Glycerol Carbonate Yield Research Articles

Transesterification of biodiesel byproduct glycerol and dimethyl carbonate over porous biochar derived from pyrolysis of fishery waste

Glycerol carbonate (GC), an oxygenated fuel additive was synthesized from oversupplied glycerol in transesterification with dimethyl carbonate (DMC) over fishmeal biochar. Fishmeal was carbonized at various temperatures (550–750 °C). The most suitable carbonization temperature based on GC yield was utilized in transesterification. Biochar was characterized to investigate textural and basic properties and surface functional groups. Thermal treatment, methanol washing, and solvent addition techniques were adopted to investigate biochar reusability after each reuse. At the most suitable reaction conditions of 85 °C, 2 wt% catalyst dosage, and DMC-to-glycerol molar ratio of 2, 99.5% GC yield and complete conversion of glycerol were attained over biochar carbonized at 650 °C. Strong basicity of biochar initiated decarboxylation reaction, which resulted in formation of glycidol (0.5%). Addition of methanol without catalyst treatment after each reuse sustained GC yield of 93% at the end of fifth reuse.

Microwave-assisted transesterification of glycerol with dimethyl carbonate over sodium silicate catalyst in the sealed reaction system

Microwave-assisted transesterification of glycerol to glycerol carbonate (GC) using calcined sodium silicate (Na2SiO3) as a catalyst in the sealed reaction system was studied in this work. Effects of the parameters, including the molar ratio of dimethyl carbonate (DMC) to glycerol, the reaction temperature, the amount of the catalyst, the reaction time and, especially, the microwave-assisted reaction modes on glycerol conversion and GC yield were carefully investigated. It was found that the microwave-assisted reaction modes, namely, the temperature constant mode (TCM) and the power constant mode (PCM), greatly influenced the reaction. When the reaction was conducted in TCM, with the catalyst amount of 5 wt%, reaction temperature of 95 °C, DMC-to-glycerol molar ratio of 4:1, and reaction time of 15 min, the glycerol conversion and the GC yield reached 96.7% and 94.3%, respectively. Similar glycerol conversion and GC yield were also obtained under the condition of the catalyst amount of 1 wt%, DMC-to-glycerol molar ratio of 4:1, microwave irradiation input power of 175 W and reaction time of 50 s in PCM. The reaction in PCM showed much more advantages in reducing the amount of the catalyst and shortening the reaction time than that in TCM. Meanwhile, the transesterification of glycerol with DMC in PCM catalyzed by Na2SiO3 exhibited much higher reaction rate than that catalyzed by CaO. Moreover, in terms of the reaction in PCM, energy consumption could be reduced with the increase of the irradiation power. The investigation on the reusability of the Na2SiO3 catalyst in PCM showed that this catalyst could be reused in five reaction cycles without significant deactivation.

Vapor phase synthesis of glycerol carbonate over honeycomb monolith coated with zirconia based base catalysts

In this article the synthesis, characterization and catalytic activity studies of zirconia based base catalysts such as Mg(II)/ZrO2, Ca(II)/ZrO2 and Ba(II)/ZrO2 coated on honeycomb monoliths is reported. Honeycomb monoliths were coated with Mg(II)/ZrO2, Ca(II)/ZrO2, Ba(II)/ZrO2 and characterized for their physico-chemical properties such as surface basicity, crystallinity and morphology by using relevant techniques. The catalytic activity of these catalytic materials was evaluated in vapor phase synthesis of glycerol carbonate. The reaction conditions were optimized by varying reaction parameters such as nature of catalytic material, molar ratio of the reactants, catalyst bed temperature, feed-rate of the reactants and time-on-stream to obtain highest possible yield of glycerol carbonate with greater selectivity. The catalytic materials were found to be highly efficient in the synthesis of glycerol carbonate with a possible highest yield up to ~98%. These catalytic materials can be easily reactivated and reused in this reaction.Bangladesh J. Sci. Ind. Res.53(1), 21-28, 2018

Influence of Zr on the performance of Mg-Al catalysts via hydrotalcite-like precursors for the synthesis of glycerol carbonate from urea and glycerol

A series of Zr-containing Mg-Al hydrotalcite-like (HTl) precursors were prepared using co-precipitation method with Zr4+: (Al3+ + Zr4+) from 0 to 0.7. It was demonstrated by X-ray diffraction that the yield of the HTl phase declined on increasing of Zr content. Then, Mg-Al-Zr mixed oxide (CHT-Zr) catalysts were obtained by calcining of the corresponding HTl precursors and they all exhibited mesoporous structure after heat treatment. Based on systemic characterization, it was observed that the amount of Zr additive showed a great effect on the structure and acidic-basic property of CHT-Zr samples. Meanwhile, such CHT-Zr catalysts were effective catalysts for the glycerol carbonate (GLC) synthesis from glycerol and urea. Afterwards, the function of acidic and basic sites in each reaction path identified in this research was elucidated based on the reactant conversion and product selectivity. It proved that the acidic sites were inclined to promote the reaction towards GLC synthesis, while all the paths towards the by-products were significantly catalyzed by the basic sites. However, the catalysts with extra strong acidity did not facilitate the GLC production due to poisoning of surface active sites by urea adsorption. So, a well-balanced acidic-basic property was important to obtain high GLC yield with good selectivity. Among all the catalytic samples, the catalysts with Zr4+: (Al3+ + Zr4+) = 0.3 showed the best catalytic performance with 87.8% yield of GLC. Moreover, different reaction parameters such as reaction temperature, reaction time, catalyst amount and vacuum degree were investigated and optimum conditions were established. Additionally, this catalyst could be readily recycled and reused for at least four times without any activation treatment, while still possessing high activity.

Transition metal-promoted hierarchical ETS-10 solid base for glycerol transesterification.

A transesterification reaction has been carried out over a transition metal modified hierarchical ETS-10 (METS-10) catalyst to synthesize glycerol carbonate (GC) from glycerol. The inherent Lewis basicity of ETS-10 favors oriented conversion of glycerol, and the hierarchical structure benefits exposure of more active sites, shortens the molecular diffusion path, suppresses the formation of coke in the micropores, and then enhances the catalytic reactivity and stability. Furthermore, the influence of transition metals (Fe, Co, Ni, Cu, Zn and Mn) on the basic sites of supports has been investigated in detail. It is found that basicity change of the catalyst depends on not only the cation size, nature and composition of the transition metal but also the zeolite structure and pore topology. Besides, the presence of a certain amount of Ni0 species from catalyst reduction has proved to play a critical role in strengthening the interaction of Lewis basic sites (TiO62−) with active glycerol hydroxyl groups. Finally, a 97.7% glycerol conversion and 97.1% GC yield have been obtained over Ni/METS-10, of which the high catalytic performance can be maintained after 8 runs.

Development of a trapezoidal MgO catalyst for highly-efficient transesterification of glycerol and dimethyl carbonate

Trapezoidal MgO has been developed for the transesterification of glycerol and dimethyl carbonate with a glycerol carbonate yield of more than 99%.

Dual catalysis over ZnAl mixed oxides in the glycerolysis of urea: Homogeneous and heterogeneous reaction routes

In this work, we prepared ZnO, ZnAl2O4, and ZnAl mixed oxides with different metal molar ratios and applied them for synthesizing glycerol carbonate (GC) from glycerol and urea. The reaction routes related to the Zn species over the ZnAl mixed oxides were investigated. The ZnAl mixed oxides were found to consist of two Zn crystalline phases: ZnO and ZnAl2O4. From the reaction results, the ZnAl mixed oxides showed much higher glycerol conversion and GC yield than the ZnO and ZnAl2O4. During the reaction, the dissolution of the Zn species from the ZnO phase over the ZnAl mixed oxides was observed while the ZnAl2O4 phase remained insoluble. The ZnO phase provided a homogeneous reaction route via the dissolved Zn species, resulting in the formation of a Zn complex containing the isocyanate (NCO) and zinc glycerolate. In contrast, the insoluble ZnAl2O4 phase was responsible for not only a heterogeneous reaction route, but also adsorption of the Zn NCO complex on the catalyst. We proposed that the adsorbed Zn NCO complex could play a role as an active site for an additional heterogeneous reaction route. Therefore, the ZnAl mixed oxides exhibited high GC yields through the dual catalysis routes: the homogeneous reaction route over the ZnO phase and the heterogeneous reaction route over the ZnAl2O4 phase.

Magnesia-ceria mixed oxide catalysts for the selective transesterification of glycerol to glycerol carbonate

MgO-CeO2 catalysts were investigated for selective synthesis of glycerol carbonate by glycerol transesterification with dimethyl carbonate as carbonating source. Co-precipitation technique was used to prepare Mg-Ce oxides by with different molar ratios. Samples characteristics were derived by N2 adsorption, XRD, FE-SEM, TGA-DTA and CO2 -TPD. The catalysts surface structural properties and basicity were directed by the composition of oxides and treatment temperature. The sample with 3:1 Mg/Ce ratio exhibited highest basicity. The same catalyst treated at a temperature of 650°C, exhibited highest glycerol carbonate yield of 86%. The reaction conditions were also optimized.

Biodiesel byproduct glycerol upgrading to glycerol carbonate over lithium–oil palm ash zeolite

Mesoporous oil palm ash zeolite (OPAZ) was synthesized and impregnated with various lithium ion loadings (5–15wt%). The synthesized Li–OPAZ catalyst was used to upgrade biodiesel byproduct glycerol to glycerol carbonate (GC) via transesterification pathway. Results indicated that Li–OPAZ sustained the transesterification reaction to appreciably high glycerol conversion (100%) and GC yield (98.1%) under the optimal reaction conditions of 343K, 90min, DMC/glycerol molar ratio of 2, and 2wt% catalyst loading. The crystallinity and framework of zeolite was preserved after lithium incorporation with a slight decrease in pore volume and surface area. However, basicity increased with increased lithium impregnation, explaining the observed high catalytic activity of the theoretical 10wt% Li loaded OPAZ. Hence, 10wt% Li–OPAZ was reused in five successive cycles of experiment with sustained appreciable catalytic activity toward glycerol conversion and GC yield.

Heterometallic metal-organic framework-templated synthesis of porous Co3O4/ZnO nanocage catalysts for the carbonylation of glycerol

The efficient synthesis of glycerol carbonate (GLC) has recently received great attention due to its significance in reducing excess glycerol in biodiesel production as well as its promising applications in several industrial fields. However, the achievement of high conversion and high selectivity of GLC from glycerol in heterogeneous catalytic processes remains a challenge due to the absence of high-performance solid catalysts. Herein, highly porous nanocage catalysts composed of well-mixed Co3O4 and ZnO nanocrystals were successfully fabricated via a facile heterometallic metal-organic framework (MOF)-templated synthetic route. Benefiting from a high porosity and the synergistic effect between Co3O4 and ZnO, the as-prepared composite catalysts exhibited a significantly enhanced production efficiency of GLC in the carbonylation reaction of glycerol with urea compared to the single-component counterparts. The yield of GLC over the Co50Zn50-350 catalyst reached 85.2%, with 93.3% conversion and near 91% GLC selectivity, and this catalytic performance was superior to that over most heterogeneous catalysts. More importantly, the proposed templated synthetic strategy of heterometallic MOFs facilitates the regulation of catalyst composition and surface structure and can therefore be potentially extended in the tailoring of other metal oxide composite catalysts.

Synthesis of glycerol carbonate from glycerol and dimethyl carbonate catalyzed by calcined silicates

Several anhydrous silicates were prepared by calcination at 400°C and utilized as solid base catalyst for synthesizing glycerol carbonate (GC) by transesterification of glycerol with dimethyl carbonate (DMC). Among them, calcined sodium silicate showed the best catalytic activity with glycerol conversion of 97.7%. Then, a series of sodium silicates calcined at different temperatures were characterized using TGA, Hammett indicator method, BET, XRD, FT-IR and FESEM. Effect of calcination temperature on their catalytic ability was carefully investigated, followed by a reaction optimization study. The basicity of sodium silicates calcined at different temperatures highly depended on calcination temperature; their catalytic ability was affected by their total basicity rather than by their BET surface area; and the increased amount of strong basic sites resulted in the formation of by-product which decreased the GC yield and GC selectivity. Sodium silicate calcined at 200°C (Na2SiO3-200), which had the intermediate total basicity and relative low amount of strong basic sites, incurred the highest GC yield. The highest catalytic performance of Na2SiO3-200 was achieved under the condition that the 4:1 molar ratio of DMC to glycerol was reacted at 75°C for 2.5h. This catalyst could be reused five times without noticeable drop in catalytic activity.

Upgrading of glycerol from biodiesel synthesis with dimethyl carbonate on reusable Sr–Al mixed oxide catalysts

The high demand for renewable energy has led to the upsurge of methanol-assisted biodiesel synthesis. Therefore, glycerol as a byproduct entered the waste stream given the oversupply of biodiesel to the market. The dimethyl carbonate (DMC)-assisted transesterification of glycerol on a catalyst has been a popular approach for converting glycerol into valuable glycerol carbonate (GLC). The synthesis of GLC from the DMC-assisted transesterification of glycerol on mixed oxide catalysts (Srx–Al) with different Sr/Al ratios was examined in this study. A glycerol conversion of 99.4% and a GLC yield of 100% were achieved in a catalyst with Sr/Al=0.5 (Sr0.5–Al). Both values are higher than those in catalysts synthesized with Sr/Al=0.25 and 0.75. The Sr0.5–Al catalyst withstood five transesterification reaction cycles without a serious deactivation induced by the leaching of active SrO. Therefore, the Sr0.5–Al catalyst is suitable for consecutive uses in the DMC-assisted transesterification of glycerol with DMC into GLC.

CaO催化非均相体系制备碳酸甘油酯

以CaO为催化剂，将其用于催化甘油与碳酸二甲酯酯交换反应制备碳酸甘油酯，考察了CaO预处理条件和反应条件对碳酸甘油酯产率的影响。实验结果表明：催化剂焙烧温度对碳酸甘油酯产率影响显著，800℃焙烧的CaO具有较高的催化活性。在反应温度65℃，甘油与碳酸二甲酯摩尔比1:3，催化剂用量5%(基于甘油质量)条件下，CaO催化反应1 h碳酸甘油酯产率可达87.02%。 CaO was applied to glycerol carbonate production by the transesterification of glycerol and dimethyl carbonate. The effects of the catalyst preparation conditions and reactions condition on the performances of CaO in the transesterification were investigated. The results showed that the catalyst activity of CaO was greatly influenced by the different calcination temperatures, and the catalyst possesses a good activity when it was calcined at the temperature 800˚C. A desired glycerol carbonate yield of 87.02% was obtained at glycerol/dimethyl carbonate of 1:3, catalyst amount of 5%, and reaction time of 1 h at 65˚C.

High-efficiency and low-cost Li/ZnO catalysts for synthesis of glycerol carbonate from glycerol transesterification: The role of Li and ZnO interaction

A series of efficient and low-cost Li/ZnO catalysts were prepared by a simple impregnation method and investigated for the synthesis of glycerol carbonate (GC) from the transesterification of glycerol with dimethyl carbonate (DMC). The Li/ZnO catalysts were characterized using XRD, SEM, FT-IR, TG-DSC, TPD and XPS. It was found that the basicity of the catalysts highly depended on the Li loading and calcination temperature. The weak and moderate basic sites on the catalyst surfaces originated from the ZnO and Li+ interaction. The strong basic sites were attributed to the substitution of Zn2+ by Li+ in the ZnO lattice, which led to straining of Zn-O bonds and the formation of [Li+ O−] species. It was the strong basic sites rather than the weak and moderate basic sites that catalyzed the transesterification of glycerol with DMC. The highest catalytic activity was observed over the ZnO loaded with 1wt.% LiNO3 and calcined at 500°C. Glycerol conversion of 97.40% and GC yield of 95.84% were obtained over this catalyst at 95°C in 4h.

Synthesis of Glycerol Carbonate from Glycerol and Dimethyl Carbonate Using Ionic Liquid Catalysts

Acidic, basic and neutral ionic liquids (ILs) were prepared by two-step method. Their IR and NMR spectra showed that their structures were in accordance with their theoretical structure. Then these ILs were used as catalysts in the Glycerol carbonate (GC) of glycerol with dimethyl carbonate (DMC). The results show that basic ILs have high catalytic activity compared with acidic or neutral ILs and inorganic basic catalysts in the reaction. Under the suitable conditions using [Bmin]lm as a catalyst led to the yield of GC reached 94%, glycerol conversion reached 96%, GC selectivity reached 97% at molar ratio of DMC to glycerol at 3: 1, mass fraction of ionic liquid 12% (omega), reaction temperature 80 degrees C and reaction time 70 min. The ionic liquid was stable, and its activity did not decrease after using for 8 times (i. e., 85% glycerol conversion and near 90% GC selectivity). The results showed that the basic ionic liquid is more ideal green catalyst in esterification reaction.

Stabilized ladle furnace steel slag for glycerol carbonate synthesis via glycerol transesterification reaction with dimethyl carbonate

Abundant waste from ladle furnace (LF) steel slag industry was utilized to catalyze the glycerol transesterification reaction with dimethyl carbonate (DMC) to synthesize valuable glycerol carbonate (GC). LF slag was modified using various sodium hydroxide (NaOH) loadings (1–15wt.%), and the catalyst samples were characterized using XRD, FTIR, TPD-CO2, and EDS techniques. Modifying the LF using different NaOH loadings enhanced the stability, basicity, and basic strength of LF. Favorable reaction conditions at the best glycerol conversion and GC yield were investigated via reaction influencing parameter screening. Thus, the 10wt.% NaOH incorporated in LF under the reaction conditions of 75°C, DMC-to-glycerol molar ratio of 2, and 3wt.% catalyst dosage achieved 99% glycerol conversion and 97% GC yield. The catalyst exhibited sufficient heterogeneity and was utilized in five successive cycles of the experiment without serious deactivation.

Glycerol carbonate synthesis from glycerol and dimethyl carbonate using trisodium phosphate

Glycerol, a major biodiesel byproduct, was valorized using anhydrous trisodium phosphate (TSP) as a reusable heterogeneous catalyst in glycerol carbonate (GC) synthesis. The reaction progressed via catalytic carboxylation pathway of glycerol with dimethyl carbonate (DMC) under various reaction conditions. The TSP catalyst was characterized using TPD-CO2, TGA and XRD technique. Under reaction conditions of 70 °C, glycerol/DMC molar ratio of 2, 60 min, and 3 wt% catalyst loading, TSP achieved 99.5% glycerol conversion and GC yield, respectively. The appreciable high basicity and strong basic sites of TSP catalyst contributed to its remarkable performance. Also, the crystalline phase was preserved after the nine times reusability indicating high structural stability of TSP catalyst. The catalyst was heterogeneous without leaching and can easily be recovered and reused. Hence, the catalyst was repeatedly used in nine successive cycles of experiment without deactivation.

Activated red mud-supported Zn/Al oxide catalysts for catalytic conversion of glycerol to glycerol carbonate: FTIR analysis

Catalytic conversion to glycerol carbonate (GC) from glycerol and urea was investigated with Zn/Al oxide catalysts supported by activated red mud (ARM), a waste material. Compared to an unsupported catalyst, ARM-supported Zn/Al oxide catalysts exhibited higher GC yields. ARM-supported Zn/Al oxide catalysts showed a volcano curve for the GC yield as a function of the Zn/Al loading. FTIR analysis revealed the ARM-supported Zn/Al oxide catalysts to be more selective, resulting in higher GC yield. The balance of active sites from ARM and Zn/Al oxide was related to rates of each reaction step in GC synthesis, which eventually influenced on the selectivity and yield of GC.

Esterification of glycerol from biodiesel production to glycerol carbonate in non-catalytic supercritical dimethyl carbonate.

Conversion of glycerol from biodiesel production to glycerol carbonate was studied by esterification with dimethyl carbonate in a non-catalytic supercritical condition. It was found that in a non-catalytic supercritical condition, glycerol at higher purity gave higher yield of glycerol carbonate at 98 wt% after reaction at 300 °C/20–40 MPa/15 min. The yield of glycerol carbonate was observed to increase with molar ratio, temperature, pressure and time until a certain equilibrium limit. The existence of impurities such as water and remnants of alkaline catalyst in crude glycerol will direct the reaction to produce glycidol. Although impurities might not be desirable, the non-catalytic supercritical dimethyl carbonate could be an alternative method for conversion of glycerol from biodiesel production to value-added glycerol carbonate.Graphical abstractPlausible reaction scheme for conversion of glycerol to glycerol carbonate in non-catalytic supercritical dimethyl carbonate.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-016-2643-1) contains supplementary material, which is available to authorized users.

Sustainable Production of Glycerol Carbonate from By-product in Biodiesel Plant

Biomass upgrading is becoming a key alternative for handling difficulties associated with fossil sources of chemicals. The rapid growth in biodiesel production has triggered the availability of abundant glycerol feedstock with potentials for upgrade to valuable chemicals and intermediates. Glycerol carbonate is one of those compounds that can be derived from glycerol via heterogeneous catalysis. Its industrial applications as solvent, for detergents, cosmetics and in lithium ion batteries among others have great concerns. The paper therefore tailored recent literature on the role of solid catalysts for the glycerol to glycerol carbonate route. The activities of catalysts such as zeolites, heteropoly acids, oxides and hydrotalcites in improving glycerol carbonate yield by modifying catalyst compositions and reaction conditions were documented. Issues for further investigations were also identified.