Advancing sustainable bioenergy systems through trait-based design, hybrid conversion technologies, and circular bioeconomy integration

Bioenergy frameworks have been extensively examined as components of low-carbon energy paradigms because lignocellulosic biofuels can achieve life-cycle greenhouse gas (GHG) emission reductions of approximately 40-80% relative to conventional fossil fuels, contingent on feedstock composition, conversion technologies, and land-use dynamics. Nevertheless, the sustainable implementation of bioenergy technologies is hampered by intricate interactions among biological feedstock characteristics, conversion process efficacy, and environmental feedback mechanisms. Fluctuations in biomass composition, particularly lignin, ash, and moisture content, significantly affect pretreatment intensity, enzymatic hydrolysis efficiency, and thermochemical conversion stability, thereby influencing overall energy outputs and economic feasibility. This review rigorously synthesises advancements documented over the past decade across four interconnected domains: (i) advancements in trait-based optimisation and genetic breeding of bioenergy feedstock; (ii) hybrid biochemical-thermochemical conversion technologies in integrated biorefineries; (iii) life-cycle and biogeochemical modelling frameworks for assessing carbon, water, and nutrient flows; and (iv) socio-economic and governance considerations affecting large-scale implementation. By integrating insights from molecular feedstock design to landscape-scale system assessment, the review delineates critical technological and environmental uncertainties that constrain scalability and shape research priorities to enhance conversion efficacy, supply-chain resilience, and life-cycle sustainability in prospective bioenergy frameworks.