Carbon-negative valorization of biomass waste into affordable green hydrogen and battery anodes.

The global Sustainable Development Goals highlight the necessity for affordable and clean energy, designated as SDG7. A sustainable and feasible biorefinery concept is proposed for the carbon-negative utilization of biomass waste for affordable H 2 and battery anode material production. Specifically, an innovative tandem biocarbon + NiAlO + biocarbon catalyst strategy is constructed to realize a complete reforming of biomass pyro-vapors into H 2 +CO (as a mixture). The solid residues from pyrolysis are upgraded into high-quality hard carbon (HCs), demonstrating potential as sodium ion battery (SIBs) anodes. The product, HC-1600-6h, exhibited great electrochemical performance when employed as (SIBs) anodes (full cell: 263 Wh/kg with ICE of 89%). Ultimately, a comprehensive process is designed, simulated, and evaluated. The process yields 75 kg H 2 , 169 kg HCs, and 891 kg captured CO 2 per ton of biomass achieving approx. 100% carbon and hydrogen utilization efficiencies. A life cycle assessment estimates a biomass valorization process with negative-emissions (−0.81 kg CO 2 /kg-biomass, reliant on Sweden wind electricity). A techno-economic assessment forecasts a notably profitable process capable of co-producing affordable H 2 and hard carbon battery anodes. The payback period of the process is projected to fall within two years, assuming reference prices of 13.7 €/kg for HCs and 5 €/kg for H 2. The process contributes to a novel business paradigm for sustainable and commercially viable biorefinery process, achieving carbon-negative valorization of biomass waste into affordable energy and materials. [Display omitted] • Fully valorization of biomass into hydrogen, battery anodes, and negative emission. • Tandem biocarbon + NiAlO + biocarbon catalyst reform pyro-vapors into H 2 -rich syngas. • High-performance SIB anodes with 263 Wh/kg of capacity and 89% of ICE. • A sustainable and profitable biorefinery realizing payback period within two years. [ABSTRACT FROM AUTHOR]