Sustainable production of aromatics-rich gasoline stock from bio-glycerol over hierarchically porous Zn-decorated HZSM-5 catalyst

In the present study, we report an efficient vapor-phase catalytic process operating on a hierarchically porous non-noble metal decorated HZSM-5 catalyst to produce high octane aromatics-rich hydrocarbon-stock and valuable fuel gases from crude-glycerol in the presence of methanol. A novel hierarchically porous HZSM-5 catalyst (synthesized by 0.2 M alkali solution followed by 1 wt% Zn loading) exhibited 100% carbon conversion of glycerol-methanol with superior aromatics selectivity >80% with a prolonged catalyst lifetime. Here, the combination of well-preserved micropores and optimum Lewis acidity observed in the synthesized catalyst are collectively responsible for enhanced aromatics selectivity, while mesopores of the catalyst help in the ease of diffusion of bulky product molecules (including coke precursor) to facilitate improved catalyst lifetime. The liquid stock possessing aromatics-rich hydrocarbons with high octane rating (RON 92) is suitable for gasoline blending applications. The C-3-C-4 and H-2 gases formed as byproducts also attract LPG and green fuel applications. Overall study indicates that the co-processing of glycerol with methanol facilitated higher carbon atomic efficiency for the production of gasoline stocks. The reaction environment with a higher H/C-eff also contributed to the improved product quality and catalyst life that attracts sustainable features of the process.

Automated summary

In this study, an efficient catalytic process using a non-noble metal decorated hierarchical porous catalyst is used to produce high octane aromatics-rich hydrocarbon-stock and valuable fuel gases from crude glycerol in the presence of methanol. The synthesized catalyst showed excellent aromatics selectivity and prolonged catalyst lifetime, making it suitable for gasoline blending and green fuel applications.