A Clean Hydroprocessing of Jatropha Oil into Biofuels over a High Performance Ni-HPW/CNT Catalyst

Abstract

The nickel (Ni) and phosphotungstic acid (HPW) supported on carbon nanotubes (CNT) were prepared by impregnation method for hydroprocessing of Jatropha oil. The Ni-HPW/CNT catalyst was characterized by XRD, XPS, FT-IR, N2 adsorption-desorption, SEM, NH3-TPD, and TGA. The effects of reaction parameters, such as reaction temperature (280–400[Formula: see text]C), time-on-stream (0–100[Formula: see text]h), types of support, the amount of added HPW, and coking deposition were investigated. The cracking performance was evaluated by gas chromatography (GC). The yield of C15–C18 alkanes was 88.5[Formula: see text]wt.%, Iso/n ratio was 0.8 and conversion was 97.7% at 320[Formula: see text]C, 3.0[Formula: see text]MPa and 1.0/h over the Ni-HPW/CNT catalyst, while the yield of [Formula: see text] alkanes reached 51.9[Formula: see text]wt.% at 400[Formula: see text]C. The distribution of products could be adjusted by reaction temperature. The cracking performance was elevated by the addition of HPW and the electrical conductivity. The C15–C18 alkanes were further cracked through two cracking circulations. Meanwhile, the catalyst was used without sulfurization and the cracking process was green.

Indigenous Materials as Catalyst Supports for Renewable Diesel Production in Malaysia

“…The introduction of another metal catalyst enhanced the homogeneity morphology and formation of small metal particles on the surface of MWCNTs, but at the expense of metal particles embedded inside the support as the actual amount of metal, particle traces were lower than the theoretical amount [137]. Similar results were observed for the EDAX mapping of Ni-HPW/MWCNT at various loading of HPW, as the experimental value of chemical element contents was lower than the theoretical values although they were homogeneously dispersed on MWCNT [138]. However, the metal loading of a particular metal type influences the degree of deoxygenation.…”

“…The study of Asikin-Mijan et al has concluded that the high dosages of Fe and Zn (in NiO-Fe 2 O 3 and NiO-ZnO catalysts) contribute to inefficient deoxygenation, as the enhancement of n-(C 15 +C 17 ) selectivity was observed in low metal loading with a large density of weak and medium acidic sites along with strong basic sites [139]. As from the study by Yang et al, the higher loading of HPW (i.e., 50 wt% and 60 wt%) led to lower total pore volume, specific surface area, and pore diameter as compared to low loading of HPW as the pores of support were clogged by excessive catalyst content [138].…”

“…It was noticeable that the common metal type used to mix with other metal catalysts is Ni, exhibiting good catalyst activity to produce high quality renewable diesel. The highest conversion of 97.7% was reported by Yang et al, with a total of 51.9 wt% for the yield of <C 15 alkenes to process jatropha oil via hydroprocessing using 40 wt% of HPW in Ni-HPW as catalyst [138]. The processing of jatropha oil using 20 wt% NiO-5 wt% Fe 2 O 3 also led to a favorable conversion of hydrocarbon, yielding 89% hydrocarbon with a selectivity of 79% n-(C 15 +C 17 ).…”