Search

In the present study, the deoxygenation of canola oil was performed in a continuous fix-bed reactor. Wormhole-like mesostructured γ-alumina with nano-sized crystalline domains and pores in the range of 8 nm was one-pot synthesized using polymeric template assisted sol-gel method via evaporation-induced self-assembly (EISA). Nanoporous catalysts were prepared by employing the incipient wetness co-impregnation method followed by a calcination step, 15 wt% MoO 3 and 3 wt% NiO or CoO, were impregnated on the nanoporous support. Both catalysts favored the hydrodeoxygenation reaction pathway, and the liquid hydrocarbons consisted mostly of C15–C18 n -alkanes. The effects of LHSV and temperature on the liquid product composition were investigated in the range of, LHSV: 1 to 3 h − 1 , and temperature of 325 to 400 °C while keeping other reaction conditions constant at a pressure of 450 psi and H 2 /oil of 600 mL mL − 1 . Slightly better catalytic activity was perceived for NiMo-S/γ-alumina at higher LHSV compared to CoMo-S γ-alumina catalyst. The liquid conversion on NiMo-S/γ-alumina is higher than that on CoMo-S/γ-alumina over the temperature range of 325 to 350 °C. At 375 °C, the conversion reached 100% over both catalysts. The production of green diesel range liquid products over NiMo-S/γ-alumina and CoMo-S/γ-alumina was found optimal at 325 °C and 1 h − 1 LHSV. [ABSTRACT FROM AUTHOR]

Red mud (RM) is a metal oxide-enriched solid waste material that was subjected to various acid treatments to assess their effect on catalytic performance for hydrodeoxygenation (HDO). Acid pretreatment induces structural changes in RM, which enhances its stability and catalytic performance for HDO. Among the different acid treatments, acetic acid-treated RM catalyst (Ni/RM-HAC) exhibited superior catalytic performance and stability, yielding 81% cetane selectivity and maintaining efficient conversion for up to 400 h. The acetic acid treatment increased the Fe 2 O 3 content in the catalyst, removed inert components such as Na 2 O and CaO that block pore channels, and greatly improved specific surface area and pore size. Moreover, the acetic acid treatment increased medium acid sites and oxygen vacancy in the catalyst, enhancing its catalytic performance. The increase of Fe3+ makes the catalyst have better stability. These results are expected to aid in the development of efficient, sustainable, and cost-effective catalysts for the production of the second-generation biodiesel. [Display omitted] • The specific surface area and total pore volume of the catalysts increased significantly after acid pretreatment. • The selectivity of RM treated with acetic acid showed high hexadecane selectivity of 81%. • Decarbonylation (DCO) and decarboxylation (DCO 2) are the major pathways at 300 °C and HDO route becomes stronger at 320 °C. • Ni/RM-HAC exhibited the best catalytic performance and sustained efficient conversion for 400 h. [ABSTRACT FROM AUTHOR]

Drop-in fuels have attracted great interest for automotive and aeronautical use. In this work, bio-hydrocarbons were obtained from palm kernel oil (palmist oil) within the distillation range of diesel and jet fuel. Green fuels were produced through the hydrodeoxygenation of palmist fat and its hydrolyzed product by using Pd/C as a catalyst. The process is efficient for hydrodeoxygenation with conversions of up to 96% after 5 h of reaction, at 10 bar of H 2 pressure and 300 °C, which are mild conditions compared with the majority of the processes described in the literature. The hydroprocessing products were analyzed by infrared spectroscopy, thermal analysis and gas chromatography–mass spectrometry. The freezing temperatures of the biofuels were determined by DSC. Up to 5% deoxygenation products can be used in commercial jet fuel without compromising the cold fuel properties. [ABSTRACT FROM AUTHOR]

This paper demonstrates the initiated use of relevant refining palm oil for bio-hydrogenated diesel production. The conversions of crude palm oil (CPO) and its physical refining including degummed palm oil (DPO) and palm fatty acid distillate (PFAD) to diesel fuel by hydroprocessing were studied. The effects of operating parameters (i.e. reaction time, operating temperature, and pressure) and catalyst (i.e. Pd/C and NiMo/γ-Al2O3) were examined in order to determine suitable operating condition for each feedstock. It was found that the hydroprocessing of CPO with Pd/C catalyst at 400°C, 40bar, and reaction time of 3h provides the highest diesel yield of 51%. When gum which contains phospholipid compounds is removed from CPO, namely DPO, the highest diesel yield of 70% can be obtained at a shorter reaction time (1h). In the case of PFAD, which consists mainly of free fatty acids, a maximum diesel yield of 81% could be observed at milder conditions (375°C with the reaction time of 0.5h). The main liquid products are n-pentadecane and n-heptadecane, having one carbon atom shorter than the corresponding fatty acids according to decarboxylation/decarbonylation pathways. Pd/C catalyst shows good catalytic activity for fatty acid feedstocks but becomes less promising for triglyceride feedstocks when compared to NiMo/γ-Al2O3. [ABSTRACT FROM AUTHOR]

Abstract: In order to obtain a fuel with properties similar to diesel, the thermal catalytic cracking (TCC) of buriti oil was accomplished over LaSBA-15 mesoporous materials. In function of the Lewis acid sites and the unidirectional pore system of the LaSBA-15, this material presented good deoxygenating activity for TCC of the oil, resulting in a reduction of the oxygenate content in the organic liquid (OL) collected above 190°C, obtaining as main product, a mixture of hydrocarbons similar to mineral diesel, called green diesel. [Copyright &y& Elsevier]

The promoting action of W in the Ni-Al 2 O 3 co-precipitated catalysts with high nickel loading (31–46 wt% Ni) has been investigated in the selective deoxygenation of sunflower oil and waste cooking oil towards green diesel production. A WNi-Al 2 O 3 catalyst containing 8 wt% W and 35 wt% Ni (Ni Ni + W = 0.9 atomic ratio) proven the most efficient. The detailed characterization of the catalysts allowed an insight concerning the tungsten promoting action. It was attributed to the increase in the catalyst specific surface area and metallic nickel surface area, the acidity regulation, the decrease of the amount of catalytically inactive nickel aluminate formed and to the participation of W5+-oxo species via their defect oxygen sites in the selective deoxygenation network. The optimum reduction – activation temperature was found at 500 °C, where a good compromise between the increase of metallic Ni relative amount, the decrease of the specific surface area and the increase of Ni mean crystal size is achieved. Addition of W to highly loaded Ni-Al 2 O 3 co-precipitated catalyst (best Ni Ni + W atomic ratio equal to 0.9) improves drastically its ability to convert vegetable oils to renewable diesel (n-alkanes). [Display omitted] • Co-precipitation results to WNi-Al 2 O 3 catalysts with high SSA BET and [Ni + W] loading. • W promote Ni-Al 2 O 3 catalysts for the transformation of triglycerides to green diesel. • Catalyst activation at 500 °C maximizes the catalyst performance. • The most efficient catalyst has Ni Ni + W atomic ratio equal to 0.9. • W does not change the selective deoxygenation network established for Ni catalysts. [ABSTRACT FROM AUTHOR]

The present work investigated the production of Green Diesel through the deoxygenation of palm oil over Ni catalysts supported on γ-Αl 2 O 3 , ZrO 2 and SiO 2 for a continuous flow fixed bed reactor. A comprehensive experimental study was carried out in order to examine the effects of temperature, pressure, LHSV and H 2 /oil feed ratio on catalytic activity during short (6 h) and long (20 h) time-on-stream experiments. The catalysts were prepared through the wet impregnation method (8 wt% Ni) and were extensively characterized by N 2 adsorption/desorption, XRD, NH 3 -TPD, CO 2 -TPD, H 2 -TPD, H 2 -TPR, XPS, TEM/HR-TEM and Raman. The characterization of the materials prior to reaction revealed that although relatively small Ni nanoparticles were achieved for all catalysts (4.3 ± 1.6 nm, 6.1 ± 1.8 nm and 6.0 ± 1.8 nm for the Ni/Al 2 O 3 , Ni/ZrO 2 and Ni/SiO 2 catalysts, respectively), NiO was better dispersed on the Ni/ZrO 2 catalyst, while the opposite was true for the Ni/SiO 2 sample. In the case of Ni/Al 2 O 3 , part of Ni could not participate in the reaction due to its entrapment in the NiAl 2 O 4 spinel phase. Regarding performance, although an increase in H 2 pressure led to increases in paraffin conversion, the increase of temperature was beneficial only up to a critical value which differed for each catalytic system under consideration (375 °C, 300 °C and 350 °C for the Ni/Al 2 O 3 , Ni/ZrO 2 and Ni/SiO 2 catalysts, respectively). All catalysts favored the deCO 2 and deCO deoxygenation paths much more extensively than HDO, irrespective of testing conditions. Time-on-stream experiments showed that all catalysts deactivated after about 6 h, which was attributed to the sintering of the Ni particles and/or their covering by a thin graphitic carbon shell. • An increase of temperature benefits the overall reaction only up to a critical value. • The optimum reaction temperature differs between catalytic systems. • The catalysts tested herein promote mainly the deCO 2 and deCO deoxygenation paths. • All catalysts suffered varying degrees of sintering during reaction. • The carbon formed on to the spent catalyst surface was a very thin graphitic shell. [ABSTRACT FROM AUTHOR]

Palm oil is largely produced in Thailand and sufficient to utilize as a biofuel feedstock through hydrodeoxygenation (HDO). In this work a new bifunctional catalyst consisting of nickel phosphide supported on zeolite mordenite in sodium form (Ni-P/NaMOR) was prepared by sequential impregnation and characterized extensively by several techniques to understand the reduction behavior, phases and distribution of nickel phosphides on the support. Nickel and phosphate precursors were transformed to Ni 2 P 2 O 7 species by calcination and to a mixed phase between Ni 12 P 5 and Ni 2 P by reduction. The phosphide species distributed in the zeolite cavities and external surface. The HDO of palm oil was tested in a down-flow stainless steel trickle bed reactor and the atmosphere was hydrogen. The mixed phase of nickel phosphides enhanced the HDO reaction. When tested by various temperatures and pressures, the optimum condition in this work was at 425 °C and 50 bar in which a complete of palm oil conversion, the largest HDO yield and selectivity toward C 15 -C 18 alkanes were obtained. The green diesel and HDO yields from reduced Ni-P/NaMOR were larger than those from pure Ni 2 P and mixed Ni 2 P-Ni 12 P 5. Interestingly, a small amount of isoparaffins was also observed likely due to the contribution of NaMOR support. Unlabelled Image • Nickel phosphide on NaMOR was tested in hydrodeoxygenation (HDO) of palm oil. • The catalyst contained a mixed phase between Ni 12 P 5 and Ni 2 P with bifunctionality. • The mixed phosphide phase gave high yield and selectivity toward C 15 -C 18 alkanes. • The NaMOR support contributed a formation of isoparaffins. • The optimum condition to yield the largest HDO was at 425 °C and 50 bar. [ABSTRACT FROM AUTHOR]