1 Introduction
2 Methodology
2.1 Functional unit and alternatives
2.2 System boundaries
Soil preparation (year 1) | |
Seed | 10 kg/ha |
Fertilizer—ammonium nitrate | 100 kg/ha |
Fertilizer—P2O5
| 40 kg/ha |
Fertilizer—K2O | 80 kg/ha |
Lime | 3,000 kg/ha |
Herbicide—advance (bromoxynil/ioxynil/fluroxypyr) | 2 kg/ha |
Herbicide—trifolex-tra (MCPA + MCPB) | 7.7 kg/ha |
Herbicide—isoproturon | 2 kg/ha |
Yield | 0 t/ha |
Production (year 2–20) | |
Fertilizer—ammonium nitrate | 100 kg/ha |
Manganese (MnSO4) | 4 kg/ha |
Herbicide—advance (bromoxynil/ioxynil/fluroxypyr) | 2 kg/ha |
Herbicide—trifolex-tra (MCPA + MCPB) | 7.7 kg/ha |
Herbicide—isoproturon | 2 kg/ha |
Yield (25% moisture) | year 2 and 3: 12 t/ha |
year 4–20: 16 t/ha | |
Total yield over 20 years (25% moisture) | 296,000 t/ha |
CO2 from air | 1.54 kg/kg DMa
|
Energy | 17 MJ/kg DMb
|
Soil preparation (year 1) | Production (year 2–20) | Total 20 years | |
---|---|---|---|
Emissions to air (kg/ha) | |||
Nitrogen oxides | 1.02 | 1.02 | 20.5 |
Dinitrogen monoxide | 4.88 | 4.88 | 97.5 |
Ammonia | 2.43 | 2.43 | 48.6 |
Emissions to water (kg/ha) | |||
Nitrate | 48.00 | 48.00 | 960.00 |
Phosphorus to ground water | 0.06 | 0.06 | 1.20 |
Phosphorus to surface water | 0.28 | 0.25 | 5.03 |
Phosphorus from erosion to surface water | 0.71 | 0.71 | 14.20 |
Cadmium (Cd) | 3.90 × 10−5
| 1.72 × 10−6
| 7.17 × 10−5
|
Copper (Cu) | 3.21 × 10−3
| 1.85 × 10−3
| 3.84 × 10−2
|
Zinc (Zn) | 1.52 × 10−2
| 5.53 × 10−3
| 0.12 |
Lead (Pb) | 2.60 × 10−4
| 2.14 × 10−5
| 6.67 × 10−4
|
Chromium (Cr) | 2.11 × 10−2
| 6.04 × 10−3
| 0.14 |
Emissions to soil (kg/ha) | |||
Cadmium (Cd) | 1.79 × 10−5
| 7.93 × 10−7
| 3.29 × 10−5
|
Copper (Cu) | 1.21 × 10−3
| 7.01 × 10−4
| 1.45 × 10−2
|
Zinc (Zn) | 2.22 × 10−3
| 8.05 × 10−4
| 1.75 × 10−2
|
Lead (Pb) | 7.83 × 10−4
| 6.52 × 10−5
| 2.02 × 10−3
|
Nickel (Ni) | 1.48 × 10−3
| 7.69 × 10−4
| 1.61 × 10−2
|
Chromium (Cd) | 1.78 × 10−3
| 5.09 × 10−4
| 1.14 × 10−2
|
2.3 Life cycle inventory: data sources and software
2.4 Life cycle inventory: allocation
2.5 Life cycle impact assessment
-
Abiotic depletion potential (ADP)
-
Global warming potential (GWP)
-
Ozone depletion potential (ODP)
-
Photochemical oxidation potential (POCP)
-
Acidification potential (AP)
-
Eutrophication potential (EP)
-
Human toxicity potential (HTP)
-
Ecotoxicity potential (ETP)
2.6 Interpretation
3 Results and discussion
3.1 LCA results
3.2 Sensitivity analysis
3.2.1 Allocation method
Partitioning factor | GWP of 1-km driving (kg CO2 eq.) | |||
---|---|---|---|---|
Ethanol | Electricity | E10 | E85 | |
Energy allocation | 0.855 | 0.145 | 0.241 | 0.090 |
Economic allocation | 0.742 | 0.258 | 0.240 | 0.075 |
3.2.2 Soil preparation
Impact category | Unit | Base scenario | Alternative scenario | Range (%) |
---|---|---|---|---|
ADP | kg antimony eq. | 6.79 × 10−4
| 6.52 × 10−4
| −3.98 |
GWP | kg CO2 eq. | 8.96 × 10−2
| 8.14 × 10−2
| −9.15 |
OPD | kg CFC-11 eq. | 2.18 × 10−8
| 2.15 × 10−8
| −1.37 |
POCP | kg ethylene eq. | 5.91 × 10−4
| 5.86 × 10−4
| −0.85 |
AP | kg SO2 eq. | 7.52 × 10−4
| 7.03 × 10−4
| −6.52 |
EP | kg PO4 eq. | 2.69 × 10−4
| 2.51 × 10−4
| −6.69 |
HTP | kg 1,4-DCB eq. | 3.22 × 10−2
| 2.89 × 10−2
| −10.3 |
ETP | kg 1,4-DCB eq. | 6.33 × 10−3
| 5.75 × 10−3
| −9.12 |
3.2.3 Transport distance
Impact category | Unit | 20 km | 40 km | 80 km | ||
---|---|---|---|---|---|---|
ADP | kg antimony eq. | 6.79 × 10−4
| 6.97 × 10−4
| +2.65% | 7.31 × 10−4
| +7.66% |
GWP | kg CO2 eq. | 8.96 × 10−2
| 9.16 × 10−2
| +2.23% | 9.57 × 10−2
| +6.81% |
OPD | kg CFC-11 eq. | 2.18 × 10−8
| 2.22 × 10−8
| +1.83% | 2.28 × 10−8
| +4.59% |
POCP | kg ethylene eq. | 5.91 × 10−4
| 5.96 × 10−4
| +0.93% | 6.03 × 10−4
| +2.03% |
AP | kg SO2 eq. | 7.52 × 10−4
| 7.61 × 10−4
| +1.23% | 7.86 × 10−4
| +4.52% |
EP | kg PO4 eq. | 2.69 × 10−4
| 2.72 × 10−4
| +0.94% | 2.75 × 10−4
| +2.23% |
HTP | kg 1,4-DCB eq. | 3.22 × 10−2
| 3.24 × 10−2
| +0.68% | 3.29 × 10−2
| +2.17% |
ETP | kg 1,4-DCB eq. | 6.33 × 10−3
| 6.42 × 10−3
| +1.46% | 6.58 × 10−3
| +3.93% |