| Summary: | In this work, the production of renewable hydrocarbons was explored by the means of waste cottonseed oil (WCSO) micropyrolysis at 500 °C. Catalytic upgrading of the pyrolysis vapors was studied using α-Al<sub>2</sub>O<sub>3</sub>, γ-Al<sub>2</sub>O<sub>3,</sub> Mo-Co/γ-Al<sub>2</sub>O<sub>3</sub>, and Mo-Ni/γ-Al<sub>2</sub>O<sub>3</sub> catalysts. The oxygen removal efficiency was much lower in non-catalytic pyrolysis (18.0%), whilst γ-Al<sub>2</sub>O<sub>3</sub> yielded a very high oxygen removal efficiency (91.8%), similar to that obtained with Mo-Co/γ-Al<sub>2</sub>O<sub>3</sub> (92.8%) and higher than that attained with Mo-Ni/γ-Al<sub>2</sub>O<sub>3</sub> (82.0%). Higher conversion yields into total renewable hydrocarbons were obtained with Mo-Co/γ-Al<sub>2</sub>O<sub>3</sub> (61.9 wt.%) in comparison to Mo-Ni/γ-Al<sub>2</sub>O<sub>3</sub> (46.6%). GC/MS analyses showed a relative chemical composition of 31.3, 86.4, and 92.6% of total renewable hydrocarbons and 58.7, 7.2, and 4.2% of oxygenated compounds for non-catalytic bio-oil (BOWCSO), BOMoNi and BOMoCo, respectively. The renewable hydrocarbons that were derived from BOMoNi and BOMoCo were mainly composed by olefins (35.3 and 33.4%), aromatics (31.4 and 28.9%), and paraffins (13.8 and 25.7%). The results revealed the catalysts’ effectiveness in FFA decarbonylation and decarboxylation, as evidenced by significant changes in the van Krevelen space, with the lowest O/C ratio values for BOMoCo and BOMoNi (O/C = 0–0.10) in relation to the BOWCSO (O/C = 0.10–0.20), and by a decrease in the presence of oxygenated compounds in the catalytic bio-oils.
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