2014 Victoria Fellowship – Solid amine sorbents for post combustion CO2 capture

Recent global warming / climate change trends, attributed in particular to the CO2 emissions from air fired fossil fuel power generators, are projected to have serious impacts on both humanity and the environment1. Post combustion carbon capture and storage and/or utilisation technologies are thus being considered amongst other strategies to mitigate / halt these trends1,2. Capture by adsorption type process technologies is being considered, as adsorption technologies are thought to provide a potentially more cost efficient solution than other gas separation technologies2. Solid amine sorbents are of particular interest for their potential to provide rapid, large, water tolerant and selective CO2 working capacities at moderately high process temperatures, as would seem well suited to facilitate CO2 capture from hot wet flue gas3,4,5.

The preparation, pelletization, structure and chemistry of a range of solid amine sorbents, separately prepared via aminoalkylsilylation of, and the wet infiltration of amines into, a range of ordered mesoporous silicas (OMSs), and their potential for post combustion CO2 capture via adsorption, as developed at Monash University, will be discussed. The sorbents were found to exhibit useful selective CO2 working capacities, via a reversible carbamate formation process. Larger porosity OMSs were found useful to prepare higher capacity sorbents. High process temperatures were particularly useful to facilitate rapid gas diffusion throughout the higher capacity sorbents, but also lead to partial deactivation of the sorbents due to the dehydration of the carbamates under anhydrous conditions. However, the presence of water was found to inhibit this deactivation process. Thus, such solid amine sorbents are promising for post combustion CO2 capture in particular.

The 2014 Victoria Fellowship was awarded by the State Government of Victoria, Australia, to facilitate further study of these sorbents with specialised facilities at the University of Edinburgh in collaboration with Prof Stefano Brandani, and to meet with other researchers active in the development of materials for CO2 capture. An additional AFAS-Associate award was provided by the Australia French Association for Science and Technology to facilitate additional meetings with similar interest researchers in France.