Step change adsorbents and processes for CO₂ capture "STEPCAP''

STEPCAP is a multipartner consortium project, the aim of which is to develop a targeted range of novel CO2 adsorbents for carbon capture. This research into materials and process development is essential to achieve the potential cost and efficiency benefits offered by solid sorbents capture technologies over the current state of the art processes. Firstly, this paper will discuss the key materials and process challenges associated with developing solid sorbents. This will lead into a discussion of materials development in STEPCAP which is based on a fundamental understanding of adsorption processes to design and optimise material properties and form. The development and performance of the three classes of materials under development in this study, microporous polymers, surface modified hydrotalcites, and co-doped sorbents, which offer potential for a step change increase in adsorption capacity and performance over previously developed materials will be discussed. Modified hydrotalcites such as, amine modified layered double hydroxides (LDH’s) have been synthesized via the exfoliation and grafting route. In addition, novel conjugated microporous polymers synthesized through Sonogashira-Hagihara coupling have also been investigated and have demonstrated similar capacities. Critically, due to the hydrophobic nature of some of these adsorbents, identical performance has been observed in the presence of moisture, an advantageous property for operation in the water saturated environment of flue gases. This presentation will also present data on the performance of these materials in simulated flue gases as well after simulated temperature swing regeneration cycles to assess the stability and lifetime of the sorbents.