Chemistry Scholarships

Novel adsorbents for carbon dioxide capture

This project aims to identify, synthesise and characterise novel materials that are highly selective for CO2 adsorption in the presence of other gases. The adsorbents will then be evaluated for their ability to capture CO2 from high volume emission sources, such as power station flue gas, using a process known as Pressure Swing Adsorption (PSA).

Background: The project will involve a mixture of computational chemistry, synthetic chemistry and physical evaluation focused on the development of new inorganic-organic hybrid materials that can potentially separate and concentrate carbon dioxide from major emission points (such as the flue gas from power stations). This will potentially facilitate carbon dioxide to be captured for reuse or long-term storage (sequestration).

Molecular model showing attached tethers and N atoms (blue) where CO2 adsorption occurs.

Inorganic mesoporous substrates with diameters between 30 and 60 Angstroms will be prepared, to which basic organic groups (eg, N- containing silanes) can be attached, forming tethered amine derivatives. The hybrid organic-inorganic adsorbents synthesised by this approach will then be evaluated (using both gravimetric and volumetric methods) for their capacity and selectivity towards carbon dioxide adsorption from simulated flue gas streams. Recent work has demonstrated that high adsorption capacities can be achieved and we are working to improve this further through improved material design.
Molecular modeling techniques will be used to help identify appropriate combination(s) of inorganic substrate, the density of the organic tethers and the basicity of the N-containing functional groups that might lead to optimal CO2 adsorption. The results of computational and laboratory experiments will be compared to enhance our understanding of structure-property relationships.
The project will be carried out in close collaboration with the adsorbent development group of the Department of Chemical Engineering.

Funding: This project is supported through the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC). For further information about the CO2CRC see http://www.co2crc.com.au/

References:
AL Chaffee, GP Knowles, Z Liang, J Zhang, P Xiao and PA Webley - CO2 Capture by Adsorption: Materials and Process Development, International Journal of Greenhouse Gas Control, 1, 11-18 (2007).

2 AL Chaffee - Molecular modeling of HMS-hybrid materials for CO2 adsorption. Fuel Processing Technology, 86 (14-15), 1471-1484 (2005).