A comparative cradle-to-grave GHG assessment approach of cultivated and residual woody and herbaceous biomass utilization pathways

This study presents a systematic cradle-to-grave assessment of greenhouse gas (GHG) emissions from four biomass utilization pathways: combustion, pyrolysis, gasification, and anaerobic digestion. Emission factors (EF) were developed through comprehensive literature synthesis of 149 datasets from 29 peer-reviewed publications, encompassing cultivation, transport, pretreatment, conversion, and construction emissions, as well as carbon sequestration and energy offset benefits. The studies were compared using an emission factor as approximate value. Potential GHG sinks through the use of biogenic residues were calculated based on the emission factor and residue potential databases. Results indicate that previously unused biogenic residues using the utilization pathways pyrolysis have significant GHG reduction potential (from 11.0 million to 19.1 million t CO 2e ). Quantitative analysis reveals woody biomass residues in pyrolysis applications achieved the most favorable GHG performance (-0.87 ± 0.44 t CO 2e /t feedstock), followed by combustion (-0.78 ± 0.28 t CO 2e /t feedstock). Herbaceous biomass residues demonstrated similar trends with pyrolysis (-0.67 ± 0.37 t CO 2e /t) outperforming combustion (-0.60 ± 0.20 t CO 2e /t). From 2045, avoidable GHG emissions from urea and lime fertilization in Germany (2023: 13.7 million t CO 2e ) could be fully compensated on average by focusing on the technically usable potential of biogenic woody and herbaceous biomass residues.