Kinetics and Optimization of Catalytic Transfer Hydrogenation of WCO Using 2-Propanol as a Hydrogen Donor over NiO_x–MoO_x–CoO_x/Zeolite

Abstract

Process optimization and reaction kinetics of catalytic transfer hydrogenation (CTH) of waste cooking oil (WCO) into jet fuels using zeolite-supported Ni−Co−Mo oxides catalyst in a packed-bed reactor were studied. Experiments were conducted at three different temperatures (360, 390, and 420 °C) to determine the rate constants, the order of reaction, and the activation energy. The kinetics study showed a first-order reaction with the activation energy estimated to be 84 ± 18.7 kJ/mol WCO with 95% confidence. Design of experiment (DOE) was employed to estimate the optimum reaction parameters using the polynomial model (383.7 °C; 14.8 bar; WCO-to-2-propanol ratio = 1.57 mL/ mL; weight hourly space velocity (WHSV) = 6.7 h −1 ). Validation of the model at the optimum operating conditions generated 80% yield of liquid products with 77% alkanes, 3.8% alkenes, and 12.3% aromatics composition, and 6.7% gases, and 100% conversion of WCO. The catalyst was prepared via the wet impregnation method and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer−Emmett−Teller (BET) adsorption and desorption, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and thermogravimetric analysis (TGA). Characterization of the catalyst revealed a cubic structure, which was maintained after one cycle of CTH reaction. Present in both the fresh and the used catalysts were Na 2 O, K 2 O, MgO, Al 2 O 3 , SiO 2 , CaO, FeO, Fe 2 O 3 , which highlight the composition of zeolite. The active sites were dominated by Co 3+ , Ni 2+ , and Mo 6+ that were respectively present in the form of Co 2 O 3 , NiO, and MoO 3 .

Synthesis and Characterization of Trimetallic Fe-Co-V/Zeolite and Fe-Co-Mo/Zeolite Composite Nanostructures

“…Spectra at 2355 cm -1 could be due to the interaction between Fe-Co-Mo, Fe-Co-V ions, and TO 4 in the zeolite during the doping process. Because of weak dative covalent bonding in the V metal, this peak observed very weak in this spectrum 35,36 .…”

Hybridization of Synthetic Humins with a Metal–Organic Framework for Precious Metal Recovery and Reuse

“…Complete conversion of cinnamaldehyde to cinnamyl alcohol was achieved by the optimization of the Ag loading (2 wt %) and varying the solvent (Figure A,B). Iso-propanol was found to be the optimal solvent because of its effective hydrogen donating ability . It is noted that the Fe-BTC/humin/Ag catalyst is highly selective toward cinnamyl alcohol over the other semihydrogenation product, hydrocinnamaldehyde, or the full hydrogenation product, hydrocinnamyl alcohol (Scheme S1).…”

“…Iso-propanol was found to be the optimal solvent because of its effective hydrogen donating ability. 47 It is noted that the Fe-BTC/humin/Ag catalyst is highly selective toward cinnamyl alcohol over the other semihydrogenation product, hydrocinnamaldehyde, or the full hydrogenation product, hydrocinnamyl alcohol (Scheme S1). This is likely due to the Lewis acidic Fe 3+ sites within the MOF, which can activate the terminal CO functionality of cinnamaldehyde.…”

Recent Advances in Catalysis Based on Transition Metals Supported on Zeolites

“…Diesel-range alkanes production was performed over Ni/zeolite from different feedstock for example, Ni/Hβ used for fatty acid methyl esters ( Chen et al, 2014 ), Ni/micro-mesoporous β for methyl palmitate ( Papanikolaou et al, 2020 ), Ni/β for vegetable oil ( Wang et al, 2014 ), Ni/ZSM-5 for palmitic acid ( Ojeda et al, 2018 ) and Ni/MOR for stearic acid ( Crawford et al, 2020 ), etc. For hydrogenation of waste cooking oil into jet fuels, multicomponent Ni-contained zeolite-based materials like NiMo core-shell supported on hierarchical USY@Al-SBA-15 ( Zhang et al, 2018 ) and NiCoMo oxides supported on an A-type zeolite ( Asiedu and Kumar, 2019 ). The catalytic pyrolysis of the lipid-extracted residue of Tribonema with a maximum yield of alkylbenzene was reported over 6% NiO-2% MgO/ZSM-5 ( Ji et al, 2017 ).…”