Investigation of carbon dioxide (CO2) capture in a falling film contactor by computer simulation
Oil & Gas Science and Technology
In this work, mathematical models of carbon dioxide (CO 2 ) absorption by monoethanolamine amine (MEA) in a falling film contactor are developed. The proposed models aim to predict conversion of the gas-liquid reaction along the contactor, gas-liquid interface temperature profile (axial and radial), liquid film thickness along the contactor length, axial and radial concentration profiles of reactants in liquid film, and axial and radial profiles of velocity in the liquid film. A code written in
... . A code written in MatLab was used to obtain these profiles based on multi grid method through programming of kinetic and thermodynamic equations and physical properties of the absorption system. The mathematical model is validated by an experimental measurement based on absorption of CO 2 gas by MEA solution. Four parameters are studied as independent variables namely, mole fraction of carbon dioxide in gaseous mixture, molar concentration of absorbent (MEA, volumetric flow rate of MEA, and its temperature. It is found that the entrance effect of the falling film contactor is related to axial distance from the contactor entrance exponentially: An optimization technique based on minimization of the sum of the squared error between the experimental and predicted composition of absorption process is used to obtain B 0 and B 1 . It is found that reaction between carbon dioxide and MEA is instantaneous, and the axial conversion of carbon dioxide in the gas phase varies exponentially with the contactor length.