Environmental burdens of source-selected biowaste treatments: comparing scenarios to fulfil the European Union landfill directive. The case of Catalonia

Figures & data

Table 1 Inventory data obtained from the installations considered in this study (AD: anaerobic digestion; CT: in-vessel composting; AWC: aerated windrows composting; TWC: turned windrows composting, HC: home composting) previously published in (Colón et al. 2012). AWB (aerated and turned windrows with gaseous emissions treatment) data have been theoretically calculated.

Facility		AD	CT	AWC	TWC	HC	AWB
Inputs	MJ electricity	166.32	770.4	235.8	33.41	33.77	354.8 (119)^*
	MJ electricity self-generation	167.04	0	0	0	0	0
	L diesel	3.64	2.66	9	5.33	0	9
	Total MJ (electricity+diesel)	472.26	871.9	579.24	236.8	33.77	698.24
	Water (m^3)	0.12	0.56	0.02	0	0.051	0.02
Outputs	kg NH3	0.23	0.11	2	8.63	0.84	0.2 (90)^**
	Kg VOC	0.86	0.36	6.22	5.7	0.56	1.87 (70)^**
	kg N2O	0.035	0.075	0.076	0.251	0.676	0.076 (0)^**
	kg CH4	2.39 (5.4)^***	0.34	1.68	4.37	0.16	1.51 (10)^**
	kg CO2 (non-biogenic)	10.6	7.7	26.1	15.5	0.0	26.1
	kg NOx	0.120	0.088	0.297	0.176	0.000	0.297
	kg SOx	0.016	0.011	0.039	0.023	0.000	0.039
	m^3 biogas	98.9	n/a	n/a	n/a	n/a	n/a
	MJ electricity	550.08	n/a	n/a	n/a	n/a	n/a

^*Value in brackets is the surplus of energy needed for the implementation of a gas treatment in AWB plants.

^**Values in brackets are the gas treatment removal efficiency considered in AWB plants.

^***Value in brackets is the CH₄ emitted considering a 10% of fugitive emissions plus the biogas combustion (theoretically calculated).

Figure 1 Definition and boundaries of the composting systems studied, including the main composting stages and the input and output flows considered.

Table 2 Impact categories determined for OFMSW treatment plants representative of the treatment technologies implemented in Catalonia (Colón et al. 2012).

		Impact potentials
		GWP	ADP	AP	EUP	ODP	POP
Treatment technology	Gaseous emissions treatment	(kg CO2 equiv. t^–1)	(kg Sb equiv. t^–1)	(kg SO2 equiv. t^–1)	(kg PO4^3- equiv. t^–1)	(kg CFC-11 equiv. t^–1)	(kg C2H4 equiv. t^–1)
Anaerobic Digestion (AD)	Wet scrubber+biofilter	45.2 (119.9)^*	–0.16	0.16	0.11	–2.67 × 10^–7	0.36
In-vessel composting (CT)	Wet scrubber+biofilter	150	0.87	1.3	0.12	7.12 × 10^–6	0.19
Aerated windrows composting (AWC)	No	123	0.43	3.75	0.82	5.42 × 10^–6	2.59
Aerated windrow composting with biofiltration (AWB)	Biofilter	182	0.56	1.59	0.21	6.41 × 10^–6	1.22
(theoretical)
Turned windrows composting (TWC)	No	196	0.14	14	3.08	2.37 × 10^–6	2.38
Home composting (HC)	No	209	0.04	1.4	0.3	3.05 × 10^–7	0.23

Notes: GWP: global warming potential; ADP: abiotic depletion potential; AP: acidification potential; EUP: eutrophication potential; ODP: ozone layer depletion potential; POP: photochemical oxidation potential.

^*Value in brackets is the GWP considering a 10% of fugitive emissions plus the biogas combustion (theoretically calculated).

Figure 2 Waste treatment scenarios considered in the study.

Table 3 Scenario 0: OFMSW treatment technologies, design capacity per type of plant, percentage of the total waste treated (in brackets), impact categories of the installations in operation and % contribution to the total impact (in brackets) (AD: anaerobic digestion; CT: in-vessel composting; AWC: aerated windrows composting; TWC: turned windrows composting).

			Impact potentials
		Total design capacity (Gg year^–1) (% total)	GWP	ADP	AP	EUP	ODP	POP
Treatment technology	Number of plants		(kg CO2 eq year^–1)	(kg Sb eq year^–1)	(kg SO2 eq year^–1)	(kg PO4^3- eq year^–1)	(kg CFC-11 eq year^–1)	(kg C2H4 eq year^–1)
AD	5	279	1.26 × 10^7 (3.35 × 10^7)^*	–4.46 × 10^4	4.46 × 10^4	3.06 × 10^4	–7.46 × 10^–2	1.00 × 10^5
		(55.8%)	(26.9%) (49.5%)^**	(–43,9%)	(4.9%)	(14.9%)	(5.9%)	(31.85)
CT	7	146.2	2.19 × 10^7	1.27 × 10^5	1.90 × 10^5	1.75 × 10^4	1.04	2.78·10^4
		(29.2%)	(46.8%) (32.3%)^**	(124.9%)	(21%)	(8.53%)	(82.8%)	(8.9%)
AWC	3	32.5	4.00 × 10^6	1.40 × 10^4	1.22 × 10^5	2.66 × 10^4	1.76 × 10^–1	8.42 × 10^4
		(6.5%)	(8.6%) (5.9%)^**	(13.8%)	(13.5%)	(13.0%)	(14.0%)	(26.8%)
TWC	7	42.5	8.33 × 10^6	5.95 × 10^3	5.95 × 10^5	1.30 × 10^5	1.01 × 10^–1	1.01 × 10^5
		(8.5%)	(17.8%) (12.3%)^**	(5.2%)	(60.5%)	(63.4%)	(9.1%)	(32.5%)
Total	22	500	4.68 × 10^7 (6.77 × 0^7)^*	1.02 × 10^5	9.03 × 10^5	2.05 × 10^5	1.26	3.14 × 10^5

Notes: GWP: global warming potential; ADP: abiotic depletion potential; AP: acidification potential; EUP: eutrophication potential; ODP: ozone layer depletion potential; POP: photochemical oxidation potential

^*Value in brackets is the GWP considering a 10% of fugitive emissions (theoretically calculated).

^**Values in brackets are the GWP percentage including a 10% of fugitive emissions plus the biogas combustion coming from AD facilities.

Table 4 Impact categories under Scenario LFD (Landfill Directive requirements) and % contribution to the total impact (in brackets), quantity of waste treated per type of plant and percentage of total waste treated (in brackets) (AD: anaerobic digestion; CT: in-vessel composting; AWC: aerated windrows composting; TWC: turned windrows composting).

		Impact categories
	Waste treated (% total) (Gg year^–1)	GWP	ADP	AP	EUP	ODP	POP
Treatment technology		(kg CO2 eq year^–1)	(kg Sb eq year^–1)	(kg SO2 eq year^–1)	(kg PO4^3- eq year^–1)	(kg CFC-11 eq year^–1)	(kg C2H4 eq year^–1)
AD	322	1.46 × 10^7 (3.86 × 10^7)^*	–5.15 × 10^4	5.15 × 10^4	3.54 × 10^4	–8.60 × 10^–2	1.16 × 10^5
	(34.9%)	(13.8%) (29.8%)^**	(–12.1%)	(3.6%)	(13.82%)	(2.2%)	(28.9%)
CT	524.5	7.87 × 10^7	4.56 × 10^5	6.82 × 10^5	6.29 × 10^4	3.73	9.97 × 10^4
	(56.9%)	(74.6%) (60.7%)^**	(107.4%)	(47.1%)	(24.6%)	(95.1%)	(24.9%)
AWC	32.5	4.00 × 10^6	1.40 × 10^4	1.22 × 10^5	2.66 × 10^4	1.76 × 10^–1	8.42 × 10^4
	(3.5%)	(3.1%) (3.0%)^**	(3.3%)	(8.4%)	(10.4%)	(4.5%)	(21.0%)
TWC	42.5	8.30 × 10^6	5.93 × 10^3	5.93 × 10^5	1.31 × 10^5	1.00 × 10^− 1	1.01 × 10^5
	(4.6%)	(7.9%) (6.4%)^**	(1.4%)	(40.9%)	(51.2%)	(2.6%)	(25.2%)
Total	921	1.06 × 10^8 (1.30 × 10^8)^*	4.25 × 10^5	1.45 × 10^6	2.56 × 10^5	3.93	4.01 × 10^5

GWP: global warming potential; ADP: abiotic depletion potential; AP: acidification potential; EUP: eutrophication potential; ODP: ozone layer depletion potential; POP: photochemical oxidation potential

^*Values in brackets are the surplus of GWP due to CH₄ emitted considering a 5 % of fugitive emissions (theoretically calculated).

^**Values in brackets are the GWP percentage including the fugitive emissions plus the biogas combustion coming from AD facilities.

Table 5 OFMSW treated by each treatment technology under the different scenarios and sub-scenarios considered (total OFMSW treated = 921 Gg year^–1) and percentage of total waste (in brackets) (AD: anaerobic digestion; CT: in-vessel composting; AWC: aerated windrows composting; TWC: turned windrows composting; AWB: aerated windrows with gaseous emissions biofiltration; HC: home composting).

	Treatment technology	OFMSW treated in each technology (Gg) and percentage over total (in brackets)
Scenario		Sub-scenario 1	Sub-scenario 2	Sub-scenario 3
sAD	AD	402.5 (43.7)	483.0 (52.4)	563.5 (61.2)
	CT	444.0 (48.2)	363.5 (39.5)	283.0 (30.7)
	AWC	32.5 (3.5)	32.5 (3.5)	32.5 (3.5)
	TWC	42.4 (4.6)	42.4 (4.6)	42.4 (4.6)
sAWB	AD	322.0 (34.9)	322.0 (34.9)	322.0 (34.9)
	CT	524.5 (56.9)	524.5 (56.9)	487.0 (52.9)
	AWC	32.5 (3.5)	0.0 (0)	0.0 (0)
	TWC	0.0 (0)	0.0 (0)	0.0 (0)
	AWB	42.4 (4.6)	74.9 (8.1)	112.3 (12.2)
sHC	AD	322.0 (34.9)	322.0 (34.9)	322.0 (34.9)
	CT	499.5 (54.2)	474.5 (51.5)	449.5 (48.8)
	AWC	32.5 (3.5)	32.5 (3.5)	32.5 (3.5)
	TWC	42.4 (4.6)	42.4 (4.6)	42.4 (4.6)
	HC	25.0 (2.7)	50.0 (5.4)	75.0 (8.1)

Figure 3 Impact potential differences (%) with regard to Scenario LFD (100%) for each of the alternative scenarios proposed: (a) Scenario Anaerobic Digestion (AD), (b) Scenario Aerated Windrows Composting with Biofiltration (AWB), (c) Scenario HC HC.

Figure 4 Impact potential variation for the Combined Scenario in reference to Scenario LFD (100%). It is also included the sensitivity analysis including 10% of fugitive emissions plus the biogas combustion for the GWP analysis.

Colón J, Cadena E, Pognani M, Barrena R, Sánchez A, Font X, Artola A. 2012. Determination of the energy and environmental burdens associated with the biological treatment of source-separated Municipal Solid Wastes. Energy Environ Sci. 5:5731–5741.

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