Synthesis Of Glycerol Carbonate Research Articles

Can Glycerol Carbonate be Synthesized Without a Catalyst?

Abstract: Biodiesel and oleo-chemical industries have been producing huge quantities of glycerol as a by-product. Value-added products can be synthesized from glycerol through different chemical and enzymatic reactions, such as oxidation, carbonylation, reforming, acetalyzation, etherification, dehydration, hydrogenolysis, hydrolysis, esterification, and transesterification. Glycerol is a low-cost polyol that can be converted into glycerol carbonate, which has potential applications in polymer and biobased non-isocyanate polyurethanes industries (Bio-NIPUs). The present contribution is the first of its kind to report on the synthesis of glycerol carbonate via catalyst and solvent-free transesterification of glycerol with dimethyl carbonate under conventional as well as microwave heating. Additionally, a comparative study of conventional and microwave-assisted transesterification was performed. Under conventional heating, 78% glycerol carbonate is obtained at 120oC in 36 hours, whereas, using microwaves, 92% of glycerol carbonate can be achieved in 30 minutes. Presently, biomass-based heterogeneous materials are used in catalysis due to their importance within the context of sustainability. In line with this, in this work, a series of green catalysts, namely, molecular sieves (MS, 4Å), Hβ- Zeolite, Montmorillonite K-10 clay, activated carbon prepared from the shell of groundnut (Arachis hypogaea), and biochar from sawdust pyrolysis were successfully employed. Glycerol carbonate was thoroughly characterized by 1H and 13C NMR, FT-IR and MS. The method described here is facile and green since the utilization of bioresource (glycerol) for the production of glycerol carbonate is performed under microwave.

Role of Zirconium Counter ions Content in the Secondary Structure of Keggin-type Heteropoly Tungstate for the Solvent-free Glycerol Carbonate Synthesis

Role of Zirconium Counter ions Content in the Secondary Structure of Keggin-type Heteropoly Tungstate for the Solvent-free Glycerol Carbonate Synthesis

Glycerol Carbonate Synthesis: Critical Analysis of Prospects and Challenges with Special Emphasis on Influencing Parameters for Catalytic Transesterification

Glycerol Carbonate Synthesis: Critical Analysis of Prospects and Challenges with Special Emphasis on Influencing Parameters for Catalytic Transesterification

Enhancing the Green Synthesis of Glycerol Carbonate: Carboxylation of Glycerol with CO2 Catalyzed by Metal Nanoparticles Encapsulated in Cerium Metal-Organic Frameworks.

The reaction of glycerol with CO2 to produce glycerol carbonate was performed successfully in the presence of gold nanoparticles (AuNPs) supported by a metal-organic framework (MOF) constructed from mixed carboxylate (terephthalic acid and 1,3,5-benzenetricarboxylic acid). The most efficient were two AuNPs@MOF catalysts prepared from pre-synthesized MOF impregnated with Au3+ salt and subsequently reduced to AuNPs using H2 (catalyst 4%Au(H2)@MOF1) or reduced with NaBH4 (catalyst 4%Au@PEI-MOF1). Compared to existing catalysts, AuNPs@MOFs require simple preparation and operate under mild and sustainable conditions, i.e., a much lower temperature and the lowest CO2 overpressure ever reported, with MgCO3 having been found to be the optimal dehydrating agent. Although the yield of the process is still not competitive with previously developed systems, the most promising advantage is the highest TOF (78 h-1) ever reported for this reaction. The optimal parameters observed for AuNPs were also tested on AgNPs and CuNPs with promising results, suggesting their great potential for industrial application. The catalysts were characterized by XRD, TEM, SEM-EDS, ICP-MS, XPS, and porosity measurements, confirming that AuNPs are present in low concentration, uniformly distributed, and confined to the cavities of the MOF.

Efficient Catalytic Synthesis of Glycerol Carbonate Using Optimized Na and K Titanate Nanotubes Catalysts

The synthesis of glycerol carbonate from glycerol has garnered significant research attention because of its wide application in the lithium-ion battery and pharmaceutical industries. This study summarizes the catalytic transformation of glycerol to glycerol carbonate using Na and K titanate nanotubes as catalysts. We report the synthesis of Na and K titanate nanotubes catalyst by a simple co-precipitation route and investigate their catalytic activity in the transesterification of glycerol. The physicochemical properties of the Na and K titanate nanotubes catalyst were successfully studied by CO2-TPD and XRD. The designed catalyst possesses high catalytic efficiency and stability in the transesterification reaction of glycerol. Based on its surface area and basicity, several experiments were performed, and it was observed that under optimized conditions (i.e., 5 wt.% catalyst loading, 5:1 molar ratio of DMC to glycerol, 90 °C, and 90 min), the highest conversion of glycerol was achieved, 92.6% glycerol carbonate. The high thermal stability and recyclability make it an efficient heterogeneous catalyst for the synthesis of glycerol carbonate.

Tuning catalytic performance: comparative study of magnesium–strontium mixed oxide catalysts for glycerol carbonate synthesis

Tuning catalytic performance: comparative study of magnesium–strontium mixed oxide catalysts for glycerol carbonate synthesis

Synthesis of glycerol carbonate from glycerol and CO2 over Cu-Zr complex oxide

A series of Cu1–xZrxO2 bimetallic oxides with different Cu-Zr molar ratios for glycerol carbonate synthesis from glycerol and CO2 were prepared by hydrothermal method. The results found that the performance was significantly affected by the Zr doping amounts. Under the optimal reaction conditions, the Cu0.99Zr0.01O2 catalyst had the best catalytic performance. The conversion of glycerol and the selectivity of glycerol carbonate reached 64.1% and 85.9%, respectively. Cu1–xZrxO2 complex oxide exhibited better activity than pure CuO and pure ZrO2. The structures, morphologies and surface properties of the catalysts were characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption and desorption, Temperature programmed reduction (H2-TPR), Temperature programmed desorption (TPD) and Fourier Transform Infrared Spectroscopy (FT-IR). It is speculated that the high activity is related to the degree of dispersion of Zr on the surface of CuO, the surface content of oxygen species and the number of acidic-basic sites. In addition, catalytic activity did not change significantly after six cycles, indicating the excellent stability of the catalyst.

Reaction Kinetics and Mechanism for the Synthesis of Glycerol Carbonate from Glycerol and Urea Using ZnSO4 as a Catalyst

A series of Zn salts were used as catalysts for the reaction of glycerol and urea to produce glycerol carbonate and it was found that ZnSO4 showed the highest catalytic activity. Furthermore, the effects of reaction parameters on the glycerol conversion and glycerol carbonate yield were studied in detail. The results indicated that the glycerol conversion and glycerol carbonate yield were increased with the reaction temperature, reaction time, and catalyst amount while the optimal reaction conditions were 140 °C, 240 min, catalyst amount of 5 wt% (based on the glycerol weight), and urea-to-glycerol molar ratio of 1.1:1. During the reaction, the ZnSO4 catalyst is transformed into Zn(NH3)2SO4 at the initial stage of the reaction and then further transformed into Zn(C3H6O3). Zn(C3H6O3) and (NH4)2SO4 may be the true active species for the activation of urea and glycerol, respectively. The reaction mechanism is proposed in this article. Based on the experimental results, a reaction kinetics model considering the change in volume of the reaction system was also established, and the model parameters were obtained by fitting the experimental data. The statistical results showed that the established kinetics model is accurate.

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.

Efficient synthesis of glycerol carbonate by doping metallic copper in palladium-catalyzed glycerol system for carbonylation reaction

The synergistic effect between copper and palladium promotes electron transport by using ZIF-8-derived Cu–NC materials to support palladium nanoparticles, which plays a crucial role in the ringing of glycerol carbonate.

Synthesis of glycerol carbonate using Li/Mg/K modified zeolite beta: a kinetic study

In the present investigation, the transesterification of glycerol with dimethyl carbonate was studied in the presence of Li, Mg, and K-modified zeolite beta. Out of all the modified catalysts, Li-modified zeolite beta comes out to be the best catalyst for the synthesis of glycerol carbonate.

Synthesis and Optimization of Glycerol Carbonate from Crude Glycerol Using Sodium Carbonate (Na2CO3) as a Heterogeneous Catalyst.

The essential need for sustainable energy sources to replace fossil fuels has fueled interest in renewable energy and biorefinery processes. Biodiesel production generates a considerable amount of crude glycerol (CG), which poses a challenge for the industry. This study aims to address this challenge by purifying CG through acidification. The acidification process successfully purified crude glycerol (PCG), resulting in a purity of 98.4 wt %. Subsequently, synthesizing glycerol carbonate (GC) from PCG and dimethyl carbonate (DMC) was undertaken by using heterogeneous catalysts. Sodium carbonate (Na2CO3) emerges as the most promising catalyst, considering its suitability in the presence of impurities such as 0.72 wt % of water and 0.57 wt % of matter organic nonglycerol (MONG) in PCG. The optimum catalyst dosage of Na2CO3 was determined as 2.1% mol of PCG. The experiments were carried out using a central composite design (CCD) methodology. By employing the response surface method (RSM), the optimal reaction conditions were determined to be a PCG/DMC molar ratio of 1:2.37 and a reaction time of 1.83 h. Under these conditions, an observed GC yield of 72.13% and PCG conversion of 78.39% were achieved. Despite the purification process, PCG still contains residual water, making Na2CO3 a suitable catalyst capable of tolerating a water content up to 3 wt %. This study not only enhances the effective utilization of CG within the biodiesel industry but also offers valuable insights for further exploration of sustainable chemical processes in future research.

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.

Enzyme-Catalyzed Synthesis of Glycerol Carbonate in Solventless Liquid One Phase Conditions: Role of Reaction Medium Engineering on Catalytic Performance

Enzyme-Catalyzed Synthesis of Glycerol Carbonate in Solventless Liquid One Phase Conditions: Role of Reaction Medium Engineering on Catalytic Performance

Synthesis of glycerol carbonate from industrial by-products by alcoholysis of urea: Crude glycerol and red gypsum

In this study, a heterogeneous catalyst was developed from red gypsum for the synthesis of glycerol carbonate through a glycerolysis reaction with urea. Under optimum reaction conditions, a simple heat treatment on bare red gypsum in a static air environment produces an 87% yield of the targeted glycerol carbonate product. The higher catalytic activity of the calcined catalyst is due to its basic characteristics and the presence of different phases of anhydrite CaSO4 with additional elements, especially an active hematite (Fe2O3) phase. The catalytic process was also found to be insensitive to the type of flowing gas that was used to remove the evolved ammonia gas, whereby, either inert nitrogen gas or reactive air containing oxygen did not significantly impact the glycerol carbonate yield. Indeed, with a promising yield, the developed catalytic system was able to directly synthesise glycerol carbonate from industrial crude glycerol from a biodiesel plant. The red gypsum-based catalytic system seems resistant to the presence of a certain level of moisture and other impurities in crude glycerol. The catalyst efficiency is being retained for consecutive reaction cycles, which are subsequently reused for the next batch reaction without requiring any pre-treatment.

A Green Approach to Obtaining Glycerol Carbonate by Urea Glycerolysis Using Carbon-Supported Metal Oxide Catalysts.

The results of sustainable and selective synthesis of glycerol carbonate (GC) from urea and glycerol under ambient pressure using carbon-fiber-supported metal oxide catalysts are reported. Carbon fibers (CF) were prepared via a catalytic chemical vapor deposition method (CCVD) using Ni as a catalyst and liquefied petroleum gas (LPG) as a cheap carbon source. Supported metal oxide catalysts were obtained by an incipient wetness impregnation technique using Zn, Ba, Cr, and Mg nitrates. Finally, the samples were pyrolyzed and oxidized in an air flow. The obtained catalysts (10%MexOy/CFox) were tested in the reaction of urea glycerolysis at 140 °C for 6 h under atmospheric pressure, using an equimolar ratio of reagents and an inert gas flow for NH3 removal. Under the applied conditions, all of the prepared catalysts increased the glycerol conversion and glycerol carbonate yield compared to the blank test, and the best catalytic performance was shown by the CFox-supported ZnO and MgO systems. Screening of the reaction conditions was carried out by applying ZnO/CFox as a catalyst and considering the effect of reaction temperature, molar ratio of reagents, and the mode of the inert gas flow through the reactor on the catalytic process. Finally, a maximum yield of GC of about 40%, together with a selectivity to glycerol carbonate of ~100%, was obtained within 6 h of reaction at 140 °C using a glycerol-to-urea molar ratio of 1:1 while flowing Ar through the reaction mixture. Furthermore, a positive heterogeneous catalytic effect of the CFox support on the process was noticed.

Multifunctional Halogen-Free Guanidine-Based Ionic Liquids for the One-Pot Two-Step Synthesis of Glycerol Carbonate from CO2 and Glycerol under Mild Conditions

Multifunctional Halogen-Free Guanidine-Based Ionic Liquids for the One-Pot Two-Step Synthesis of Glycerol Carbonate from CO₂ and Glycerol under Mild Conditions

Glycerol carbonate synthesis over nanostructured titanate catalysts: Effect of morphology and structure of catalyst

The indirect conversion of CO2 into glycerol carbonate using DMC was investigated using pristine sodium titanate nanotubes (NaTNT) and nanostructured titanates (calcined NaTNT at different temperatures) as catalysts. The calcination changes the morphology of the nanostructured titanates, between 200 and 400 °C the nanotubes shape is retained, however above these temperatures (500 and 600 °C) nanoribbons were identified, as well as nanorods obtained at 700 °C. A significant decrease in specific surface area and total pore size in temperatures up 500 °C was also observed. Furthermore, a decrease in the Ti+4/Ti+2 ratio and in the binding energy of Ti 2p3/2 and Ti 2p1/2 were observed, indicating an increase in the electron density and consequently increase in the Lewis acidity character of the titanium atom. All the nanostructured titanates showed good catalytic activity with glycerol conversion and GC selectivity above 90%. The results of the recycling showed that the nanostructured catalysts retained a good catalytic activity with high glycerol conversion (> 90%) although the GC selectivity decreased due the formation of glycidol, a high value-added by-product.

Recent Advances in Conversion of Glycerol: A Byproduct of Biodiesel Production to Glycerol Carbonate

Owing to erupted ecological concerns and escalated energy consumption, biodiesel produced by transesterifying nonedible and used cooking oils has been acknowledged as a viable source of clean and sustainable energy, alternative to fossil fuels. This transesterification process led to an excessive supply of glycerol as the primary byproduct which can then be transformed into value-added derivatives, primarily glycerol carbonate (GC), thereby drawing attention to its potential use in industrial applications. Although several methods for synthesis of GC utilize glycerol as building block, the transesterification approach using dimethyl carbonate (DMC) is the most effective route implementing safer and greener reaction conditions. This review is focused on different types of heterogeneous catalysts and characterization techniques used for identifying and deactivating those catalysts, covering the literature from the last decade to till date on this topic. Potent applications of GC as a versatile compound are elucidated in brief. Finally, a conclusion, outlook, and author’s perspective have been provided in brief.

Indium exchanged heteropoly tungstates: Efficient catalysts for the synthesis of glycerol carbonate from glycerol and urea

In this study, heteropoly tungstate protons were exchanged with various amounts of indium to impart Lewis acidity in Keggin heteropoly acid catalysts. The synthesis of glycerol carbonate from urea and glycerol was investigated using the synthesized InxTPA catalysts. The prepared catalysts were characterized by Fourier transforms infrared (FTIR), X-ray diffraction (XRD), Laser Raman, and temperature programmed desorption of ammonia studies. The obtained characterization results confirmed that the existence of Keggin ion structure of heteropoly acid after modification with indium ions. The modification of heteropoly tungstate with transition metal ions was found to improve its acidity and the stability of heteropoly acids (HPAs). The presence of Lewis acidic sites associated with the indium ions present in the catalyst was indicated by pyridine adsorbed FT-IR spectra. The amount of indium ions in heteropoly tungstate had an impact on the catalysts acidity, which in turn affected the activity of catalyst. The partially exchanged In0.66TPA catalyst demonstrated 69.4% glycerol conversion with 98.8% selectivity to glycerol carbonate. The study also investigated the impact of various reaction parameters such as reaction time, mole ratio of glycerol to urea, reaction temperature, and catalyst concentration and established the optimum reaction conditions.