Absorption Of Ethylene Oxide And Synthesis Of Ethylene Glycol By Catalytic Hydration

The method of direct hydration from EO is one of the ways to synthesis EG today. About 85% water in the products must be evaporated using massive energy, which brought about the disadvantages, such as long process flows, large equipments and enormous waster of energy and affected the cost of production of EG seriously. Recently, the studies of catalytic hydration show good prospect in solving above-mentioned problems, and has a virtue of good conversion and selectivity as well, so exploratory research on related fields are drawing more and more attention.In this study, batch-type reactions were sequentially carried out. Then a series of developed catalysts with high activity and selectivity were investigated, by which reaction conditions were optimized. And the catalysts were contrasted. Through the process of reactive absorption, factors that affect conversion and quantity of absorption were mainly studied, and absorptive conditions were optimized. Based on the experiments of absorption, degree of absorption affected by reaction was studied through process computation. In the end, a packing tower of 600t/a was designed.Catalysts with higher activities were found through the thesis, which can lower the ratio of water and ethylene oxide and lower the use level of catalysts. Meanwhile, process of reactive absorption designed according to NY homogeneous catalytic system organically combined absorption with reaction, which may obviously shorten the process flow. The main contents of this thesis are listed as follows:1. In the study of batch-type reaction, activity of NY catalysts was studied by reaction temperature, and selectivity by the use level of catalysts and the ratio of water and ethylene oxide. And different selectivity was found with different inert gas in the reactions, from which COi was shown to have better effects on selectivity than Na.2. The results of batch-type reactions showed that NY5 has the better performance than any others. When the mass ratio of water and ethylene oxide was 3.2:1 and the CO2 was existed, the optimum synthesisconditions were obtained: the content of catalysts was not less than 3.1%, reactive temperature was more than 81 and the pressure was above O.SMPa, under which the conversion of ethylene oxide could reach 99.3%, and the selectivity of ethylene glycol 100%.3. The results of reactive absorption revealed that partial pressure of ethylene oxide and temperature are the key factors that had deep effects on absorption and conversion of ethylene oxide. When the use level of the catalysts m(NY)/m(H2O)=l/12.5 and the reaction temperature was 45 "C, recycling ratio of ethylene glycol solution was 2, ethylene oxide partial pressure higher than 0.06MPa, residence time of ethylene oxide not less than 0.1 minute, residence of reaction liquor not less than 20 minutes, the mass fraction of total ethylene oxide reached 20%, and conversion of ethylene oxide about 22.5%.4. Degree of absorption affected by reaction was investigated through process computation, and then a packing tower of 600t/a was designed.