From: Benchmarking biofuels—a comparison of technical, economic and environmental indicators
Pathway step | Drivers of GHG emissions | Relevant aspects | Uncertainties related to drivers |
---|---|---|---|
Biomass production | |||
Oil, sugar, starch, lignocellulosica | dLUC/iLUCb | Carbon inventory | |
Lack of primary data | |||
Amount of N2O releasesh associated with parameters mentioned [58] | |||
Cultivation and transport [18] | Fuel consumptionf | Parameters influencing fuel consumption | |
Soil compaction [63] | Lack of primary data/site specificity for soil compaction and GHG emissions | ||
Biofuel conversion | |||
Biodiesel, HVO/HEFA, bioethanol, BTL/FT Biomethane | Energy consumption | Upstream emissions from fossil and renewable energy chainsg | Uncertainties related to the emission factors for energy productioni |
Auxiliary materialsc | Upstream emissions due to the production of required chemicals/catalystsg | Use of generic values taken from available databases e.g., Ecoinvent [64], NRELj | |
Overall conversion efficiencyd | The overall efficiency of the biomass used has an impact on the upstream emissions from biomass production per MJ of biofuel | Uncertainties related to data availability for the assessment of advanced biofuel technologies [56] |