Reaction from Dimethyl Carbonate (DMC) to Diphenyl Carbonate (DPC). 2. Kinetics of the Reactions from DMC via Methyl Phenyl Carbonate to DPC

Abstract

The kinetics of the reaction of dimethyl carbonate (DMC) and phenol to methyl phenyl carbonate (MPC) and the subsequent disproportion and transesterification reaction of methyl phenyl carbonate (MPC) to diphenyl carbonate (DPC) have been studied. Experiments were carried out in a closed batch reactor in the temperature range from 160 to 200°C for initial reactant ratios of DMC/phenol from 0.25 to 3 and varying catalyst (titanium-(n-butoxide)) concentrations. The concept of a closed, ideally stirred, isothermal batch reactor incorporating an activity based reaction rate model has been used to fit kinetic parameters to the experimental data taking into account the catalyst concentration, the initial reactant ratio DMC/phenol and the temperature.

Thermodynamics and kinetics of transesterification reactions to produce diphenyl carbonate from dimethyl carbonate catalyzed by tetrabutyl titanate and dibutyltin oxide

“…Preliminary model fitting results showed that the reverse reaction rate constants of equilibrium reactions (2) and (3) changed little with temperatures within the investigated ranges in this work (see Table S2 of Supplementary Material). It is worth noting that Haubrock et al found similar results for equilibrium reaction (3) . So in the following model fitting it is assumed that the reverse reactions of equilibrium reactions (2) and (3) are independent of temperature.…”

“…This suggests that the estimated values of the pre‐exponential factor and activation energy are quite reliable. The obtained activation energies in this work for forward reactions of reaction (1) and reaction (2) are 38.5 kJ/mol and 40.9 kJ/mol (which are equal to reaction heat in Table ) respectively, while those of a previous study with a Ti‐only catalyst are 73.5 kJ/mol and 59.9 kJ/mol respectively . The reduction of activation energy in this work may be ascribed to the synergistic effect of titanium and tin catalysts.…”

“…Thirdly, the pseudo‐first order reaction assumption with respect to reactants and catalyst is employed. A similar simplification methodology has been used in the kinetic model formulation of DMC transesterification with phenol using titanium as a catalyst . So according to these simplification strategies the net reaction rate equation concerning Equations (1–4) can be formulated as follows: where k i and K i stand for the forward reaction rate constants and equilibrium constants of the i th reaction step respectively, and m cat and C j represent the concentration of catalyst with the unit of g/L and that of the j th component with the unit of mol/L.…”

“…As early as 2010, the world's annual production of PC has exceeded 3 000 000 tons, most of which was manufactured by phase interfacial polymerization . This process, which was commercialized 60 years ago, utilizes phosgene as an intermediate and methylene chloride as solvent, which bring a number of disadvantages . Firstly, to produce 10 kg of PC about 4 kg of phosgene is needed, which is a colourless deadly gas used during World War I as a chemical weapon causing massive soldiers death.…”

Kinetics of Transesterification of 1,4‐Butanediol With Methyl Acetate by the Ion‐exchange Resin

“…Additional experiments are conducted without another reactant besides BMAc. The results show that neither BDAc nor BDO is detected in the reaction system, which proves that the disproportion reaction of BMAc can be ignored in the following study …”