Transesterification Of Triglycerides Research Articles

Modeling and simulation of biodiesel synthesis in fixed bed and packed bed membrane reactors using heterogeneous catalyst: a comparative study

In this study, modeling and simulation of biodiesel synthesis through transesterification of triglyceride (TG) over a heterogeneous catalyst in a packed bed membrane reactor (PBMR) was performed using a solid catalyst and compared with a fixed bed reactor (FBR). The kinetic data for the transesterification reaction of canola oil and methanol in the presence of solid tungstophosphoric acid catalyst was extracted from the published open literature. The effect of reaction temperature, feed flow rate, disproportionation of the reactants, and reactor length on the product performance was investigated. Two-dimensional and heterogeneous modeling was applied to PBMR and the resultant equations were solved by the Matlab software. Moreover, the velocity profile in the membrane reactor was obtained. The results showed the best conditions for this reaction are 180 °C, the molar ratio of methanol to oil equal 15:1, and the input flow rate of 0.5 mL/min. In this condition, a conversion of 99.94% for the TG can be achieved in the PBMR with a length of 86 cm while a length of 2.75 m is required to achieve this conversion of the FBR. Finally, the energy consumption for the production of 8000 ton/y biodiesel in a production plant using the PBMR and the FBR was obtained as is 1313.24 and 1352.44 kW, respectively.

Synthesis of Guanidine and Its Deposition on Bacterial Cellulose as Green Heterogeneous Catalyst for Transesterification to Methyl Esters

Green catalysts used in the transesterification reaction of biodiesel must have biodegradability and non-toxicity as their main characteristics, being thus friendly to the environment, since they perform in processes in which the content of CO2, which is increasing from year to year, should be reduced. As a consequence, their manufacture can be extremely rigorous. This work presents the two-step construction, synthesis, and deposition of such a green heterogeneous catalyst and its testing in the catalysis of the transesterification of triglycerides with methanol, resulting in methyl esters. A CSTR-type reactor was used to perform transesterification, and the biodiesel yields obtained had values in the range of 91.7–95.7%, using 2, 3, and 4 g/g catalyst to oil, under conditions like those for obtaining commercial biodiesel in homogeneous catalysis, i.e., a 65 °C process temperature and a 4:1, 5:1 or 6:1 methanol-to-oil molar ratio.

Utilization of Keplerate-type polyoxomolybdates {Mo132} supported on hierarchical porous SOM-ZIF-8 as reusable catalyst boosts biodiesel production from acidic soybean oils by simultaneous transesterification-esterifications

Improving the reactant mass transfer on the catalyst surface is a feasible approach to fabricate a robust solid catalyst for efficiently promoting the biomass macromolecules-involving reactions, specifically for biodiesel production by using non-edible acidic oils as feedstocks. In this premise, to reduce the mass transfer resistance, the hierarchical porous SOM-ZIF-8 was firstly synthesized using polystyrene spheres (PS) as templates and then employed as catalyst supports for loading of Keplerate-type polyoxomolybdates {Mo132} to prepare a novel {Mo132}@SOM-ZIF-8 solid acid catalyst. The catalyst characterization results revealed that the active species of {Mo132} clusters were well-dispersed on the SOM-ZIF-8 support and the primary framework of the SOM-ZIF-8 support remained nearly unaltered after the preparation processes. This prepared catalyst featured three-dimensional ordered hierarchical porous structure and dual Bronsted-Lewis acid sites, with a large surface area of 736.26 m2/g and high acidity of 903 μmol/g, presenting high activities for concurrent triglyceride transesterification and free fatty acids (FFAs) esterification. With the acidic soybean oils as feedstocks, 93.9 % of oil conversion and full FFA conversion to biodiesel were achieved over this solid catalyst at 130 °C for 8 h with a catalyst loading of 2 wt%, thus imparting the great potential for a one-pot efficient biodiesel manufacture from the acidic oils to comply with the demand of green and clean production. The synergy between the hierarchical porous structure and the strong acidity emerged, thus boosting the catalytic performance of this solid catalyst for the heterogeneous biodiesel production. The good FFA and moisture-resistance capacity was shown for this catalyst even in the case of moisture content of 3 % and FFA content of 25 %. Further, this catalyst showed excellent reusability without significantly losing its catalytic performance even after five runs, providing a deeper insight into constructing efficient solid catalysts with hierarchical porous structure that are utilized for cost-effective production of biodiesel from the non-edible acidic oils.

Purification and use of crude green glycerol from the transesterification of triglycerides in the formulation of an alcohol gel hand sanitizer

The aim of this study was to produce an alcohol gel hand sanitizer containing green glycerol. Crude glycerol was purified using chemical and physical treatments. The sanitizer was prepared using 71.100 g of 99.3° GL ethanol, 28.0 g H2O, 0.5 g of Carboxypolymethylene [Carbopol 940® or Carbomer], 5 drops of triethanolamine (pH 5–7), and glycerol (1.5% w/w). The thermal behavior of the ethanol, carbopol, triethanolamine, glycerol, and alcohol gels were evaluated using Thermogravimetry and Differential Thermal Analysis. The apparent viscosity was obtained using a rotary viscometer. The determination of in vitro spreadability was achieved by an adaptation of the Knorst method. The ethanol content was measured by headspace gas chromatography using a flame ionization detector. The thermal behavior of the gels was influenced by the presence of glycerol, which confirms the possible network interactions formed. The relative densities of the samples were between 0.887 and 0.890 g/cm3. No alteration of the pH of the formulation resulted from the incorporation of glycerol. The apparent viscosities of the alcohol gels were greater than 20,000 cP. No alteration in the in vitro spreadability of the gel alcohol (530.6 mm2) resulted from the addition of glycerol. Hand sanitizer was produced using glycerol from a transesterification reaction. It represents an alternative use for the glycerol being produced in biodiesel processes. The product satisfied the requirements of WHO that preconize a formulation containing 1.45% glycerol as an humectant to protect skin against dryness and dermatitis.

Novel concepts for the biocatalytic synthesis of second-generation biodiesel

Biodiesel is synthesized by the transesterification of triglycerides of oils with short-chain alcohols, such as methanol and ethanol. According to the Renewable Energy Directive guidelines (RED II 2018/2001/EU) the contribution of advanced biofuels, which do not include edible oils, towards the overall EU target, is at 1% in 2025 and at least 3.5% in 2030. Bioprocesses that valorize non-edible oils for the production of second-generation biodiesel could play a critical role in achieving this goal. Immobilized lipases, as well as other enzyme classes, such as cutinases and acyltransferases, are utilized as biocatalysts for this process. For the sustainability of the process, renewable materials can be used as immobilization matrices, or even enzymes anchored on the cells as whole-cell biocatalysts. Membrane reactors can also be employed to facilitate the enzymatic transesterification by conducting a continuous enzymatic reaction and simultaneously separate the products in a single operation. The advances on the aforementioned fast-pacing fields are presented in this work.

Macro porous ZIF-8 beads: Promising supports for enzyme immobilization

In recent years, metal–organic frameworks (MOFs) have emerged as promising supports for enzyme immobilization because they are highly designable and structurally diverse. However, the high porosities of conventional MOFs cannot be fully utilized for reactions involving large molecules, such as triglyceride transesterification reactions that produce biodiesel. Macroporous MOFs have been used to enhance diffusivity and, consequently, the reaction rate. Modifying MOFs with alginate to form MOF–polymer beads has also been proposed as a method for simplifying separation and reusability. Macroporous ZIF-8 (M-ZIF-8), sodium alginate ZIF-8 beads (SA@ZIF-8), and M-ZIF-8 combined with SA@ZIF-8 (SA@M-ZIF-8) were prepared for immobilizing lipase. M-ZIF-8 showed the highest adsorption capacity of 113.7 mg/g at 40 °C and was found to be more thermodynamically stable than ZIF-8. The experimental data for all three supports are best fitted to the Freundlich isotherm model. The adsorption kinetic data for M-ZIF-8 and SA@M-ZIF-8 are best described by a pseudo-first-order model, whereas a pseudo-second-order model provided a better fit for SA@M-ZIF-8. Lipase immobilized on M-ZIF-8 showed the highest catalytic activity, whereas that immobilized on SA@M-ZIF-8 showed the best reusability.

Application of snail shells as a heterogeneous catalyst for rapeseed oil butyl esters production

ABSTRACT Synthesis of fatty acid butyl esters using snail shells is attractive and increases the share of renewable resources because the snail shells are a waste of the food industry and 1-butanol can be obtained from renewable resources. Chemical and instrumental analysis methods (XRDA, FT-IR, EDS) were used for the evaluation of the chemical composition of snail shells. It was found that composition slightly depends on the kind and growing conditions, but in all the cases the main component in raw shells is CaCO3. After calcination for 5 h at a temperature of 850 °C, almost pure CaO (93.69 ± 0.43% %) is formed, which is used as a catalyst in the triglyceride transesterification process. SEM studies showed that the structure of the shells becomes porous after calcination, which increases the efficiency of the process. The Response surface methodology was used for the optimization of rapeseed oil transesterification with 1-butanol. It was found that the optimum transesterification conditions when the reaction temperature is 110°C are the following: 1-butanol-to-oil molar ratio of 10.6:1, a snail shell content of 7.53 wt%, and a reaction time of 10.77 h. Under these conditions, the 99.25 wt% yield of rapeseed butyl esters was obtained.

Kinetic modeling of papaya seed triglyceride transesterification catalyzed by calcined banana peel ash in methyl ester production

A model defining kinetics of papaya seed triglyceride PST transesterification heterogeneously catalyzed with calcined banana peel ash (CBPA) in papaya seed triglyceride methyl ester PSTME synthesis was established. The model was based on the reverse-basic reaction mechanism RB of transesterification. The transesterification reaction was performed at the optimum conditions of methanol to oil molar ratio 9:1, CBPA catalyst amount 2.5 wt%, stir- speed 600 rpm within a time range of 0–2 h at varying temperatures of 50 °C, 55 °C and 60 °C. The concentration vicissitudes of reactants/products reached its maximum at 1 h and remained constant across the temperature readings. Elevated temperature was noted to favor the reaction. The rate expression based on tri-glyceride to di-glyceride conversion as rate-controlling step in the reverse-basic reaction mechanism was established as the most dependable description of the experimental data. The activation energy and frequency factor were determined to be 61.7 kJ/mol and 9.8E9h−1 respectively. The enthalpy change ∆H, entropy change ∆S, and Gibb’s free energy ∆G of the process were determined as 61.7 kJ/mol, 19.1 kJ/mol K and − 60.75 kJ correspondingly. The estimation capacity of the model was verified by fixing the experimental data which indicated satisfactory relationship.

Process Optimization of Biodiesel from Used Cooking Oil in a Microwave Reactor: A Case of Machine Learning and Box–Behnken Design

In the present investigation, response surface methodology (RSM) and machine learning (ML) are applied to the biodiesel production process via acid-catalyzed transesterification and esterification of triglyceride (TG). In order to optimize the production of biodiesel from used cooking oil (UCO) in a microwave reactor, these models are also compared. During the process, Box–Behnken design (BBD) and an artificial neural network (ANN) were used to evaluate the effect of the catalyst content (3.0–7.0 wt.%), methanol/UCO mole ratio (12:1–18:1), and irradiation time (5.0–9.0 min). The process conditions were adjusted and developed to predict the highest biodiesel yield using BBD with the RSM approach and an ANN model. With optimal process parameters of 4.94 wt.% catalyst content, 16.76:1 methanol/UCO mole ratio, and 8.13 min of irradiation time, a yield of approximately 98.62% was discovered. The coefficient of determination (R2) for the BBD model was found to be 0.9988, and the correlation coefficient (R) for the ANN model was found to be 0.9994. According to the findings, applying RSM and ANN models is advantageous when optimizing the biodiesel manufacturing process as well as making predictions about it. This renewable and environmentally friendly process has the potential to provide a sustainable route for the synthesis of high-quality biodiesel from waste oil with a low cost and high acid value.

The assessment of sustainability indicators for triglycerides transesterification with alcohols catalyzed by ion exchange resins

The research was aimed at determining the dependences of sustainability indicators on the parameters of the sunflower oil transesterification with ethyl, propyl, and butyl alcohol catalyzed by anion exchange resin AV-17-8 with OH– ions or cation exchange resin KU-2-8 with H+ or immobilized Zn2+, Sn2+, Ni2+, Co2+, and Cu2+ ions. Such sustainability indicators as the E-factor, atomic efficiency, mass intensity and mass productivity, reaction mass efficiency, stoichiometric factor, etc., have been determined. We established that sustainability indicators of transesterification catalyzed by ion exchange resins depend on the yield of higher fatty acid esters that can be achieved by immobilized metal ions. The unreacted alcohol regeneration significantly reduces the E-factor value and increases the reaction mass efficiency. During the sunflower oil ethanolysis, the minimum E-factor value is achieved at the ethyl alcohol:triglyceride molar ratio corresponding to the maximum yield of higher fatty acid esters. The reaction mass efficiency calculated without considering the unreacted alcohol regeneration is one of the criteria for determining its regeneration expediency. The sustainability indicators are the additional criteria for selecting optimal conditions of the sunflower oil transesterification with aliphatic alcohols catalyzed by ion exchange resins. The calculated sustainability indicators indicate that the investigated ion exchange resins as heterogeneous transesterification catalysts provide a high yield of higher fatty acid esters. Using the researched catalysts ensures a low E-factor, making the process environmentally friendly.

Minimising Leachate Wastewater Generated from NaOH-Catalysed Biodiesel Synthesis from Methanol

Currently, energy generation based on fossil fuels is producing negative environmental impacts; two of the main symptoms of these impacts are water pollution and climate change. Consequently, the search for new technologies to satisfy the energy demand must have the goal to minimise possible impacts to the environment. There are alternatives with biofuels and, among them, biodiesel. The cheapest reaction pathway for biodiesel production is the transesterification of triglycerides by methanol in the presence of sodium hydroxide; however, this option can contaminate large volumes of water used in the final leach of the biodiesel product. Therefore, a feasible way of producing this biofuel while simultaneously minimising leaching water will be environmentally friendly and will improve economical savings. The present study developed an experimental design in order to minimise the addition of NaOH during biodiesel production by the basic homogeneous pathway. The best operating conditions were 46 °C, methanol in situ 7.5% v/v and NaOH 0.035 M. These conditions allowed to reduce the leaching water amount by 25% compared to techniques reported in the literature; however, the yield to biodiesel decreased from 98 wt.% to 87 wt.% when a model waste oil was used instead of virgin oil.

Purified Glycerine from Biodiesel Production as Biomass or Waste-Based Green Raw Material for the Production of Biochemicals

Glycerine (glycerol) is a polyol consisting of three carbon atoms bonded to hydroxyl groups. It is a by-product of the transesterification of triglycerides, such as animal fats, vegetable oils, or used cooking oils during the biodiesel production process. Crude glycerine is subject to purification processes resulting in distilled glycerine containing at least 99.5% glycerol. Currently, produced high-quality distilled glycerine is used in the food, pharmaceutical, and cosmetic industries. Recently, technologies for converting glycerol to other chemicals through catalytic processes have been intensively developed, e.g., production of bio-based 1,2-propanediol. In the near future, glycerol will certainly become a promising renewable raw material in many modern biorefineries for the synthesis of biofuels, chemicals, and bioenergy production. This paper presents the possibility of using ion exchange resins to remove impurities with trace amounts of sulphur and nitrogen compounds from crude and distilled glycerine, produced during the biodiesel production process from used cooking oils. It was determined that using ion exchange resins at the preliminary purification stage (before distillation) was ineffective. Using cationite resins to purify distilled glycerine produced from waste materials enables the removal of impurities in the form of sulphur and nitrogen compounds.

Biocatalysis of triglycerides transesterification using fungal biomass: a biorefinery approach

BackgroundThe use of microbial biomasses, such as fungal biomass, to catalyze the transesterification of triglycerides (TG) for biodiesel production provides a sustainable, economical alternative while still having the main advantages of expensive immobilized enzymes.ResultsBiomasses of Aspergillus flavus and Rhizopus stolonifera were used to catalyze the transesterification of TG in waste frying oil (WFO). Isopropanol as an acyl-acceptor reduced the catalytic capability of the biomasses, while methanol was the most potent acyl-acceptor with a final fatty acid methyl ester (FAME) concentration of 85.5 and 89.7%, w/w, for R. stolonifer and A. flavus, respectively. Different mixtures of the fungal biomasses were tested, and higher proportions of A. flavus biomass improved the mixture's catalytic capability. C. sorokiniana cultivated in synthetic wastewater was used as feedstock to cultivate A. flavus. The biomass produced had the same catalytic capability as the biomass produced in the control culture medium. Response surface methodology (RSM) was adopted using central composite design (CCD) to optimize the A. flavus biomass catalytic transesterification reaction, where temperature, methanol concentration, and biomass concentration were selected for optimization. The significance of the model was verified, and the suggested optimum reaction conditions were 25.5 °C, 250 RPM agitation with 14%, w/w, biomass, 3 mol/L methanol, and a reaction duration of 24 h. The suggested optimum conditions were tested to validate the model and a final FAME concentration of 95.53%. w/w was detected.ConclusionBiomasses cocktails might be a legitimate possibility to provide a cheaper technical solution for industrial applications than immobilized enzymes. The use of fungal biomass cultivated on the microalgae recovered from wastewater treatment for the catalysis of transesterification reaction provides an additional piece of the puzzle of biorefinery. Optimizing the transesterification reaction led to a valid prediction model with a final FAME concentration of 95.53%, w/w.

BIODIESEL PRODUCTION: POTENTIAL AND FUTURE TRENDS – A REVIEW

Biodiesel is a potential renewable energy that can reduce greenhouse gas (GHG) emissions and increase energy security. Biodiesel has been shown to have lower carbon emissions compared to petroleum diesel, and it can reduce GHG by as much as 86%. Governments around the world have set targets for renewable energy, with a specific focus on the use of biofuels like biodiesel. Biodiesel can be derived from various feedstocks such as animal lipids, vegetable oils, and waste oils. It can be made through the transesterification of triglyceride with ethanol or methanol. This reaction requires strong base catalysts, such as sodium hydroxide or potassium hydroxide, in order to produce methyl esters. The potential of biodiesel has led to advancements in its production, such as the use of enzymatic transesterification, novel feedstocks, and the optimization of production parameters. Additionally, various companies have ventured into biodiesel production with a range of business models and approaches.

Preparation and characterization of biodiesel from waste cooking oils using heterogeneous Catalyst(Cat.TS-7) based on natural zeolite

Biodiesel is known as renewable biodegradable and less polluting material. It is produced by transesterification of triglycerides found in vegetable oil or animal fats. Many studies have been conducted on biodiesel production using homogeneous catalysts, but they are very expensive and not environmentally friendly. On the other hand, heterogeneous catalysts are cost-effective from the production process and ecofriendly. In this study, zeolite ore was used as a solid heterogeneous catalyst for the production of biodiesel by the transesterification reaction of waste cooking oils and studying the possibility of reusing it for several cycles under optimal reaction conditions. The catalyst was characterized by different techniques, such as TG-DTA, FTIR, XRD and TPD methods. High-quality biodiesel with 93% yield was obtained under optimal reaction conditions with the ratio of oil to methanol (1:9) mol, amount of catalyst (1.5% by weight of oil), at temperature (60 °C), and reaction time of 2 h. Biodiesel has been characterized using infrared spectroscopy, GC/MS, its physical and chemical specifications have been studied and compared with the American (ASTM) and European (EN) standards.

Synthesis of novel ternary NiO–CdO-Nd2O3 nanocomposite for biodiesel production

Novel tri-phase NiO–CdO-Nd2O3 nanocomposite was prepared by coprecipitation method and its catalytic activity in transesterification reaction was studied. The synthesized nanocomposite was characterized by using FTIR, XRD, SEM and EDX to explore the functional, structural morphological and compositional properties respectively. In FTIR studies the vibrational bands for NiO, CdO and Nd2O3 have been observed. The XRD pattern of nanocomposite revealed its crystalline nature and average particle size was calculated as 28nm. The SEM studies of nanocomposite revealed that the shape of nanocomposite is semi-circle and oval shaped. EDX analysis represented elemental composition of ternary composite. The newly prepared catalyst was used as heterogeneous catalyst in transesterification of triglycerides from mustard oil into fatty acid methyl esters as biodiesel fuel. The oval shaped nanoparticles showed good catalytic activity in biodiesel synthesis. The obtained biodiesel was thoroughly characterized using FTIR and 1H NMR spectroscopic techniques. FT-IR analysis was also used to find out percentage yield using absorption spectra of different oil & methanol molar ratio. The FAMEs composition of obtained biodiesel was determined by GC-MS analysis which showed presence of methyl palmitoleate (C16:1), methyl linoleate (C18:2), methyl oleate (C18:1), metyl erucate (C22:1) and methyl behenate (C22:0) at various retention time. The quality of fuel parameters such as density, viscosity, cloud, pour and flash points were determined using ASTM methods and found within limits. The effect of several parameters on yield of biodiesel such as oil to methanol ratio (1:6, 1:9, 1:12, 1:15 and 1:18) catalyst amount (0.1, 0.5 and 0.9g) time of reaction (1.5, 2.5, 5.0 and 7.5h) and effect of temperature (60–80 °C with interval of 5 °C) were studied in detail and optimized. The 80% yield of biodiesel was achieved at optimum conditions of 1:15 oil:methanol ratio, 0.5 g catalyst concentration, 5 h reaction time and 80 °C temperature. The reusability of catalyst was tested by using three times and the results were good with minor loss of catalytic activity.

Biodiesel fuel. Part III. Quantum chemical research and simulation of the process

THE PURPOSE. The purpose of this work was to use the associated paradigm for a correct quantum-chemical description of non-catalytic and catalytic supercritical fluid processes of transesterification of triglycerides with alcohols and hydrolysis of triglycerides and to model a one-stage process for obtaining biodiesel fuel, carried out under supercritical fluid conditions with its subsequent scaling to the commercial level.METHODS. The Gaussian09 software product was used to describe quantum chemical studies. The process modeling was carried out using the ASPEN Plus® v2006 software product. The behavior of thermodynamic systems at high temperatures and pressures is modeled using "RK ASPEN EOS". For modeling processes carried out at low pressures, mathematical models UNIQUAC and UNIFAC-LL were used. The scaling of the process was carried out in the VMGSim program.RESULTS. The third part of the review focuses on the quantum-chemical modeling of the transesterification reaction carried out under supercritical fluid conditions. It is shown that taking into account the associative paradigm makes it possible to obtain calculated reaction rate constants that agree in order with the experimental values. And also an analysis was carried out and the results of modeling the process of obtaining biodiesel fuel and scaling it to a commercial level, with a capacity of up to 9000 tons / year, were presented.CONCLUSION. The conducted analysis showed that biodiesel fuel can be a competitive fuel in our and the world market.

Synthesis of eicosapentaenoic acid-enriched medium- and long-chain triglyceride by lipase-catalyzed transesterification: a novel strategy for clinical nutrition intervention.

Eicosapentaenoic acid (EPA) has been recognized as a promising nutrient to improve therapeutic efficacy for cancer patients. Nevertheless, there are certain limitations to the application of EPA due to its structural characteristics. To maximize the nutritive value of EPA, a type of medium- and long-chain triacylglycerol (MLCT) enriched with EPA was designed and synthesized using the lipase-catalyzed transesterification of medium-chain triglyceride (MCT) and EPA-enriched fish oil (FO). The optimum synthesis conditions for EPA-enriched MLCT used Lipozyme RM as catalyst, and had a substrate mass ratio (MCT/EPA-enriched FO) of 3:1, lipase loading of 80 g kg-1 , a reaction temperature of 60 °C, and a reaction time of 6 h. The MLCT content was as high as 80.79% after the transesterification reaction and the purification, and the content of MLCT containing EPA accounted for 70.21%. The distribution of EPA at the sn-2 position showed a significant increase in MLCT compared with the original substrate, from 18.89% to 26.93%. The in vitro digestion results demonstrated that MLCT had a significantly higher EPA bioaccessibility than the original substrate. Eicosapentaenoic acid-enriched MLCT was developed. This may provide a novel strategy for clinical nutritional intervention. © 2023 Society of Chemical Industry.

Synthesis and Characterization of Physically Mixed V2O5.CaO as Bifunctional Catalyst for Methyl Ester Production from Waste Cooking Oil

Synthesis of the solid bifunctional vanadium-calcium mixed oxides catalyst was accomplished by application of a simple physical mixing approach. In this work, we compared the catalytic activity of CaO and 2%V2O5.CaO catalyst. Various characterization methods, such as X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR), BET surface area, and temperature-programmed desorption (TPD) of CO2 and NH3, were involved in studying the newly synthesized catalysts. The presence of CaO, CaCO3, and Ca(OH)2 compounds in the synthesized catalyst were detected by XRD and FTIR analysis. The existence of 2% V2O5 on the CaO catalyst surface was demonstrated by XRF analysis. From TPD-NH3, TPD-CO2, and BET surface area analysis, it was known that the 2% V2O5-CaO catalyst had a higher total number of acid-base sites and surface area than the CaO catalyst. In the fatty acid methyl esters (FAME) production from waste cooking oil (WCO) with higher free fatty acid (FFA), CaO could only catalyze the transesterification reaction. In contrast, 2%V2O5-CaO could successfully catalyze both the esterification of FFA and the transesterification of triglyceride (TG) simultaneously in a one-step reaction process. Thus, these results prove that 2%V2O5.CaO can act as a bifunctional catalyst in the production of biodiesel from WCO. Moreover, the synthesized 2%V2O5.CaO catalyst could achieve a maximum FAME yield of 51.30% under mild reaction conditions, including a 20:1 methanol to oil molar ratio, 60 °C reaction temperature, 1 wt% of catalyst loading, and 3 hours of reaction time.

Rapeseed Oil Transesterification Using 1-Butanol and Eggshell as a Catalyst

Biodiesel can be produced both in homogeneous and heterogeneous ways. Heterogeneous synthesis allows to easily separate catalyst from esters. In this work, eggshells as a heterogeneous catalyst were used for triglyceride transesterification with 1-butanol. Response surface methodology was used for process optimization. It was obtained that eggshells are a suitable catalyst for transesterification processes. A longer process duration and higher catalyst amount have a high influence on ester yield. However, the amount of 1-butanol should not be maximized. Optimum transesterification reaction conditions were obtained when the process temperature was 110 °C, 1-butanol-to-oil molar ratio 11.3:1, eggshells amount 7.41 wt%, and process duration 11.81 h. Under these conditions, 98.78 wt% of ester yield was obtained.