Modeling Study of the Sorption-Enhanced Reaction Process for CO₂ Capture. I. Model Development and Validation

Abstract

A one-dimensional reactor model has been developed to describe the performance of a sorption-enhanced steam-methane reforming and water−gas shift reactor. In part I of this paper, the model is verified using the analytical solution for the breakthrough curve and validated using the results of laboratory-scale CO2 sorption-only experiments. Langmuir and Freundlich isotherms are fitted to an experimentally derived adsorption isotherm, while a linear driving force model is used to describe the sorption kinetics. The breakthrough profile is accurately described using the Freundlich isotherm. This holds also when the purge flow or duration of the desorption step are decreased, provided the mass transfer coefficient is changed accordingly during the desorption step. A sensitivity analysis shows that the breakthrough profile is sensitive to the adopted isotherm model and its parameters. The molecular diffusion coefficient affects the slope of the breakthrough curve, while particle size and heat of adsorption show hardly any effect. In part II, the model will be applied to laboratory-scale sorption-enhanced steam-methane reforming experiments.