Study On The Separation And Reaction Process Of The Tdi With Low Boiling Point Solvent

The toluene diisocyanate (TDI) is basic raw material of the polyurethane production. Its production technology level and the output have the important influence on the polyurethane industry development. Based on the simulation and experiments, light solvent toluene diisocyanate separation and reaction processes are studied.Firstly, the research has been done on the phosgenation of TDI. The operating condition and the different jet-type reactor structure were determined through simulation and computation. Thereafter did the single factor experiment and then the orthogonal experiment. The factors influencing the reaction significantly were found. The suitable reactor structure and the operating condition were obtained, which could provide the guideline for the large scale production of TDI.Secondly, the reaction of amide in the rectifier tower at the hot reaction stage was confirmed based on the experiment. Using the kinetics equation from the literature, the reaction ratio constants under different temperature were calculated. Compared the amide conversion rate got from the simulation and computation of PRO/II with the experiment result. They were about the same.Finally, the analysis was carried out on the simulation and optimization with PRO/II. Based on the industrial experience and simulation results, the controls parameter and the tolerance were obtained. The optimal operating condition was established through the combination with the pilot plant experiment. Through the experiments and the theoretical analysis, the separation process of TDI was modified. The Number of monochlorobenzene removing tower was changed from one to two. With the hot integration analyzed, the condenser of preceding tower was used as the mid reboiler for the next tower just to reuse the condensation heat. e boiling of the latter tower. So the heat of condensation is used. Carries on the simulation under the different operating condition to this flow: In the situation of same separation product quality, the cold project load and the hot project load of used the hot integrated flow reduce 16％and 25％compared to the original flow.Based on the research work mentioned above, reconstruction of the current process could lower the production cost and improve the product purity. So the production capability and competitiveness could be improved.