Advanced Biofuel Value Chains Sourced by New Cropping Systems With Low iLUC Risk

Abstract

Increasing lignocellulosic feedstock for advanced biofuels can tackle the decarbonization of the transport sector. Dedicated biomass produced alongside food systems with low indirect land use change (iLUC) impact can broaden the feedstock availability, thus streamlining the supply chains. The objective of this study was the design and evaluation of advanced ethanol value chains for the Emilia-Romagna region based on low iLUC feedstock. Two dedicated lignocellulosic crops (biomass sorghum and sunn hemp) were evaluated in double cropping systems alongside food crop residues (corn stover and wheat straw) as sources to simulate the value chains. A parcel-level regional analysis was carried out, then the LocaGIStics2.0 model was used for the spatial design and review of the biomass delivery chain options regarding cost and greenhouse gas (GHG) emissions of the different feedstock mixes. Literature data on bioethanol production from similar feedstocks were used to estimate yields, process costs, and GHG emissions of a biorefinery process based on these biomasses. Within the chain options, GHG emissions were overly sensitive to cultivation input, mostly N-fertilization. This considered, GHG emissions resulted similar across different feedstock with straw/stover (averaging 13 g CO₂eq MJ⁻¹ fuel), sunn hemp (14 g CO₂eq MJ⁻¹ fuel), and biomass sorghum (16 g CO₂eq MJ⁻¹ fuel). On the other hand, the bioethanol produced from biomass sorghum (608 € Mg⁻¹ of bioethanol) was cheaper compared with straw (632 € Mg⁻¹), sunn hemp (672 € Mg⁻¹), and stover (710 € Mg⁻¹). The bioethanol cost ranged from 0.0017 to 0.020 € MJ⁻¹ fuel depending on the feedstock, with operations and maintenance impacting up to 90% of the final cost. In summary, a single bioethanol plant with an annual capacity of 250,000 Mg of biomass could replace from 5% to 7% of the Emilia-Romagna's ethanol fuel consumption, depending on the applied sourcing scenario.