Optimization and Process Intensification of Ketal Reaction in Industrial Ibuprofen Synthesis

Abstract

Ketal reaction is one of the most important reactions in the synthetic of ibuprofen. The reaction mechanism was analyzed to increase the rate and conversion. Mechanical stir, forced external circulation and combination of the above two ways were compared to achieve the best mixing effect and the results show that the combined strategy performs better in mass transfer. Water as the product was removed to improve the efficiency of the reaction by introducing a process coupled reactive distillation and azeotropic distillation. The best conversion rate can be obtained when the boiling-range of petroleum ether is 90 - 120 °C and the feed ratio of petroleum ether and chlorinone is 2:1. After the improvement of the equipment and optimization of operating parameters, the reactive time of the ketal reaction is reduced from more than 22 h to less than 8 h. The improved ketal technology has been industrialized and demonstrated good economic efficiency for two enterprises.