Selective Production of Bio-Based Linear Alpha-Olefin from Wasted Fatty Alcohol on Al₂O₃ for Bio-Based Chemicals

The catalytic dehydration of a bio-based fatty alcohol was performed using Al₂O₃ prepared by solvothermal synthesis for selective production of long-chain linear-alpha-olefins (LAO). The effect of the synthesis temperature of alumina precursors on the dehydration of 1-octadecanol (C₁₈H₃₈O) was examined based on the textural properties and Lewis acid-base properties of the catalysts. Amorphous alumina synthesized at 325 °C showed the highest surface area (233.07 m²/g) and total pore volume (1.237 cm³/g) among the catalysts and the best dehydration results: 93% conversion, 62% selectivity of 1-octadecene (C₁₈H₃₆), and 89% LAO purity. This was attributed to the increased Al/O ratio and atomic concentration of surface O in alumina, which were important factors in the catalytic dehydration of 1-octadecanol through the synergistic catalysis of acid-base pairs. The produced bio-based LAO can be key intermediates for synthesis of oxo alcohols and poly-alpha-olefins, as alternatives to petroleum-based LAO to achieve carbon neutrality in chemical industry.