Study On The Inhibitor In The Styrene Distillation Processing

Styrene is an important organic chemical raw material and it is generally prepared by the method of ethylbenzene dehydrogenation. But it is known that styrene is easily self-polymerization in the processing of production, particularly in the distillation processing. Common industrial method for inhibiting the polymerization of styrene is adding the inhibitor to the system. Based on the study of inhibition performance of mono-component inhibitor, two-component inhibitors and three-component inhibitors at low conversion rate(less than 10%), the subject of this paper was finally to get an efficient, low toxicity, eco-friendly, economic inhibitor in styrene distillation processing.Firstly, the study on the mono-component inhibitor showed that 4-hydroxy-2,2,6, 6-tetramethyl-piperidingloxy (OH-TEMPO), diethyl hydroxylamine, N, N'-diphenyl-1, 4-phenylenediamine and benzoquinone belonged to the true inhibitor. Whereas 4,6-dinitro-2-sec-butyl phenol(DNBP) and 2,5-di-tert-butyl hydroquinone(DTBHQ) were retarder with good retardation performance. Secondly, based on the study of mono-component inhibitor and the properties of true inhibitor and retarder, two-component inhibitors were designed which came respectively from the two types. The inhibition effective of two-component inhibitors with different types and different ratios were studied at the same temperature and the same addition amount. And the result showed that the two-component inhibitors of OH-TEMPO and DNBP had the better inhibition performance, and the optimum ratio was 2:1. Meanwhile, the other two-component inhibitors of diethyl hydroxylamine and DNBP also had the better inhibition performance, and the optimum ratio was 2:1, too. Then, three-component inhibitors were designed according to the results of two-component inhibitors. The three-component inhibitors of OH-TEMPO, diethyl hydroxylamine, DNBP were studied at different ratio at the same temperature and the same addition amount. The result of the study on three-component inhibitors showed that the optimum ratio of OH-TEMPO, diethyl hydroxylamine and DNBP were 2:1:1. At the same time, the three-component inhibitors at the best optimum were investigated at different temperatures and different addition amounts. Finally, comparing the three-component inhibitors at the best optimum to the DNBP, which has been used commonly in the styrene distillation processing, the study showed that the three-component inhibitors were better than the DNBP in the range of the study's temperatures.The results of this study can provide reference to the styrene distillation processing.