Role of Support in Hydrotreatmentof Jatropha Oilover Sulfided NiMo Catalysts.

Hydrotreatment of jatropha oil over a series of sulfidedNiMo/SiO2–Al2O3and NiMo/ZSM-5–Al2O3catalysts in a fixed-bed reactor was carriedout. Effect of support on various reactions occurring in hydrotreatmentwas investigated. For NiMo/SiO2–Al2O3series catalysts, the rates of decarboxylation and/or decarbonylationincreased with increasing Si/(Si+Al) ratio, while the ratio of hydrodeoxygenationdecreased with increasing Si/(Si+Al) ratio. For NiMo/ZSM-5–Al2O3series catalysts, with increasing amounts ofZSM-5, the rate of decarboxylation and/or decarbonylation versus hydrodeoxygenationdid not change. These results could be attributed to the total acidicsites of catalyst having a positive effect on the decarboxylationand/or decarbonylation pathways. NiMo/SiO2–Al2O3catalysts showed a much higher isomerization/crackingratio than NiMo/ZSM-5–Al2O3catalysts.It was suggested that isomerization reaction was favorable for weakand middle acidic sites but cracking reaction was favorable for strongacidic sites. [ABSTRACT FROM AUTHOR]