Diamond Light Source is being used to improve low cost methods for carbon capture. Scientists from the University of Leeds are using the UK's national synchrotron to investigate the efficiency of calcium oxide (CaO) based materials as carbon dioxide (CO2) sorbents. Their results, published in the journal of Energy & Environmental Science, provide an explanation for one of the key mechanisms involved. This new knowledge will inform efforts to improve the efficiency of this economically viable method of carbon capture and storage.
Current techniques for post-combustion carbon capture filter out CO2 from a power plant's flue gases as they travel up a chimney. The filter is a solvent that absorbs the CO2, before being heated, releasing water vapour and leaving behind the CO2. In pre-combustion, the CO2 is filtered out by use of a catalytic converter before the fossil fuel is burned and the CO2 is diluted by other flue gases. These methods can prevent 80% to 90% of a power plant's carbon emissions from entering the atmosphere.
CaO based materials have a large range of applications including pre- and post-combustion carbon capture technologies and thermochemical fuel upgrading. They are low cost, high abundance, have a large sorption capacity and fast reaction rates during the chemical process. They capture CO2 in the temperature range 400-800 C via the formation of calcium carbonate (CaCO3) which can be regenerated with subsequent release of CO2, ready for compression and storage. However, after multiple capture and regeneration cycles, the materials' capacity for capture decreases due to the loss of surface area through sintering, a process that fuses powders together to create a single solid object. Although the surface area can be restored through hydration, the material suffers a reduction in mechanical strength. If these problems can be overcome, CaO based materials could provide a low cost answer for carbon capture on a very large scal
|Contact: Paula Gould|
University of Leeds