Technical Improvement and Hazard Research of the Second Stage Semi-Batch Toluene Nitration

Trinitrotoluene is usually made by continuous multistage nitration of the toluene and mixed acid system, the second stage semi-batch nitration of toluene based on the first stage was studied by DSC and the reaction calorimeter(RC1e). DSC was used to test the therma1 decomposition behaviors of mixed acid and mononitrotoluene reaction system. a series of mononitrotoluene nitration experiments were carried out in RC1e to study the influences to parameters of the exothermic rate and the heat and so on by changing the different operating conditions such as stirring speed、feeding rate 、setting temperature to confirm the optimal conditions and provide the basis of technical improvement. Results indicate that temperature influent most and the optimal condition is T=80℃，R =400rpm，t =120min. By using semi-batch reaction model can effectively reduce the runaway reaction severity from medium to lower degree.