Sustainable synergy: unleashing the potential of biomass in integrated biorefineries

To keep the engine of humanity running, dependence on fossil resources must be curbed due to potent environmental impacts underlying anthropocene. The paradigm shift towards an integration of bioeconomy with circular economy (IBECE) necessitates advancements in integrated biorefineries (IBRs) for sustainable biomass valorization, with IBRs being a key player. IBRs do not only yield environmental gains, but also address techno-economic and social benefits, contributing to global sustainability targets. Hence, to shed more light on the subject, this review underscores the pressing need for IBR potentials to overcome existing barriers and harness the full potential of biorefineries within the global sustainability framework. Further, it critically assesses the role of IBR in facilitating the transition towards IBECE, with a focus on biofuel product diversification and sustainable resources' use. Moreover, it discusses different generations of biorefinery, elaborating on their features and potential. Various biomass feedstocks, with a focus on lignocellulosic and algal sources, are explored along with conversion processes, their limitations, and prospects. In addition, IBR's significance in waste mitigation, integration schemes, and potential for industrial symbiosis are highlighted by clarifying how integrated processes enhance efficiency and performance compared to traditional methods. Subsequently, challenges and future directions are discussed. The review offers strategic recommendations to guide future research, aiming to close empirical gaps and advance the progress of a robust IBECE.