Catalytic activity of trimetallic sulfided Re-Ni-Mo/γ-Al2O3 toward deoxygenation of palm feedstocks

Abstract

Catalytic activities of trimetallic ReNiMo sulfide supported on γ-Al2O3 toward the deoxygenation of oleic acid, palm fatty acid distillate (PFAD), refined palm stearin (RPS) and refined palm olein (RPO) were studied. Relevant monometallic and bimetallic (i.e. Mo-, W-, Re-, ReMo-, ReW-, NiMo-) sulfides were also tested for comparison. Experiments revealed that, among all catalysts, ReNiMo sulfide catalyst exhibited the highest diesel yield of 76.5% from oleic acid, 72.5% from PFAD, 69.7% from RPS and 69.5% from RPO. Furthermore, the catalyst could maintain constant diesel yield level for at least six consecutive runs, whereas significant deactivation was observed from other catalysts due to high carbon deposition. Importantly, glycerol was also successfully employed as a hydrogen donor for deoxygenation reaction over this catalyst. From the catalyst characterizations, additional of Re increased the NiMo surface area by 20.4%, furthermore, it reduced the metal particle size and promote the metal dispersion on the support.