Solid amine sorbents for CO₂ capture by chemical adsorption: A review

Abstract

Amines are well-known for their reversible reactions with CO₂, which make them ideal for CO₂ capture from several gas streams, including flue gas. In this respect, selective CO₂ absorption by aqueous alkanolamines is the most mature technology but the process is energy intensive and has also corrosion problems. Both disadvantages can be diminished to a certain extent by chemical adsorption of CO₂ selectively. The most important element of the chemical adsorption of CO₂ involves the design and development of a suitable adsorbent which consist of a porous support onto which an amine is attached or immobilized. Such an adsorbent is often called as solid amine sorbent. This review covers solid amine-based studies which are developed and published in recent years. First, the review examines several different types of porous support materials, namely, three mesoporous silica (MCM-41, SBA-15 and KIT-6) and two polymeric supports (PMMA and PS) for CO₂ adsorption. Emphasis is given to the synthesis, modifications and characterizations -such as BET and PXRD data-of them. Amination of these supports to obtain a solid amine sorbent through impregnation or grafting is reviewed comparatively. Focus is given to the adsorption mechanisms, material characteristics, and synthesis methods which are discussed in detail. Significant amount of original data are also presented which makes this review unique. Finally, relevant CO₂ adsorption (or equilibrium) capacity data, and cyclic adsorption/desorption performance and stability of important classes of solid amine sorbents are critically reviewed. These include severa PEI or TEPA impregnated adsorbents and APTES-grafted systems.

Keywords

Amine-impregnation / Amine-grafting / CO₂ capture / Chemical adsorption / Mesoporous silica / Solid amine sorbent / Polymeric support / Temperature swing adsorption

Acknowledgments

This work has been Supported by Turkish Scientific and Technological Research Council (Project Number: 111A016). Authors gratefully acknowledge the financial support.

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