Highly dispersed MgInCe-mixed metal oxides catalyzed direct carbonylation of glycerol and CO_(2)into glycerol carbonate

Glycerol carbonate,an important glycerol value-added product,has been widely used as an active intermediate and inert solvent in the synthesis of cosmetics,detergents,chemical intermediates,polymers,and so on.The direct carbonylation from glycerol with CO_(2)is considered a promising route,but still tough work due to the thermodynamic stability and the kinetic inertness of CO_(2).In this work,highlyselective direct carbonylation of glycerol and CO_(2)into glycerol carbonate has been achieved over highly dispersed MgInCe-mixed metal oxides(MgInCe-MMO),which were prepared through the topological transformation derived from the MgInCe-layered double hydroxides(MgInCe-LDHs).By precisely modulating the surface basic-acidic properties and the oxygen vacancies,an efficient carbonylation of glycerol with CO_(2)has been achieved with a selectivity of up to>99%to glycerol carbonate.Deep investigation into the synergistic catalysis of base-acid sites and oxygen vacancies has been clarified.

Glycerol carbonate synthesis from glycerol and dimethyl carbonate using guanidine ionic liquids

A large number of surplus glycerol from the biodiesel production can be used as renewable feedstock to produce glycerol carbonate. In this paper, a series of guanidine-based ionic liquids were synthesized to catalyze the transesterification of glycerol and dimethyl carbonate. The tunable basicity and the anion–cation cooperative effect were responsible for the obtained results. The [TMG][TFE] showed the best activity turnover frequency(TOF)of 1754.0 h^(-1), glycerol(GL) conversion of 91.8%, glycerol carbonate(GC) selectivity of 95.5%) at 80 °C with 0.1 mol% catalyst for 30 min. The reaction mechanism of the transesterification was also proposed.

Production of glycerol carbonate via reactive distillation and extractive distillation: An experimental study

A process for the production of glycerol carbonate(GC) is proposed with the transesterification of glycerol(GL)and dimethyl carbonate(DMC) with CaO as catalyst by reactive distillation and extractive distillation. The performance of solvents in separating DMC-methanol azeotrope and the effects of operation parameters on the reactive distillation process are investigated experimentally. The results indicate that both the GL conversion and GC yield increase with the DMC/GL molar ratio, reflux ratio, final temperature of tower bottom, and CaO/GL molar ratio and decrease as the recycle number of CaO increases. The calcium concentration in the residual reaction mixture also decreases remarkably as the DMC/GL molar ratio increases. At DMC/GL molar ratio 4.0, reflux ratio 1.0, final temperature of tower bottom 358 K, and CaO/GL molar ratio 0.05, both the GL conversion and GC yield can reach above 99.0%, and the mass concentration of calcium in the product is less than 0.08%.

Production of glycerol carbonate using crude glycerol from biodiesel production with DBU as a catalyst

The biodiesel production technology catalyzed by 1,8-diazabicycloundec-7-ene（DBU）is developed in this work.Crude glycerol containing DBU and DBU/glycerol/CO2（DGC）ionic compounds reacts directly with dimethyl carbonate（DMC）to produce high value-added glycerol carbonate（GC）catalyzed by DBU and DGC.The catalytic performance of DBU and DGC,as well as the kinetics of the reaction catalyzed by DBU,were investigated.The results show that DGC has a weak catalytic effect on the transesterification of glycerol and DMC.When the temperature is higher than 60℃,DGC catalyzes the reaction jointly with DBU,which is produced from the decomposition of DGC.DBU has a good catalytic effect on the reaction between glycerol and DMC,with 90%conversion of glycerol and 84%selectivity to GC under the following conditions：DMC-to-glycerol molar ratio of 3：1,4.0%DBU（based on glycerol mass）,reaction time of 60 min,and reaction temperature of 40℃.The apparent kinetics results show that the activation energies are 30.95 kJ·mol^-1 and 55.16 kJ·mol^-1 for the forward and reverse GC generation reactions,respectively,and the activation energy of the decomposition reaction of GC to glycidol（GD）is 26.58 kJ·mol^-1.

Economic Analysis of Biodiesel and Glycerol Carbonate Production Plant by Glycerolysis

Techno-economic analysis of an indirect use of carbon dioxide within the route of glycerolysis of glycerol with urea is investigated. The results show that the net present value of the biodiesel-glycerol carbonate production by glycerolysis is higher than the biodiesel-glycerol carbonate production by direct carboxylationat at the end of the 12-year operation with similar capacities. The stochastic model has predicted that using glycerolysis route for the synthesis of glycerol carbonate production might increase the probability of getting positive net present value by about 15%.

Mechanism study on direct synthesis of glycerol carbonate from CO_(2)and glycerol over shaped CeO_(2)model catalysts

Direct synthesis of glycerol carbonate(GC)from CO_(2)and glycerol(a byproduct of biodiesel production)is a route to obtain a high-value chemical from waste and low-cost byproducts but has not yet industrialized due to the lack of efficient catalysts.Ceria(CeO_(2))exhibits the highest catalytic activity and GC selectivity among the heterogeneous catalysts studied so far.However,the mechanism of this reaction over CeO_(2)catalysts has not been studied in detail.Herein,we synthesized CeO_(2)nanocrystals with different morphologies as model catalysts that can predominantly expose(111),(110),and(100)facets,and their surface acid-base properties were characterized using high-sensitivity temperature-programmed desorption of NH3 and CO_(2)with quadrupole mass spectrometry as detector(NH3-TPD-QMS and CO_(2)-TPD-QMS).We found that the catalytic performance(GC formation rate)is strictly linearly dependent on the density of basic sites,which is relevant to the adsorption and activation of CO_(2).In addition,to illustrate a more microscopic reaction mechanisms underlying the formation of GC from CO_(2)and glycerol on all three low-index surfaces(111),(110)and(100),we also performed comprehensive first principles calculations.A three-step Langmuir-Hinshelwood(LH)mechanism was identified in which the annulation reaction is the rate-limiting step.The CeO_(2)(11)surface exhibits the lowest overall activation energy,which agrees well with the catalytic performance that the CeO_(2)nano-octahedra,predominantly exposing(111)facets,have the highest GC formation rate.This work is the first to combine experiments on shaped CeO_(2)model catalysts with first-principles calculations to gain insight into the mechanism of direct synthesis of GC from CO_(2)and glycerol,and will aid in the development of catalysts with improved performance.

An efficient catalytic system for the synthesis of glycerol carbonate by oxidative carbonylation of glycerol

Glycerol carbonate was synthesized by the oxidative carbonylation of glycerol catalyzed by the commercial Pd/C with the aid of NaI. High conversion of glycerol （82.2%）, selectivity to glycerol carbonate （〉99%）, and TOF （900 h-1） were obtained under the conditions of 5 MPa （Pco：Po2 = 2：1）, 140 C, 2 h. The highly active palladium species were generated in situ by dissolution from the carbon support and stabilized by re-deposition onto the support surface after the reaction was finished. Palladium dissolution and re-deposition were crucial and inherent parts of the catalytic cycle, which involved heterogeneous reactions. This Pd/C catalyst could be recycled and efficiently reused for four times with a gradual decrease in activity. Moreover, the in- fluences of various parameters, e.g., types of catalysts, solvents, additives, reaction temperature, pressure, and time on the conversion of glycerol were investigated. A reaction mechanism was proposed for oxidative carbonylation of glycerol to glyc- erol carbonate.

Ordered mesoporous Ba CO_3/C-catalyzed synthesis of glycerol carbonate from glycerol and dimethyl carbonate

Ordered mesoporous BaCO3/C composites were synthesized by a multi-component co-assembly method combined with a carbonization process using phenolic resol as carbon source, barium nitrate as barium precursor, and triblock copolymer Pluronic F127 as template. The synthesized materials were characterized by X-ray diffraction, transmission electron microscopy, N2 physical adsorption, thermogravimetric analysis, and temperature-programmed desorption of CO〉 When BaCO3 contents were increased from 9.1 wt% to 44.7 wt%, pore size increased from 3.1 to 4.3 nm and the BET （Brunauer-Emmett-Teller） surface area initially increased to a maximum value of 390 m2 g^-1 （at a BaCO3 content of 18.5 wt%） before subsequently decreasing. BaCO3 was well dispersed in the amorphous carbon framework, and no phase separation was observed. The mesoporous BaCO3/C composites exhibited high catalytic activities toward the transesterification of glycerol and dimethyl carbonate into glycerol carbonate. A glycerol conversion of 97.8% and a glycerol carbonate selectivity of 98.5% were obtained under the optimized reaction conditions.

Controlled synthesis of magnetic carbon nanoparticles via glycerol/ferrocene co-pyrolysis with magnetic induction

We performed a controlled synthesis of magnetic carbon nanoparticles （M-CNPs） via co-pyrolysis of glycerol and ferrocene with magnetic induction. The morphology of the synthesized M-CNPs was confirmed by transmission electron microscopy, and thermogravimetric analysis was used to analyze the carbon and Fe contents. M-CNPs that responded to magnetic stimulation were also examined with an AC-magnetic susceptibility analyzer. Our investigations on the influence of synthesis temperature in the range 700-1000℃ suggested that for an initial glycerol to ferrocene weight ratio of 3：1 and a temperature of 800 ℃ gave the highest yield of M-CNPs. Comparing the synthesis with and without magnetic induction, the controlled synthesis under the influence of magnetic induction shows promise as a method for producing high quality M-CNPs in high yields.