Study On High-pressure Phase Equilibria Of Binary Systems Of Carbon Monoxide And Propionic Acid/ Methyl Formate

There are many methods in synthesis of propionic acid in industry,such as hydroformylation of ethylene, carbonylation of ethanol. The synthesis of methyl formate also has many methods ,for instance, carbonylation of methanol, esterification, dehydrogenation of methanol, oxidative dehydrogenation of methanol, one-step method by synthesis of CO, H2, synthesis of methanol, carbon dioxide and hydrogen. At present, carbonylation of carbon monoxide has become a new method of synthesis of PA and MeF. Therefore, the gas-liquid equilibrium data for this reaction system in the industrial production of MeF and PA is of great significance.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. A simple equipment was also built up for analysizing the composition of the vapor and liquid samples. The experiment equipment was proved to be reliable and accurate comparing with literature data. The vapor-liquid equilibrium data (including ingredient, density and volume, et al) of the two binary systems (CO + PA;CO + MeF)of synthesizing propionic acid and methyl formate by carbonylation of carbon monoxide have been measured at different temperatures and pressures with isothermal static analytical method. The vapor-liquid equilibrium data show that the solubilities of carbon monoxide in propionic acid and methyl formate increase slightly with increasing pressures at the given temperatures. The contents of propionic acid and methyl formate in the carbon monoxide rise with increasing pressures.The high pressure GLE data of the two 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 propionic and methyl formate by carbonylation of carbon monoxide.