Continuous-Flow Synthesis of Methyl Sulfone with Microchannel Reactors: A Safer and Efficient Production Strategy

The traditional batch production process for methyl sulfone (MSM) from dimethyl sulfoxide (DMSO) is highly exothermic and poses serious safety risks. In this work, we present a continuous-flow synthesis strategy using microchannel reactors to enhance the safety and efficiency of industrial-scale MSM production. Four specifications of microchannel reactors have been constructed and then were applied for the continuous-flow synthesis of MSM with both high yield and purity. The effects of the channel diameter, water bath temperature, catalytic dosage, residence time, and segmented temperature control on MSM yield were systematically investigated. By gradually optimizing the design parameters, the yield of MSM in the industrialized microchannel reactor reached 95.3%, and the average annual time yield of MSM was 18.36 t·a^-1. In addition, the maximum overlimit temperature in the continuous flow does not exceed 10 °C, and the overtemperature time is less than 20 s. Dual temperature-controlled continuous-flow process was more beneficial to increase the yield of MSM. The microchannel continuous-flow amplification process can greatly improve the productivity of MSM while ensuring the high yield of MSM, which is a promising strategy for the efficient and safe production of MSM at an industrial scale.