A green process for biodiesel and hydrogen coproduction from waste oils with a magnetic metal-organic framework derived material

Abstract

Magnetic self-assembly metal-organic frameworks (MOFs) were constructed for the co-production of biodiesel and hydrogen from waste oils. The highly active MOF nanoparticles were synthesized and catalyzed crude glycerol with 126.8% hydrogen yield in subcritical water (350 °C, 5 min). By coupling alkali with MOF-derived carriers, continuous process of fast production of biodiesel (with microwave heating at 90 °C in 15 min, 15:1 methanol/oil molar ratio and 9 wt.% catalyst dosage) and hydrogen (350 °C, 5 min) were achieved with yield of 95.3% biodiesel from waste oil (AV of 3.95 mg KOH) and 102.6% H2 from crude glycerol by-product, respectively. The nanoparticles were magnetically separated for 5 cycles with 95% biodiesel yield. Subsequently, the deactivated catalyst was used for hydrothermal gasification with 50% increasing in hydrogen yield. Characterization techniques showed active sites of MOF-derived nanoparticles were well dispersed with surface area increased by 3.9 times for highly efficient production of biodiesel and hydrogen. It revealed that MOF materials can be designed to make active catalysts and carriers for loading catalytic sites for biomass conversions to targeted biofuels.