Adsorption Processes for CO2 Capture: An Overview

Adsorption processes for CO2 capture have gained significant attention in the last decade with hundreds of reports on new adsorbents and processes for capture and removal of carbon dioxide from a range of gas streams. To date, the only commercial examples are removal of trace carbon dioxide in gas streams such as LNG and ASU upstream molecular sieve units. There are no commercial examples of the use of adsorbents to capture carbon dioxide by adsorption processes and deliver a stream of high purity carbon dioxide for sequestration or further processing. In this study, we present the range of processing options available for CO2 capture using adsorbents and show how these processes must be adapted to the condition of the feed stream. We also show how these processes make requirements of the adsorbents (or adsorbent systems) and highlight what features new adsorbent should have to help advance adsorption technology. Specific examples of near commercial adsorption processes will be discussed, eg vacuum swing adsorption, high temperature dry regenerable fluidized bed systems, and rapid temperature swing systems