Phase Equilibria Of Binary Systems Of Synthesis Dimethyl Carbonate By Oxidation Carbonylation Of Dimethyl Ether And High Pressure Solid-liquid Equilibria Research

A set of variable-volume autoclave with a quartz window has been made domestically for the first time. The accurate volume of a sample could be measured with a hall-effect probe, and the precise adjustment within wide range of temperatures and pressures could be actualized. At high pressure, the samples were taken directly from the autoclave with a small steel vessel. So the accurate vapor-liquid equilibrium data could be obtained. The experiment equipment was proved to be reliable and accurate comparing with literature data. A simple equipment was also built up for analysizing the composition of the vapor and liquid samples. The vapor-liquid equilibrium data (including ingredient, density and volume) of the five binary systems of synthesizing dimethyl carbonate by oxidation carbonylation of dimethyl ether (oxygen+ dimethyl carbonate(O2 + DMC), carbon monoxide+ dimethyl carbonate(CO + DMC), carbon dioxide + dimethyl carbonate(CO2 + DMC), nitrogen+ dimethyl carbonate(N2 + DMC) and dimethyl ether+ dimethyl carbonate(DME + DMC)) have been measured at different temperatures and pressures with isothermal static analytical method. The vapor-liquid equilibrium data show that the solubilities of five gases in dimethyl carbonate increase drastically with increasing pressures at the given temperatures. The contents of dimethyl carbonate in the dimethyl ether gas rise with increasing pressures, but the contents of dimethyl carbonate in other four gases increase faintly.The high-pressure GLE data are also calculated with eight methods for above five systems. The PR and PRSV EOS and four different mixing rules were used. The Suitability of those EOSs and calculated precision were discussed systemically. Three methods showed excellent calculation effects which each other were made up of (PR EOS with activity coefficient and associated theory) and (PR EOS with var der waals mixing rules).The high pressure GLE data of the five binary systems could provide abundant fundamental data for the study of the solution theory and the calculation of GLE, which could develop of the phase equilibrium theory and the calculation methods. At the same time, it could provide the necessary data for the process design of synthesizing dimethyl carbonate by oxidation carbonylation of dimethyl ether.This paper also reports the fusion curves of carbon tetrachloride, chloroform, bromoform, silicon tetrachloride, benzene, nitrobenzene, bromobenzene and chlorobenzene at pressures up to 3500 MPa between 226 K and 915 K. The fusion equations based on the two– and one-phase approaches were used to fit experimental data. The changes of the molar enthalpy and molar thermdynamical energy on fusion were calculated using the parameters of fitted equation.