Glycerol Molar Ratio Research Articles

Transesterification of glycerol with dimethyl carbonate for the synthesis of glycerol carbonate and glycidol by Iron (III) salen complex

The transesterification of glycerol and dimethyl carbonate (DMC) was investigated in the presence of μ-oxo-Fe(salen)2 under the optimal reaction condition. Several transition metal(salen) were tested, and only Fe (salen) shows an excellent results towards transesterification of glycerol. Therefore, Fe (salen) was characterized by IR, elemental analysis, MS, XPS and Surface Basicity test, and it can be confirmed that the as-synthesized Fe(salen) was existed in the form of μ-oxo-Fe(salen)2. It was proposed that the μ-oxo-Fe(salen)2 can provide two different reaction pathway based on its molecular structures and the electronic configuration of iron itself. μ-oxo-Fe(salen)2 was reacted with the mixture of glycerol and DMC under microwave-heating in 60 min at 100°C and at the molar ratio of glycerol:DMC:μ-oxo-Fe(salen)2 of 1:2:0.01 and obtaining the highest glycerol carbonate yield of 93.8 %.

TRANSACETALIZATION OF GLYCEROL WITH 2,2-DIMETHOXYPROPANE USING ZEOLITES UNDER MILD CONDITIONS

The acetalization or transacetalization reactions produce acetals or ketals used in cosmetics, food, pharmaceuticals, and fuel additives. Besides synthesizing several products, the acetalization or transacetalization reactions can protect carbonyl groups, 1,2 and 1,3-diols in multi-step synthesis. This work studies the transacetalization of glycerol with 2,2-dimethoxypropane (2,2-DMP) to yield 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane (solketal) by catalyzing with USY, HBeta, and HZSM-5 zeolites under cleaner and mild reaction conditions (reaction temperature: 25 °C; 2,2-DMP/glycerol molar ratio: 1; reaction time: 1 h; and catalyst concentration: 0.05-5 wt.%). For catalyst concentration equal to or greater than 2,5 wt.%, glycerol conversion stabilized near 96-97% for the three zeolites tested. The product selectivities also assume a constant value, close to 97% for solketal. For the lowest concentration of catalyst, the influence of the zeolite properties on the glycerol conversion, such as acidity and the strong/weak acid site ratio, was observed. Concerning the selectivity of the products, the results suggested that it can be based on zeolite topology, active sites at the particle surface, and the relative amount of micro and mesoporous HBeta, the most selective catalyst for acetals production, was reused at least once without loss of activity and selectivity.

Combined fermentation and ARTP mutagenesis to enhance lipase activity of Penicillium camembertii and its application for high-purity 1,3-diacylglycerol preparation

Penicillium camembertii lipase (PCL) is a glycerol-biased enzyme isolated from P. camembertii, exhibiting high esterification activity. The PCL activity was enhanced by combining fermentation optimization with atmospheric and room temperature plasma (ARTP) mutagenesis. Following multiple rounds of high-throughput screening and serial passages, a genetically stable mutant, P12, was obtained. In shake flask culture, P12 exhibited a lipase activity of 1600 U/g, representing an 800 % increase compared to the wild type (WT), with improved thermostability and methanol stability. Subsequently, P12 was used as a whole-cell biocatalyst to catalyze the esterification of oleic acid with glycerol in a solvent-free system to prepare 1,3-diacylglycerol (1,3-DAG). With an oleic acid /glycerol molar ratio of 4:1, 8 % biocatalyst, and a reaction temperature of 40 °C, the content of 1,3-DAG was 74.7 % after 24 h. These results suggest that the mutant P12 demonstrates considerable potential as a whole-cell biocatalyst for synthesizing high-purity 1,3-DAG.

Optimizing the production of solketal from glycerol: a case study integrating Aspen Plus and a MATLAB subroutine

The use of process simulators has increased dramatically due to their ability to solve complex engineering problems. However, most simulators use a black-box modeling approach, which hinders the application of derivative-based optimization models. This work aims to present a case study of the glycerol ketalization reaction by integrating the Aspen Plus® simulator with MEIGO, an optimization tool available for MATLAB®. The kinetic parameters of the reaction were estimated using a Python algorithm. The simulation was validated, and the optimization of the reactive section was performed using an Enhanced Scatter Search method. After optimization for 80% glycerol conversion, the temperature, acetone:glycerol molar ratio in the reactor feed, and reactor volume were 80 °C, 8.83, and 24.17 m³, respectively, for processing 5.149 m³/h of glycerol. The integration of Aspen Plus® with MATLAB® using the MEIGO add-on is shown as a valid strategy for optimizing complex problems involving black-box models.

Cs4PMo11VO40-Catalyzed Glycerol Ketalization to Produce Solketal: An Efficient Bioadditives Synthesis Method

In this work, a series of vanadium-substituted phosphomolybdic acids were synthesized and tested as the catalysts for the synthesis of solketal, a green fuel bioadditive, from the condensation reaction of glycerol with acetone. The objective was to demonstrate that an easily synthesizable solid catalyst can efficiently promote glycerol condensation with acetone at room temperature. The activity of pristine heteropolyacid (i.e., H3PMo12O40) and its vanadium-substituted cesium salts (Cs3+nPMo12-nVnO40; n = 0–3) was evaluated in condensation reactions carried out at room temperature. Among the catalysts tested, Cs4PMo11VO40 was the most active and selective towards a five-member ring solketal isomer (dioxolane). A high yield of solketal (i.e., 95% conversion and 95% selectivity to solketal) was achieved in glycerol condensation with acetone at room temperature within a short reaction time (2 h). The influence of the main reaction parameters, such as the acetone–glycerol molar ratio, catalyst load, and reaction temperatures, was investigated. The greatest activity of the Cs4PMo11VO40 catalyst was correlated to its greatest acidity.

K2CO3-Modified Smectites as Basic Catalysts for Glycerol Transcarbonation to Glycerol Carbonate.

A novel and cost-effective heterogeneous catalyst for glycerol carbonate production through transesterification was developed by impregnating smectite clay with K2CO3. Comprehensive structural and chemical analyses, including X-ray diffraction Analysis (XRD), Scanning Electron Microscopy (SEM)-Electron Dispersion Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) surface area analysis measurements, were employed to characterize the catalysts. Among the various catalysts prepared, the one impregnated with 40 wt% K2CO3 on smectite and calcined at 550 °C exhibited the highest catalytic activity, primarily due to its superior basicity. To enhance the efficiency of the transesterification process, several reaction parameters were optimized, including the molar ratio between propylene carbonate and glycerol reactor loading of the catalyst and reaction temperature. The highest glycerol carbonate conversion rate, approximately 77.13% ± 1.2%, was achieved using the best catalyst under the following optimal conditions: 2 wt% reactor loading, 110 °C reaction temperature, 2:1 propylene carbonate to glycerol molar ratio, and 6h reaction duration. Furthermore, both the raw clay and the best calcined K2CO3-impregnated catalysts demonstrated remarkable stability, maintaining their high activity for up to four consecutive reaction cycles. Finally, a kinetic analysis was performed using kinetic data from several runs employing raw clay and the most active K2CO3-modified clay at different temperatures, observing that a simple reversible second-order potential kinetic model of the quasi-homogeneous type fits perfectly to such data in diverse temperature ranges.

The effects of partially or fully linked boron with a cross-linking structure of an organic precursor on the purity and morphology of ZrB2 powder.

From a chemical infrastructure perspective, it is important to ensure that all ions constituting a target product, e.g., Zr and B ions for ZrB2, are fully linked with a cross-linking structure for synthesis via an organic precursor. In the present study, glycerol is used as a chelating ligand to prepare boron both partially and fully linked with the cross-linking structure of organic precursors by a sol-gel route. The results are far from expected, in that the more linked boron there is in the precursor, the purer the ZrB2 produced. In the case of a partially linked cross-linking structure, the carbothermic reduction reaction for ZrB2 is a multi-step process with an intermediary phase of ZrC, and then a high-purity prism-like ZrB2 powder with a larger size is obtained. A minimum of 0.26 wt% for the oxygen content of ZrB2 corresponds to a 0.67 molar ratio of glycerol to H3BO3. On the other hand, in the case with the boron fully linked, a single-phase of ZrB2 cannot be obtained, and instead a double-phase is obtained. Therefore, the amount of impurity is greater, even though the size is smaller. The carbothermic reduction reaction is direct, and has only one step.

Glycerol carbonate synthesis via transesterification of enriched glycerol and dimethyl carbonate using a Li-incorporated MCM-41 framework.

Waste crude glycerol was successfully enriched and utilized as an inexpensive source for producing value-added chemicals, such as glycerol carbonate (GC) - a valuable compound with extensive industrial applications. The Li/MCM-41 heterogeneous catalyst was synthesized and used for the transesterification of enriched glycerol and dimethyl carbonate (DMC) to produce GC. The catalyst's physicochemical properties were characterized using thermogravimetric, Hammett indicator, inductively coupled plasma-optical emission spectroscopy, nitrogen adsorption-desorption, X-ray diffractometry, scanning electron microscopy, and Fourier-transform infrared spectroscopy analyses. Reaction conditions were optimized using response surface methodology and analysis of variance, yielding an accurate quadratic model to predict the GC yield under different transesterification variables. The results revealed that 5%Li/MCM-41 served as the optimal catalyst, achieving the highest TOF of 4.72 h-1. The DMC: enriched glycerol molar ratio had the greatest impact on the GC yield, with an R2 = 0.9743 and adjusted R2 = 0.9502. The optimal GC yield (58.77%) with a final purity of 78% was attained at a 5.15 wt% catalyst loading relative to the initial amount of enriched glycerol, DMC: enriched glycerol molar ratio of 4.24 : 1, and a reaction temperature of 86 °C for 165 min. The 5%Li/MCM-41 heterogeneous catalyst could be reused for four cycles with a decreased GC yield from 58.77% to 45.72%. Thus, the Li/MCM-41 catalyst demonstrated a remarkable efficiency and potential as a heterogeneous catalyst for synthesizing GC. This method not only contributes to environmental sustainability by making use of a byproduct from biodiesel production but also aligns with the principles of a circular economy.

Glycerol/organic acid-based ternary deep eutectic solvents as a green approach to recover chitin with different molecular weight from seafood waste

In this study, we designed a green and efficient approach for the fractionation of high-purity chitin with tunable molecular weights from seafood waste. This was achieved by using ternary deep eutectic solvents (TDESs) composed of choline chloride as a hydrogen bond acceptor, glycerol as the polyol-based hydrogen bond donor, together with lactic acid or malic acid. Two binary DESs and four TDESs were evaluated for their ability to recover chitin. The extracted chitin exhibited not only high yield with excellent protein and mineral removal, but also high purity with similar crystallinity patterns as standard chitin. However, the average molecular weights, viscosity behavior and morphology of chitin extracted by DESs were varied and influenced by organic acid to glycerol molar ratios. The molecular weights of chitin extracted by lactic acid-based TDES ranged from 264 kDa to 541 kDa, but malic acid-based TEDS displayed a stronger depolymerization effect, resulting in chitin with a smaller molecular weight of less than 300 kDa. Lactic acid-based TDES revealed that the purity of chitin remained higher than 92 % after three cycles. This sustainable and environmentally friendly extraction system holds great potential to recover chitin from seafood waste, opening a new era for chitin extraction and applications.

Enzymatic glycerolysis for the conversion of plant oils into animal fat mimetics

Substituting animal-based fats with plant-based fats of similar stability and functionality has always posed a significant challenge for the food industry. Enzymatic glycerolysis products are systems formed by converting native triacylglycerols in liquid oils into monoacylglycerols and diacylglycerols, mainly studied in the last few years for their unique structural ability. This study aims to modify and scale up the glycerolysis process of different plant oils, e.g., shea olein, palm olein, tigernut, peanut, cottonseed, and rice bran oils, with the goal of producing animal fat mimetics. The reactions were conducted at 65 °C, with a plant oil:glycerol molar ratio of 1:1, and without the addition of water, using a lab-scale reactor to convert up to 2 kg of oil into solid fat. Product characteristics were comparable at both laboratory and pilot plant scales, supporting the commercial viability of the process. Oil systems containing higher levels of both saturated and monounsaturated fatty acids, such as shea olein and palm olein, displayed higher solid fat content at elevated temperatures and broader melting profiles with significantly higher melting points. Comparison of the thermal softening behavior and mechanical properties of these systems with those of pork, beef, and lamb fat showed their high potential to replace adipose fat in the new generation of plant-based meat analogs.

Layered double hydroxides modified by transition metals for sustainable glycerol valorization to glycerol carbonate

The surplus of glycerol generated as a by-product in biodiesel production increased interest in the investigation of the catalytic conversion of this platform molecule into valuable chemical products, such as glycerol carbonate. Therefore, the catalytic transesterification of glycerol and dimethyl carbonate for the synthesis of glycerol carbonate was studied using Cu-Zn-Mg-Al mixed oxide catalysts with different Cu-Zn atomic ratios. Layered double hydroxides were the precursors materials to obtain multi metallic oxides. They were synthesized by coprecipitation. The materials were physico-chemically characterized by XRD, MP-AES, N2 sorption, SEM, XPS and TPD-CO2. The addition of Cu and Zn to the Mg and Al matrix improved the catalytic behaviour of the solid materials. First, the highest glycerol carbonate yield was reached with the catalyst with the highest Zn load at 70 °C for 90 min. This result was taken as a basis to modify parameters and find the optimal reaction conditions. They were a temperature of 85 °C, a reaction time of 270 min, a DMC:glycerol molar ratio of 2:1, solvent free and 7.5 wt% of catalyst. The highest yield obtained (82%) was attributable to the synergistic effect of the Cu-Zn load promoted by an adequate distribution of basicity and textural properties. The reuses of the best catalyst were also investigated.

Improved protein extraction technology using deep eutectic solvent system for producing high purity fava bean protein isolates at mild conditions

This study aimed to extract fava bean proteins using an eco-friendly deep eutectic solvent (DES) containing choline chloride and a glycerol-based system. Protein extraction conditions were optimized using response surface methodology, and the extracted protein was characterized in comparison to the protein extracted using a conventional alkaline solution. The optimum conditions obtained using the RSM model were: 28:1 w/w liquid: solid ratio, 1:2 w/w choline chloride: glycerol molar ratio, 50 °C temperature, 1 h extraction time, and 40% w/w water content. Under these optimum conditions, protein content, protein yield, and protein recovery rates of 92.33 ± 2.28%, 65.42 ± 6.53%, and 23.15 ± 2.31% were achieved. Alkaline extraction showed similar protein content (92.50 ± 1.36%) but lower protein yield (60.76 ± 1.16%) and recovery rate (21.74 ± 0.19%) when compared to DES-extracted proteins (P < 0.05). The secondary structure analysis revealed an increased α-helix (21.37%) content in DES-extracted proteins compared to alkaline-extracted proteins (10.68%). Moreover, the alkaline-extracted proteins showed intermolecular β sheets as protein aggregates (7.61%) and an increased percentage of β-turns (19.71%). The molecular weight distribution pattern of proteins extracted from both methods showed more similarities. Overall, DES protein extraction could be an alternative to the conventional alkaline extraction method, promoting sustainable plant protein production from fava beans for use in new food formulations.

Efficient Synthesis of Solketal from Glycerol and Acetone Catalyzed by FeCl3 /γ‐Al2O3**

AbstractThe porous spherical alumina (γ‐Al2O3) as catalyst support was prepared by sol‐gel method, and FeCl3/γ‐Al2O3 materials were prepared by impregnation method. The FeCl3/γ‐Al2O3 materials were used as catalyst in the Solketal production process by acetalization of acetone and glycerol, showing considerable catalytic performance. When the molar ratio of glycerol and acetone was 1 : 10, 0.2 mol% FeCl3/γ‐Al2O3 was used as the catalyst, and the reaction was carried out at 25 °C for 30 min, the conversion of glycerol was 99.89 %, the selectivity of Solketal was 98.36 %, and the yield of Solketal reached 98.25 %. The mechanism is due to the spherical γ‐Al2O3 support has high thermal stability, large specific surface area, and rich pore structure, encouraging abundant active sites and high catalytic activity of FeCl3 for the acetalization reaction. Thereafter, the experimental results prove that the prepared FeCl3/γ‐Al2O3 catalyst can be easily recovered and reused many times, indicating its great value for large‐scale research and application in the future.

Dielectric barrier discharge plasma for catalytic-free palm oil hydrogenation using glycerol as hydrogen donor for further production of hydrogenated fatty acid methyl ester (H-FAME)

Catalytic-free parallel-plate-type dielectric barrier discharge (DBD) plasma was successfully employed to hydrogenate palm oil using glycerol as hydrogen donor in place of hydrogen gas for further production of hydrogenated fatty acid methyl ester (H-FAME) with enhanced oxidation stability. Most suitable reaction condition was 1:5 oil to glycerol molar ratio, 1 cm discharge gap size, 0.5 L/min He gas flow rate, atmospheric pressure, ambient temperature (rising to about 100 °C due to plasma heating), and 500 rpm stirring rate for 2 h at 130 W input power. Findings revealed that plasma could extract hydrogen radicals from glycerol, and they successfully reacted with CC bonds. Hydrogenated palm oil was subsequently converted into hydrogenated FAME (H-FAME) via conventional base-catalyzed transesterification. Higher saturation degree of H-FAME compared to FAME produced directly from palm oil was indicated by reduction of iodine value to 52.2 from 59.2. Oxidation stability of H-FAME was significantly enhanced from 17.7 to 23.1 h while cloud point slightly changed from 14.0 to 14.8 °C. Plasma reactive species generated during reaction and possible mechanisms of glycerol decomposition and plasma hydrogenation were presented. Developed catalytic-free plasma hydrogenation process is highly environmentally friendly and presents a way to add more value to waste glycerol and provide other potential hydrogen sources.

Performance and kinetics study of glycerol ketal synthesis from biomass‐based platform chemicals catalyzed by metal salts

AbstractBackgroundMethyl levulinate glycerol ketal (MLK) is a new kind of glycerol ketal with a wide range of applications. The efficient and green synthesis of MLK from biomass‐based platform chemicals including methyl levulinate (ML) and glycerol (GLY) catalyzed by cheap metal salts was investigated. Effects of different reaction conditions on the GLY conversion and the MLK yield were discussed, and the optimization and the kinetics of ketal preparation were further developed.ResultsThe reaction time, amount of catalyst and ML:GLY molar ratio were optimized based on Box–Behnken experimental design. The average MLK yield of 97.6% could be obtained under the optimum reaction conditions of ML:GLY molar ratio 4:3, vacuum degree 90 kPa, AlCl3 1.8 g, temperature 126 °C and reaction time 2 h, and the AlCl3 could be reused ten times without deactivation. On this basis, the kinetics studies showed that the ketal reaction conforms to the pseudo‐second‐order kinetics model, and the values of pre‐referential factor and activation energy were 1.824 × 104 mol·(g·h)−1 and 90.69 kJ mol−1. A reaction pathway for the ketalization reaction was proposed.ConclusionsThese results provide references for the scale‐up of MLK synthesis and the development of a new glycerol ketal. © 2023 Society of Chemical Industry (SCI).

Enzymatic Glycerolysis of Palm Kernel Olein-Stearin Blend for Monolaurin Synthesis as an Emulsifier and Antibacterial.

Monolaurin is a monoacylglycerol, which can act as an emulsifier and antibacterial. Palm kernel oil is a monolaurin raw material that can be fractionated into palm kernel olein (PKOo) and palm kernel stearin (PKS). Therefore, this study prepares monolaurin through enzymatic glycerolysis of the PKOo-PKS blend. The effects of enzyme concentration, molar ratio of oil to glycerol, solvent to oil ratio, and reaction temperature on the products of glycerolysis were investigated. The best conditions were selected for further production, purification, and characterization of the monolaurin. The results showed that the best glycerolysis condition was obtained with an enzyme concentration of 10% w/w, an oil–glycerol molar ratio of 1:4, a solvent–oil ratio of 2:1 v/w, and a glycerolysis temperature of 40 °C with a stirring speed of 600 rpm based on the monoacylglycerol (MAG) concentration. The identification of the sample with FTIR and NMR indicated that the purified glycerolysis product is the monolaurin. The thermal analysis showed a large endothermic peak with a melting point of 35.56 °C. The purified monolaurin has a HLB value of 5.92, and an emulsion capacity and stability of 93.66 ± 1.85% and 89.54 ± 3.36%, respectively. The minimum inhibitory concentration (MIC) of the monolaurin for Escherichia coli FNCC 0091 and Staphylococcus aureus FNCC 0047 were at 500 ppm, and 100 ppm for Bacillus subtilis FNCC 0060.

Упрощенный способ синтеза триацетина – пищевой добавки E1518

Aim. Development of a simplified technology for the production of triacetin – a food additive (E1518) and a water-retaining agent. Materials and Methods. The following main raw materials were used: distilled glycerol 99.5% (LLC «Ukrkhimresursy», Ukraine), glacial acetic acid (LLC «Chemical Alliance», Russia). It is proposed to control the content of unreacted products – glycerol – spectrophotometrically with copper (II), and acetic acid – by acid-base titration. Results. The conditions for the synthesis of triacetin are as follows: the molar ratio of glycerol and acetic acid is 1:6, temperature – 120-125оC, duration – 90 minutes. The distillation of excess acetic acid was carried out at a temperature of 130-140оC for 3 hours, which ensured the receipt of 100% of the product – triacetin, which contains trace amounts of acetic acid. The residual content of acetic acid in the final product is not more than 0.01% of the mass. After distillation, acetic acid is obtained with a concentration of 79-80% (azeotropic mixture). The use of a catalyst – sulfuric acid – negatively affects the color of the final product (from yellow to light brown) and pH (about an 0). The use of a hydrobromic acid catalyst does not lead to a 100% product, but it negatively affects the pH of the finished product (near zero), which requires additional purification of the final product (vacuum distillation) and neutralization, which in turn contaminates the product with inorganic salts. Conclusion. A simplified method for the synthesis of triacetin from glycerol and acetic acid has been developed, which excludes the use of catalysts, vacuum, and sorption purification.

Valorization of Solketal Synthesis from Sustainable Biodiesel Derived Glycerol Using Response Surface Methodology

Biodiesel production has gained considerable importance over the last few decades due to the increase in fossil fuel prices as well as toxic emissions of oxygen and nitrogen. The production of biodiesel via catalytic transesterification produces crude glycerol as a co-product along with biodiesel, amounting to 10% of the total biodiesel produced. Glycerol has a low value in its impure form, and the purification of glycerol requires sophisticated technologies and is an expensive process. The conversion of crude glycerol into value-added chemicals such as solketal is the best way to improve the sustainability of biodiesel synthesis using the transesterification reaction. Therefore, the conversion of crude glycerol into the solketal was investigated in a batch reactor simulation model developed by the Aspen Plus V11.0. The non-random two liquid theory (NRTL) method was used as a thermodynamic property package to study the effect of four input ketalization parameters. The model was validated with the findings of previous experimental studies of solketal synthesis using sulfuric acid as a catalyst. The influence of the following operating parameters was investigated: reaction time of 10,000 to 60,000 s, reaction temperature of 303 to 323 K, acetone to glycerol molar ratio of 2:1 to 10:1, and catalyst concentration of 0.005 to 0.03 wt %. The optimum solketal yield of 81.36% was obtained at the optimized conditions of 313 K, 9:1, 0.03 wt %, and 40,000 s. The effect of each input parameter on the ketalization process and interaction between input and output parameters was investigated by using the response surface methodology (RSM) optimizer. The relationship between independent and response variables developed by RSM fit most of the simulation data, which showed the accuracy of the model. A second-order differential equation fit the simulation data well and showed an R2 value of 0.99. According to the findings of RSM, the influence of catalyst amount, acetone to glycerol molar ratio, and reaction time were more significant on solketal yield. The effect of temperature on the performance of the reaction was not found to be significant because of the exothermic nature of the process. The findings of this study showed that biodiesel-derived glycerol can be effectively utilized to produce solketal, which can be used for a wider range of applications such as a fuel additive. However, further work is required to enhance the solketal yield by developing new heterogeneous catalysts so that the industrial implementation of its production can be made possible.

Synthesis of Glycerol Carbonate from Glycerol and Dimethyl Carbonate Catalyzed by Solid Base Catalyst Derived from Waste Carbide Slag

Na2CO3 was loaded onto waste carbide slag (CS) by impregnation-calcination method to prepare the solid base catalyst, which was used to synthesize glycerol carbonate (GC) by the transesterification of glycerol with dimethyl carbonate (DMC). The prepared catalysts were characterized by a scanning electron microscope (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Brunner−Emmet−Teller (BET) techniques. The catalyst 15 wt.% Na2CO3-CS-800, which was prepared by impregnating CS to the Na2CO3 solution with the concentration of 15 wt.% weight of CS and calcined at 800°C for 3 hours, showed an excellent catalytic ability. When it was applied in the catalytic synthesis of GC, 98.1% glycerol conversion and 96.0% GC yield were achieved in 90 mins at 75°C with the catalyst dosage of 3 wt.% to total reactants and the DMC to glycerol molar ratio of 5. More importantly, the loading of Na2CO3 can effectively improve the reusability of catalyst. The 15 wt.% Na2CO3-CS-800 can still achieve 83.6% glycerol conversion and 80.5% GC yield after five-time reuse. Meanwhile, under the same reaction conditions, the CS-800, which was obtained by calcining CS at 800°C for 3 hours, experienced significant activity reduction with only 15.2% glycerol conversion and 14.1% GC yield after five-time reuse. FTIR and XRD characterization revealed that CO32- might play a key role in preserving active catalytic CaO component by forming protective CaCO3 shell on the catalyst surface.

Enzymatic Glycerolysis of Palm Kernel Olein and Palm Kernel Stearin in different Ratios for Monolaurin Synthesis

Monolaurin is known as a monoglyceride of lauric acid, which act as an emulsifier and antimicrobial. One potential of monolaurin raw materials is palm kernel oil (PKO), which can be fractionated into palm kernel olein (PKOo) and palm kernel stearin (PKS). This study aims to determine the enzymatic glycerolysis influence of PKOo and PKS mixture in different ratios and time, on monoacylglycerol (MAG), diacylglycerol (DAG), and triacylglycerol (TAG) profiles. The Glycerolysis process of PKOo-PKS fat blends were carried out in different ratios of (60:40, 40:60, and 20:80 w/w) using commercial lipases (Lypozime RM IM) at 50°C, with an oil:glycerol molar ratio of 1:4, in a tert-butanol solvent system, between 3 to 24 hours. The results showed that the glycerolysis of PKOo and PKS in different ratios yielded varying product reactions with similar compositions (1.8-3.9% MAG, 73.2-76.4% DAG, and 20.7-24.2% TAG). A higher and not significant MAG was observed during the period of 24 hours. Also, the monolaurin was obtained at the ratio of 40:60 PKOo:PKS, within the glycerolysis time of 3 to 24 hours, at approximately 2.18±0.59% and 3.47±0.62%, respectively. The FTIR analysis also showed that the monolaurin sample was identical to the standard type, with the formation of OH group at wave number and cluster C=O ester of 3368.64 cm-1 and 1734.03 cm-1, respectively.