Pressure Drop, Capacity and Mass Transfer Area Requirements for Post-Combustion Carbon Capture by Solvents

Abstract

Re´sume´-Pertes de charge, capacite´et aires de transfert de matie`re requises pour le captage du CO 2 en post-combustion par solvants -Les proce´de´s de captage en post-combustion utilisant des amines sont conside´re´s comme l'une des options pre´fe´re´es pour le captage et le stockage du CO 2 (CSC, CO 2 Capture and Storage). Cependant, le couˆt du CO 2 e´vite´est tre`s important et doit eˆtre re´duit. Ce couˆt est fortement lie´aux designs des colonnes, qui doivent, par conse´quent, eˆtre optimise´es. Dans cet article, les performances hydrodynamiques et le transfert de matie`re de garnissages vrac et structure´s sont discute´s en terme de perte de charge, de capacite´et, le plus important, en terme de coefficients de transfert de matie`re, notamment l'aire interfaciale, parame`tre le plus important pour la conception d'absorbeurs de CO 2 . La comparaison de diffe´rents garnissages commerciaux a`haute efficacite´est discute´e a`partir de caracte´risations expe´rimentales et de simulations CFD et une me´thodologie pour de futurs de´veloppements est propose´e.Abstract -Pressure Drop, Capacity and Mass Transfer Area Requirements for Post-Combustion Carbon Capture by Solvents -Post-combustion capture processes using amines are considered as one of the preferred options for CO 2 Capture and Storage (CCS). However, the cost of avoided CO 2 is very large and must be reduced. The latter cost is strongly linked with column designs which consequently must be optimized. In the present article, hydrodynamics and mass transfer performances of random and structured packings are discussed in terms of pressure drop, capacity and most importantly in terms of mass transfer parameters, in particular in terms of interfacial area which is the most important parameter for CO 2 absorbers design. Comparison of different commercial high efficiency packings is discussed from experimental characterization and from CFD simulations and a methodology for future developments is proposed.

Use of Computational Fluid Dynamics for Absorption Packed Column Design

“…For example, in the particular case of post-combustion CO 2 capture, Raynal et al (2013) showed that the interfacial area is the key parameter for the absorber design. This leads to promoting structured packings for such a reactive absorption application that offer higher geometric area per unit volume, from at least 250 m 2 /m 3 and preferentially more than 350 m 2 /m 3 , and a large void fraction (porosity), around 90%, which induce high mass transfer efficiency and low pressure drop, respectively (Lassauce et al, 2014). For high-pressure acid gas treatment, H 2 S removal efficiency will be more sensitive to gas-side mass transfer, since H 2 S reacts instantaneously with amine-based solvent, and, due to high-pressure operation, the column design will consider diameter optimisation as more important than height and resulting pressure drop optimisation; the corresponding choice of packing would thus differ from ambient pressure CO 2 post-combustion absorption.…”

A Review on Gas-Liquid Mass Transfer Coefficients in Packed-Bed Columns

“…Lassauce et al [89] evaluated the liquid film thickness from CFD simulations and then calculated the liquid hold-up by applying the model of Bravo [8]. Optimal agreement with experimental data was observed for small-scale plants operated under laminar flow conditions.…”