The Optimization Techniques Of Catalytic Condensation Of Accelerator M

Nowadays Accelerator M is prepared in the reaction of aniline (including part of nitrobenzene) with carbon disulfide and sulfur in four autoclaves in series at high temperature and under high pressure made in Nanjing Chemical Plant (NCP). Because autoclaves don't have stirrer, quantity of heat transfer is inefficient. This results in a lot of tar. The purity of crude Accelerator M is 88% and the yield of Accelerator M is 83.5%. In the paper we search acid catalyst that can decrease temperature and pressure of condensation. Stirrers are setted on autoclaves for enhancing flow of reactant. In this way the purity of crude Accelerator M is increased but tars are decreased. The purity of crude Accelerator M is 92% and the average yield of Accelerator M is 88.5%. Not only problems being workshop are solved but also economic benefit is increased. Combining correlative literatures and manufacture process in NCP we have finished the works below.1. Appropriate catalyst of condensation was selected .2. The influences of some factors such as the amount of catalyst, reaction temperature, reaction time, the ration adding raw materials and stirring are discussed and the optimization conditions are determined.3. The methods that controlled the amount of thionaphthene and N, N`-diphenyl thiourea were studied.4. The way of refining accelerator M was selected.5. Analytical approach of accelerator M was selected by high performance liquid chromatography.These conclusions have been drawn:1. W acid catalyst used in Salicylic acid catalyst can shorten reaction time, decrease reaction temperature and increase the purity of crude accelerator M.2. Condensation at 150℃for 0.5 hours can decrease the amount of thionaphthene and N, N`-diphenyl thiourea and so on.3. Stirring can enhance flow of reactant, the yield of accelerator M is increased by...