(154a) Steam Stability of Alumina Supported Amine Materials for CO2 Capture From Ultra Dilute Gas Streams

Solid supported amines are a promising class of adsorbents for CO₂ capture from large point sources such as post combustion flue gases, and also from ultra-dilute sources such as air. While much of the research community has focused on synthesizing materials with increased CO₂ capacity, addressing other practical issues, such as sorbent regeneration, remains a critical research need. Recently, we have shown that low grade steam can be used to regenerate supported amine sorbents, and that alumina is a promising support for amines in this application. Here, we further investigate the stability of alumina supported amine adsorbents under steaming conditions. Studies are conducted using a packed bed adsorption system capable of sorbent regeneration under flowing steam. We study both polymeric amines as well as aminosilanes grafted onto several alumina supports. Changes in the CO₂ capacities and materials properties of the adsorbents are presented after extended exposure to flowing steam, as well as exposure to flowing steam on the timescale of one desorption cycle. It is found that the alumina support shows structural changes after extended exposure to steam, and these changes appear to be influenced by the presence and type of amine incorporated into the material.