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.

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.

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.