Study On The Kinetics Of Catalytic Hydration To Ethylene Glycol

Now, the method of direct hydration from Ethylene oxide(EO) is one of the ways to produce Ethylene glycol(EG). In order to get the high selectivity, too much water is added during the reaction. So a triple-effect evaporator is needed in the process which greatly increases the investment of equipments and the energy cost for the EG production. Recently, the studies of catalytic hydration show a good prospect in solving above-mentioned problems, and have a virtue of good conversion and selectivity as well, so much attention is put on the exploratory researches in the field. In this thesis, The kinetics of catalytic hydration from EO was studied in detail. We carried out experiments according to the characteristic of the system of catalytic hydration from EO. The rate constants and the activity energy were obtained. The mechanism of the reaction was proposed according to the experimental results, and the kinetic equation was established with the parameters estimated. The reasons which made the differences of selectivity in the atmosphere of N2 and CO2 was also discussed. In the meantime, A synthesis of non-equilibrium reactive distillation processes by mixed integer nonlinear programming(MINLP) optimization was calculated. The rules of the kinetics of catalytic hydration from EO were known by the study. And the data of the kinetics were obtained. These data would do a favor for a development of process flows and the design of reactor. It could also give some help for improving on the characters of catalyst. The studies of this thesis mainly included the following aspects: 1. The kinetics of catalytic hydration from EO were studied at the different atmosphere, temperature, concentrations of the catalyst and the different quality ratio of water and EO. The data of the kinetics were obtained from the experiment. According to the results, the kinetics equation was first order with respect to the concentrations of EO and the concentrations of catalyst. 2. The mechanism of the reaction was proposed and proved according to the experimental results. The kinetic equation was established and the parameters were also estimated. It was concluded that the mechanism of the reaction could interpret the experiments. The values of the experiment had a good fit with the calculation values. 3. The reason which made the differences of selectivity in the different atmosphere was discussed. And the results that the selectivity in CO2 was higher than it in N2 were explained according to the mechanism of the reaction. 4. A MINLP model is presented for synthesizing reactive distillation columns. The General Bender's Decomposition solution procedure is used for mixed integer nonlinear programming and the solution algorithm was implemented in GAMS(the General Algebraic Modeling System). The optimal column with infinite reflux ratio contains eight trays and has a total annualized cost of 2.02×106$/a. The solution composed of water and catalyst is fed to seventh tray, and the ethylene oxide if fed to the third tray. The column diameter is 1.18m.