (2032), Chapter 1.3.

Table REC-1: Comparison of NH3 and NOx emissions of the submissions (SUB) 2022 and 2023

NH3 / NOx emissions in Gg
SUB	1990	1995	2000	2005	2010	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020	2021
NH3	2023	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	3.1782	3.1782
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
NOx	2023	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	0.1706	0.1706
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

For pollutant-specific information on recalculated emission estimates for Base Year and 2020, please see the pollutant specific recalculation tables following chapter 8.1 - Recalculations.

Uncertainty

Details are described in chapter 1.7.