叔丁醇脱水反应动力学研究

Catalytic Dehydration of tert-butyl Alcohol Using Cation Exchange Resin

以国产 NKC-9 型强酸性阳离子交换树脂为催化剂,在常压液相下进行了叔丁醇脱水的反应动力学研究,为由叔丁醇脱水生产异丁烯工艺的开发提供了基本理论依据。在消除内外扩散影响下,讨论了反应温度、反应物初始浓度和催化剂用量等条件对反应速率的影响。结果表明:反应温度升高,将加快反应速率;水的存在对此反应过程产生阻碍效应,随着反应物初始浓度中水含量的增加,反应速率减小。考虑异丁烯在液相中含量很低以及产物水对反应的阻碍效应,建立了该反应的动力学模型,并得到了相应的模型参数。在实验温度范围内,速率模型计算结果与实验结果吻合较好。

In order to explore a new technology to produce isobutylene via reactive distillation, the kinetics of dehydration of tert-butyl alcohol was studied by using the strong acid cation exchange resin NKC-9 as the catalyst under atmosphere. Effects of the operation conditions such as particle diameter of catalyst, speed of agitation, reaction temperature and reactant concentration on the reaction rate were investigated. Experimental results show that the effect of film diffusion and intraparticle diffusion can be neglected; the dehydration rate increases with temperature; water is found to inhibit the reaction rate due to the strong selective adsorption on the active acid sites of cation exchange resin in the alcohol solution. Based on these experimental results, a kinetics model was developed in which the water inhibition was considered. The relationships of the rate constant and the inhibition coefficient of water with the temperature and the activity energy were obtained. The calculation results agree well with the experimental results.