Methyl Ester Content Research Articles

Study of fluid flow movement of biodiesel production with helical static mixing reactor using computational fluid dynamics(CFD)

The simulation was carried out using the computional fluid dynamics method to find out and read the flow pattern in the reactor. Simulations were implemented in nine reactors, which every reactor have 12 helical type static mixer elements. The elements in every static mixer are twisted 180°, and between elements are glued at an angle of 90°. Also performed two scenarios on the modification of the torsion angle of the elements, namely 225° and 270° . Based on the flow velocity and viscosity, the static mixer with 270° torsion angle has a good mixing pattern compared to the torsion angle of 225° and 180° . The viscosity was descresed by 5.4% and the velocity was increased by 3.05%. The concentration of fatty acid methyl ester using static mixer 270° (as much as 97.50%) was higher than the 225° torsion angle (as much as 97.46%) and the 180° torsion angle (as much as 97.41%).

Reliable connectionist tools to determine biodiesel cetane number based on fatty acids methyl esters content

The self-ignition ability of fuels is characterized using a property called cetane number (CN). The main objective of this research work is to develop accurate models using smart algorithms to predict the CNs associated with 149 samples of biofuels collected from the literature. In this study, we use two machine learning (ML) algorithms, namely least squares support vector machine (LSSVM) and extra trees (ET) and an experimental dataset containing a variety of fatty acids methyl esters (FAME). To assess the predictive performance of the developed models, various statistical parameters including average relative deviation in percentage (ARD%), average absolute relative deviation in percentage (AARD%), and coefficient of determination (R2) are calculated. The statistical and graphical analyses presented in this study reveal that the ET model outperforms the LSSVM model in predicting the CN associated with the biodiesel systems from the collected dataset so that the value of AARD% is less than 3% for the ET method. It is also found that Linoleic (18:02) is the most important factor affecting the CN value of the biodiesels. According to the sensitivity analysis, the CN value decreases upon an increase in the concentration of Palmitoleic (16:01), Oleic (18:01), Linoleic (18:02), and Linolenic (18:03); this is in agreement with the experimental studies. The smart modelling techniques used in this study can be utilized as alternative methods to direct measurements for determination of biodiesel CN.

Flow and crystallization of saturated fatty acid methyl esters and their binary mixtures

AbstractDemand for biodiesel has increased due to being a more environmentally‐friendly fuel. Cold weather operation of biodiesel is challenging due to fatty acid methyl ester (FAME) content in biodiesel. Saturated FAMEs crystallize at relatively high temperatures, increase the viscosity of biodiesel, and can clog fuel lines. Here, several factors altered crystallization temperature (CT) of FAMEs, including composition, shear rate, and cooling rate. The crystallization of pure and binary mixtures of methyl palmitate, methyl myristate, and methyl stearate were studied under shear flow and static conditions. Static phase CTs of pure methyl palmitate, methyl myristate, and methyl stearate were 26, 14, and 35°C, respectively. In binary mixtures, CTs were depressed up to 7°C, which agreed with freezing point depression theory. Increasing shear rate up to 100 s−1 decreased CT by 2°C compared to static conditions. Decreasing cooling rate from 1 to 0.1°C/min increased CT less than 2°C. Overall, FAME composition altered CT more than shear flow or cooling rate for pure and binary mixtures of three FAMEs.

Biodiesel Production from Crude Palm Oil Using Kapok Skin KOH (<i>Ceiba Pentandra</i>) Catalyst as Solid Green Catalyst

Biodiesel is one type of renewable alternative energy that has great potential to be developed. Biodiesel is a fuel consisting of a mixture of mono-alkyl esters of long-chain fatty acids made from renewable sources, such as vegetable oils or animal fats, one of which is Crude Palm Oil (CPO). Crude Palm Oil (CPO) contains free fatty acids in high levels, so treatment is needed to reduce free fatty acids by a reaction known as the esterification reaction. Then, the transesterification process is carried out to produce biodiesel (methyl ester). The purpose of this study was to analyze the effect of catalyst mass, a mole ratio of CPO to moles of methanol and the effect of adding THF co-solvent to biodiesel purity. The catalyst used is a heterogeneous catalyst from kapok fruit peel waste. Kapok fruit rind was calcined at 700˚C for 8 hours. The independent variable varied the mole ratio of oil to methanol in a 1:4 ratio; 1:6; 1:8; and 1:10 with a catalyst weight variation of 3 and 4%. Meanwhile, for the addition of co-solvent, variations of THF: methanol v/v 1:1 and 2:1, were carried out. The biodiesel properties such as density, viscosity, water content and acid number, were evaluated and compared with the Indonesian National Standard. The results showed that the transesterification reaction with the addition of co-solvent resulted in a higher methyl ester content than that without the addition of co-solvent. The highest yield of methyl ester without the addition of co-solvent was 79.16%, while the yield of the methyl ester with the addition of THF co-solvent with a ratio of 1:1 and 2:1 v/v to methanol was 90.09 and 94.09%, respectively. The highest methyl ester content (94.09%) was achieved by the addition of THF: methanol = 2:1, CPO: methanol molar ratio = 1:6 and 4%-wt catalyst weight. The results obtained in this study indicate that a green catalyst made from kapok skin can be used to produce biodiesel and also the addition of co-solvent can increase the yield of methyl esters, so that high purity is obtained.

Analysis of The Ratio Catalys Promoters BaO/CaO to Methyl Ester Content and Yield in Biodiesel Using Electrocatalytic Reactor

The efficiency of biodiesel production from vegetable oils needs to be developed. The process of transesterification using heterogeneous catalysts has been widely studied to replace the role of homogeneous catalysts. The use of BaO promoters into metal oxides increases the activity of heterogeneous catalysts in transesterification reactions. This study was conducted to provide information about the effect of BaO concentrations that are filtered into calcium oxide (CaO) on the transesterification reaction of tofu pulp oil into methyl ester using electrocatalytic methods. The study was conducted at room temperature with a voltage of 18.5 Volts and a reaction time of 120 minutes. Methanol ratio: tofu oil is used at 10:1 with Tetra Hydro Furan (THF) as a co-solvent. The electrocatalytic process is carried out using graphite electrodes. The research variables are the concentration of BaO promoters used at 2%, 4%, and 8%. The parameter of the test is methyl ester content obtained from the results of transesterification reactions with chromatography gas analysis (GC-MS). In this study, the BaO/CaO catalyst was impregnated by wet method and calcined at 450oC for 180 minutes. From the experiments conducted the highest methyl ester yield was obtained in bao / cao catalyst 2% with a yield of 99.99% and biodiesel yield of 94%.

Scenedesmus sp. Harvesting by Using Natural Coagulant after Phycoremediation of Heavy Metals in Different Concentrations of Wet Market Wastewater for Potential Fish Feeds

The high level of organic elements and nutrients in wet market wastewater (WMW) has raised public concerns. The phycoremediation method, which utilizes microalgae, can be further valorized by converting it into various valuable potential bioproducts. The production of Scenedesmus sp. in WMW was investigated as an ingredient for fish feeds in this study. The potential of two natural plant-based coagulants, Cajanus cajan (pigeon pea) and Cicer arietinum (chickpea), for harvesting microalgae Scenedesmus sp. were compared. Statistical analysis and response surface methodology were used to investigate the flocculant dosage and pH effect on harvesting efficiency. It was found that Cajanus cajan (CC) and Cicer arietinum (CA) both had a harvesting efficiency of 89.29% and 88.56%, respectively. The optimal dosage and pH for CC were 178.75 mg/L and 11.72, and for CA, they were 137.77 mg/L and 9.15. This study indicated that Scenedesmus sp. can remove heavy metals cadmium (87.24%), chromium (85.55%), and ferum (90.35%), respectively. The level of heavy metals content (μg/kg in ppb) in dry biomass was found ultimately low and did not exceed the maximum concentration set up by the European Commission Regulation. The Fourier Transform Infrared (FTIR) analysis of microalgae biomass displayed O-H, N-H and C-H functional groups. The protein–lipid for the potential application as fish feed in the sample was 45.8–43.6% and 15–13%. Moreover, the biomass contained 53% to 40% oleic acid, which is high concentration of fatty acid methyl ester (FAME). As a result, there is high potential of Scenedesmus sp. in wastewater treatment; both natural coagulants give the possibilities for efficient microalgae biomass recovery as fish feed and are applicable for improving the quality of Scenedesmus sp. cultivated in WMW.

Design and fabrication of smooth periodic constriction reactor to biodiesel production from waste cooking oil

Recently, due to decreasing fossil energy reserves, research on renewable energy production has become necessary. Biodiesel is an alternative renewable energy to gas oil fuel. The study aims to design and evaluate some smooth periodic constriction (SPC) reactor parameters for biodiesel production from waste oil. Using the Reynolds-average Navier-Stokes equations, dimensions of the constriction area, expansion area and length of each bubble were found to be 2, 5 and 13 mm, respectively. It is observed that increasing the reactor length increases the conversion percentage. After increasing the reactor length from 1 to 2 m, the conversion percentage rises from 40% to 60%. The methyl ester content increases with increasing velocity from 1 to 2.3 m/s. Increasing the molar ratio from 4:1 to 6:1 increases the methyl ester content from 51% to 60%. The optimization points of velocity, reactor length and molar ratio were 2.28 m/s, 2.75 m and 6.54, respectively. Results show that the SPC needs to be combined with another method to increase yield and meet 96% methyl ester content according to standard. Finally, the SPC can be suggested to mix two or more liquids in a continuous process.

NITROGEN STARVATION INDUCED LIPID ACCUMULATION BY Chlorococcum infusionum (EAU-10) AS POTENTIAL RENEWABLE SOURCE OF LIPID FOR BIODIESEL PRODUCTION

Microalgae are organisms effective of accumulating high quantity of industrially important lipids with promising characteristics as an excellent feedstock for biodiesel production. This study assess the possibility of using a green microalga, Chlorococcum infusionum (EAU-10) for biodiesel production by evaluating the growth characteristic, lipid yield and fatty acid profile of the microalga cultivated at varying concentrations of nitrogen source (0.375 - 1.50 g L-1 NaNO3). High lipid accumulation was observed in nitrogen-starved cultivation condition (0.375 g L-1 NaNO3) after 23 days of growth. Maximum biomass concentration of Chlorococcum infusionum (EAU-10) under nitrogen starved condition is 0.577 ± 0.003 g L−1 with 21.26% oil content per dry weight of algal biomass and lipid productivity of 22.08 mg L−1 day−1. Nitrogen starvation caused an increase in the total oil content and a decrease in biomass production of the microalga. Profiling of fatty acids of the obtained algal biodiesel shows methyl palmitate (C16:0) and methyl nonadecanoate (C19:0) contribute to almost 70% of Chlorococcum infusionum (EAU-10) fatty acid methyl esters (FAME) profile. Overall, a total of 74.58% of saturated fatty acid (SAFA) methyl ester content is present in the algal lipid, which is exceedingly high in contrast to other similar studies. Analysis of C. infusionum FAME profile in relation to some important fuel properties showed that the algal oil has the potential to produce biodiesel with excellent fuel qualities.

Fungal Fermented Palm Kernel Expeller as Feed for Black Soldier Fly Larvae in Producing Protein and Biodiesel.

Being the second-largest country in the production of palm oil, Malaysia has a massive amount of palm kernel expeller (PKE) leftover. For that purpose, black soldier fly larvae (BSFL) are thus employed in this study to valorize the PKE waste. More specifically, this work elucidated the effects of the pre-fermentation of PKE via different amounts of Rhizopus oligosporus to enhance PKE palatability for the feeding of BSFL. The results showed that fermentation successfully enriched the raw PKE and thus contributed to the better growth of BSFL. BSFL grew to be 34% heavier at the optimum inoculum volume of 0.5 mL/10 g dry weight of PKE as compared to the control. Meanwhile, excessive fungal inoculum induced competition between BSFL and R. oligosporus, resulting in a reduction in BSFL weight. Under optimum feeding conditions, BSFL also registered the highest lipid yield (24.7%) and protein yield (44.5%). The biodiesel derived from BSFL lipid had also shown good compliance with the European biodiesel standard EN 14214. The high saturated fatty acid methyl esters (FAMEs) content (C12:0, C14:0, C16:0) in derived biodiesel made it highly oxidatively stable. Lastly, the superior degradation rate of PKE executed by BSFL further underpinned the sustainable conversion process in attaining valuable larval bioproducts.

Multi-objective tailored optimization deciphering carbon partitioning and metabolomic tuning in response to elevated CO2 levels, organic carbon and sparging period.

Microalgae have garnered much contemplation as candidates to fix CO2 into valuable compounds. Although microalgae have been studied to produce various metabolites, they have not yet proved successful for commercialization. Since, handling such problems practically requires satisfying multiple parameters simultaneously, we put forth a multi-parameter optimization strategy to manipulate the carbon metabolism of Scenedesmus sp. to improve biomass production and enhance CO2 fixation to increase the production of fuel-related metabolites. The Box-Behnken design method was applied with CO2 concentration, CO2 sparging time and glucose concentration as independent variables; biomass and total fatty acid methyl ester (total FAME) content were analyzed as response variables. The strain is supplemented with both CO2 and glucose with an aim to enhance carbon flux and rechannel it towards carbon fixation. As per the results obtained in this study, Scenedesmus sp. could effectively exploit high CO2 concentration (15%) for longer duration under high concentration of glucose supplementation (9g/L) producing a biomass of 635.24±39.9μg/mL with a high total fatty acid methyl ester (FAME) content of 71.29±4.2μg/mg, significant acetyl-CoA carboxylase enzyme activity and a favorable fatty acid profile: 35.8% palmitic acid, 10.5% linoleic acid and 30.6% linolenic acid. The carbohydrate content was maximum at 10% CO2 sparged for the longest duration of 90min under glucose concentration of 9g/L. This study puts forth an optimal design that can provide evidence on comprehending the carbon assimilation mechanism to enhance production of biomass and biofuels and provide conditions to microalgal species to tolerate CO2 rich flue gas.

Using discarded oyster shells to obtain biodiesel

Objective: To evaluate the CaO made from oyster shell (C. virginica) as a heterogeneous catalyst in the transesterification of edible vegetable oil used for the production of biodiesel. Design / methodology / approach: A completely randomized experimental design was used, which grouped 3 treatments with 3 repetitions, generating a total of 9 experimental units. The response variable was the performance of the transesterification reaction that was evaluated with 2%, 3% and 4% of CaO obtained from oyster shells. The density, kinematic viscosity, acidity, and conversion efficiency to methyl esters were determined by 1H NMR of the products of each treatment. Results: The treatment with 3% catalyst showed the highest reaction yield (92.2%) compared to the treatments with 2% (86.8%) and 4% catalyst (87.13%). The 1H NMR spectra confirmed the presence of methyl esters in the product of the three treatments. The treatment with 3% and 4% by weight of catalyst presented products with similar characteristics with acceptable values ​​of density, viscosity and acid number in accordance with the ASTM D6751 and EN1421 standards. Study limitations / implications: A concentration of 2% by weight of CaO generates a conversion percentage far from the content of methyl esters established by the ASTM D6751 and EN14214 Standards (> 96.5%). Findings / conclusions: 1H NMR results indicate that the conversion efficiency to methyl esters is positively affected by the amount of catalyst. In the treatments with catalyst loading greater than 2%, the conversion to methyl esters increased significantly to values ​​around 90%.

Dehydration of fatty acid methyl ester mixtures from enzymatic biodiesel using a modified PVDF membrane

This study aimed to investigate the efficiency of microfiltration with a polymeric membrane in the dehydration of fatty acid ester mixtures. The dip-coating method was used to modify the surface of polyvinylidene fluoride (PVDF) hydrophilic membranes using silazane to render them hydrophobic. The membranes were characterized by the contact angle, Fourier-transform infrared spectroscopy (FTIR), zeta potential, field emission scanning electron microscopy (FESEM), membrane water absorption, silazane crosslinking to the membrane surface, and chemical compatibility of membranes to methanol. The microfiltration experiments were carried out in the dead-end and crossflow configurations. Membrane performance was evaluated by permeate flux values, mass reduction ratio, moisture, acidity, and glycerol content in the permeate. Mixtures with different compositions and concentrations of methyl ester, methanol, water, oleic acid, glycerol, and enzyme were used. Silazane deposition time of 60 min at 1 mg silazane/g toluene resulted in the best performance. The modification resulted in chemical and morphological changes in the membrane surface to render it hydrophobic changing its water contact angle from 0 to 94°. For dead-end and crossflow filtration configurations, the modified membranes presented the highest fluxes when compared to the unmodified control membrane, regardless of the composition of the mixtures. All biodiesel mixtures treated with the modified membrane had a decreased water content and an increased oleic acid content in the permeate. This work demonstrated that biocatalyzed fatty acid methyl esters (FAME) can be dehydrated using silazane-modified membranes, resulting in increased separation efficiency.

CO2-triggered switchable solvent for lipid extraction from microalgal biomass

This study proposed a novel and energy-efficient method using switchable polarity solvents for lipid recovery from microalgae. Different from the existing methods, use of switchable polarity solvents does not require the fractional distillation for separation of lipid and solvent by only converting the polarity of the solvent after lipid extraction. When a non-polar amine solvent reacts with CO2, amino group (NH) can be transformed to a polar form, i.e. carbamate (NHCOO−). Nuclear magnetic resonance (NMR) spectrum indicated that only secondary amines are convertible to a polar compound of carbamate after CO2 treatment. The polarity switching potential of each amine candidate was quantitatively evaluated by normalized polarity energy (ETN). Dipropylamine (DPA) showed the greatest change in ETN from 0.452 to 0.789 kcal/mol (ETN of water = 1.0 kcal/mol) before and after CO2 treatment. DPA is a potential polarity switchable solvent capable of achieving an excellent lipid extraction yield of 7.51% from tested microalgal biomass (Chlorella vulgaris) with 9.16% of total lipid content and 95.5% fatty acid methyl esters (FAMEs) content. Furthermore, the used solvent could be recovered at the high efficiency of 84.0%. With a significant polarity switchability from nonpolar amine to carbamate in the presence of CO2, DPA, a secondary amine, could be suggested as a suitable solvent used for both extraction of lipids with a higher FAMEs content from microalgae and separation of lipid by only adding CO2.

Biodiesel Generation from Palm Kernel Biomass via an In-situ Transesterification Approach

This study investigated an in-situ transesterification of palm kernel biomass at variable reaction times (4 h, 5 h and 6 h) and catalyst loading (2 wt%, 3 wt.% and 5 wt.%). The biodiesel yields were observed to vary with these parameters. GC-MS analysis showed high fatty acid methyl esters (FAMEs) contents for all the prepared biodiesel samples (C-18:1, C-14:0, C-16:0, and C-18:0). 2 wt.% catalyst loading and 4 h reaction time were observed to be the best reaction conditions from the experimented parameters that gave the best biodiesel yield at 300 rpm mixing intensity. The in-situ method recorded a higher degree of oil extraction and efficient conversion of oil to biodiesel (93.93%) compared to the conventional transesterification method which gave 89.45%. The kinematic viscosity, acid value and iodine value of 3.96 mm2/s, 0.56 mg KOH g–1 and 120 g 100 g–1 were found to be within the limits of ASTM D6751-09 and EN14214 standards. These results confirm that efficient production of biodiesel from palm kernel biomass could be possible through an in-situ acidic transesterification process.
 Keywords: Biodiesel, fatty acid methyl ester, palm kernel biomass, transesterification

Comparative analysis of combustion and heat release characteristics of Alexandrian Laurel methyl ester fueled VCR DI diesel engine

This work explores the comparative analysis of some important characteristics related to combustion and heat release of a four stroke diesel engine, using Alexandrian Laurel methyl ester. The diesel-methyl ester blends were in the ratio of 05:95, 10:90, 15:85, 20:80, 25:75, and 30:70 by volume and were designated as AL05, AL10, AL15, AL20, AL25, and AL30, respectively. Under steady state conditions, the experimentation was carried out at constant speed. The characteristics such as cylinder pressure, rate of pressure rise, mass fraction burned, heat release rate, cumulative heat release, and mean gas temperature of methyl ester blends were studied. Higher maximum cylinder pressures were observed for methyl ester blends. The mass fraction burned was better for the AL20 blend, but with an increase in methyl ester concentration, the mass fraction burned decreased. The heat release rate of diesel at all compression ratios was found to be the maximum compared to methyl ester blends. The combustion and heat release characteristics indicate that Alexandrian Laurel methyl ester has the properties that make it an attainable additive to conventional fossil diesel.

Optimization of the real conversion efficiency of waste cooking oil to fame

This work presents a polynomial regression model for the optimization of the content of fatty acid methyl esters and the conversion yield of waste vegetable oil to biodiesel. The equations are optimized to obtain the maximum fatty acid methyl esters yield, which is the product of the conversion yield and the fatty acid methyl esters content in the biodiesel. The independent variables considered are the type of catalyst used (KOH and NaOH), percentage of catalyst (0.6%, 1.0%, and 1.5% w/w with respect to oil), and the methanol: oil molar ratio (6:1, 7.5:1, and 9:1). The prediction models are obtained by using nine experimental points for each catalyst. The validation is developed with four main experimental points from the mapping. A polynomial relation is obtained as a consequence, which correlates each of the experimental variables with the fatty acid methyl esters and conversion yield. The optimization of the proposed models shows an error of 2.66% for the fatty acid methyl esters, and an error of less than 1% for the conversion yield are obtained. This work presents a straight forward methodology to obtain the best chemical conditions in the production of biodiesel by using a small number of experiments, obtaining good results. This methodology can be applied for biodiesel production from any raw material, recalculating each of the regression constants thus allowing to obtain the highest quantity of oil to be converted in fatty acid methyl esters.

Sunflower oil methanolysis over modified CaO catalysts

Oil methanolysis over modified CaO catalysts was studied to assess the catalytic performance and to define an appropriate kinetic model. CaO was modified by commercial glycerol and a deep eutectic solvent (DES), choline chloride : glycerol (ChCl : Gly), to obtain catalytically active complexes of CaO and glycerol. The main goal was to investigate the effect of the obtained complexes on the reaction rate and fatty acid methyl ester (FAME) content and to describe the variation of the triacylglycerol (TAG) conversion degree during the reaction time. Fourier transform infrared spectroscopy (FTIR) was applied to confirm the formation of CaO complexes with glycerol or the glycerol-based DES. Different catalyst loadings (0.5, 1, and 5 % of oil weight) and methanol-to-oil molar ratios (6 : 1 and 12 : 1) were applied for investigation of the sunflower oil methanolysis at 60 oC. Two kinetic models were employed yielding the kinetic parameters, which depended on the catalyst loading and the methanol-to-oil molar ratio. Both models showed valid applicability for describing the kinetics of the reactions catalyzed by both complexes (the mean relative percent deviation was lower than 10 %).

Transesterification synthesis of high-yield biodiesel from black soldier fly larvae by using the combination of Lipase Eversa Transform 2.0 and Lipase SMG1

The larvae of black soldier fly (BSFL) are rich in lipids, and in the current study, BSFL was used to produce biodiesel by enzymatic transesterification with methanol. Biodiesel obtained by free lipase-catalyzed transesterification is always with side-reactions. To address the limitation of free lipase, for the first time, Lipase SMG1 and Lipase Eversa Transform 2.0 were combined to use as catalysts at the same time. The effects of different reaction conditions on the yield of biodiesel were investigated, including the type of enzyme, reaction temperature, and molar ratio of BSFL to methanol. The molar ratio of BSFL to methanol 1:3, one-step addition of methanol at 25 °C were selected as optimal conditions. The fatty acid methyl ester content achieved to 98.45% after 8h reaction under the optimal conditions. Moreover, the main properties of the final biodiesel indicators met the EN14214 biodiesel standard.

Evaluation of a New Cerium Oxide-Bismuth Oxide-Based Nanobiocomposite as a Biocatalyst for Biodiesel Production

Biodiesel is a promising renewable energy source that can be used together with other biofuels to help meet the growing energy needs of the rapidly increasing global population in an environmentally friendly way. In search for new and more efficient biodiesel production methods, this work reports on the synthesis and use of a novel biocatalyst that can function in a broader range of pH and temperature conditions, while producing high biodiesel yields from vegetable oils. Biodiesel was synthesized by transesterification of non-edible Eruca sativa oil using a lipase from Aspergillus niger that was immobilized on cerium oxide bismuth oxide nanoparticles. The synthesized nanoparticles were first grafted with polydopamine which facilitated the subsequent anchoring of the enzyme on the nanoparticle support. The enzyme activity, pH and temperature stability, and reusability of the immobilized lipase were superior to those of the free enzyme. Following response surface methodology optimization, the highest biodiesel yield of 90.6% was attained using 5 wt% biocatalyst, methanol to oil ratio of 6:1, reaction temperature of 40 °C, pH of 7, and reaction time of 60 h. The produced biodiesel was characterized by Fourier transform infrared spectroscopy and its fatty acid methyl ester composition was determined by gas chromatography-mass spectrometry. Erucic acid methyl ester was identified as the major component in biodiesel, with 47.7 wt% of the total fatty acid methyl esters content. The novel nanobiocatalyst (Bi2O3·CeO2@PDA@A.niger.Lipase) has the potential to produce high biodiesel yields from a variety of vegetable oils.

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).