Vapor-liquid Equilibrium Of Dimethyl Carbonate Related Synthesis Systems Using GEMC Method

Dimethyl carbonate?DMC?is a green and safety organic intermediates,the phase equilibrium data of related synthesized systems of DMC can offer guidance for studying the reaction mechanism and developing synthesis reactor.Synthesis of dimethyl carbonate?DMC?by methanol gaseous oxidative carbonylation was a high voltage reaction,the phase equilibria data obtained by traditional method usually exist difficulties,such as high equipment investment and difficult operation.So,the literature about phase equilibria data is scarce.In this paper,Gibbs ensemble Monte Carlo method was used with Towhee software to calculate the phase equilibria data of synthetic systems of DMC.Methanol is an important reactant in DMC synthesized systems.In this contribution,first,study the phase equilibrium of methanol to lay a theoretical basis of DMC synthesized systems,TraPPE-UA force field was employed to calculate the density of CH₃.Comparing the simulation value with literature value,the maximal deviation of liquid density was 3.87%,the maximal deviation of vapor density was3.87%,which was verified that the setting up of movement probability and potential functions were correct.And then,calculating the solubility of CO in methanol,the minimum deviation was 5.68%,the maximal deviation was 17.80%.The missing bond parameters of DMC in TraPPE-UA force field were added by the method of force field parameters transfer.The simulated result of liquid density was deviated with the literature value,it means that the force field parameters require modification.The method of quantum chemistry was used to compute the interaction energy between pairs of DMC and the results were fitted to Lennard-Jones 12-6function,and the potential function parameters from the fitting were used to modify force filed parameters.The modified force field was used to calculate the liquid density again,the deviations between the simulated and literature value were obviously reduced.It indicated that the modified intermolecular non-bond parameters described the DMC.Finally,the solubility of CO in DMC and in the mixed DMC-CH₃OH solvents were calculated by NPT-GEMC method.The highest deviation of binary mixture system was 10.15%,and ternary mixture system was 25.80%.This demonstrates that it was necessary developing more accurate potential function parameters to describe the related synthesized systems of DMC,which leads to more precise vapor-liquid equilibrium data in GEMC simulation.