(300g) Novel Steady State Process Modeling Methodology for Pressure Swing Adsorption

Authors: 
Sees, M., Texas Tech University
Scott, J., Georgia Institute of Technology
Chen, C. C., Texas Tech University
Kim, T., Clemson University
Kirkes, T., Texas Tech University
Although rigorous dynamic simulation models are available for use in design and operations of pressure swing adsorption (PSA) units, such models involve sophisticated numerical solution of a complex system of partial differential equations. To explore the potential use of PSA as an intensified process alternative to conventional thermal separation processes, chemical engineers need a robust and practical PSA simulation model that properly captures the essential process fundamentals of PSA in steady state process simulation environments. We present a novel PSA steady state process modeling methodology that takes into consideration PSA unit capacity, cyclic steady state operations, mass and energy balances, and adsorption isotherms. In a way similar to “tray efficiency” in multistage thermal separation processes such as distillation, an “adsorption efficiency” is introduced to model rate-based adsorption processes. The relationship between “adsorption efficiency” and effective mass transfer coefficients are further examined with a rigorous dynamic PSA model. The modeling methodology is illustrated with two PSA examples: 1) nitrogen rejection from methane, and 2) carbon dioxide capture from natural gas. This novel PSA process modeling methodology should reprsent a new process modeling paradigm for chemical engineers to effectively examine the process intensification potential of PSA for their separation needs.