An Investigation on the Effects of Iodide Salts in Iridium Catalyst in Methanol Carbonylation Process

In this study, iodide salts and carbonyl complexes of specific metals used as promoters in carbonylation of methanol in iridium/iodide based catalyst. the iridium catalyzed carbonylation of methanol to acetic acid is promoted by two distinct classes of promoters; simple iodide salts of zinc, cadmium, mercury, indium and gallium and carbonyl or halocarbonyl complexes of tungsten, rhenium, osmium and ruthenium. all of these promoters are led to increase the rate of methanol carbonylation. in this experimental research, it has been observed that the effect of ruthenium promoter in rate of methanol carbonylation and high reaction rate is achieved by increasing the ruthenium concentration. the experimental tests are carried out to identify the effect of different promoters. in the presence of ruthenium and iridium, it has been observed that the maximum activity is achieved between 5 to 6 weight percent of water concentration.