Gas-liquid multiphase computational fluid dynamics (CFD) of amine absorption column with structured-packing for CO2 capture
Abstract The gas−liquid multiphase Eulerian computational fluid dynamics (CFD) model was used to investigate hydrodynamics and CO2 removal efficiency of a pilot-scale amine absorber with structured-packing. The structured-packing was represented by a porous media zone having porous resistance, gas−liquid interfacial drag force, and liquid dispersion force. This study aimed to find a reasonable way to identify four modification factors of the Ergun coefficient that determine the hydrodynamic characteristics of structured-packing. The two modification factors (a and b) for porous resistance were mainly related to the liquid holdup (hL) with respect to the liquid load. The other two factors (c and d) for gas−liquid interfacial drag force depended on the specific wet pressure drop (ΔPwet/L) versus the gas load factor. The hL and ΔPwet/L increased in parallel with the increase of a and c, respectively, while the slopes of hL and ΔPwet/L increased with b and d, respectively.
CFD simulation of the structured packings: A review
ABSTRACT Extensive usage of the structured packings in various industrial applications has led to comprehensive investigations of their properties and performance. Among various methods of modeling, computational fluid dynamics (CFD) is an efficient approach to present full details of fluid behavior inside structured packings. This review focuses on the application of CFD for investigation and development of the structured packings. Applications of the CFD for the simulation of gas–liquid flow behavior, flow distribution, liquid hold-up, and mass transfer are extensively reviewed. Literature survey of the available CFD studies can provide a comprehensive and descriptive insight about governing mechanisms of fluid flow inside packings and reveals qualitative/quantitative effects of the process variables on the packed system.
Heat of Absorption of Carbon Dioxide (CO2) in Monoethanolamine (MEA) and 2-(Aminoethyl)ethanolamine (AEEA) Solutions
A method is proposed for measuring the enthalpy of absorption of CO2 (ΔHabs) that is differential in temperature and semi-differential in loading. A 2-L reaction calorimeter was used to measure the enthalpy of absorption of CO2 with aqueous solutions of monoethanolamine (MEA) and (2-aminoethyl)ethanolamine (AEEA) over the temperature range of 40−120 °C. By feeding CO2 in several steps and keeping the change in loading between each new equilibrium rather low (∼0.03−0.07 mol CO2/mol amine), it was possible to obtain values of ΔHabs that were semi-differential in loading. Experiments conducted at different temperature levels gave enthalpy values that were differential in temperature. Measured ΔHabs values were compared with integral values found in the literature and with differential values calculated from solubility measurements. The experimental results indicate that the use of the Gibbs−Helmholtz equation in an aggregate form does not necessarily give an accurate description of the ΔHabs values.