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Catalytic thermochemical conversion offers a sustainable method to upgrade oil‐based feedstocks into highly valuable biofuel, aligning with the modern biorefinery concept. Herein, a series of IrRe/SAPO‐11 catalysts with different Ir to Re molar ratios compared to reference Ir/SAPO‐11 and Re/SAPO‐11 catalysts was prepared using a wetness impregnation method. These catalysts were used for the direct production of sustainable aviation fuels (SAFs) via efficient hydrodeoxygenation and hydroisomerization of triglycerides. The catalyst screening confirmed that the optimum IrRe/SAPO‐11 catalyst, with an equivalent Ir to Re molar ratio, exhibited the highest hydrodeoxygenation activity under milder operation conditions than the conditions used in previous studies. Increasing the reaction temperature up to 330 °C enhanced the formation of iso‐alkanes in the liquid product, achieving a freezing point of −31.4 °C without additional cold flow improvers. Furthermore, a long‐term stability experiment demonstrated that the developed Ir−Re system exhibited exceptional performance over 150 h. This excellent catalytic activity and stability of the bifunctional IrRe/SAPO‐11 catalyst was owing to its suitable interface between metallic and oxide sites, mixed mesoporous structures, reduced catalyst size, and increased Lewis acid ratio, as confirmed by our comprehensive characterizations. [ABSTRACT FROM AUTHOR]

The novel bifunctional Ni−Re supported on bimodal SAPO‐11 catalyst was designed for an economically combined process of direct triglycerides hydro‐deoxygenation and isomerization into low‐cold flow diesel. The catalyst with a Ni to Re molar ratio of 1 : 0.12 exhibited superior performance for diesel production containing large fraction of iso‐alkanes in comparison to Ni and Re benchmarks. Comprehensive characterizations revealed that the detection of Ni and Re co‐existed with NiO and ReOx on SAPO‐11 after the reduction confirmed by XRD, XANES, and XPS analysis gave a large distribution of Lewis acid sites (>80 %) noticed by Pyridine‐DRIFTS measurement. Under investigations of WHSV, reaction temperature, and H2 pressure, the NiRe0.12 catalyst contributed a nearly theoretical 77.1 % liquid yield, accompanied by a 18.2 % jet‐range and 52.1 % diesel‐range yields with a classification for 46.8 % iso‐alkanes and 23.5 % normal alkanes yields; whereas, the cold‐flow properties of liquid product were in the ranges of winter diesel standard. It was remarkably noticed that the combination effects of Ni and nanosized Re species substantially improved the diesel production comprising iso‐alkanes components with proper catalyst lifetime and low carbon deposition attributing to the fabricated active metal species on bimodal SAPO‐11 features with large distribution of Lewis acidic sites. [ABSTRACT FROM AUTHOR]

Keywords: Hydrodeoxygenation; Isomerization; NiRe catalyst; Palm oil; Synthetic diesel EN Hydrodeoxygenation Isomerization NiRe catalyst Palm oil Synthetic diesel 1 1 1 10/12/23 20231006 NES 231006 B The Front Cover b illustrates an artwork design for showcasing the developed bifunctional NiRe/SAPO-11 catalyst along with "KHON", the masked dance drama in Thailand. Hydrodeoxygenation, Isomerization, NiRe catalyst, Palm oil, Synthetic diesel Front Cover: Enhancing the Hydrodeoxygenation and Isomerization using Re Nanoparticles Decorated on Ni/SAPO-11 Catalysts for Direct Production of Low-Cold Flow Diesel from Triglycerides (ChemCatChem 19/2023). [Extracted from the article]

In the current study, palm kernel oil was used as a renewable feedstock for production of jet fuel-like hydrocarbons via the deoxygenation over the Ni-MoS 2 /γ-Al 2 O 3 catalyst. The dominant C12 fatty acid content in palm kernel oil makes it promising for jet fuel application. Synthesized by a liquid processing method with thiourea organosulfur agent, the catalyst revealed MoS 2 structure with low stacking, while Ni substitution in the MoS 2 structure and interaction with the Al 2 O 3 support were determined based on the Ni K-edge XANES and EXAFS results. A high hydrodeoxygenation (HDO) activity, which as the major pathway in the deoxygenation, was observed upon application of a H 2 pressure of 30–50 bar over Ni-MoS 2 /γ-Al 2 O 3 . The optimum product yield of approximately 92% was obtained mainly from the HDO pathway (∼60%) with 58% selectivity to C10–C12 jet fuel hydrocarbons. The flow property of the jet fuel-like hydrocarbons was more desirable than those obtained from palm olein oil-derived fuel. [ABSTRACT FROM AUTHOR]

Diesel-like alkanes, so-called green diesel, produced from vegetable oil, have emerged as an important biofuel to replace petroleum diesel. In the present work, the deoxygenation of palm oil to green diesel was performed in a trickle-bed reactor over four γ-Al 2 O 3 -supported monometallic catalysts (Co, Ni, Pd, and Pt). The catalysts with various metal loadings (2–10 wt.%) were prepared by the incipient wetness impregnation method and were characterized by XRD, TPR, N 2 sorption, TEM, and CO pulse chemisorption. The results revealed that metallic sites of the catalysts were formed after pre-reduction in H 2 with differences in metal particle size and metal dispersion on γ-Al 2 O 3 . The reaction tests revealed that the catalytic activity was in the order of Co > Pd > Pt > Ni, whereas the turnover frequency (TOF) increased with increments of the metal particle size. The decarbonylation reaction was more dominant than the hydrodeoxygenation reaction when the reaction was catalyzed by Ni, Pd, and Pt catalysts. Meanwhile, the contribution of decarbonylation and/or decarboxylation was nearly comparable to that of the hydrodeoxygenation reaction over Co catalyst. By combining the reaction tests with a model compound, oleic acid, a reaction network for the deoxygenation of palm oil was suggested and discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Catalytic hydrotreating of palm oil to bio-hydrogenated diesel over NiMoS2/Al2O3. [•] Optimized reaction conditions (temperature, pressure, LHSV, and H2/oil ratio). [•] Three major pathways of hydrodeoxygenation, decarboxylation and decarbonylation. [•] Major contribution of 65–80% from hydrodeoxygenation. [•] Isomerization and cracking as minor pathways above 360°C. [ABSTRACT FROM AUTHOR]