Abstract：Benzene dinitration in a microreactor was studied using mixed acid as nitration agent. The effects of molar ratio of nitric acid to benzene, reaction temperature, HNO3/H2SO4 molar ratio, feed flow rate and water content in mixed acid were investigated. It was found that increasing the molar ratio of nitric acid to benzene and reaction temperature, or decreasing the HNO3/H2SO4 molar ratio and water content in mixed acid could improved the formation of dinitrobenzene, while the selectivity of dinitrobenzene first decreased and then increased with the increase of feed flow rate. The combination of microreactor and stirred tank could decrease the selectivity of nitrobenzene significantly. When molar ratio of nitric acid to benzene of 2.30, reaction temperature was 80℃, HNO3/H2SO4 molar ratio was 0.5, water mass fraction in mixed acid of 2%, benzene flow rate was 0.6 mL/min, mixed acid flow rate was 2.60 mL/min and the residence time in the microreactor was 135 s, further reacting 10 min in the stirred batch reactor reduced the selectivity of nitrobenzene from 0.643% to 0.002%. At this condition, the benzene conversion was 99.970%, and the total selectivity of dinitration products was 99.998% with the selectivity of m-dinitrobenzene of 83.292%. The study provided technical support for the development of continuous synthesis process of m-dinitrobenzene from benzene.
JU Yufan,LIAN Yingjiang,YANG Mei et al. Study on the Process of Benzene Dinitration in a Microreactor[J]. Chemical Reaction Engineering and Technology, 2023, 39(1): 45-52.
