A Non-Isothermal General Rate Model of Liquid Chromatography Considering Bi-Langmuir Adsorption and Temperature Variations.

Abstract

In preparative chromatography, the adsorption of substances onto solid surfaces is influenced by temperature variations, leading to changes in the migration velocities of solutes within the chromatographic column. This research provides a detailed analysis of thermal fluctuations in porous media with dual adsorption sites, utilizing a non-isothermal General Rate Model (GRM) specifically tailored to the bi-Langmuir adsorption isotherm. Solute transport within heterogeneous porous media is governed by a system of nonlinear partial differential equations, characterized by convective flow dominance. This system is further coupled with a nonlinear algebraic equation describing the bi-Langmuir adsorption isotherm. To effectively address the challenges posed by this system, it is essential to develop robust and accurate numerical techniques capable of reliable simulations. This study extends and applies a second-order, semidiscrete, high-resolution finite volume method to simulate the governing equations. Numerical experiments, involving multicomponent mixture flows, are conducted to theoretically evaluate the influence of intraparticle diffusion, film mass transfer resistance, axial dispersion, enthalpy of adsorption, adsorption energy coefficients, and Henry constants on the velocity of simulated elution profiles.