Screening of transition metal/oxide-impregnated ZSM-5 catalysts for deoxygenation of biomass oxygenates via direct methane intervention

ABSTRACT

Removal of oxygen from biomass (deoxygenation) is a significant challenge that needs to be overcome to effectively produce hydrocarbon-based biofuel. The present technology needs extraneous hydrogen (H₂) to act as a proton donor, to effectively remove this oxygen. This work is geared toward finding an effective catalyst that accommodates the direct use of methane, instead of H₂, for deoxygenation reactions. Here, we studied the impact of three oxides (Ga₂O₃, MoO₃, Cr₂O₃) and two metals (Pt, Ni) impregnated (at 1, 2 and 5% loadings) on ZSM-5 support on furan conversion, benzene-toluene-ethylbenzene-xylenes (BTEX) selectivity, and coke formation when furan was catalytically pyrolyzed in methane and methane-free environments. The results indicate that Ga-, Pt- and Ni-based catalysts increase BTEX selectivity in a methane environment as opposed to methane-free conditions. The type of metal and the amount of loading had a significant impact on furan conversion as well. Ga/ZSM-5-based catalyst displayed the highest BTEX selectivity, while Ni/ZSM-5 resulted in the highest furan conversion. The results are significant since there is strong evidence of select catalysts’ ability to activate methane and in turn allow furan deoxygenation. This work paves the way to use methane (or natural gas) instead of H₂ as a direct proton donor for deoxygenation reactions.

KEYWORDS:

• Biomass oxygenates
• catalyst
• transition metal
• metal impregnation
• deoxygenation

Acknowledgements

This material is based upon work supported by the National Science Foundation under Grant No. CBET 0965772.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Directorate for Engineering. This material is based upon work supported by the National Science Foundation under Grant No. CBET 0965772.