The article evaluates the quality characteristics and Life Cycle Assessment (LCA) of multi-crop biofuel pellets, proposing them as a sustainable alternative to wood biomass. While the study highlights the environmental benefits of pellets derived from certain crop combinations, several methodological and interpretive concerns arise. The reliance on uniform system boundaries and assumptions, such as the environmental neutrality of pellet ash recycling, may overlook the nuanced impacts of fertilizer substitution and ash management, potentially underestimating the true environmental footprint. Similarly, while the carbon footprint of maize biomass (S-Mz) is highlighted as the highest among scenarios, the analysis underemphasizes the socio-economic and productivity trade-offs associated with such single-crop systems.
The study’s approach to multi-crop scenarios, particularly MIX2-1 and MIX2-3, frames them as the most environmentally favorable options. However, the exclusion of factors like biodiversity impacts, land use change, and long-term soil health compromises the comprehensiveness of the assessment. Furthermore, the dataset, primarily drawn from experimental plots, may not adequately reflect field-scale variations or account for uncertainties in multi-year biomass yields, leading to potential biases in the results.
Discrepancies also arise in elemental composition and emissions data. For instance, while chlorine content in several pellet variants exceeds standard limits, the implications for boiler corrosion and emissions during combustion are downplayed. Additionally, the study’s focus on calorific value and ash content as primary quality metrics insufficiently considers critical operational parameters such as slagging and fouling tendencies, which are key concerns for non-wood biomass fuels.
Moreover, the reliance on the Ecoinvent v3 database and assumptions about transport and energy use lacks transparency and regional specificity, potentially misrepresenting the life cycle impacts. The omission of a sensitivity analysis to test key variables, such as transportation distances or fertilizer application rates, further weakens the robustness of the conclusions.
Addressing these gaps—through broader inclusion of environmental and socio-economic metrics, improved transparency in LCA assumptions, and validation of findings against field-scale studies—would enhance the study’s reliability and policy relevance. Future research should explore the balance between productivity, environmental impacts, and regional feasibility in scaling multi-crop biofuel systems, contributing to a more nuanced understanding of their role in sustainable energy transitions.