Unlocking glycerol Potential: Novel pathway for hydrogen production and Value-Added chemicals

• Hydrogen and high-value compounds production from glycerol and sodium metaborate. • Alternating feed of reagent in in consecutive steps in batch reactor at 300 °C. • Gas stream of 38–60% hydrogen, biogenic CO 2 (31–54%) and CO (4–13%) and CH 4 traces. • Aliphatic hydrocarbon resin with oxygenated carbon and aromatic cluster production. • C5-C6 cyclo -oxygenate selectivity varies between 40–60% based on biobased feedstock. In the global fight against climate change, the bio-based supply chain represents an interesting solution as it offers the potential to produce high-value-added products and bioenergy through the utilization of waste and by-products. In this work, a new route is proposed for the conversion of bio-based glycerol to H 2 /CO 2 and high value-added liquid and solid products. The innovative process used pure or crude glycerol or ethanol-glycerol mixture along with water and sodium metaborate as reagents at 300 °C under discontinuous conditions. The gas stream consists mainly of hydrogen, followed by biogenic CO 2 (31–54 %), CO (4–13 %) and CH 4 in traces. The presence of water in the tested crude glycerol improved the hydrogen selectivity to 55 %. Characterization of the liquid reaction products revealed the synthesis of products such as 1,2-propanediol, propanoic acid, acetic acid, cyclopentenones and cyclic diglycerol. In the solid phase, an aliphatic hydrocarbon resin with oxygenated carbon along the saturated chain and an aromatic cluster were also characterized by NMR, FTIR and TG analyses. Based on these findings, the global reaction route to the general reaction products was proposed.