Hydrodeoxygenation Of Vegetable Oils Research Articles

Hydrodeoxygenation of vegetable oil over the Pt/WOx-Al2O3 catalyst

Hydrodeoxygenation of vegetable oil over the Pt/WOx-Al2O3 catalyst

Nickel/Biochar from Palm Leaves Waste as Selective Catalyst for Producing Green Diesel by Hydrodeoxygenation of Vegetable Oil

The objective of this research was to prepare low-cost catalyst for green diesel conversion from vegetable oil. The catalyst of nickel-dispersed biochar (Ni/BC) was prepared by direct pyrolysis of nickel precursor with palm leaves waste under N2 stream at 500 °C. The obtained catalyst was examined by using x-ray diffraction, scanning electron microscope-energy dispersive x-ray, transmission electron microscopy, gas sorption analysis, FTIR and surface acidity examination. The catalytic activity testing was performed on rice bran oil hydrodeoxygenation at varied temperature and time of reaction. Based on analyses, the results showed the successful preparation of Ni/BC with the characteristic of single nickel nanoparticles decorated on surface. The increasing specific surface area of material was conclusively remarked the surface area enhancement by nickel dispersion along with the increased surface acidity, suggesting that the material can be applied for acid catalysis applications. The Ni/BC exhibited excellent catalytic conversion of rice bran oil with the high selectivity toward diesel fraction with 85.3% yield and 92.6% selectivity. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Chemical-switching strategy for the production of green biofuel on NiCo/MCM-41 catalysts by tuning atmosphere

NiCo bimetallic catalyst was one of potential candidates used toward the hydrodeoxygenation of vegetable oils. However, there is still lack for digging out the relationship between micro-structure pretreated by various atmosphere and its catalytic performance. To hunting the relationship, NiCo/MCM-41 precursor was synthesized via the conventional co-impregnation method, and further pretreated by different atmospheres, including NH3, CH4/H2 and H2 in order to tune the particle size, active component dispersion, and acid properties of the catalysts. NiCo/MCM-41-H pretreated by H2 exhibits superior catalytic performance (65.8 wt% biofuel yield and 98.2% C12-C18 alkanes selectivity) on converting jatropha oil than that by NH3 and by CH4/H2. For comparison, the NiCo/MCM-41-H shows the smallest NiCo alloy grains, the smallest amount of strong acid, the lowest Brønsted acid/Lewis acid ratio, and the most uniform dispersion of Ni and Co. All the distinct surface properties of NiCo/MCM-41-H reasonably account for high efficiency in hydrodeoxygenation of jatropha oil. The work reveals the relationship between NiCo bimetallic catalyst structure and its hydrodeoxygenation performance, and provides a robust pretreatment method for tuning the surface properties to improve its catalytic performance for converting biomass oils into green biofuel.

Superior Long-Term Stability of a Mesoporous Alumina-Supported Pt Catalyst in the Hydrodeoxygenation of Palm Oil

Catalyst stability in the hydrodeoxygenation of vegetable oils is one of the big challenges for practical production of bio-jet fuel. Particularly, supported Pt catalysts are known to show activity...

The deactivation of acidic sites of NiMo/B2 O3 -Al2 O3 catalysts during vegetable oil hydrodeoxygenation studied by EPR spectroscopy.

This paper presents the study results of NiMo/B2 O3 -Al2 O3 (0-30% wt. of B2 O3 ) catalysts for vegetable oil hydrodeoxygenation before and after catalytic tests by different electron paramagnetic resonance (EPR) methodologies. For the initial catalysts, the concentration of Brønsted acidic sites (BAS) determined by probe EPR with perylene increases linearly with an increase in the modifier (B2 O3 ) content in the samples. It was found that the isomerization activity of the catalysts increases with increasing the concentration of determined BAS. As for the spent catalysts, linear correlation of paramagnetic species concentration with the content of carbon deposits (determined by thermogravimetric analysis [TGA]/differential thermal analysis [DTA]) was found. The main reasons for the NiMo/B2 O3 -Al2 O3 catalysts deactivation over the formation of carbon deposits related to the participation of acidic sites (both Lewis and Brønsted) in the polycondensation of hydrocarbons via radical species are also proposed.

Hydrodeoxygenation of Vegetable Oil in a Trickle Bed Reactor for Renewable Diesel Production

Hydrodeoxygenation of Vegetable Oil in a Trickle Bed Reactor for Renewable Diesel Production

Hydrodeoxygenation of vegetable oil in batch reactor: Experimental considerations

The generation of reliable experimental data in any experimental scale requires proper procedures not only for the reaction step but also for the feed preparation, separation, and characterization of products as well as calculations of conversion and product yields. Batch reactor is the most used experimental setup for carrying out exploratory studies for catalyst screening and development. This work is focused on describing and discussing a step-by-step methodology for conducting experiments for catalytic hydrotreating of vegetable oils in batch reactor. The proposed methodology considers literature and own experiences on advantages and disadvantages of different feed types, catalysts, experimental setup and procedures, effect of reaction parameters, separation and characterization of products, and calculations.

Hydrodeoxygenation of vegetable oils over biochar supported bimetallic carbides for producing renewable diesel under mild conditions

Conversion and product selectivity of canola oil HDO over various metal carbides under mild condition, T = 250 °C, p = 450 psig, WHSV = 5 h−1, TOS = 2–3 h.

Kinetics of the Hydrodeoxygenation of Ethyl Ester of Decanoic Acid over the Ni–Cu–Mo/Al2O3 Catalyst

The use of nickel-based catalysts in the hydrodeoxygenation of vegetable oils is an alternative to employing systems based on noble metals and sulfided hydrotreatment catalysts. Modifying nickel hydrodeoxygenation catalysts with molybdenum and copper increases the yield of target reaction products and the resistance of catalytic systems to the effect of an aggressive medium. The aim of this work is to determine the dependence between the temperature, contact time, and activity of modified nickel-containing catalyst in the hydrodeoxygenation of esters of fatty carboxylic acids and determine the effective kinetic parameters for the consumption of the reagent. The experiments are performed in a continuous flow reactor with a fixed catalyst bed at $${{P}_{{{{{\text{H}}}_{2}}}}}$$ = 0.25 MPa, temperatures of 270, 285, 300, and 315°C, and a contact time varying from 600 to 1800 s. The results show the selectivity toward the main reaction products (nonane and decane) remains the same when either the temperature of experiment or the contact time are varied. Experimental data are used to determine the effective rate constant and energy of activation of ester consumption.

Transformation of Jatropha Oil into High-Quality Biofuel over Ni-W Bimetallic Catalysts.

The production of fuel from the hydrodeoxygenation of vegetable oils has been extensively investigated on account of the decline of petroleum-based fuels and increase of ecological problems. The conversion of jatropha oil over Al-MCM-41-supported Ni, W, and Ni–W catalysts was studied at 3 MPa and 360 °C. Over the monometallic Ni and W catalysts, the biofuel yield was low, about 19.3 and 12.5 wt %, respectively, whereas the highest biofuel yield reached 63.5 wt % over the Ni–W bimetallic catalysts. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and high-resolution TEM results suggested that the proper amount of Ni and W would form a Ni17W3 active phase, the particle size of which varied with the content of Ni and W or preparation methods. The crystalline Ni17W3 phase formed when the content of both Ni and W reached 10%. With further increase of the content of W or Ni to 15%, the crystal size of Ni17W3 grew from 7 to 14 nm or to 20 nm, whereas the biofuel yield decreased with the increase of the Ni17W3 crystal size. The 10Ni–10W/Al-MCM-41 catalyst with the Ni17W3 crystal size of 7 nm showed the best performance for the transformation of jatropha oil into high-grade biofuel.

EPR Spectroscopic and Thermal Analysis Study of Spent NiMo/WO3–Al2O3 Catalysts for Hydrodeoxygenation of Vegetable Oil

This paper presents the results of an electron paramagnetic resonance (EPR) and thermal analysis (TGA, DTA) study of a series of bifunctional NiMo/WO3–Al2O3 catalysts containing 0 to 30 wt % WO3 modifier before and after testing them in the process of hydrodeoxygenation of vegetable oil. The dependence of the content of carbonaceous deposits in the spent samples (according to EPR and TGA) on the concentration of acid sites as determined by EPR of perylene probe molecules in the initial catalysts is determined. Deactivation is explained by the participation of medium- and weak-strength Bronsted acid sites in the condensation of the initial unsaturated hydrocarbon molecules and their intermediates leading to the formation of various forms of coke precursors.

Hydrodeoxygenation of Vegetable Oils and Fatty Acids over Different Group VIII Metal Catalysts for Producing Biofuels

Energy security and environment protection are two important aspects of sustainable development. Biofuels are renewable and carbon neutral. They are suitable replacement for conventional fossil derived transport fuels. Their use leads to sustainable development. Among several technological options, catalytic hydrodeoxygenation of vegetable oils leading to diesel-range hydrocarbons is the most attractive approach for producing biofuels. The green diesel, thus produced, could be blended with petro–diesel or used as standalone fuel in the conventional diesel engines. Our research group has been active in developing efficient solid catalysts for hydroprocessing of vegetable oils. This account presents some of our efforts using supported group VIII metals and the importance of electronic contact between metal and support on the catalytic activity and hydrodeoxygenation selectivity in hydroprocessing of vegetable oils.

Original Pt-Sn/Al2O3 catalyst for selective hydrodeoxygenation of vegetable oils

The preparation of biodiesel from fatty materials HDO provides a very constructive idea to solve the global clean energy problem. The application of catalytic technology to convert oils into green liquid hydrocarbon fuel has great potential for industrial application. The main problem with the development of green diesel technology is the limited number of available non-food sources of fatty acid triglycerides. Also the researchers have made remarkable achievements in the field of catalyst, the stability of the catalyst is insufficient and the selectivity of large molecules of direct alkanes is low. These defects hinder the large-scale resource development of biodiesel. In current paper the potential of hydrodeoxygenation (HDO) of fatty materials and model esters was explored by enhancing the synergy of platinum and tin by using heterometallic (PPh4)3 [Pt (SnCl3)5 complex. Heterometallic (PPh4)3 [Pt (SnCl3)5] complex provides in its structure platinum and tin atoms linked by a metal–metal bond that causes the originality of catalytic performance. The performance of bimetallic Pt-Sn/Al2O3 catalyst, which is characterized by the Sn/Pt molar ratio of 5/1, has been studied at hydrogen pressure 50 atm and temperature 400–480 °C. HDO reaction of a number of fatty materials has been shown to proceed with the highest ever yield of direct hydrocarbons derived from alkoxy and acyl groups of the initial ester. Also it was investigated a performance in HDO reaction of mixture containing rapeseed oil oleic acid and water that simulate cooked oil that may be a prospective soure for green hydrocarbons in megalopolises. A structural studies of the catalyst showed that its high selectivity in HDO reaction of fatty materials provided by two important factors: impregnated particles size and formation of intermettallic species of PtSn3±σ. Finally, catalysts sustained activity and stability were tested during five turns of 24 h each.

Kinetic Studies of Hydrodeoxygenation of Ethyl Ester of Decane Acid over a Ni-Cu-Mo/Al2O3 Catalyst

Nickel-based catalysts for hydrodeoxygenation of vegetable oils are an alternative to the systems based on noble metals and sulfide catalysts for hydrotreatment. Modification of the nickel catalysts with molybdenum and copper allows the yield of target products to be increased and the corrosion resistance of the catalytic system to be improved. The studies were aimed at establishing relationships between temperature, contact time and activity of the modified nickel-containing catalyst to hydroxygenation of esters of fatty carboxylic acids, as well as at determining effective kinetic parameters of the reactant consumption. A flow reactor with the fixed catalyst bed was used for experimental studies at РН2 = 0.25 MPa, temperatures 270, 285, 300 and 315 °C, contact time varied from 600 to 1800 s. It was shown that the selectivity to the main reaction products – nonane and decane – did not change upon varying the reaction temperature and contact time. The experimental data were used for determining the effective rate constants and activation energy of the reaction.

Cover Feature: Selective Hydrodeoxygenation of Vegetable Oils and Waste Cooking Oils to Green Diesel Using a Silica‐Supported Ir–ReOx Bimetallic Catalyst (ChemSusChem 9/2018)

The Cover Feature shows the use of waste cooking oils, collected from local restaurants, to produce green diesels with high selectivity through an energy-efficient catalytic hydrodeoxygenation reaction. More information can be found in the Full Paper by Liu et al. on page 1446 in Issue 9, 2018 (DOI: 10.1002/cssc.201800321).

Selective Hydrodeoxygenation of Vegetable Oils and Waste Cooking Oils to Green Diesel Using a Silica-Supported Ir-ReO x Bimetallic Catalyst

Selective Hydrodeoxygenation of Vegetable Oils and Waste Cooking Oils to Green Diesel Using a Silica-Supported Ir-ReO_<i>x</i> Bimetallic Catalyst

Selective Hydrodeoxygenation of Vegetable Oils and Waste Cooking Oils to Green Diesel Using a Silica-Supported Ir-ReOx Bimetallic Catalyst.

High yields of diesel-range alkanes are prepared by hydrodeoxygenation of vegetable oils and waste cooking oils over ReOx -modified Ir/SiO2 catalysts under mild reaction conditions. The catalyst containing a Re/Ir molar ratio of 3 exhibits the best performance, achieving 79-85 wt % yield of diesel-range alkanes at 453 K and 2 MPa H2 . The yield is nearly quantitative for the theoretical possible long-chain alkanes on the basis of weight of the converted oils. The catalyst retains comparable activity upon regeneration through calcination. Control experiments using probe molecules as model substrates suggest that C=C bonds of unsaturated triglycerides and free fatty acids are first hydrogenated to their corresponding saturated intermediates, which are then converted to aldehyde intermediates through hydrogenolysis of acyl C-O bonds and subsequently hydrogenated to fatty alcohols. Finally, long-chain alkanes without any carbon loss are formed by direct hydrogenolysis of the fatty alcohols. Small amounts of alkanes with one carbon fewer are also formed by decarbonylation of the aldehyde intermediates. A synergy between Ir and partially reduced ReOx sites is discussed to elucidate the high activity of Ir-ReOx /SiO2.

Hydrodeoxygenation of Vegetable Oil on NiMoS/WO3–Al2O3 Catalysts

Tungstate-containing aluminum oxide is suitable as a catalyst support for hydrodeoxygenation of sunflower oil, ensuring 81–83 wt % yield of liquid products at 380°С, 4.0 MPa, and feed space velocity of 1 h–1. The catalyst acidity increases with increasing tungsten oxide content, leading to an increase in the content of decarboxylation/decarbonylation products and isoparaffins in the product mixture.

The Direct Hydrodeoxygenation of Vegetable Oil over Pt-sn/al2o3 Catalysts

The Direct Hydrodeoxygenation of Vegetable Oil over Pt-sn/al2o3 Catalysts

Cooperative catalysis for the direct hydrodeoxygenation of vegetable oils into diesel-range alkanes over Pd/NbOPO4.

Near quantitative carbon yields of diesel-range alkanes were achieved from the hydrodeoxygenation of triglycerides over Pd/NbOPO4 under mild conditions with no catalyst deactivation: catalyst characterization and theoretical calculations suggest that the high hydrodeoxygenation activity originated from the synergistic effect of Pd and strong Lewis acidity on the unique structure of NbOPO4.