Comprehensive modeling and CFD simulation of absorption of CO₂ and H₂S by MEA solution in hollow fiber membrane reactors

Abstract

A comprehensive mathematical model has been developed for the simulation of simultaneous chemical absorption of carbon dioxide and hydrogen sulfide by means of Monoethanolamine (MEA) aqueous solution in hollow fiber membrane reactors is described. In this regard, a perfect model considering the entrance regions of momentum, energy, and mass transfers was developed. Computational Fluid Dynamics (CFD) techniques were applied to solve governing equations, and the model predictions were validated against experimental data reported in the literature and excellent agreement was found. Effects of different disturbances on the dynamic behavior of the reactor were investigated. Moreover, effects of various parameters such as wetting fraction, gas and liquid inlet velocities, inlet temperature of the solvent, MEA concentration, and CO 2 and H 2 S compositions were carefully studied. It was found that for large values of gas velocity or small values of liquid velocity, the thermal energy equation can play an important role in the model predictions. MEA concentration 5 0.5 M, gas flow rate 5 1000 mL/ min, and liquid flow rate 5 25 mL/min. Inlet liquid velocity 5 0.0503 m/s, inlet liquid temperature 5 308 K, inlet gas pressure 5 100 kPa, gas feed: 0.14 CO 2 , and MEA concentration 5 1.0 M. Inlet liquid velocity 5 1.0 m/s, inlet liquid temperature 5 308 K, inlet gas pressure 5 100 kPa, gas feed: 0.15 CO 2 and 0.05 H 2 S, MEA concentration 5 1.0 molar, wetting fraction 5 0.1, and inlet gas velocity 5 2.0 m/s. AIChE Journal February 2014 Vol. 60, No. 2 Published on behalf of the AIChE Inlet liquid velocity 5 1.0 m/s, inlet liquid temperature 5 308 K, inlet gas pressure 5 100 kPa, gas feed: 0.15 CO 2 and 0.05 H 2 S, MEA concentration 5 1.0 molar, and wetting fraction 5 0.1. 668

CFD Modeling of CO2 Absorption in Membrane Contactors Using Aqueous Solutions of Monoethanolamine–Ionic Liquids

“… where V z ‑shell is velocity distribution in the shell side that is estimated by Navier–Stokes equation. Boundary conditions for eq are as follows …”

Computational modeling of drug separation from aqueous solutions using octanol organic solution in membranes

“…The package operates based on finite element method (FEM), which is a numerical technique used for solving partial differential equations (PDEs) [35][36][37][38] . Using FEM to solve the PDEs possesses significant advantages such as easy performance of non-uniform meshes and easy handling the complicated geometries [39][40][41] . A 64-bit operating system with an Intel core™ i5-6200U CPU at 2.30 GHz and an 8 Gigabyte RAM was utilized for the simulations.…”

Response to “Comment on ‘CFD Modeling of CO2 Absorption in Membrane Contactors Using Aqueous Solutions of Monoethanolamine-Ionic Liquids’”

“…In this study, we also used the Comsol outflow boundary condition, and boundary condition is incorrectly given in this manuscript. This boundary condition is also true, of course, and we have seen it in previous research, , but this condition has been used more in research done with MATLAB software.…”