Performance Analysis And Optimization Of Pressure Swing Adsorption Cycle For Hydrogen Purification

Hydrogen has the characteristics of low pollution,high calorific value and recyclability,so it is regarded as the most promising secondary energy at present.If hydrogen is applied to the automotive field,it will greatly reduce greenhouse gas emissions.Hydrogen-powered vehicles have high requirements for hydrogen purity,so hydrogen purification is very important for the application of hydrogen in the automotive field.The common method of hydrogen purification is PSA?Pressure Swing Adsorption?technology.Therefore,this thesis studies some parameters involved in PSA cycle performance,then analyzes and optimizes on this basis.First,the mathematical models of PSA cycle modeling are introduced.These models contain conservation of energy during heat transfer,conservation of mass and momentum during mass transfer,as well as adsorption kinetics and adsorption isotherms and ideal gas equations.Based on these equations,the theoretical introduction and simulation verification of the adsorption isotherm are emphasized.The simulation uses an extended Langmuir adsorption isotherm equation.In addition,on activated carbon AC5-KS and R2030 adsorption beds,the adsorption amount of multi-component gases N₂,CO,CO₂,CH₄ and H₂ varying with temperature and pressure are also studied.Second,the thesis studies the breakthrough curves of multi-component gases N₂,CO,CO₂,CH₄ and H₂ in activated carbon AC5-KS and R2030 beds and the thermal effects generated during the breakthrough process.Also,the appropriate adsorbent for hydrogen purification is selected.The simulation of breakthrough curve is based on the Aspen Adsorption simulation platform.The simulated results of the model are compared with the experimental data to verify the correctness of breakthrough curve model.This model is applied to study parameters affecting the breakthrough curve,such as pressure and volume flow rate during the inflation process,which is a preparation for the construction of PSA cycle model and parametric study.Then,based on breakthrough curve model,a PSA cycle model is established,with five-component gas?H₂/CO₂/CH₄/CO/N₂=0.79/0.17/0.021/0.012/0.007?in activated carbon AC5-KS for hydrogen purification.The simulated and experimental data are compared to verify the correctness of PSA cycle model.The PSA cycle and the VPSA?Vacuum Pressure Swing Adsorption?cycle are compared to select a more suitable method for hydrogen purification.Effects of inlet pressure,intake volume flow rate,cycle number,feeding time and purging time on PSA cycle performance are investigated.Finally,data affecting PSA cycle performance is selected,for artificial neural network?ANN:Artificial Neural Network?training,verification and testing.Then,the network is combined with interior point method to optimize PSA performances.The optimum conditions are selected for the PSA cycle in the activated carbon AC5-KS adsorption bed with five component gases?H₂/CO₂/CH₄/CO/N₂=0.79/0.17/0.021/0.012/0.007?,to obtain high hydrogen purity,high recovery and productivity,which can provide some theoretical reference for the development of hydrogen vehicle.