Process Intensification: Continuous Synthesis of Nitrosyl Sulfuric Acid in a Rotating Packed Bed Reactor

As an important intermediate, nitrosyl sulfuric acid(NSA) iswidely used in diazotization in the fine chemical industry. However,the conventional gaseous SO2 method in the Venturi tubularreactor has low reaction efficiency and high energy consumption dueto insufficient gas-liquid contact. In this work, a rotatingpacked bed (RPB) reactor was first applied for the synthesis of NSA,in which a liquid SO2 and HNO3 reaction occurred.Effects of the rotational speed, reaction temperature, mole ratioof SO2/HNO3, and flow rate of SO2 on the product quality and NSA yield were investigated. Resultsindicated that the NSA yield increased by 9.5% with the rotationalspeed from 100 r/min to 500 r/min. Compared with the conventionalVenturi reactor with gas-liquid reaction, the RPB reactor witha liquid-liquid reaction could reduce the volume of the reactorby 1 order of magnitude, quantity of equipment by 69%, steam consumptionby 100%, and electricity consumption by 43%