Optimizing propylene production via acetone hydrodeoxygenation: Insights from catalytic studies with Cu/γ-Al2O3 and Hβ zeolite

Propylene is a crucial light olefin in the petrochemical industry and can be produced via acetone hydrodeoxygenation, which involves two sequential reactions: first, acetone undergoes hydrogenation catalyzed by metallic sites, followed by the dehydration of the resulting isopropanol catalyzed by acidic sites. In this study, propylene production through acetone hydrodeoxygenation was investigated using a physical mixture of 35 wt% Cu/γ-Al₂O₃ and Hβ zeolite to investigate how various reaction parameters affect acetone conversion and propylene yield. Using the experimental design methodology, empirical models were developed to correlate acetone conversion ($X_{\mathrm{acet}}$) and propylene yield $\left(Y_{\mathrm{prop}}\right)$ with the ratio of 35 wt% Cu/γ-Al₂O₃ to Hβ (CR), total catalyst weight (Cw), hydrogen volumetric flow rate (FH₂) and reaction temperature (T). The maximum propylene yield achieved in the catalytic tests was 73.46 %. A long-term test demonstrated the catalyst's reusability, remaining active even after 22 hours of reaction with only a slight decrease in propylene yield. Analysis of the experimental data revealed that increasing T and Cw positively affected propylene yield, whereas higher CR and FH₂ had negative effects. According to the Pareto chart, reaction temperature was the most influential variable for propylene yield, followed by CR, FH₂ and Cw. For acetone conversion, the order of significance among the variables was T > CR > Cw > FH₂.