Fractal-Inspired Biorefineries for Sustainable Polymer Production: A Conceptual Framework Integrating Artificial Intelligence and Industry 5.0

The transition from petroleum-derived polymers to renewable materials requires biorefineries capable of managing the compositional variability and multiscale structure of lignocellulosic biomass. This conceptual narrative review examines fractal-inspired principles—including hierarchical organization, branching, modularity, and finite-range statistical self-similarity—as a design perspective for integrated biorefineries. Deterministic mathematical fractals are distinguished from statistical fractals and hierarchical engineered systems, and methods for characterizing scale-dependent surfaces, porous catalysts, and transport networks are reviewed. The coordinated valorization of cellulose, hemicellulose, and lignin is then considered within an integrated biomass-to-chemicals framework for producing platform chemicals, functional materials, and polymer precursors. Petroleum crude-to-chemicals processing, including the S-OIL Shaheen Project, is discussed as a limited industrial benchmark for integrated fractionation, residue upgrading, and product diversification rather than as direct evidence of fractal engineering. An integrated framework is proposed in which fractal-inspired design provides the physical and organizational architecture, artificial intelligence supports characterization, prediction, optimization, and control, and Industry 5.0 provides the objectives of sustainability, resilience, and human-centered manufacturing. The framework remains conceptual. Its potential benefits must be evaluated through transport modeling, mass and energy balances, process simulation, experimental comparison, techno-economic analysis, and life-cycle assessment.