Hierarchical calibration and validation framework of bench‐scale computational fluid dynamics simulations for solvent‐based carbon capture. Part 2: Chemical absorption across a wetted wall column

Abstract

Part 1 of this paper presents a numerical model for non‐reactive physical mass transfer across a wetted wall column (WWC). In Part 2, we improved the existing computational fluid dynamics (CFD) model to simulate chemical absorption occurring in a WWC as a bench‐scale study of solvent‐based carbon dioxide (CO2) capture. To generate data for WWC model validation, CO2 mass transfer across a monoethanolamine (MEA) solvent was first measured on a WWC experimental apparatus. The numerical model developed in this work can account for both chemical absorption and desorption of CO2 in MEA. In addition, the overall mass transfer coefficient predicted using traditional/empirical correlations is conducted and compared with CFD prediction results for both steady and wavy falling films. A Bayesian statistical calibration algorithm is adopted to calibrate the reaction rate constants in chemical absorption/desorption of CO2 across a falling film of MEA. The posterior distributions of the two transport properties, i.e., Henry's constant and gas diffusivity in the non‐reacting nitrous oxide (N2O)/MEA system obtained from Part 1 of this study, serves as priors for the calibration of CO2 reaction rate constants after using the N2O/CO2 analogy method. The calibrated model can be used to predict the CO2 mass transfer in a WWC for a wider range of operating conditions. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.

Direct Effect of Solvent Viscosity on the Physical Mass Transfer for Wavy Film Flow in a Packed Column

“…After successful validation of the CFD prediction for wavy film flow, CFD simulations were further validated for the physical mass transfer phenomenon. In our previous study of physical mass transfer in the wetted wall column, , VOF predictions for the physical mass transfer coefficient were found to compare well with the experimental results. To ensure reliability of the present simulation, the predicted results are qualitatively and quantitatively compared with those obtained from experiments.…”

“…To ensure reliability of the present simulation, the predicted results are qualitatively and quantitatively compared with those obtained from experiments. Wang et al , conducted experiments to transport N 2 O into MEA solvents on a WWC to generate data for WWC validation. Measurements were performed using a custom-built WWC apparatus consisting of a stainless-steel tube contained within a cylinder.…”

The influence of random packed column parameters on the liquid holdup and interfacial area

“…The viscosity has a range of [0.0009, 0.015] (Pa s), and the surface tension has a range of [0.01, 0.08] (N/m). These ranges of the physical properties cover the solvents such as aqueous sodium hydroxide solution (NaOH), 45 aqueous Monoethanolamine solution (MEA), 46–49 and CO 2 ‐Binding‐Organic‐Liquids (CO 2 BOL), 20,50,51 commonly used for CO 2 capture process.…”