Catalytic Hydrotreating of Crude <i>Pongamia pinnata</i> Oil to Bio-Hydrogenated Diesel over Sulfided NiMo Catalyst

oleh: Yuwadee Plaola, Wanwipa Leangsiri, Kanokthip Pongsiriyakul, Worapon Kiatkittipong, Atthapon Srifa, Jun Wei Lim, Prasert Reubroycharoen, Kunlanan Kiatkittipong, Apiluck Eiad-ua, Suttichai Assabumrungrat

Format: Article
Diterbitkan: MDPI AG 2022-02-01

Deskripsi

This work studied the catalytic activity and stability of Ni-MoS<sub>2</sub> supported on γ-Al<sub>2</sub>O<sub>3</sub>, SiO<sub>2</sub>, and TiO<sub>2</sub> toward deoxygenation of different feedstocks, i.e., crude <i>Pongamia pinnata</i> oil (PPO) and refined palm olein (RPO). PPO was used as a renewable feedstock for bio-hydrogenated diesel production via catalytic hydrotreating under a temperature of 330 °C, H<sub>2</sub> pressure of 50 bar, WHSV of 1.5 h<sup>−1</sup>, and H<sub>2</sub>/oil (v/v) of 1000 cm<sup>3</sup>/cm<sup>3</sup> under continuous operation. The oil yield from a Soxhlet extraction of PPO was up to 26 wt.% on a dry basis, mainly consisting of C18 fatty acids. The catalytic activity in terms of conversion and diesel yield was in the same trend as increasing in the order of NiMo/γ-Al<sub>2</sub>O<sub>3</sub> > NiMo/TiO<sub>2</sub> > NiMo/SiO<sub>2</sub>. The hydrodeoxygenation (HDO) activity was more favorable over the sulfided NiMo supported on γ-Al<sub>2</sub>O<sub>3</sub> and TiO<sub>2</sub>, while a high DCO was observed over the sulfided NiMo/SiO<sub>2</sub> catalyst, which related to the properties of the support material and the intensity of metal–support interaction. The deactivation of NiMo/SiO<sub>2</sub> and NiMo/TiO<sub>2</sub> occurred in a short period, due to the phosphorus and alkali impurities in PPO which were not found in the case of RPO. NiMo/γ-Al<sub>2</sub>O<sub>3</sub> exhibited the high resistance of impure feedstock with excellent stability. This indicates that the catalytic performance is influenced by the purity of the feedstock as well as the characteristics of the catalysts.