Synthesis Of Fatty Acid Methyl Esters Research Articles

Magnetic induction heating-assisted synthesis of biodiesel using an alumina/iron oxide nanocatalyst

While generating biodiesel from vegetable oils presents various advantages over fossil fuels, ongoing actions aim to improve the efficiency of this production process. Emphasis is placed on optimizing experimental conditions, including the catalyst selection, reaction media and the energy source for heating and mixing, thereby revealing existing research gaps in biodiesel production. In this sense, we have designed a magnetic nanocatalyst based on iron oxide nanoparticles (IONPs) of 18 nm in diameter incorporated within an alumina matrix of around 500 nm infused with potassium hydroxide that provides the catalyst's mesoporosity and basicity. Magnetization analyses confirmed the superparamagnetic behaviour of the nanocatalyst at room temperature and a saturation magnetisation high enough to ease magnetic recovery for reuse. Additionally, magnetic nanoparticles can serve as nanoheaters when subjected to an alternating magnetic field. The heating efficiency of the isolated IONPs was assessed under various frequency and field conditions, yielding specific absorption rate values of up to 80 W/g. Such heating capacity has allowed the synthesis of fatty acid methyl ester (FAMEs), which constitute the biodiesel at 65 °C under optimal field conditions (100 kHz and 48 kA/m) and ideal reaction parameters: 5 % catalyst, methanol/oil ratio 12:1 and 6 h of reaction, with a conversion of up to 98.6 % determined through NMR characterization of the FAMEs and a 95.6 % yield. FAMEs presence was confirmed by optimizing a swift and efficient FTIR method and their purity by TLC. Overall, the designed nanocatalyst presented for FAME synthesis, which incorporates magnetic separability and effective heating capabilities, holds great promise for cost reduction and process efficiency.

Methyl oleate for plant protection products formulations: Enzymatic synthesis, reaction kinetics and application testing

This study presents a solvent-free enzymatic approach for the synthesis of fatty acid methyl esters (FAMEs), such as methyl oleate, for their application as adjuvant in plant protection products (PPP) formulations. The direct esterification between free fatty acid and methanol was optimized to achieve 98% acid conversion. The kinetics of this conversion was accurately described by a simple second order mechanism and non-linear regression was applied to calculate the rate constants of the forward and backward reactions based on full progress curves data. The rate constant of the forward reaction (synthesis) was one order of magnitude higher than the backward reaction (hydrolysis) and favored formation of the target methyl ester product, rendering the removal of water unnecessary. Enzymatically synthesized methyl oleate was benchmarked against the chemically synthesized compound, showing matching results in terms of stability, spreadability and emulsifying capacity in plant care formulations. The enzymatic synthesis of FAMEs under solvent free conditions allows to achieve a safer and more sustainable character for carrier solvents in PPP formulations.

Intensification and Optimization of FAME Synthesis via Acid-Catalyzed Esterification Using Central Composite Design (CCD).

The acid-catalyzed pre-treatment esterification process is required for low-cost feedstock with high free fatty acids (FFAs) to avoid the saponification that occurs during alkali-catalyzed transesterification for the production of fatty acid alkyl esters (FAAE). Reverse hydrolysis in acid-catalyzed esterification causes a decrease in fatty acid methyl ester (FAME) yield. Therefore, the esterification process must be intensified. This study aims to develop and optimize a low-temperature intensification process to enhance biodiesel yield and reduce energy consumption. Three intensification systems were studied: co-solvent technique, co-solvent coupled with adsorption of water using molecular sieves, and entrainer-based continuous removal of water. The process variables of esterification reaction in co-solvents without the adsorption system were optimized by using central composite design (CCD). The study showed that the co-solvent without the adsorption system was effective in intensifying the FFA conversion (XFFA) at low temperatures, compared to the other two systems, due to the dilution effect at high co-solvent/entrainer amount required for sufficient vapors in the adsorption system. Optimized process variables have achieved 95% XFFA within 75 min at 55 °C, 20 mL/100 g of oil DEE, 9 MR, 3 wt % H2SO4, and 320-350 RPM in a co-solvent without the adsorption system.

Adsorptive pretreatment of waste cooking oil using quicklime for fatty acid methyl esters synthesis

Synthesis of biodiesel from various plant oils is realized by the transesterification of triglycerides with methanol or by a reaction usually defined as methanolysis. The usage of low-quality oils, such as waste cooking oil (WCO), is followed by undesirable side reactions as a result of the increased content of free fatty acids (FFA), and water. The presence of FFA in WCO usually requires a pretreatment stage before subjecting it to methanolysis. In the present work, heterogeneously catalyzed methanolysis of WCO with and without pretreatment was investigated. Removal of FFA from WCO was conducted by using only quicklime or with the addition of a small amount of methanol (FFA to methanol = 1:3 molar ratio). The obtained results showed that pretreatment of WCO with quicklime at 30 ?C after 1 h reduces the FFA content by 72 %, while the adsorption capacity was determined to be 910 mg g-1. The adsorptive pretreatment, as a simple operation, using low-cost quicklime under mild conditions, had a positive effect on the transesterification rate with CaO?ZnO as a catalyst, enabling the achievement of over 96 % of biodiesel yield in only 15 min, compared to 1 h without the pretreatment. Furthermore, pretreated WCO allows an increase in repeated catalyst use and overall savings in the necessary amount of catalyst. The present study showed that quicklime is an economic, environmental-friendly, and sustainable material for FFA removal from WCO.

Comparative modelling, molecular docking and immobilization studies on Rhizopus oryzae lipase: evaluation of potentials for fatty acid methyl esters synthesis

Elucidation of lipase–substrate interactions will guide the proper industrial use and applicability of the enzyme. The aim of this study was to predict the 3 D structure of Rhizopus oryzae ZAC3 (RoZAC3) lipase, study its interactions with some natural substrates and evaluate the feasibility of fatty acid methyl esters (FAME) production by the immobilized lipase. Protein identification of RoZAC3 lipase was carried out using LC-MS/MS. The 3 D structure of the lipase was built using homology modelling and natural substrates such as tributyrin, tripalmitin and triolein were docked to the optimized 3 D model for investigation of enzyme-ligand interactions. RoZAC3 lipase, immobilized by adsorption on Lewatit VP OC 1600 was applied in the synthesis of fatty acid methyl esters (FAME). From the phylogenetic analysis, it was observed that RoZAC3 lipase was closely related (48%) to Rhizopus javanicus lipase (Q7M4U7). The predicted 3 D model was validated using the SWISS model validation server. Ramachandran and ERRAT plots were used to assess the amino acid environment and overall quality of the model. From the docking studies, the values of the binding energies obtained for tributyrin, tripalmitin and triolein were − 5.37, −5.27 and −5.77 respectively. At an enzyme:immobilization support ratio of 50 mg/g, transesterification reaction duration of 18 h and a temperature of 40 oC, the conversion reached above 80%. The molecular docking studies provided information on the interaction/modifications between the RoZAC3 lipase and triacylglycerols that can be exploited for numerous applications. The immobilized lipase could serve in hydro-esterification reactions adaptable for biodiesel production. Communicated by Ramaswamy H. Sarma

Biodiesel production from nonedible feedstocks catalyzed by nanocatalysts: A review

Biodiesel produced from vegetable oil has recently increased in popularity. However, these edible feedstocks (which are the apparent choice of triglycerides) will not be sufficiently sustainable, given the increasing demand for energy and food, and guaranteed inedible feedstocks are needed. Biodiesel can be generated from these alternative feedstocks using various catalysts. Current studies show that nanocatalysts are extensively used for this purpose and are more preferred than usual homogeneous and heterogeneous catalysts. These nanocatalysts exhibit many advantageous features, including efficient separation steps for both products and catalysts, elimination of the quenching process, high catalytic activity, and large surface area, and provide the possibility for reusability. According to recent reports, the use of nonedible oils and nanocatalysts, such as titanium-doped zinc oxide, magnesium oxide-doped magnesium aluminate, zirconium oxide and many others, are potent with an approximately 80–98 wt% yield of biodiesel under optimized conditions, suggesting that this approach is a suitable option for biodiesel synthesis. This review aims to explore the potency of nonedible feedstocks and nanocatalysts for fatty acid methyl ester synthesis. The findings of the most recent published studies are critically summarized. The catalytic reaction mechanism for biodiesel production is highlighted, focusing on the nanocatalysts. Some nonedible seeds have been reported, and their potency for biodiesel production has been assessed in detail.

Kinetic and thermodynamic study of enzymatic hydroesterification mechanism to fatty acid methyl esters synthesis

Eversa® Transform 2.0 lipase used as biocatalyst to biodiesel (fatty acid methyl esters – FAME) synthesis has been the target of interesting studies due to its thermostability and cost-effectiveness. In these researches, data about reaction conditions that result in satisfactory yields were investigated. Nevertheless, kinetic and thermodynamic parameters considering this enzyme are scarce. This paper presents an estimation of kinetic and thermodynamic parameters for the Eversa® Transform 2.0-mediated hydroesterification to FAME synthesis. Kinetic studies were performed for different methanol, water and lipase loads in distinct temperatures. Parameters adjusted by the thermodynamic model indicate that the hydrolysis is decisive in the overall hydroesterification reaction rate and the esterification reaction is endothermic (ΔHe = 38.98 kJ/mol). Formation of enzymatic complexes is favored by increasing the temperature, especially the enzyme-methanol inhibition complex. Statistical analysis showed that the model was not overparameterized, and the small confidence interval indicated good reliability of the estimated parameters.

Transesterification of used cooking sunflower oil catalyzed by hazelnut shell ash

Hazelnut shell ash was investigated as a new base catalyst for the transesterification of used cooking sunflower oil to biodiesel. To understand its catalytic properties, the prepared ash was characterized by EDX, XRD, TGA/DTA, Hg porosimetry, N2 physisorption, FE-SEM, and basic strength measurements. The effects of the catalyst loading in the range of 1–5% of the oil weight and the methanol-to-oil molar ratio of 6:1–18:1 on the kinetics of the fatty acid methyl esters synthesis were established. Moreover, the leaching and reusability of the catalyst were assessed. The obtained results revealed that hazelnut shell ash was mostly composed of K, Ca, and Mg. The highest ester content (98%) was achieved at the catalyst loading of 5%, the methanol-to-oil molar ratio of 12:1, and the reaction time of 10 min. The contribution of homogeneous catalysis because of the catalyst leaching was confirmed but did not determine the overall reaction rate. The catalyst can be reused after the recalcination at 800 °C for 2 h achieving the high methyl esters content (>96%) in 30 min after three subsequent runs. The overall reaction followed the pseudo-first-order kinetics with respect to triacylglycerols. A linear relationship between the apparent reaction rate constant and the catalyst loading and the methanol-to-oil molar ratio was determined. The determined value of the reaction rate constant was 0.0576 dm6/(min·mol2).

Design of a Genetically Programmed Biomimetic Lipase Nanoreactor

Alternative to the traditionally independent production of lipase, chemical synthesis of nano-carriers, and then preparing nanoimmobilized enzymes, we exploit a yeast genetically programmed virus biomimetic lipase nanoreactor in a sustainable manner. The nanoreactor biogenesis process integrated lipase production, protein component (coat-protein subunit and scaffold protein) production, self-assembly of protein components, and the encapsulation of lipase into protein nanocages using a simple process. It included overexpression of nanocage components, coat-protein subunits, and fused lipase-scaffold proteins and subsequent spontaneous self-assembly and encapsulation based on the specific interaction between the coat-protein subunit and the scaffold protein fused in the target lipase enzyme. The genetically programmable lipase nanoreactor showed improved stability under various harsh conditions, and was validated in fatty acid methyl ester synthesis with 86% yield at a high concentration of waste cooking oil (200 mM), which demonstrates the robustness and feasibility of the lipase nanoreactor in biodiesel production.

Fatty Acid Methyl Ester Synthesis in the Cold Plasma Reactor using CO_2 and Steam Mixture

Fatty Acid Methyl Ester Synthesis in the Cold Plasma Reactor using CO_2 and Steam Mixture

Fatty Acid Methyl Ester Synthesis through Transesterification of Palm Oil with Methanol in Microchannels: Flow Pattern and Reaction Kinetics

This work studied the flow pattern and reaction kinetics for fatty acid methyl ester (FAME) synthesis through transesterification of palm oil with methanol in a microchannel reactor. It was observe...

Utilization of waste automotive landfill engine oil for fatty acid methyl ester synthesis using microwave irradiation: an intensified approach

With increasing automotive vehicles, disposal of waste automotive landfill engine oil (WALEO) is foremost challenge. Present work investigated synthesis of fatty acid methyl esters (FAMEs) from WALEO using first stage of orthophosphoric-catalyzed acid esterification followed by subsequent stage of potassium hydroxide-catalyzed alkaline transesterification using conventional and intensified microwave methods. Process parameters for study were molar ratio of oil–methanol, and catalyst concentration. The optimize parameters of acid esterification for reducing acid value from 33.72 to 1.71 mg of KOH/g of oil were catalyst concentration: 12% weight/weight, reaction temperature: 60 $$^\circ{\rm C} $$ and molar ratio: 1:2 using conventional method. Nearly same results were obtained using microwave-assisted esterification but there was considerable decrease in process time requirement using intensified approach of microwave irradiations. Time required for processing was 210 and 30 min for conventional and microwave methods, respectively. Microwave accelerated the rate of reaction by 7.5 times. There was substantial decrease in energy requirement for esterification process and energy utilization was 14.2–26.4 mg/kJ for conventional and microwave methods, respectively. Transesterification of esterified oil were performed using microwave method. The optimized parameters for transesterification process were molar ratio: 1:6, catalyst concentration: 1% weight/weight, reaction time: 15 min and yield: 92.3%.

Microwave-Assisted, Base-Catalyzed Synthesis of Fatty Acid Methyl Esters from Seeds and Fish Oil Supplements.

Growing health awareness has resulted in the increased use of dietary supplements derived from plants and marine sources, leaving consumers unsure of their best options. There were three objectives of the present study. The first was to design and evaluate an efficient derivatization procedure. The second was to perform a comparative analysis of liquid oils and their corresponding capsules of hemp, chia, and flax seeds. The final objective was to determine the fatty acid (FA) composition of six fish oil products and compare it to the one provided on the label. For the FA profiling, we implemented two efficient, one-step, sustainable methods with high percentage recovery for the synthesis of FA methyl esters (FAME), which use base catalysis and microwave-assisted heating. Our results found no difference in nutritional value between liquid oils and capsules of the seed supplements, with flaxseed and chia offering a higher, beneficial n-3:n-6 ratio compared to hemp oil. Four of the fish oils analyzed contained significantly less eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) than their reported label, and the other two not only agreed with the manufacturers' declaration but were able to fulfill the daily adequate intake (AI) with fewer capsules.

Green Biodiesel Production from Various Plant Oils Using Nanobiocatalysts Under Different Conditions

The lipase-immobilized polyethyleneimine (PEI)- and polyacrylic acid (PAA)–coated magnetic silica nanocomposite particles (L-PEI-MS and L-PAA-MS, respectively) were prepared and applied at various transesterification reaction conditions. The reactions were carried out with soybean, sunflower, canola, and palm oils along with methanol or ethanol in the solvent-free and n-hexane systems. The highest fatty acid methyl ester (FAME) and fatty acid ethyl ester (FAEE) synthesis yields were obtained from the transesterification of palm oil, i.e., almost 7.7–10.2% higher than other oils. At the constant reaction conditions, the application of ethanol leads to higher (6.0–8.7%) reaction yields in comparison with methanol. In addition, irrespective of reaction conditions, the best performance was acquired by L-PEI-MS; e.g., the FAME and FAEE synthesis yield values of 81.2% and 88.3% were obtained from transesterification of palm oil in the solvent-free systems, respectively. Addition of n-hexane improved the synthesis of FAME and FAEE yield values to 88.9% and 93.3%, respectively, using L-PEI-MS. The transesterification reactions kinetics follows the Ping-Pong Bi-Bi mechanism with alcohol inhibition effects. The high catalytic performance of L-PEI-MS might be related to its hydrophobic nature, which enhances the accessibility of oil molecules to the immobilized lipases and hampers the deactivating effect of alcohol molecules on them.

Effect of Free Fatty Acid Pretreatment to Yield, Composition and Activation Energy in Chemical Synthesis of Fatty Acid Methyl Ester

Transesterification of waste cooking oil (WCO) for fatty acid methyl ester synthesis using calcium oxide (CaO) as a catalyst with absence and presence of free fatty acid (FFA) pretreatment (untreated and pretreated) prior to reaction have been investigated. The preliminary study was started from theoretical stoichiometric amount molar ratio of methanol to oil. This preliminary experiment showed that indeed, in transesterification with the chemical catalyst the molar ratio of methanol to oil should be exceeding the theoretical stoichiometric molar ratio, due to the fast reversible reaction. The highest FAME content of 81% was achieved at a temperature of 75 °C with pretreated FFA. The composition of methyl ester with pretreated FFA was affected by temperature, where increasing temperature leads to increasing of methyl oleate as major methyl ester in the product. The relation of temperature dependence was further studied by Arrhenius law correlation. It is shown that activation energy was affected by pretreatment of fatty acid. The activation energy (Ea) of transesterification with untreated and pretreated free fatty acid were found as ± 16 kJ/mol and ± 68 kJ/mol, respectively. Unlike untreated FFA, the Ea of transesterification with pretreated FFA was within the range of activation energy for transesterification for the base catalyst. This study showed that methyl ester synthesis was best obtained when FFA was pretreated prior to transesterification. In addition, WCO is a potential feedstock for biodiesel production since it is biodegradable, economic, environmentally friendly and abundantly available.

Roux-en-Y gastric bypass surgery alters serum metabolites and fatty acids in patients with morbid obesity.

AimBariatric surgery induces significant weight loss, increases insulin sensitivity, and reduces mortality, but the underlying mechanisms are not clear. It was hypothesized that Roux‐en‐Y gastric bypass (RYGB) surgery improves metabolic profile along with weight loss. The objective of this pilot study was to evaluate changes in serum metabolites and fatty acids (FA) at 2 weeks and 6 months after RYGB.Materials and MethodsSerum samples were collected pre‐surgery, at 2 weeks and 6 months post‐surgery from 20 patients undergoing RYGB surgery. Serum non‐esterified free FA (NEFA) were measured. Serum metabolites and FA were measured using nuclear magnetic resonance spectroscopy and improved direct fatty acid methyl ester synthesis and the gas chromatography/mass spectrometry method, respectively, in subjects who completed follow‐up at 6 months (n = 8).ResultsMean (standard deviation) percent total weight loss was 6.70% (1.7) and 24.91% (6.63) at 2 weeks (n = 15) and 6 months (n = 8) post‐surgery, respectively. NEFA were significantly reduced at 6 months post‐surgery (P = 0.001, n = 8). Serum branched chain amino acids, 2‐aminobutyrate, butyrate, 2‐hydroxybutyrate, 3‐hydroxybutyrate, acetone, 2‐methylglutarate, and 2‐oxoisocaproate were significantly reduced, while serum alanine, glycine, pyruvate, and taurine were significantly elevated at 6 months post‐surgery compared with pre‐surgery (n = 8, P < 0.05). Also, serum FA C10:0, C13:0, C14:0, C15:0, and C18:0 increased significantly (n = 8, P < 0.05) by 6 months post‐surgery.ConclusionsChanges in serum metabolites and FA at 6 months post‐RYGB surgery in this pilot study with limited number of participants are suggestive of metabolic improvement; larger studies are warranted for confirmation.

Bio-inspired silica lipase nanobiocatalysts for the synthesis of fatty acid methyl esters

Abstract Green production of biodiesel via enzymatic transesterification necessitates technological improvements for practical implementation. Heterogenization of biocatalysts has long demonstrated its advantages in biocatalytic processes. In this work, a lipase from Thermomyces lanuginosus (TL) has been immobilized on biomimetic silica nanoparticles using two different strategies: in situ entrapment and adsorption/covalent surface immobilization. Variables such as mass of nanobiocatalyst, amount of immobilized enzyme, and activity per gram of silica were studied following a factorial design for the in situ immobilization. The influence of the enzymatic load on the stability and activity of the catalyst was studied for both the surface immobilized and the entrapped lipase. Immobilized preparations were characterized and assayed in the production of fatty acid methyl esters (FAMES). The entrapped nanobiocatalysts were more stable and active than the soluble TL, the commercial immobilized TL and the surface immobilized counterparts. However, surface immobilized lipase reached a maximum yield of 88% in the synthesis of FAMES from canola oil and methanol, surmounting from the yield obtained with the commercial immobilized TL by 10%. Accumulated specific productivity for the entrapped biocatalyst reached 65.6 μmoles FAME/g catalyst/min after repeated batch operation. Biomimetic silica demonstrated its versatility and robustness as a support for TL immobilization in the synthesis of FAMES.

Graphene Oxide and Microwave Synergism for Efficient Esterification of Fatty Acids

The synthesis of biodiesel or fatty acid methyl esters (FAMEs) from alternative feedstocks such as waste cooking oil through conventional transesterification process is challenged by the presence of significant amounts of free fatty acids (FFAs). Alternatively, these FFAs can also serve as raw material for the synthesis of FAMEs through acid-catalyzed esterification. In this study, we utilized graphene oxide (GO) as a carbon-based heterogeneous acid catalyst in synergy with microwave (MW) heating as a novel approach for an efficient synthesis of FAMEs by esterification reaction at a shorter reaction time. Under this process, 99.2% FAME was achieved at 3 min, methanol/oleic acid molar ratio of 12, MW power of 200 W, and 1 wt % catalyst. It shows excellent catalytic performance, which is more active than Amberlyst 15, sulfated zirconia, and graphite oxide. Among the process variables investigated, the ratio of methanol/oleic acid is the most important factor for higher FAME yield. Additionally, the MW absor...

Synthesis of kemiri sunan (reutealis trisperma (blanco) airy shaw) H-FAME through partially hydrogenation using Ni/C catalyst to increase oxidation stability

Hydrogenated FAME (H-FAME) synthesis of Kemiri Sunan (Reutealis Trisperma (Blanco) Airy Shaw) using Nickel/Carbon catalyst is one of the methods to improve the oxidation stability of Kemiri Sunan biodiesel. The partial hydrogenation reaction breaks the unsaturated bond on FAME (Fatty Acid Methyl Ester), which is a key component of the determination of oxidative properties. Changes in FAME composition by partial hydrogenation reaction are predicted to change the oxidation stability, so it does not cause deposits that can damage the diesel engine injection system, pump system, and storage tank. Partial hydrogenation reaction is under conditions of 120 °C and 6 bars with 100:1, 100:5, 100:10 % wt catalyst in the stirred semi-batch autoclave reactor. H-FAME synthesis with 100:5 % wt Ni/C catalyst can decrease the iodine number which is the empirical measure of the number of unsaturated bonds from 166.77 to 155.64 (g-I2/100 g) with an increase of oxidation stability from 650 to 665 minutes.

Al-alginate as acid catalyst for FAME synthesis using electrolysis process

A novel solid acid catalyst, which was prepared from sodium alginate and aluminum chlorides and characterized by SEM-EDS, XRD and FT-IR spectrometry. The catalyst was used for the synthesis of fatty acid methyl ester (FAME) via (trans)esterification reaction using electrolysis process. Purity and FAME components of biodiesel were measured by GC-MS. The results showed that the aluminum-alginate prepared in a cheap and easy way exhibited high catalytic activity. FAME conversion from used-cooking oil was obtained by 93.82% in the presence of 10 wt.% of catalyst dosage upon refluxing for 4 h of methanol and oil in a molar ratio of 6:1.