Waste-to-hydrogen (WtH₂) hubs: integrated conversion pathways, digital architectures, and deployment frameworks for circular industrial decarbonization

This study advances the concept of waste-to-hydrogen (WtH₂) hubs as integrated industrial ecosystems that jointly address waste valorization and low-carbon hydrogen supply for hard-to-abate sectors. Conversion pathways—thermochemical, biochemical, hydrothermal, and electro/photo-assisted—are critically compared using harmonized techno-economic and life-cycle metrics to enhance cross-study consistency. Thermochemical routes show the highest readiness, achieving 40–80 g·kg⁻¹ feedstock and 3–6 USD·kg⁻¹ H₂, while biochemical and electro-assisted pathways enable superior handling of wet wastes and renewable coupling. Results reveal that feedstock logistics, purification efficiency, electricity carbon intensity, and industrial co-location outweigh pathway selection in determining viability, with life-cycle outcomes highly sensitive to grid conditions. Digital twins, model predictive control, and federated analytics emerge as pivotal for ensuring purity, flexibility, and resilience. A TRL-informed roadmap identifies thermochemical and hybrid hubs, co-located with demand and supported by robust MRV frameworks, as the most bankable near-term deployment pathway.