Simulation of Nonlinear and Nonisothermal Reactive Liquid Chromatography considering Finite Mass-Transfer Rates and...

Area of Science:

• Chemical Engineering
• Reaction Engineering
• Separation Science

Background:

• Fixed-bed chromatographic reactors are crucial for simultaneous separation and reaction.
• Accurate modeling requires accounting for nonisothermal conditions, nonlinear adsorption, and reaction kinetics.
• Existing models often simplify these complex phenomena, limiting predictive power.

Purpose of the Study:

• To develop and numerically approximate a multicomponent nonisothermal lumped kinetic model (LKM) for fixed-bed liquid chromatographic reactors.
• To investigate the influence of nonlinear adsorption isotherms (Bi-Langmuir, Toth) and reaction kinetics on reactor performance.
• To analyze the interplay between thermal and concentration gradients and their effect on reactant conversion.

Main Methods:

• Developed a lumped kinetic model (LKM) incorporating nonlinear adsorption isotherms and reaction kinetics.
• Formulated the model as a system of nonlinear coupled convection-diffusion-reaction partial differential equations (CDR-PDEs).
• Applied a local-projection discontinuous Galerkin finite element (DG-FE) method for spatial discretization and a total variation bounded (TVB) Runge-Kutta method for temporal integration.

Main Results:

• Numerical simulations demonstrated the interplay between thermal and concentration gradients.
• The study quantified the impact of temperature on reactor performance and reactant conversion.
• A comparison of different adsorption isotherms validated the model and numerical approach.

Conclusions:

• The developed LKM and numerical methods accurately represent nonisothermal liquid chromatographic reactors.
• The findings provide insights into mass and energy distributions in complex separation-conversion processes.
• This work offers a foundation for optimizing the design and operation of such reactors.