Synthesis Of Diethyl Carbonate Research Articles

La‐Doped Mg‐Al Composite Oxides: Efficient Catalysts for the synthesis of Diethyl Carbonate via Transesterification of Ethylene Carbonate with Ethanol

AbstractSeries of La‐doped Mg−Al composite oxides were prepared by co‐precipitation method and used as catalysts for the synthesis of diethyl carbonate (DEC) via transesterification of ethylene carbonate (EC) with ethanol (EtOH). SEM, XRD, FT‐IR and XPS results confirmed that the introduction of La enhanced the interaction with MgO. The 8 mol % La‐doped Mg−Al composite oxide (calcined catalyst named HTC‐0.8 La) produced strong interactions and improved lattice oxygen content (27.84 %). Based on the N2 adsorption‐desorption and CO2‐TPD results, the HTC‐0.8 La catalysts possessed abundant multistage mesoporous structure, high strong base density and strength (0.941 mmol ⋅ g−1). Therefore, the HTC‐0.8La catalyst exhibited high catalytic activity with 58.5 % yield of DEC and 94.7 % selectivity to DEC (EC: EtOH molar ratio=1 : 6, reaction time=1.5 h, reaction temperature=150 °C and catalyst amount=3.2 wt %). Based on the correlation between catalytic activity and alkalinity, the yield of DEC was positively and linearly related to the strong alkali density of the catalyst. After five replicate experiments, the DEC yield after recovery and roasting reached 54.1 %, indicating that HTC‐0.8La is a renewable heterogeneous catalyst.

Product Yield Increasing More Than 20 Times Achieved by Reducing Water Poisoning for Direct Diethyl Carbonate Synthesis.

Diethyl carbonate (DEC) synthesis from CO2 and ethanol is a typical green chemical route for sustainable development and cleaner production. However, the bottleneck problem of a low DEC yield is still not solved at present. The DEC yield still maintains 0.5-5.0% unless expensive third additives are added. Compared to the cheap price of DEC, the third additives are generally more expensive. It is not advisible to use expensive chemicals to prepare cheap chemicals. In this work, the (ZrO2)1.0/(Fe2O3)1.0 catalyst was prepared by a novel template-precipitation method and the DEC yield of the DEC direct synthetic reaction only from CO2 and ethanol without third additives obtained 1.95%. After a series of supported catalysts were prepared, the DEC yield reached up to 46.1% for the (ZrO2)1.0/(Fe2O3)1.0@3A-CaO-CaC2 catalyst. This carrier can also be applied to other catalyst systems. CO2-TPD, NH3-TPD, and XRD were measured to analyze the microstructure and catalytic mechanism. Active center site theory was proposed to explain the intrinsic mechanism of catalyst activity. This new discovery of the mechanism and the DEC yield removed obstacles for the application of this reaction.

Sustainable synthesis of diethyl carbonate from carbon dioxide and ethanol featuring acetals as regenerable dehydrating agents

Featuring the regeneration of the dehydrating agent in the direct synthesis of diethyl carbonate offers a promising prospective in industrial application for the development of organic carbonate synthesis from CO2.

Effective synthesis of diethyl carbonate over Mg–Y composite oxides via alcoholysis of ethyl carbamate

Effective synthesis of diethyl carbonate from ethyl carbamate and ethanol using Mg–Y composite oxides.

Comparative Study between 2-Furonitrile and 2-Cyanopyridine as Dehydrants in Direct Synthesis of Dialkyl Carbonates from CO2 and Alcohols over Cerium Oxide Catalyst.

The shift of equilibrium by removing water with nitrile dehydrants is crucial for CeO2 -catalyzed synthesis of dialkyl carbonates from CO2 and alcohols. Two nitriles - 2-cyanopyridine and 2-furonitrile - were previously found as effective dehydrants, yet their detailed comparison as well as exploration of potential of 2-furonitrile remain insufficient. Herein, the performance of 2-cyanopyridine and 2-furonitrile was compared in the synthesis of various dialkyl carbonates. 2-furonitrile was found to be superior to 2-cyanopyridine in the synthesis of dialkyl carbonates from CO2 and bulky or long-chain (≥C3) alcohols. Namely, the yield of diisopropyl carbonate (up to 50 %) achieved using CeO2 and 2-furonitrile is comparable to or even higher than previously reported ones. Meanwhile, 2-cyanopyridine acted as a better dehydrant than 2-furonitrile in the synthesis of dimethyl carbonate and diethyl carbonate. The adsorption experiments and density functional theory calculations have indicated that the better performance of 2-furonitrile compared to 2-cyanopyridine in the synthesis of dialkyl carbonates from bulky or long-chain alcohols is due to the weaker interaction of 2-furonitrile with the CeO2 surface. Such weak interaction of 2-furonitrile offers a larger reaction field on the catalyst surface for both CO2 and alcohols.

Structure-Activity relationship and reaction mechanisms of the Cu/PSAC-Nx catalysts in the oxidation carbonylation of ethanol to diethyl carbonate

Cu catalysts supported on nitrogen-doped carbon with ultra-high specific surface area (2726 m2⋅g−1) derived from peanut shells (PSAC-Nx) were fabricated and investigated in the oxidative carbonylation of ethanol to diethyl carbonate (DEC). The Cu/PSAC-Nx catalysts exhibited superior catalytic performance with a maximum STYDEC of 3371 mg·g−1·h−1, attributed to the higher surface Cu0 and Cu+ concentration. Both Cu0 and Cu+ acted as the active species that accelerated the activation of ethanol molecules and promoted the insertion of CO, respectively, in the DEC synthesis. Among the four by-products, diethoxyethane preferred to be generated at higher temperatures or extended reaction time, while acetaldehyde and ethyl acetate tended to be produced at the Cu2+ species and ethyl formate was inclined to be created at a higher oxygen fraction. This work provided theoretical and experimental guidance for the rational design of efficient catalysts and the optimization of reaction conditions for the ethanol oxidative carbonylation to DEC.

Analysis and Simulation of Diethyl Carbonate Synthesis via CO2 and Ethanol Conversion

Objective: The objective of this study is to analyze and simulate the synthesis of diethyl carbonate (DEC) from the conversion of carbon dioxide and ethanol. The focus is on evaluating the best operating conditions, such as temperature and pressure, using the Aspen Plus software for process simulation. In addition, the study seeks to compare the results obtained with data from the literature and validate the simulation through previous studies. Methodology: To achieve the objective, thermodynamic models were used, such as the NRTL for the liquid phase and the Peng-Robinson equation state model for the vapor phase. The reactor chosen for the simulation was of the PFR type, and the catalyst used was cerium dioxide. Kinetic parameters and reactions were based on previous studies. The simulation was performed by varying the temperature and pressure of the system, feeding the data into the Aspen Plus software. Results and Conclusion: The simulation results indicated a maximum DEC production of 4.268 kmol/h, obtained at a temperature of 165°C and pressures of 150, 200 and 250 bar. Ethanol conversion reached 90.58% under these conditions. It was found that atmospheric pressure is not suitable for the reaction to occur. Comparison with previous studies and simulation validation showed satisfactory agreement. Phase analysis along the reactor revealed significant changes in the phase diagram as the reaction progressed. In short, this study contributes to the understanding of the DEC synthesis, highlighting the ideal operational conditions for its sustainable production. Originality/Value: This study focuses on the production of diethyl carbonate (DEC). It offers an original approach by analyzing the best operating conditions for the synthesis of DEC from carbon dioxide and ethanol. The results obtained demonstrate a maximum production of DEC and a high conversion of ethanol, contributing to the development of sustainable processes and the replacement of toxic compounds with environmentally friendly alternatives. This research is of significant value in expanding existing knowledge about ECD production and its potential impact on the industry.

Comparative techno-economic and environmental analysis of a new CO2 to diethyl carbonate production process

Direct conversion of CO2 to dialkyl carbonates such as diethyl carbonate (DEC) can contribute to mitigate CO2 emissions. We previously proposed a new DEC synthesis method from the reaction of CO2 and tetraethoxysilane (TEOS), an expensive functional chemical. After being used for DEC synthesis, TEOS can be regenerated from reaction of ethanol and hexaethoxy disiloxane (DS), the byproduct produced along with DEC. However, TEOS regeneration requires several processing units and high energy demand. In this study, we designed and evaluated feasibility of this new DEC synthesis process. Based on data obtained from lab experiments, the entire process, which comprised DEC synthesis and TEOS regeneration sections, was designed and optimized using process simulator Pro/II. Cradle-to-gate life cycle assessment method was applied to comprehensively evaluate the total CO2 emissions caused by the consumption of raw materials and utilities in DEC synthesis and TEOS regeneration sections. In addition, the total production cost was evaluated. On the basis of the evaluation results, process hotspots were identified. Optimal conditions used for TEOS regeneration (ethanol/DS = 18.2) were proposed to improve total process performances. The total production cost and CO2 emissions are 1.7 $/kg DEC, 3.6 kg CO2/kg DEC, respectively. The new process was compared to the most commonly used process which synthesizes DEC from the reaction of CO2 with ethanol, assisted by the dehydrating agent 2-cyanopyridine. Our results show that the new DEC synthesis process gains higher economic and environmental viability.

A multifunctional carrier for composite ZnFe2O4: a catalyst for improved one-step diethyl carbonate synthesis from CO2 and ethanol

ZnFe2O4 was prepared for the synthesis of diethyl carbonate (DEC). The mechanism underlying the improved yield is proposed, which involves acid-base active sites, to fundamentally solve the current situation.

Novel ZrFe2ZnO6 with multiple functional composite supports for one-step synthesis of diethyl carbonate from CO2 and ethanol

The yield was 3.93% when catalyzed by Fe2O3–ZrO2–ZnO (1 : 1 : 1) while the yield was 57.7% when catalyzed by 15 wt% Fe2O3–ZrO2–ZnO@3A-CaO–CaC2.

Mechanistic insights into CeO2-catalyzed direct synthesis of diethyl carbonate from CO2 and ethanol assisted by zeolite and 2,2-diethoxypropane

A mechanistic study on the production of diethyl carbonate on a CeO2 catalyst assisted by H-FAU and 2,2-diethoxypropane was conducted based on detailed kinetics.

Zr0.1/(Fe[sbnd]Ce) as highly efficient catalyst for direct synthesis of diethyl carbonate from ethanol with fermentation tail gas as CO2 raw material

In the production process of bioethanol, stripping is usually required to improve the production efficiency of ethanol, and the generated CO2 fermentation gas direct emissions contribute to increased carbon. Herein, we prepared Zrx/(FeCe) catalyst by co-precipitation method to catalyze CO2 and ethanol for production of diethyl carbonate (DEC). Compared with FeCe catalysts, the introduction of Zr significantly improved the acid-base active sites and the oxygen vacancies on the catalyst surface, resulted in higher activity and selectivity of the catalysts. The ratio of Zr:(FeCe) in the catalyst, reaction temperature, pressure and time were optimized, resulting a high DEC selectivity of 96.7% under the Zr0.1/(FeCe) catalyst. Finally, we used the fermentation tail gas as CO2 source to react with ethanol for the formation of DEC, and obtained 56.0% selectivity of DEC. This study provides a new idea for the utilization of CO2 fermentation gas and the development of cleaner fuel production process.

Optimization and model-based control of sustainable ethyl-methyl carbonate and diethyl carbonate synthesis through reactive distillation

As excellent solvents of lithum-ion electrolyte, ethyl-methyl carbonate (EMC) and diethyl carbonate (DEC) are synthesized through transesterification of dimethly carbonate (DMC) and ethanol. Process intensification, optimization and the corresponding control scheme of the synthesized process are essential when sustainability is becoming a necessity. In the present work, the intensified flowsheet for EMC and DEC production process was firstly proposed and optimized with conventional reactive distillation (RD) and reactive dividing wall column (RDWC), respectively. Compared with RD process, RDWC could achieve 25.3% and 8.2% total annualized cost reduction for EMC and DEC production process, respectively. And carbon dioxide emission could be decreased by 29.4% and 11.7% by further integrating RD and separation column into RDWC arrangement for DEC and EMC production. Then multi-loop PI control schemes were developed as benchmark and linear model predictive controller was designed to handle the persistent feed disturbance. The superiorities of model-based controllers for the strongly interactive and coupled system are demonstrated by the dynamic response comparisons in terms of settling time, overshoot and integral of squared error (ISE), especially for the controlled variables with poor control performance under conventional multi-loop PI control structure. To summarize, the comprehensive control performance index-ISE with MPC is reduced by 55.9%–99.1%, as compared to those under PI control strategy.

Effective synthesis of dialkyl carbonate from CO2 and alcohols using dibutyltin(IV) oxide catalyst and dehydrating agents

The combination of a dibutyltin(IV) oxide catalyst with an ortho ester as the dehydrating agent exhibited high activity for the direct synthesis of diethyl carbonate from CO2 and ethanol in 78% yield. With water as a by-product limiting the reaction, a recoverable dehydrating agent is required. When alkoxysilanes were employed for this purpose, various dialkyl carbonates were obtained in yields of 33–45%.

Synthesis of diethyl carbonate from CO2 and orthoester promoted by a CeO2 catalyst and ethanol

The combination of a CeO2 catalyst and ethanol effectively promotes the direct synthesis of diethyl carbonate (DEC) from CO2 and an orthoester. The reaction temperature, initial CO2 pressure, and the ethanol/orthoester volume ratio were found to significantly influence DEC formation and were systematically studied to determine the optimum conditions. DEC amount of 5.2 mmol was obtained at 160 °C, 5 MPa of CO2, and a reaction time of 20 h, providing high productivity (1.21 mmolDEC mmolcatalyst−1 h−1) using a CeO2 catalyst. The recovered CeO2 catalyst was recyclable at least four times without any significant loss of activity when both triethyl orthoacetate and triethyl orthovalerate were used. A series of orthoesters bearing various alkyl substituents, aromatic substituents and halide moieties were evaluated for their activities with and without ethanol. In the presence of ethanol, orthoesters bearing longer alkyl substituents led to higher DEC yields, and orthoesters bearing aromatic and halide moieties negatively impacted DEC formation. In the absence of ethanol, triethyl orthoacetate provided the highest DEC yield; in all cases, the use of ethanol resulted in a greater DEC formation than when the reaction was performed without ethanol.

Thermodynamics and Kinetics Study of Diethyl Carbonate (DEC) Synthesis from CO2, Ethanol, and Epoxides with Various Catalysts

Carbon dioxide (CO2) has been the main contributor for global warming over the past decades. However, it can potentially be utilized as raw material of valuable products, such as organic carbonate compound namely diethyl carbonate (DEC). Formation of DEC via indirect route from CO2 and ethanol is accompanied with epoxides as dehydrating agent. This work has been devoted to study thermodynamics and kinetics of indirect DEC synthesis using ethylene oxide (EO), propylene oxide (PO), and butylene oxide (BO) with various catalysts. Data from scientific journals and previous experiments conducted at Laboratory of Thermodynamics, ITS were analyzed in this study. Based on the value of (ΔG), it was found that indirect synthesis using EO is the most spontaneous reaction, followed by BO and PO, respectively. Simulation using Aspen HYSYS V8.8 also reveals that reactant and product system after 3 hours of reactions falls into vapor-liquid region and superheated region. Meanwhile, kinetics evaluation of experiment using PO and KI/EtONa catalyst showed that the aforementioned reactions are exothermic due to decreasing value of reaction constant upon reaching certain temperature. Based on Arrhenius equation while presuming that the reaction is elementary and non-elementary, activation energy was estimated as 55.62 kJ/mol and 54.80 kJ/mol, respectively. Furthermore, the use of KI/EtONa as catalyst resulted the highest yield among other catalysts namely KI, KI/CeO2, and KI/Zeolite.

Readily-fabricated supported MgO catalysts for efficient and green synthesis of diethyl carbonate from ethyl carbamate and ethanol.

Developing cost-effective, high-efficiency and heterogeneous catalysts is of prime importance for the green synthesis of diethyl carbonate (DEC) from ethyl carbamate (EC) and ethanol. Herein, a series of MgO/γ-Al2O3 catalysts were readily fabricated by an impregnation method for DEC synthesis from EC and ethanol. The activities of the as-prepared MgO/γ-Al2O3 catalysts as well as the individual MgO or γ-Al2O3 were first tested in the batch reactor. Among the investigated samples, the MgO/γ-Al2O3 with a MgO loading of 10 wt% (denoted as 10% MgO/γ-Al2O3) exhibited the largest amount of stronger basic sites, and the highest activities with EC conversion of 41.8% and DEC yield of 30.4%, respectively. Furthermore, the DEC yield was greatly boosted to 52.1% with a high DEC selectivity of 93.8% over the 10% MgO/γ-Al2O3 catalyst under the optimized reaction conditions in the fixed bed reactor, outperforming most of the reported catalysts.

Sustainable Catalytic Synthesis of Diethyl Carbonate.

New sustainable approaches should be developed to overcome equilibrium limitation of dialkyl carbonate synthesis from CO2 and alcohols. Using tetraethyl orthosilicate (TEOS) and CO2 with Zr catalysts, we report the first example of sustainable catalytic synthesis of diethyl carbonate (DEC). The disiloxane byproduct can be reverted to TEOS. Under the same conditions, DEC can be synthesized using a wide range of alkoxysilane substrates by investigating the effects of the number of ethoxy substituent in alkoxysilane substrates, alkyl chain, and unsaturated moiety on the fundamental property of this reaction. Mechanistic insights obtained by kinetic studies, labeling experiments, and spectroscopic investigations reveal that DEC is generated via nucleophilic ethoxylation of a CO2 -inserted Zr catalyst and catalyst regeneration by TEOS. The unprecedented transformation offers a new approach toward a cleaner route for DEC synthesis using recyclable alkoxysilane.

Synthesis of diethyl carbonate from ethanol and CO2 over ZrO2 catalysts

Diethyl carbonate (DEC) is a versatile chemical with several commercial uses. The synthesis of DEC from carbon dioxide and ethanol is both environmentally friendly and can be integrated into the ethanol biorefinery. A thermodynamic evaluation was made to predict the amount of DEC produced at equilibrium at the reaction conditions used in this work. Zirconium oxide solids were prepared using sol–gel methodology and were loaded with Na, Mg or PO4−3 using the incipient wetness impregnation method. Catalytic tests were carried out in a 500 mL stainless steel Parr reactor at 423 K. The DEC yield decreased as the Na or Mg load increased, while increasing the yield of acetaldehyde. However, DEC yield and selectivity increased as the PO4−3 load increased, while the acetaldehyde yield decreased. Lower overall acid site density and lower than 2.8 µmol-CO2/m2 basic site density resulted in a higher DEC yield.

Diethyl carbonate synthesis from CO2 with dehydrating agent of ethylene over catalysts of supported and mixed Ni–Cu@Na3PW12O40

Excessive CO2 emissions and alternative energy fuels are two major difficult issues. The utilization of CO2 into fine chemicals is an optimal route. Diethyl carbonate (DEC) is an extremely versatile chemical intermediate. DEC is used in gasoline, pharmaceutical, chemical and other fields. DEC synthesis from CO2 and ethanol is a typical green synthetic route. Ni–Cu@Na3PW12O40 catalysts were synthesized by two novel methods of supported and mixed. The catalyst prepared by mixed method showed nice catalytic performance. It was confirmed that water removal was the key to improving conversion efficiency. In the presence of dehydrating agent of ethylene, ethanol conversion increased from ca. 3% to ca. 40%. Propylene oxide (PO) participated in the reaction and ethanol conversion continued to reach to ca. 90% while DEC selectivity dropped by half. Under optimal conditions, our Ni–Cu@Na3PW12O40 catalyst effectively solved the two major issues above.