(200c) Flare Gas – Carbon Dioxide Assisted Synergistic Biomass Reforming for Hydrogen Rich Syngas Production on Self-Regenerable Carbon Nanofiber (CNF) Supported Fe – Mo2c Catalyst

Biomass reforming for hydrogen rich syngas production was achieved through synergistic co-processing with flare gas and carbon dioxide over Fe-Mo₂C catalyst supported on carbon nanofiber (CNF). Methane – carbon dioxide activated biomass gasification can produce syngas with H₂:CO of 2 to 4 with H₂ product concentration ranging from 40 to 70 vol.%. Hydrogen rich syngas was generated over 15 cycles on Fe-Mo₂C catalyst at temperatures of 800^oC, 850^oC, and 900^oC with varying Fe loading of 0.5 to 5 wt.% and Mo₂C concentration of 4 wt.%. CNF supported catalyst subjected to multiple cycles showed excellent resistance to deactivation and was discovered to be self-regenerable. The amount of iron loading was instrumental in the nature of support synthesized from pyrolysis at 700^oC. Results showed that 0.5Fe catalyst led to synthesis of graphene supported nanoclusters of Fe and β-Mo₂C, whereas 2.5% Fe and 5% Fe loading materialized into CNF / CNT supported nanoparticles of Fe, β-Mo₂C. Conversion and gas yield nosedived to < 20% in 2 of 15 cycles on Fe-Mo₂C-CNF catalyst. These regeneration cycles possibly indicate nucleation or saturation of graphene layer synthesis or CNF growth. Nucleation of regeneration occurred mostly in cycle 2 and continued until saturated regeneration cycle varying in occurrence from subsequent cycles. Self-regeneration was the effect of free-C on the surface and complete conversion of Fe⁰ active sites to Fe₃C / Fe₃C_1.5 active sites. Once elemental Fe was converted to Fe₃C_x, free-C led to 2D graphene layer formation on 2.5% Fe and 5% Fe catalysts. On graphene supported 0.5% Fe catalysts, CNF growth was observed on Fe₃C. Mo₂C active sites were much stable and did not participate in catalyst regeneration process. Self-regeneration mechanism for the CNF supported catalyst was proposed incorporating carbon from lignin oxygenates after being hydrodeoxygenated on β-Mo₂C in the framework of original mechanism from methane reforming perspective.