Process optimization study on the carbonylation of methyl acetate

Acetic anhydride is the important organic chemical raw material, and is used widely in chemical industry, pharmaceutical industry, dyes, spices and other fields. In this paper, the process of carbonylation of methyl acetate in rhodium iodine catalyst system was studied, and the suitable reaction conditions were determined. At the same time, the kinetic model was established. The optimum reaction conditions were as follows: the reaction pressure was 5 MPa, the hydrogen content was 8%, the amount of iodomethane was 15%, the amount of lithium iodide was 3%, the reaction temperature was 150 °C and the reaction time is 3 h. Under the above reaction conditions, the selectivity of the reaction is close to 100% and the conversion is as high as 92%. The macroscopic kinetic model of the reaction was established in the temperature range of 120 °C-150 °C. The reaction is an irreversible reaction without the formation of by-products and the dynamic equation is also given in the Conclusions section.