In a significant stride towards enhancing carbon capture technologies, researchers at the University of Surrey have developed a novel adsorbent that could revolutionize intermediate-high temperature CO₂ capture processes. The study, led by Ali Goksu from the School of Chemistry and Chemical Engineering, introduces CaO-modified ZnO adsorbents, offering a promising avenue for integrating CO₂ capture with conversion processes in the energy sector.
The research, published in the journal “Carbon Capture Science and Technology,” focuses on the development of adsorbents that can operate at intermediate-high temperatures, a critical factor for process intensification and coupling gas separation with chemical reactions. Goksu and his team synthesized five different adsorbents with varying Ca loadings on ZnO, ranging from 0% to 15% by weight. Through fixed bed reactor experiments and thermogravimetric analysis (TGA-DSC), they demonstrated that the extent of CaO doping significantly influences both the CO₂ adsorption/desorption temperature and capture capacity.
One of the key findings of the study is that the highest adsorption capacity, 0.73 mmol/gcat, was achieved with a 5% Ca loading on ZnO. This discovery underscores the potential of tuning the adsorption properties by adjusting the CaO dispersion on the ZnO scaffold. “By modifying the CaO content, we can fine-tune the adsorbent’s performance to meet specific industrial requirements,” Goksu explained. “This flexibility is crucial for optimizing CO₂ capture processes in various energy-intensive applications.”
The study also revealed that the desorption temperatures for CO₂ were influenced by the Ca loading, providing further evidence of the adsorbent’s tunable characteristics. Characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), TGA, Brunauer-Emmett-Teller (BET) surface area analysis, and inductively coupled plasma mass spectrometry (ICP-MS) were employed to understand the structure and composition of the adsorbents. It was determined that CaO deposits on ZnO pores as separate domains, contributing to the enhanced performance.
The implications of this research are far-reaching for the energy sector. Efficient CO₂ capture at intermediate-high temperatures can facilitate the integration of capture and conversion processes, leading to more sustainable and cost-effective solutions for reducing carbon emissions. “This technology has the potential to significantly impact industrial processes where CO₂ capture is crucial,” Goksu noted. “By improving the efficiency and tunability of adsorbents, we can make strides towards achieving net-zero emissions targets.”
As the world continues to grapple with the challenges of climate change, innovations in carbon capture technologies are more important than ever. The development of CaO-modified ZnO adsorbents represents a significant step forward in this field, offering a versatile and effective solution for CO₂ capture. With further research and development, this technology could play a pivotal role in shaping the future of the energy sector and contributing to a more sustainable planet.