Comparison of modern packings : assessing proper choice for post-combustion carbon capture absorption columns

Abstract

CO2 capture from industrial flue gases is expected by IEA [1] to contribute to up to 19% of carbon mitigation by 2050. Absorption of CO2 into chemical solvents used in post-combustion capture processes is widely recognized as a reference path due to its high selectivity and CO2 recovery rate [2]. However, absorption and solvent regeneration columns required for that purpose are of huge sizes and further induce high investments impacting avoided CO2 cost. This impact is important enough so that it cannot be neglected when compared with operating unit costs [3]. We are presenting in this paper what is required in terms of packing characteristics, that is pressure drop, mass transfer performances and also liquid dispersion properties. This latter property, even if little discussed in the literature, is of great importance, since it will be used for determining the maximum height for packed beds as well as for column redistribution internals design. All these properties are presented for both random and structured packings and a discussion about packing choice is proposed, especially based mass transfer performances and on original dispersion results obtained for Mellapak and IMTP packings