Investigation Of Modular Catalytic Structured Packing And Optimization Design Of Catalytic Distillation Column

The design of catalytic distillation equipment still relies on empirical methods,even though catalytic distillation technology has been widely used in industry.The prime cause of the problem is the lack of thorough research about the transfer phenomenon in catalytic distillation equipment.The systematic quantitative research on the transfer phenomenon in the modular catalytic structured packing(MCSP)is carried out in this thesis.Then,a theoretical design method for the catalytic distillation tower is established based on the experimental research results.Two cases are implemented to test the validity of the design method.Firstly,the mass transfer process on Winpak sheets is studied,and the enhanced mass transfer mechanism caused by window structure on Winpak sheets is analyzed.A new MCSP structure,Winpak-C series,is designed based on Winpak sheets.Secondly,in order to research the residence time distribution(RTD)performance of catalytic distillation packing,an experimental device is designed and built.The RTD density functions of different packings are calculated based on the RTD curves obtained by the RTD curve measurement experiments.Though comparing the mathematical characteristics of the RTD density function,it was found that Winpak-C have longer average residence times.For further study about the flow characteristics of the liquid phase in MCSP,another experimental device for measuring the reaction module in MCSP is designed and set up.The RTD curve measurement experiments of various reaction sections are completed,and the effects of Winpak sheets on the residence time and system stability of the reaction sections are analyzed.Subsequently,the two-dimensional diffusion model was employed to study the liquid phase diffusion phenomenon in the reaction section.By measuring the RTD curves at different positions on various reaction section and fitting the RTD density function,the radial and axial diffusion coefficient of different modules can be obtained.The structured packing sheets within the reaction section have an impact on the liquid diffusion properties,and the enhanced liquid diffusion mechanism caused by these sheets is discussed.The effect of the specific surface area,channel inclination and catalyst particle size distribution on the liquid diffusion behavior in reaction sections is also investigated.Finally,an optimized design method for catalytic distillation column based on particle swarm optimization algorithm is proposed.Aspen Plus software is used to simulate the catalytic distillation process,and MATLAB is used to write the particle swarm algorithm operation code.The software integration platform of MATLAB and Aspen Plus is established to complete the optimal design of multiple reactive distillation columns with the minimum annual total cost as the objective function.