Oil Fatty Acid Methyl Esters Research Articles

Epoxidation of Calophyllum inophyllum oil fatty acid methyl esters as a potential base-stock for green cutting fluid

Epoxidation of Calophyllum inophyllum oil fatty acid methyl esters as a potential base-stock for green cutting fluid

ИССЛЕДОВАНИЕ ВОЗМОЖНОСТИ ПРИМЕНЕНИЯ АЛЬТЕРНАТИВНЫХ СЫРЬЕВЫХ ИСТОЧНИКОВ В КАЧЕСТВЕ ЭНЕРГОНОСИТЕЛЕЙ ДЛЯ ДВС

The areas of application of synthetic oil fractions and fatty acid methyl esters (FAME) were determined. Conducted: Research on two types of alternative fuels has been carried out: 1 – various fractions of synthetic oil obtained using the Fischer-Tropsch method; 2 – mixed fuels (B7) based on hydrotreated petroleum diesel fraction with the addition of 7% FAME of rapeseed oil. The prospects for their use as an additive to petroleum fuels are shown based on the results of tests of various fractions of synthetic oil. Since the main disadvantages of biodiesel and mixed fuels are poor oxidative stability and a tendency to form deposits, studies of the effectiveness of the antioxidant additive Agidol-1 in mixed fuel with the addition of 7% rapeseed oil FAME under test conditions on an OSV-M non-engine unit were carried out. The positive effect of the antioxidant additive Agidol-1 on the reduction of high-temperature deposits on the bottoms of injectors when operating on mixed fuels containing up to 7% FAMEs has been established. Quantitative assessment of deposits on the bottom of the spray nozzle was carried out using an FT-801 IR-Fourier spectrometer with a wide-range infrared microscope. Based on the results obtained at OSV-M using IR-Fourier spectrometry, the promise of using the antioxidant additive Agidol-1 to reduce deposits on the injectors of engines operating on mixed fuels was shown.

Investigation of process variable effects on palm kernelamidopropyl betaine production

Abstract Cocamidopropyl betaine is a coconut oil-based surfactant that is widely used in cosmetics and personal care products due to its milder and less irritating properties compared to conventional petroleum-based surfactants. Palm kernel oil can be used for the synthesis of betaine (palm kernel amidopropyl betaine), following the same route as for the synthesis with coconut oil via two reaction steps. However, there was little information on the optimal operating conditions for each process. The method for the production of betaine and its operating conditions were studied in order to obtain a compatible betaine product with better properties than those of the commercial product. The studied method and operating conditions allowed the production of low viscosity betaine with a higher surfactant content (31.55 wt%) than that of the commercial betaine products (25.10 wt%). In addition, other feedstocks such as coconut oil, split palm kernel oil and coconut oil-based fatty acid methyl ester were used in this study to produce betaine from low-cost production.

Prediction of thermal and mechanical properties of acrylate-based composites using artificial neural network modeling

Poly(methyl methacrylate) (PMMA) has a broad spectrum of uses, especially in medical applications. The role of fine-grained alumina particles of PMMA composites was investigated in this study. The composites were based on PMMA modified with dimethyl itaconate (DMI) as a matrix and alumina particles (Al2O3) and alumina doped with iron (Al2O3-Fe) modified with 3-aminopropyl-trimethoxysilane (AM) and flax oil fatty acid methyl esters (biodiesel) as reinforcements. Three particle sizes were measured (~0.4, ~0.6 and ~1.2 ?m). The highest thermal conductivity values were measured for the composite 5 wt.% Al2O3-Fe-AM. With the addition of 3 wt.% Al2O3-AM to the PMMA/DMI matrix, mechanical properties were improved (tensile strength, strain, and modulus of elasticity). An artificial neural network model based on the Broyden-Fletcher-Goldfarb-Shanno iterative algorithm was investigated for prediction of thermal conductivity and mechanical properties of the composites showing satisfactory results. This is relevant for applications for optimization of dental materials to produce dentures, which were exposed to variations in temperature during the application.

Lipozyme® TL IM Biocatalyst for Castor Oil FAME and Triacetin Production by Interesterification: Activity, Stability, and Kinetics

Global climate change and present geopolitical tensions call for novel, renewable, and, ideally, sustainable resources and processes that, in the end, will be integrated in the natural cycles of carbon and water, progressively replacing non-renewable feedstocks. In this context, the production of biofuels and, in consequence, of biodiesel plays a notable role. This work is focused on the production of fatty acid methyl esters (FAME) from castor oil, an abundant non-edible oil, using a sustainable technology approach based on industrial lipases and methyl acetate as a methylating reagent to reduce biocatalyst inactivation. We have selected a stable industrial enzyme preparation to determine its suitability for FAME production: Lipozyme® TL IM (an inexpensive lipase from Thermomyces lanuginosus immobilized by agglomeration in silica gel). Several operational variables affecting the enzyme activity have been studied: methanol excess (6:1 to 13:1), temperature (from 40 to 60 °C), and enzyme concentration (10 and 30% w/w). At all temperatures and reagent ratios, we have also tested the enzyme stability for six cycles, showing its low to negligible inactivation under operational conditions. Finally, a novel multivariable kinetic model has been proposed and fitted to experimental data obtained in a wide experimental range for the first time, showing that direct and reverse in-series reactions are present. We have estimated the values of the kinetic constants and their standard errors, and goodness-of-fit parameters, observing that the kinetic model fitted very reasonably to all retrieved experimental data at the same time.

Reactive Extraction for Fatty Acid Methyl Ester Production from Castor Seeds Using a Heterogeneous Base Catalyst: Process Parameter Optimization and Characterization

Fatty acid methyl ester (FAME) from oil seeds is conventionally produced via a two/three-process-step method: extraction of oil and subsequent esterification/transesterification to fatty FAME (biodiesel). However, in the present study, we investigated the production of castor kernel oil (CKO) FAME by reactive extraction for extraction and transesterification in a single process using a heterogeneous catalyst. The content of oil that can be extracted was checked by investigating several nonreactive extraction parameters such as solvent type (polar, nonpolar, and mixture), the solvent to kernel ratio, and extraction time. Maximum oil was extracted using methanol as a solvent with a methanol-to-seed ratio of 6.25:1 for 6 h extraction time. The viscosity of CKO obtained by nonreactive extraction was reduced from 288.83 to 19.04 mm2/s by reactive extraction using a 4.09 wt % catalyst concentration (BaO) and a 330.9:1 methanol-to-oil molar ratio for 6 h reaction time at 64 °C. Reactive extraction for transesterification of CKO was performed using BaO, CaO, and ZnO heterogeneous catalysts. BaO results in the increased yield of CKO FAME compared to other catalysts. Central composite design (CCD) using the response surface methodology (RSM) was implemented to design the experimental matrix, process parameter optimization, maximize the yield of CKO FAME, and investigate interaction effects of parameters such as reactive extraction temperature (55-65 °C), catalyst concentration (3-5 wt %), and methanol-to-oil molar ratio (175:1-350:1) on the yield of CKO FAME. A second-order model equation with a p-value < 0.05 and an R 2 value near 1.0 was obtained to predict the yield using the input parameters. The maximum yield CKO FAME of 96.13 wt % with 94.4% purity of produced CKO FAME was obtained at a catalyst concentration of 4.09 wt % and a methanol-to-oil molar ratio of 330.9:1 for 6 h with a reaction temperature of 64 °C. Therefore, a comparable conversion of castor seed oil triglyceride (96.13 wt %) was obtained in a single step directly from castor seeds. Furthermore, the rheological behavior investigation of castor kernel oil and castor methyl ester revealed that the dynamic viscosity of both samples was found to be dependent on triglyceride content and temperature.

Effect of Processing Parameters to The Fish Oil from Fish Waste Via Modified Soxhlet Extraction

The oil production and fatty acid methyl ester (FAME) contents of fish waste were studied. Solvent, temperature, and extraction time were the processing parameters involved. The oil and FAME were extracted using a modified soxhlet extraction method. The best solvent for fish oil extraction was found to be ethanol, which yielded 49.0%, followed by ethanol:heptane (1:1), methanol:heptane (1:1), and methanol. The oil extract composition contained a high yield of oleic acid (C18:1), ranging from 42% to 66%. Followed by palmitic acid (C16:0), palmitoleic acid (C16:1), and stearic acid (C18:0). According to the statistical model obtained, at the 95% confidence level, extraction time had a significant effect on both oil and oleic acid yield (C18:1). These results demonstrated that a high oleic acid fraction can be obtained from fish waste with ethanol, implying that there is a high potential for cost-effective biofuel production.

Modification of epoxidized methyl esters of sunflower oil fatty acids with some diols

It is possible to obtain products with a wide range of useful properties as a result of the modification of epoxidized vegetable oils and their derivatives. The aim of this work was to develop methods for the synthesis of new products by the reaction of epoxidized sunflower oil fatty acid methyl esters (FAME) with dihydric alcohols: ethylene glycol, butanediol-1,4, diethylene glycol, as well as in the study of their structure and properties. Dependences of the structure of the obtained products on the conditions of the process and the type of the modifier have been established. It was shown that carrying out the modification at a higher temperature (100 ° C) leads to the formation of crosslinked products as a result of intermolecular dehydration with the participation of both hydroxyl groups of the diol molecule. In addition to the opening of the oxirane ring, the transesterification process with the participation of the ester fragment is realized. Certain characteristics of the obtained products, including the acid number, saponification number, were determined, and the emulsifying effect was evaluated. In addition, the solidification temperature and pour point were determined for the products obtained. It was found that the products of modification of epoxy derivatives of FAME of sunflower oil obtained at 50 ° C have the greatest emulsifying effect.

Fractionation of fatty acid methyl esters via urea inclusion and its application to improve the low-temperature performance of biodiesel

Biodiesel is viewed as the alternative to petroleum diesel, but its poor low-temperature performance constrains its utilization. Cloud point (CP), the onset temperature of thermal crystallization, appropriately shows the low-temperature performance. The effective way to reduce CP is to remove saturated fatty acid methyl esters (FAMEs). Compared to current methods, this work describes an extraordinary approach to fractionating FAMEs by forming solid urea inclusion compounds (UICs). Urea inclusion fractionation reduces the CPs by removing high melting-point linear saturated FAME components. Urea inclusion fractionation in this study was performed under various processing conditions: mass ratios of urea to FAMEs and solvents to FAMEs, various solvents, FAMEs from various feedstocks, and processing temperatures. Supersaturation of urea in the solution is the driving force, and it significantly affects yield, composition, CP, separation efficiency, and selectivity. Through a single urea inclusion fractionation process, FAMEs, except palm oil FAMEs, resulted in CP reduction ranging from 20 to 42 oC with a yield of 77–80% depending on the compositions. CP of palm oil FAMEs could reach as low as -17 oC with a yield of 46% after twice urea inclusion fractionation. According to the model prediction, the cetane number after urea inclusion fractionation decreased about 0.7–2 but was still higher than the minimum biodiesel requirement. Oxidation stability after urea inclusion decreased according to the proposed model, but this can be mitigated by adding antioxidants. Emission evaluation after urea inclusion fractionation indicated decreased hydrocarbons, carbon monoxide, and particulate matter. However, it resulted in the increasing emission of nitrogen oxides.

Effective Epoxidation of Fatty Acid Methyl Esters with Hydrogen Peroxide by the Catalytic System H3PW12O40/Quaternary Phosphonium Salts

Six quaternary phosphonium salts (QPSs) in combination with phosphotungstic heteropolyacid, H3PW12O40, were tested in the epoxidation of rapeseed oil fatty acid methyl esters with a hydrogen peroxide aqueous solution. The QPSs consisted of trihexyl(tetradecyl)phosphonium [P6], tributyl-tetradecylphosphonium [P4] or tetraoctylphosphonium [P8] cation and different anions—chloride (Cl−), bromide (Br−), tetrafluoroborate (BF4−), bis(trifluoromethylsulfonyl)amide (NTf2−), bis(2,4,4-trimethyl-pentyl)phosphinate (Phosf−). The influence of the kind of QPS and temperature on the epoxy number, iodine number, glycol content has been determined. The epoxidation was confirmed using Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) and elemental analysis CHO. Two QPSs with a trihexyltetradecyphosphonium cation—[P6][Fosf] and [P6][Cl]—were selected as the most effective in the studied epoxidation process. The proposed kinetic model takes into consideration the two reactions, namely, epoxidation and epoxy ring opening involving the formation of hydroxyl groups. The rate constants and activation energies for epoxidation fatty acid methyl esters were determined.

EMPIRICAL MODELING OF KINETICS OF TRANSESTERIFICATION AND COLD FLOW PROPERTIES OF USED SOYA OIL BIODIESEL

This research work focused on empirical modeling of kinetics of transesterification and cold flow properties of homogeneous catalyzed used soya oil fatty acid methyl ester (USOFAME]. Used soya oil (USO) was prepared by frying food (yam, potato plantain etc) with virgin soya oil for a total of 72 hours [1]. The oil was characterized based on American Society for Testing and Materials (ASTM) method. The fatty acid profile of used soya oil was analyzed using gas chromatography mass spectroscopy (GC MS) while the functional groups of the triglyceride were determined using Fourier transform infrared spectroscopy (FTIR). The oil was pretreated to reduce the free fatty acid level below 1% and then transesterified using methanol in the presence of sodium hydroxide catalyst. The fuel properties of the USOFAME produced were determined based on ASTM standards. Kinetic experiments were conducted in batches at different temperatures of 450C, 550C and 650C. Application of rate laws to the three-step reversible reaction scheme of transesterification yielded a series of ordinary differential equations (ODEs) solved with polymath 5.1 software to give the forward and reverse rate constants k1,k2, k3, k4, k5 and k6 from which the rate limiting step (RLS) and activation energy (∆E) were derived. The cold flow properties, cloud point (CP), cold filter plugging point (CFPP) and pour point (PP) were determined experimentally for different blends of biodiesel with #2 diesel, at a percentage volume ratio of biodiesel to diesel 0, 20, 40, 60, 80, and 100. The values obtained for CP, CFPP, and PP were plotted against the biodiesel fraction in the blends. Least square regression of the data of the plots were tested on linear, quadratic and polynomial models using Microsoft excel. The fuel properties of the USOFAME which is within the ASTM standards were determined as acid value 0.4mgKOH/g, density 863mm2/s, kinematic viscosity 4.60mm2/s, flash point 1620C, cetane number 61.00, calorific value 40.06MJ/Kg, pour point -40C, cold filter plugging point -2.80C, cloud point 00C, iodine value 30.60gI2/100g. Kinetic modeling of transesterification of USOFAME shows that the forward rate constants K1, K2, and K3 are greater than those of the reverse reaction k2, k4, k6, imply that the forward reaction dominates while the reverse reaction could be neglected. The rate constant k1 for triglyceride conversion to diglyceride is the least among the forward rate constants at 450C, 550C and650C imply that this step is the rate limiting step (RLS). Application of least square regression analysis of Microsoft excel on the data of variation of cold flow properties with biodiesel fraction, revealed polynomial model to be the best fitting equation.

TWO STEP HOMOGENEOUS CATALIZED METANOLYSIS OF RUBBER SEED OIL TO BIODIESEL

The rapid depletion of fossil fuel and its environmental impact has resulted in the search for alternative energy sources . Among the various alternatives investigated for diesel replacement, biodiesel has emerged the most suitable alternative to diesel fuel. This research work is therefore focused on the use of low cost none-edible rubber seed oil, methanol solvent and sodium hydroxide catalyst for production of rubber seed oil (RSO) fatty acid methyl ester (RSOFAME). as a renewable energy. The oil content of rubber seed was extracted using solvent extraction method. The RSO extracted was characterized based on American Society for Testing and Materials (ASTM) methods. The fatty acid profile was determined using gas chromatography mass spectrometry while the functional group of the oil was analyzed using Fourier transform infrared spectroscopy. The effect of process parameter on the yield of RSOFAME was investigated using one factor at a time method. The RSO was pretreated to reduce the free fatty acid below 1% and then transterified using methanol in the presence of sodium hydroxide (NaOH) catalyst. The fuel properties of the RSOFAME produced was determined based on ASTM standards. The physiochemical properties of RSO , acid value, free fatty acid, saponification value, iodine value , peroxide value, kinematic viscosity, fire point, flash point, cloud point, pour point, refractive index specific gravity, moisture content, and density gave the values 28.72mgKOHg-1, 14.36%, 185.66mgKOHg-1 120.4gI2100g-1, 14.62meqkg-1, 38.5mm2s-1 @ 400C, 1800C, 1320C, 60C, 20C 1.428, 0.92, 7%, 920Kgm-3, respectively. The fatty acid profile of RSO shows the constituent unsaturated fatty acids to be oleic acid 19.6% and linoleic acid 22.588%, while the saturated fatty acid constituents are lauric acid 3.983%, myristic acid 7.750%, palmitic acid 16.698%, stearic acid 39.058% The process parameters greatly affected the biodiesel yield. The experimentally determined properties of the RSOFAME, density, kinematic viscosity, cetane number,, flash point, cloud point, water content, acid value, calorific value, iodine value, and pour point gave the values, 880kgm-3 4.25mm2s-1, 58.2, 1640C, 40C. 0.44%, 0.32mgKOHg-1, 38.5MJkg-1,72gI2100g-1,20C,respectively.

Enzymatic production of biodiesel from alperujo oil in supercritical CO2

The synthesis of fatty acid methyl esters (FAMEs) as biodiesel from alperujo oil was studied in scCO2 using a mixture of Novozym 435 and Lipozyme TL IM at 10% as a catalyst to enhance the productivity. The reaction performance was investigated at different temperatures (40–60 °C), reaction times (1–48 h) and with a mixture of methylating agents in molar ratios of oil:methanol:methyl acetate from 1:0:40 to 1:5:35. Conversion of triglycerides achieved values up to 96% at>50 °C and reaction times of 24 h with FAMEs yields of over 90%. The presence of methyl acetate and the use of scCO2 as solvent improved the oil conversion and FAMEs yield in comparison with other works. The residual activity of the enzymes dropped at high reaction temperatures (>40 °C), reaction times (>1 h) and if the molar oil: methanol ratio was increased from 1:1 to 1:2 or higher.

The Effect of Biofuel on the Emission of Exhaust Gas from an Engine with the Common Rail System

The paper presents the results of experimental tests of a FIAT MultiJet 1.3 SDE 90 KM engine equipped with the common rail system, running at full load operation at rotational speeds of n= 1000, 1750, 2000, 2500, 3000, 35000, 4000 and 4200 rpm, carried out on a dynamometer stand. During the tests, the engine was supplied with, respectively, diesel oil and rape oil fatty acid methyl esters (FAME) and their mixtures: B20 (80% diesel oil and 20% FAME), B40 (60% diesel oil and 40% FAME), B60 (40% diesel oil and 60% FAME) and B80 (20% diesel oil and 80% FAME). The paper has assessed the effect of the additions of rape oil fatty acid methyl esters to diesel oil on the unit fuel consumption and the emission of harmful exhaust gas components: nitrogen oxides, hydrocarbons, carbon monoxide, particulates and carbon dioxide. The fuel consumption was measured using a AVL 730 Dynamic Fuel Consumption fuel dosimeter. The measurements of the concentrations of the above-mentioned harmful exhaust gas components were done with a MEXA-1600 DEGR analyzer manufactured by Horiba, while particulate emissions were measured with a MEXA-1230PM analyzer by Horiba.

Utilization of waste vegetable oil methyl esters as lubricant oil

Increasing environmental awareness and threats to the environment have made the recycling of biomass products necessary. The goal of this paper is to study the tribological properties of fatty acid methyl esters derived from waste frying oils under different lubrication conditions. For this purpose, the performance of candidate fatty acid methyl esters was compared with a mineral base oil. For the determination of tribological properties, a pin-on-disc wear tester was used. The experiments were carried out in three replications at different loads (5, 10, and 15 N) and different sliding speeds (100, 300, and 600 r/min) and a 1000 m sliding distance under dry, boundary-mixed, and fluid lubrication conditions. After the wear amount of the test specimens was determined by the mass loss method, their Archard wear indexes were calculated. Scanning electron microscopy surface images were used for visual analysis and energy-dispersive X-ray spectroscopy images for chemical analysis. The surface contact angles and surface tensions of the lubricant test specimens were also measured experimentally. In all experimental results, it has been found that the tribological properties of used frying oil fatty acid methyl esters such as friction, wear, and surface adhesion are generally better than the base oil under all lubrication conditions. Fatty acid methyl esters is a biodegradable, recycling, and environmentally friendly product and can be confirmed as a lubricant and/or an oil additive candidate.

Thermal vision of fracture behavior on acrylic composites

The aim of this work was to investigate thermal properties of acrylate-based composite combined with alumina-based particles. The composites were made of poly (methyl methacrylate) (PMMA) modified with dimethyl itaconate (DMI) as a matrix. As reinforcement were used alumina particles (Al2O3) and alumina doped with iron oxide (Al2O3-Fe) modified with 3-aminopropyl-trimethoxylane (AM) and flax oil fatty acid methyl esters (biodiesel - BD). According to the thermal conductivity measurements, the highest thermal conductivity values had the composite with alumina particles with the highest alpha phase content. With the addition of modified alumina particles to PMMA/DMI matrix mechanical properties were improved (tensile strength, modulus of elasticity and elongation at break). Composite with 3 wt. % Al2O3-Fe-AM particles had the most improved mechanical properties. It was noticed that this composite, compared to PMMA, had the lowest temperature in a crack zone (10.28%) and that is due to the better stiffness and highest thermal conductivity. The results indicated that the Sobel fractured surface area is related to the crack energy, which is reflected by the temperature of sample monitored by thermal vision.

Investigation of physical and chemical properties of tobacco seed oil fatty acid methyl ester for biodiesel production

Tobacco seeds, which holds oil in it was one of the major by-products of tobacco leave production in India. India was second largest producer of tobacco. Cigars, Hookah, Snuffs and Chewing tobacco are the major products of tobacco plant. Its seeds are found to be prominent source of non-edible oil. Extraction process have proved that seeds hold almost 41% of oil in its weight basis. In this work the physical as well as chemical properties of the tobacco seed oil and its methyl ester were investigated. Results were compared against other vegetable oil and their respective methyl esters. This work concludes that tobacco seed oil methyl ester might be an appropriate alternate fuel for diesel engines. Extraction of oil and its trans-esterification process were analysed in this study. The yield of oil in native and grounded seeds at different temperature was also studied in this work.

The effect of culture medium on the oil yield and fatty acid methyl ester of freshwater microalgae Chlorella vulgaris

Microalgae are commonly used in the biodiesel industry to produce lipids. The selection of media is one of the vital factors to culture the microalgae. The Chlorella vulgaris used in this study as a microalgae was cultured in three different culture media, namely the Modified Bold’s Basal medium (BBM), Blue-Green medium (BG11) and Jaworski’s medium (JM) using the immobilization method. Through this method, all the cultured microalgae were cultivated for 11 days to evaluate the oil yield. Then, the extracted oil was transesterified to produce fatty acid methyl ester (FAME). It was found that the BBM medium showed the highest oil yield (71.43%), followed by JM (67.50%) and BG11 (53.14%). In addition, BBM also is the best composition to produce FAME as it contains high nitrogen.

Mechanism Controlling High‐Temperature Degradation of Sunflower Oil Triacylglycerols in the Absence of Oxygen

AbstractThe aim of the present study is to describe the mechanism controlling heat‐induced formation of sunflower oil triacylglycerol and fatty acid methyl ester oligomers. The unique combination of high‐performance size‐exclusion chromatography with hyphenated electrospray ionization mass spectrometry (MS), atmospheric pressure chemical ionization‐MS, and high‐temperature gas chromatography‐MS techniques allows differentiating between radical coupling species and Diels–Alder cycloadducts. Targeted analysis of thermally degraded sunflower oils confirms the exact structures of various acyclic oligomers accompanied by less‐abundant products of pericyclic transformations. A series of model experiments simulate the impact of dienophile nature on the course of Diels–Alder reactions. Thus, α‐tocopherylquinone, δ‐tocopherylquinone, and methyl‐(E)‐11‐oxoundec‐9‐enoate are synthesized as naturally occurring dienophiles bearing electron‐withdrawing groups. The geometry of poor dienophiles does not affect concerted cyclization, while the structure of electron deficient dienophiles can overcome low reactivity.Practical Application: In the absence of oxygen, heat‐induced degradation of polyunsaturated triacylglycerols proceed predominantly via a radical pathway, whereas concerted reactions represent minor mechanisms. Sunflower oil triacylglycerol molecules in the system without propagation stage can be effectively protected by natural and/or synthetic antioxidants. Application of chelates is also recommended. However, antioxidant‐derived quinones, such as α‐tocopherylquinone, can enter the Diels–Alder reaction even more easily than dienophiles without electron‐withdrawing groups. Unsaturated core aldehydes possess the same reactivity. Examination of the mechanism controlling high‐temperature degradation of triacylglycerols is especially important for processing engineers in edible oil refineries and food technologists. New perspective may help them to minimize undesirable changes in polyunsaturated species.

Partial Hydrogenation of Palm Oil-Derived Biodiesel over Ni/Electrospun Silica Fiber Catalysts

Given the high accessibility of reactants to the active metal sites of fibrous catalysts, in this research, an electrospun silica fiber was applied as a support of nickel catalysts (Ni/SF) for the partial hydrogenation of palm oil fatty acid methyl ester (FAME) in a fixed-bed reactor. The textural properties, reducibility, Ni dispersion and morphology of Ni/SF catalysts were characterized and compared to those of a Ni/porous silica ball (Ni/SB). Under 1 bar H2 pressure at 140 °C, the 30 wt% Ni/SF catalyst exhibited a high turnover frequency (TOF) of 1396 h−1 to convert methyl linoleate (C18:2) to more saturated structures. On the other hand, the system using Ni/SB catalysts showed a TOF of only 141 h−1. This result was due to the effect of the higher acidity of the silica fiber, which promoted the higher adsorption of polyunsaturated portions in FAME. The non-porous characteristics and open morphology of the Ni/SF catalysts also allowed FAME and H2 molecules to easily access the Ni active sites deposited on the surface of the silica fiber and suppressed the selectivity to cis–trans isomerization. Stability testing of the Ni/SF catalyst showed that the C18:2 conversion decreased from 71% to 60% after long-term operation for 16 h possibly due to the weak metal–support interaction that facilitated Ni particle loss from the catalyst surface.