Numerical and statistical determinations of the controlling factors in biomass-derived alcohol dehydration over La-incorporated γ-Al2O3 catalysts

This study aimed to develop a sustainable and renewable production process for linear α-olefins (LAOs) through the dehydration of alcohols. Lanthanum (La)-incorporated γ-Alumina (Al2O3) was selected as the catalyst, with a loading of up to 10 wt%. The addition of La modified the properties of Al2O3, including its acidity and basicity. The prepared catalysts were then used to dehydrate 1-octanol, resulting in the selective production of 1-octene due to the suppression of isomerization activity by lanthanum oxide (La2O3) species anchored on Al2O3, which caused a significant decrease in the number of strong acid sites of Al2O3. The effects of temperature and La loading on the dehydration and isomerization rates were also investigated. The results revealed that the reaction temperature had a stronger influence on the isomerization rate, while the La loading had a greater impact on the dehydration rate. The addition of 5% La to Al2O3 enabled the selective formation of 1-octene with high yield (90.9%), purity (92.3%), productivity (69.9 mmol1-octene gcat–1h−1), and moderate separation energy (317 kJ mol–1h−1) to achieve 99% 1-octene purity. At a comparable 1-octene productivity of 66–67 mmol1-octene gcat–1h−1, the addition of 5 wt% La resulted in a lower separation energy (290.3 kJ mol–1h−1) than that of Al2O3 (349.4 kJ mol–1h−1). This finding is particularly beneficial in the production of poly α-olefins that requires high purity LAOs.