The Study Of Azeotropic-reactive Dividing Wall Column For Production Of Ethyl Acetate

In the process of petroleum and chemical industry production,the energy consumption required for the distillation process is huge.Especially in the condition where the world's energy is becoming scarce,it is of great social significance to develop new distillation technology and decrease the energy consumption of the distillation process.Combining the reactive dividing wall column with azeotropic distillation,the azeotropic-reactive dividing wall column is proposed.Choosing the synthesis of ethyl acetate by esterifying method as the object of the study,the process of producing ethyl acetate with azeotropic-reactive dividing wall column and the process of co-producing ethyl acetate and n-butyl acetate with reactive dividing wall column are studied in this paper.The synthesis of ethyl acetate in the zeotropic-reactive dividing wall column which can separate the water from the side-draw can not only reduce the reflux ratio of the column but also increase the relative volatility of the intermediate component and the heavy component by making use of the performance of carrying water of n-butyl acetate.The process for co-producing ethyl acetate and n-butyl acetate in the reactive dividing wall column is that the n-butanol and ethanol as reaction raw material with acetic acid reacted in the reaction zone to produce ethyl acetate and n-butyl acetate.The n-butyl acetate is not only the production,but also acts as entrainer to remove the water generating by the two esterification reaction.The operating performance and energy-saving mechanism of the two processes mentioned above are studied by experiment and simulation respectively.The experimental study on the synthesis of ethyl acetate by azeotropic-reactive distillation with concentrated sulfuric acid as the catalyst is performed.The effects of the temperature of the side-draw position on the amount of water removing by the top and the side-draw as well as the effect of the temperature of the side-draw position on the acetic acid content in the aqueous phase at the side-draw position are studied by the experimental device.The relationship between the ratio of side-draw and the content of acetic acid in the aqueous phase of the side-draw position is studied by Aspen Plus,which supplies the basic data for the synthesis of ethyl acetate in the subsequent azeotropic-reactive dividing wall column.The study of the synthesis of ethyl acetate by azeotropic-reactive dividing wall column is carried out by experiment and simulation separately.The results of simulation and experiment agree with each other very well,verifying the reliability and accuracy of the previous model selection and the simulation process.The effects of the amount of entrainer,the liquid spilt,the reflux ratio of the column,and the concentration of acetic acid in the raw material are analyzed by simulation.The energy saving and the economic calculation are analysised and the results show that compared with the azeotropic-reactive distillation,the azeotropic-reactive dividing wall column can separate multi-component mixture,reduce back-mixing and decrease energy consumption dramatically.The study of the co-production for ethyl acetate and n-butyl acetate by the reactive dividing wall column is performed by experiment and simulation separately.The results of simulation and experiment agree with each other very well,verifying the reliability and accuracy of the previous model selection and the simulation process.In this paper,two different types of reactive dividing wall columns are proposed for the co-production of ethyl acetate and n-butyl acetate.The effects of the position of the side-draw,aqueous phase reflux ratio of the column,liquid spilt,vapor split are analyzed by simulation.The energy saving is analysised and the results show that compared with the traditional reactive distillation,both the two structures could separate multi-component mixture,reduce backmixing and decrease energy consumption dramatically.