Simulation And Modeling Of Adsorption Breakthroughs

Technologies for the separation,purification and storage of gases(such as natural gas,biogas etc.)play an important role in the modern chemical industry.The technologies used for the separation and purification of gases include solution absorption,membrane separation,cryogenic separation,and adsorption-based separation.Among them,adsorption-based separation technologies are most effective and economical,and most of adsorption-based separation processes are based on fixed-bed adsorption with breakthrough characteristics.Therefore,to develop a reliable engineering model to simulate and fit experimental fixed-bed adsorption breakthrough curves is very valuable in terms of fundamental research and industrial application.The main work of this thesis is devided into two sections:1)Based on an overwiew of all the models applied to the description of single-component adsorption isotherms,some proper isotherm models were chose to fit the isotherm data of CO2,CH4,and N2 on NaY,13X,NH2-MIL-125,and NH2-UiO-66,from which some corresponding adsorption parameters,such as saturation adsorption capacity,adsorption equilibrium constant,and adsorption enthalpy change etc.,were extracted.Then the interactions between adsorbate and adsorbent and the adsorption selectivity were folly analyzed,based on the extracted adsorption parameters.Additionally,these extracted adsorption parameter were applied into the simulation and fitting of fixed-bed adsorption breakthrough curves.2)Based on the conservation of materials,energy,and momentum,engineering models for fixed-bed adsorption breakthroughs were developed.In combination with the software Athena Visual Studio,the developed models were coded and used to simulate and fit the breakthroughs of the binary mixtures CO2/CH4 and CO2/N2 on NaY,13X,NH2-MIL-125,and NH2-UiO-66.The results show that the developed engineering models can appropriately describe the experimental breakthrough curves,and can be applied to analyze the adsorption processes and behaviours in the fixed bed.