Catalyzed Transesterification Reaction Research Articles

Rubber-Fe3O4@SiO2@H3PMo12O40 as heterogeneous catalyst for biodiesel production: Optimized by response surface methodology

The aim of this research is to develop magnetically recoverable Heteropoly acid (HPA) based catalyst (Rubber-Fe3O4@SiO2@H3PMo12O40) for biodiesel production. Magnetic Rubber powder with high dispensability, porosity and magnetism were prepared by co-precipitation method and covered by silica using TEOS to form Rubber-Fe3O4@SiO2. Finally, nanostructured catalyst was prepared by impregnation of phosphomolybdic acid (PMA). The proposed catalyst was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) equipped with Dispersive Energy X-ray spectroscopy (EDS), Thermogravimetric analysis (TGA), The Brunauer-Emmett-Teller (BET) surface area analysis and vibrating sample magnetometer (VSM). The results showed the Keggin structure of the catalyst. The performance of the proposed core-shell nanocomposite to catalyze transesterification reaction was evaluated and optimized by response surface methodology (RSM). According to the results, 3 w/w %, 3 h, 12:1 and 69 °C were found as optimum values for catalyst dosage, reaction time, molar ratio of methanol to oil and reaction temperature, respectively. The production yield was higher than 85% for four runs. At the fifth try, the catalyst performance was decreased slightly to 78.87%.

An Ionic Liquid Promoted Clean and Direct Conversion of Triglycerides into Bio‐Based Thermal Energy Storage Materials

AbstractIn the present study, triglycerides are subjected to an ionic liquid (IL) catalyzed and solventless transesterification reaction with a series of fatty alcohols in a 1:3 ratio, respectively. In order to prepare the corresponding wax esters, triglycerides trilaurin, trimyristin, and tristearin are treated with fatty alcohols such as lauryl, myristyl, and stearyl alcohol via 1,3‐disulfonic acid imidazolium chloride catalyzed transesterification reaction under environmentally friendly conditions. The optimum duration of the transesterification reaction is determined by proton nuclear magnetic resonance spectroscopy and the progress of the reaction can also be easily followed by thin layer chromatography. According to these studies, the reaction takes about 2 h to complete and the corresponding wax esters are obtained successfully by recrystallization from suitable solvent mixture without tedious work‐up in good to excellent yields (86–100%).Practical Applications: With this sustainable method, a homologous series of wax esters can be successfully synthesized as bio‐based thermal energy storage materials. The prominent aspect of this solventless method is that it allows the preparation of wax esters directly from triglycerides via an ionic liquid catalyzed process both in laboratory and industrial scale.

Cotton/Fe3O4@SiO2@H3PW12O40 a magnetic heterogeneous catalyst for biodiesel production: Process optimization through response surface methodology

Use of green alternative sources for energy like biofuels is one of the most important requirements of sustainable development. This research aims to design and prepare a new magnetically recoverable catalyst based on agro-wastes. For this purpose, cotton waste was selected and its application in the preparation of magnetic catalysts (Cotton/Fe3O4@SiO2@ H3PW12O40) used for the production of biodiesel, which is based on heteropoly acid (HPA), was investigated. Magnetic cotton powder with high dispersibility, porosity, and magnetism were prepared by the co-precipitation method and covered by silica using tetraethyl orthosilicate (TEOS) to form Cotton/Fe3O4 @SiO2. Finally, the nanostructured catalyst was prepared by impregnation of phosphotungstic acid (HPW). The proposed catalyst was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FESEM) equipped with Dispersive Energy X-ray spectroscopy (EDS), Thermo gravimetric analysis (TGA), The Brunauer-Emmett-Teller (BET) surface area analysis, Barrett-Joyner-Halenda (BJH) pore size and volume analysis and vibrating sample magnetometer (VSM). The performance of the proposed core-shell nanocomposite to catalyze transesterification reaction was evaluated and optimized by response surface methodology (RSM). The optimum conditions were found as 3 wt%, 3.5 h, 12:1, and 70 °C, for catalyst dosage, reaction time, the molar ratio of methanol to oil, and reaction temperature, respectively. The production yield was higher than 90% for three runs. On the fourth attempt, the catalyst performance was decreased slightly to 85.5%. The used catalyst was characterized by FT-IR, XRD, EDS, and FESEM for leaching studies. The quality of the biodiesel product was tested according to the standard procedures defined by the American Society for Testing and Materials (ASTM) and European Union (EU).

Effect of Binding Modules Fused to Cutinase on the Enzymatic Synthesis of Polyesters

In relation to the development of environmentally-friendly processing technologies for the continuously growing market of plastics, enzymes play an important role as green and sustainable biocatalysts. The present study reports the use of heterogeneous immobilized biocatalysts in solvent-free systems for the synthesis of aliphatic oligoesters with Mws and monomer conversions up to 1500 Da and 74%, respectively. To improve the accessibility of hydrophilic and hydrophobic substrates to the surface of the biocatalyst and improve the reaction kinetic and the chain elongation, two different binding modules were fused on the surface of cutinase 1 from Thermobifida cellulosilytica. The fusion enzymes were successfully immobilized (>99% of bound protein) via covalent bonding onto epoxy-activated beads. To the best of our knowledge, this is the first example where fused enzymes are used to catalyze transesterification reactions for polymer synthesis purposes.

Ultrasonication Assisted Catalytic Transesterification of Ceiba Pentandra (Kapok) Oil Derived Biodiesel Using Immobilized Iron Nanoparticles

The embedded immobilized enzymes (Rhizopus-oryzae) on the magnetic nanoparticles (Fe3O4-NPs) is a new application for the sustainable production of high-quality biodiesel. In this study, biodiesel is derived from Kapok oil via ultrasonication (US)-assisted catalytic transesterification method. A novel attempt is made to prepare magnetic nanoparticles embedded by an immobilized enzyme to solve the problem of enzyme denaturation. This innovative method resulted in optimum biodiesel conversion of 89 ± 1.17% under reactant molar ratio (methanol: oil) of 6:1, catalyst loading 10 wt% with a reaction time of 4 h at 60 °C. The kinetic and thermal study reveals that conversion of Kapok oil to biodiesel follows a pseudo first-order reaction kinetic with a lower ΔE of 30.79 kJ mol−1. The ΔH was found to be 28.06 kJ mol−1 with a corresponding ΔS of −237.12 J mol−1 K−1 for Fatty Acid Methyl Ester formation. The ΔG was calculated to be from 102.28 to 109.40 kJ mol−1 for temperature from 313 K to 343 K. The positive value of ΔH and ΔG is an indication of endothermic and non-spontaneous reaction. A negative ΔS indicates the reactant in the transition state possesses a higher degree of ordered geometry than in its ground state. The immobilized catalysts provided great advantages towards product separation and efficient biodiesel production. Highlights: 1. Effective catalytic transesterification assisted by the ultrasonication method was used for bi-odiesel production. 2. Magnetite nanoparticles synthesized by the co-precipitation method were used as heteroge-neous catalysts. 3. An immobilized enzyme (Rhizopus-oryzae) was embedded in the heterogeneous catalyst, as it is reusable and cost-effective. 4. The maximum biodiesel yield obtained from Kapok oil was 93 ± 1.04% by catalytic trans-esterification reactions.

How to improve the efficiency of biocatalysis in non-aqueous pure deep eutectic solvents: A case study on the lipase-catalyzed transesterification reaction

Non-aqueous biocatalysis has been expanding the application fields of biocatalysis and is playing an increasingly important role in industrial biocatalysis. Deep eutectic solvents (DESs) have been recognized as green reaction media of non-aqueous biocatalysis. To provide guidance for improving the catalytic performance of enzymes in pure DESs, Candida antarctica lipase B (CALB) catalyzed transesterification reaction was chosen as the model reaction to assess the catalytic efficiency in different series of pure DESs. The catalytic efficiency of CALB was strongly influenced by the properties of DESs. Hydrophobic DESs caused less inactivation of CALB than hydrophilic DESs. The highest yield in hydrophobic DESs reached 56.75% after 12 h. The amount of carboxyl group in hydrophobic DESs, the amount of hydroxyl group in hydrophilic DESs, and the length of carbon chain had positive impacts on the catalytic efficiency of CALB in DESs. Learning from the CALB behaviors in DESs, a preliminary attempt in rational design DESs for higher transesterification efficiency was provided. Except for reaction media, the catalytic activity of CALB in DESs was improved by medium engineering means and enzyme engineering measures, such as adding a trace amount of water, imprinting CALB with pH buffer or inorganic salt, and protecting CALB by lyoprotectants. Synergistic effect of multiple activation methods could also be observed in improving the catalytic efficiency. This study can provide insights into expanding the application of DESs in non-aqueous biocatalysis.

High-Tg and Degradable Isosorbide-Based Polybenzoxazine Vitrimer

This work describes new fully bio-based vitrimers prepared from isosorbide, a renewable sugar-based chemical. Isosorbide was reacted with 4-hydroxypropionic acid, paraformaldehyde, mono-ethanolamine, and/or furfurylamine via consecutive solvent-free Fischer esterification and Mannich-like ring-closure reactions. The two-step synthesis led to the formation of a di-telechelic benzoxazine-terminated isosorbide monomer, containing ester bonds and aliphatic hydroxyl and/or furan groups. The atom economy factor yields 85%. The structural features of the resulting products were substantiated by spectroscopic techniques. The ring-opening polymerization was monitored by rheological and differential scanning calorimetry (DSC) measurements. Very high Tg values afforded by the isosorbide substructure were measured (from 143 to 193 °C), which increase with furan ring content. Internally catalyzed transesterification reactions conferred fast dynamic exchanges (τ* = 300 s at 180 °C). Self-healing and chemical and mechanical recycling were also demonstrated. Finally, the degradability of the sugar-based polybenzoxazine vitrimers was demonstrated as well. The materials were highly stable in pH-neutral water, even at 80 °C for 60 days, but owing to the isosorbide structure, pronounced degradation was observed under acidic or alkaline conditions. In summary, isosorbide is a suitable building block for the design of degradable and 100% recyclable high-Tg polybenzoxazine vitrimers.

A cleaner route of biodiesel production from waste frying oil using novel potassium tin oxide catalyst: A smart liquid-waste management.

The valorization of waste frying oil (WFO) to biodiesel has been carried out via solid base catalyzed transesterification reaction. A novel potassium tin oxide (KSO) catalyst was synthesized via polymer precursor auto combustion method. The catalyst showed the best physicochemical properties when it was calcined at 800°C. Using KSO 800 catalyst, the highest FAME conversion (99.5%) of WFO found at moderated reaction condition within very short time (35min); moreover, no leaching of K-species was observed in reusability test upto 5th cycle. Kinetics proved that the above catalytic reaction followed pseudo-first-order kinetics and the rate of the reaction was doubled with increasing 10°C reaction temperature. The reaction activation energy, enthalpy of activation, entropy of activation, and Gibb's free energy of activation of the reaction were found to be 66.52kJ/mol, 62.95kJ/mol, -74.07J/mol/K and 88kJ/mol respectively. Evaluation of the green parameters revealed that KSO 800 catalyzed transesterification process approached a cleaner route with excellent efficacy in terms of turnover frequency and yield. KSO 800 helped to produce high quality biodiesel from WFO adopting faster and greener reaction pathway. Thus, KSO 800 was considered as a potential and green catalyst for transforming waste oil into biofuel.

Optimisation of Free Fatty Acid Removal in Nyamplung Seed Oil (Callophyllum inophylum L.) using Response Surface Methodology Analysis

Nyamplung seed (Calophyllum inophyllum L.) oil is a prospective non-edible vegetable oil as biodiesel feedstock. However, it cannot be directly used in the alkaline catalysed transesterification reaction since it contains high free fatty acid (FFA) of 19.17%. The FFA content above 2% will cause saponification reaction, reducing the biodiesel yield. In this work, FFA removal was performed using sulfuric acid catalysed esterification to meet the maximum FFA amount of 2%. Experimental work and response surface methodology (RSM) analysis were conducted. The reaction was conducted at the fixed molar ratio of nyamplung seed oil and methanol of 1:30 and the reaction times of 120 minutes. The catalyst concentration and the reaction temperature were varied. The highest reaction conversion was 78.18%, and the FFA concentration was decreased to 4.01% at the temperature of 60℃ and reaction time of 120 minutes. The polynomial model analysis on RSM demonstrated that the quadratic model was the most suitable FFA conversion optimisation. The RSM analysis exhibited the optimum FFA conversion of 78.27% and the FFA content of 4%, attained at the reaction temperature, catalyst concentration, and reaction time of 59.09℃, 1.98% g/g nyamplung seed oil, and 119.95 minutes, respectively. Extrapolation using RSM predicted that the targeted FFA content of 2% could be obtained at the temperature, catalyst concentration, and reaction time of 58.97℃, 3%, and 194.9 minutes, respectively, with a fixed molar ratio of oil to methanol of 1:30. The results disclosed that RSM is an appropriate statistical method for optimising the process variable in the esterification reaction to obtain the targeted value of FFA.

High resolution additive manufacturing with acrylate based vitrimers using organic phosphates as transesterification catalyst

The present study highlights the high resolution additive manufacturing of covalent adaptable acrylate photopolymers, which undergo catalyzed transesterification reactions at elevated temperature. A methacrylate phosphate is introduced as a new transesterification catalyst, which considerably extends the toolbox of acrylate monomers for 3D printing of vitrimers, as it is easily soluble in a wide range of acrylate monomers and does not affect cure kinetics or storage stability of the resins. By appropriate design of monomer composition and catalyst, a series of acrylate-based vitrimers was prepared, whose glass transition temperature was conveniently adjusted by the chemical structure and functionality of the acrylate monomers. Rheometer studies revealed that the stress relaxation rate slows down with increasing crosslink density and lower amount of –OH moieties. In contrast, increasing the catalyst concentration in the photopolymer network from 5 to 15 wt% significantly accelerated the relaxation rate, with 63% of the initial stress being relaxed within 102 min. Complex 3D objects with feature sizes below 50 μm were manufactured by bottom-up digital light processing (DLP) and the dynamic nature of the covalent crosslinks endowed the printed structures with triple-shape memory and thermo-activated mendability. As shown by tensile tests, up to 99% of the initial strength could be recovered after the first healing step, showing the potential to improve functionality and lifetime of additively manufactured duromer networks. Moreover, the fast response time (60 s) of the shape recovery and the high resolution of the 3D printed structures pave the way towards a customized fabrication and miniaturization of soft robotic applications.

Improving heterogeneously catalyzed transesterification reaction for biodiesel production using ultrasound energy and petro-diesel as cosolvent

ABSTRACT Heterogeneously catalyzed transesterification process has by far been one of the most popular methods of biodiesel production particularly for the oil feedstock containing large amount of free fatty acid. However, the major constraint of the method is the poor yield of biodiesel and a long reaction time that increased its production cost. With an objective to increase the product yield in lesser time, the current work investigated the effect of addition of ultrasound and addition of cosolvent in the heterogeneously catalyzed transesterification reaction. Three commonly used solid catalyst – calcium oxide (CaO), calcined sodium silicate (CSS) and sulfated zirconia (SZ) were chosen for study. The results suggested that there was a remarkable increase in the yield of biodiesel in comparison to the conventional mechanically stirred process. CSS showed the best catalytic activity both in first use and in repeated uses. It gave a maximum yield of 97% biodiesel in 120 minutes with 9:1 molar ratio of alcohol to oil 3 wt.% of catalyst and 10 wt.% of catalyst. For CaO and CSS a noticeable difference in biodiesel yield was observed upon addition of cosolvent. CaO gave 76% yield with cosolvent and 65% without it. SZ gave 73% biodiesel with cosolvent and 61% without. Since petrodiesel was used as the cosolvent it was not required to remove the cosolvent from biodiesel during the purification process.

Kinetic and optimization study of sustainable biodiesel production from waste cooking oil using novel heterogeneous solid base catalyst

The novel Na-SiO2@TiO2 heterogeneous base catalyst was designed and successfully applied to the trans-esterification reaction of waste cooking oil for sustainable biodiesel production. The designed catalyst was characterized by SEM, XPS, FT-IR and BET before treatment, illustrated its suitability for the catalytic trans-esterification reaction. Moreover, the influence of reaction temperature, time, catalyst concentration and WCO:MeOH molar ratio on the catalytic activity were also investigated, resultant 98% biodiesel yield was achieved. The reusability test demonstrated that the Na-SiO2@TiO2 catalyst has noticeable catalytic potency up to 5 successive runs. Besides, the kinetics study explains that the reaction is kinetically controlled by pseudo 1st order. The Ea was found to be 21.65 kJ/mol. Similarly, the important thermodynamic parameters such as ΔH#, ΔS# and ΔG# were estimated to be 18.52 kJ.mol−1, −219.17 J.mol−1K−1and 92.59 kJ.mol−1respectively.

Production of biodiesel by Burkholderia cepacia lipase as a function of process parameters.

Despite the already established route of chemically catalyzed transesterification reaction in biodiesel production, due to some of its shortcomings, biocatalysts such as lipases present a vital alternative. Namely, it was noticed that one of the key shortcomings for the optimization of the enzyme catalyzed biodiesel synthesis process is the information on the lipase activity in the reaction mixture. In addition to making optimization difficult, it also makes it impossible to compare the results of the independent research. This article shows how lipase intended for use in biodiesel synthesis can be easily and accurately characterized and what is the enzyme concentration that enables achievement of the desired level of fatty acid methyl esters (FAME) in the final product mixture. Therefore, this study investigated the effect of two different activity loads of Burkholderia cepacia lipase on the biodiesel synthesis varying the pH and temperature optimal for lipase activity. The optimal lipase pH and temperature were determined by two different enzyme assays: spectrophotometric and titrimetric. The B. cepacia lipase pH optimum differentiated between assays, while the lipase optimally hydrolyzed substrates at 50°C. The analysis of FAME during 24 hr of biodiesel synthesis, at two different enzyme concentrations, pH 7, 8, and 10, and using two different buffers, revealed that the transesterification reaction at optimal pH, 1 hr reaction time and lipase activity load of 250 U per gram of reaction mixture was sufficient to produce more than 99% FAME.

Hydrophobizing cellulose surfaces via catalyzed transesterification reaction using soybean oil and starch

Biodegradable modified natural polymers have great potential in curbing the threat of plastic pollution, but are still uncompetitive to petrochemical-based plastic. In this study, starch was hydrophobized by treating starch-dimethyl sulfoxide solutions with soybean oil at high temperature in the presence of sodium carbonate, then spray-coated on paper. The modified starch was evaluated by Fourier-transform infrared spectroscopy analysis and contact angle value measurement of coated paper. FTIR analysis confirmed the substitution of hydroxyl groups with fatty acid ester and provided an estimate of the degree of substitution. The contact angle value of starch-coated paper surfaces was 121°, and was 111° after 10 min, demonstrating the high hydrophobicity and potential of the modified starch coating as a water-resistant treatment. The high hydrophobicity of the coated paper was due to formation of a textured surface with two levels of roughness, caused by the deposition of rough hydrophobic starch particles on paper fibers.

PEG-modified lipase immobilized onto NH2-MIL-53 MOF for efficient resolution of 4-fluoromandelic acid enantiomers

A new heterogeneous bio-catalyst was prepared by the immobilization of lipase from Pseudomonas fluorescents (PFL) onto metal-organic frameworks (MOF), NH2-MIL-53(Fe), using covalent cross-linking. The immobilized lipase [PEG-PFL@NH2-MIL-53(Fe)] was firstly applied in enantioselective resolution of 4-fluoromandelic acid (4-FMA) enantiomers. After optimization of the immobilization PFL onto NH2-MIL-53, its loading capacity is 224.5 mg PFL/g MOF. The optimal enzymatic conditions are temperature of 50 °C, VA/4-FMA substrate ratio of 6:1, immobilized lipase loading of 60 mg and reaction time of 12 h. Experimental results show that the catalytic activity and thermal stability of PFL are significantly improved by polyethylene glycol (PEG) modification and immobilization. At 65 °C, the catalytic activity of immobilized lipase retains 86.0% of initial activity. Under the optimal conditions, the excellent results were obtained with conversion of 49.6% and enantiomer excess of 98.0% for the immobilized PFL catalyzed transesterification reaction. Furthermore, the immobilized lipase exhibits excellent cycle stability with 83% of its initial activity after four cycle.

Production of biodiesel from waste bio-oil through ultrasound assisted transesterification using immobilized lipase

In this study, process intensification was carried out using lipase catalyzed transesterification of waste cottonseed oil (WCSO) with ethanol in the presence of ultrasonication. A maximum conversion of 98.7% was observed for ultrasound assisted transesterification. The optimum process conditions were ethanol to oil molar ratio of 4.5:1, a reaction temperature of 45°C, enzyme loading of 5 wt%, a reaction time of 6 h, ultrasonic amplitude of 40% and the duty cycle of 15 s ON and 15 s OFF. The influence of ultrasound makes the process efficient because of an effective reduction in reaction time to 6 h with the least catalyst dosage and power consumption. Reusability tests of the catalyst were conducted after separating the immobilized Rhizopus oryzae lipase. The regenerated lipase catalyst was found to have better reusability up to the fourth cycle and the produced biodiesel was within the ASTM D6751 standard. Furthermore, the ultrasound assisted process under mild operating conditions did not affect the immobilized enzyme. It was clearly observed that ultrasonication is faster and effective for biodiesel conversion using the immobilized lipase catalyzed transesterification reactions.

Mathematical Modeling of Reversible Bimolecular Catalyzed Transesterification Reaction Kinetics for PKO and Methanol synthesis

Continuous appraisal for alternative renewable energy sources particularly for bio-diesel production is a great concern to engineers and scientist globally. Actually, vegetable oils and C1 to C3 alcohol group alkali catalyzed transesterification reaction leads to bio-diesel production. The aspect of developing reaction time and disappearance rate (-RA) mathematical models for effective various reactor types design seems impassive. Hence, in this work the authors developed a unified reaction time and disappearance rate (-RA) predictive models as a function of reactants and product reaction rate constants (K1 K2), molar masses (MW), conversion (XA), fractional volume change (ɛ) and density (ρ) dimensions using partial fraction and by parts integration methods. The developed models were simulated with Matlab codes programming approach exploiting the kinetics parameters of PKO , Methanol and biodiesel. The results of the reaction time (t) at equilibrium, none equilibrium and disappearance rate (-RɛA) show dependable relationship with the stipulated dimensions and were quite compatible with those of inferential laboratory physicochemical data reported. Thus;

A cleaner process for green biodiesel synthesis from waste cooking oil using recycled waste oyster shells as a sustainable base heterogeneous catalyst under the microwave heating system

In this study, biodiesel synthesis from waste cooking oil (WCO) using waste oyster shells derived catalyst (CaO-based catalyst) as a sustainable based heterogeneous catalyst under a microwave heating system technology was investigated. The CaO-based catalysts were characterized by Fourier Transform-Infrared (FTIR), X-ray diffraction (XRD), Electronic Data System (EDS) and Brunauer-Emmett-Teller (BET) measurements. Under optimized conditions, this study has produced tentative results with considerable performances in relations to biodiesel synthesis as follows: (1) the intensification in relation to reaction time from 120 to 180 min has significantly increases the biodiesel yield, which declines with a more intensification to 120 min; (2) the synthesis of biodiesel in this study has proved to increase with an upsurge reaction of power; (3) whereas 180 min reaction time with 800 W microwave power, a methanol-to-oil molar ration of 9:1, a reaction temperature of 65 °C; and 6 wt% catalyst concentration was revealed to be optimal and perfect reaction conditions for this present research work. The highest biodiesel yield was recorded at 87.3% in this study. Whereas the activation energy (Ea) for the catalyzed transesterification reaction was found to be 9.56 kJ/mol. In a nutshell, waste oyster shells were recycled as a sustainable base heterogeneous catalyst to synthesize new biodiesel from WCO, which can be used in diesel engines to address air pollution, especially pollutant emissions from diesel automobiles.

PRODUÇÃO DE BIODIESEL A PARTIR DA REAÇÃO DE HIDROESTERIFICAÇÃO

Fatty acid esters (Biodiesel) are commonly produced by homogeneous basic catalytic transesterification reaction, whose sensitivity to the presence of water and free fatty acids (FFAs) in the raw material is one of the main drawbacks. The search for production processes that allow the use of vegetable oils with less added value is of interest to the biofuel industry. A promising alternative is hydroesterification, whose first stage is the hydrolysis of triacylglycerols, producing FFAs and glycerol products. Therefore, instead of decreasing acidity of the raw material through refining, the hydrolysis stage purposely increases its acidity. Then, glycerol is removed and the FFAs are subjected to an esterification reaction to produce fatty acid esters and water as a by-product. Therefore, this work presents a literature review, which has as main focus the production of biodiesel from hydroesterification. Alternative raw materials with potential in the current market are also presented. It was possible to verify that hydroesterification offers advantages when compared to conventional reactions. When carried out under conditions of high temperature and pressure, it can reduce the difficulties associated with the use of catalysts, becoming a promising alternative to be used as a method of biodiesel production.

Understanding and Suppression of Side Reaction during Transesterification of Phenolic Hydroxyl Groups of Lignin with Vinyl Ester

A catalytic transesterification reaction on phenolic hydroxyl groups by a carboxylate-type ionic liquid, 1-ethyl-3-methylimidazolium p-anisate ([Emim][OAn]), was investigated using a model reaction with phenol and vinyl propionate. Undesirable contamination of the ester group formed on the phenol with an acyl group derived from the acyl anion in the [Emim][OAn] was effectively suppressed. This catalytic reaction was applied to Kraft lignin, and the desired esterification was successfully promoted on the hydroxyl groups with a conversion of up to 94 mol %.