In the quest to reduce carbon dioxide (CO2) emissions, scientists are turning to an unlikely ally: industrial waste. A recent study published in *Studies in Chemical and Environmental Engineering* explores the potential of carbide slag waste to capture CO2 through a process called mineral carbonation. Led by Manisha Sukhraj Kothari from the United Arab Emirates University, this research could pave the way for innovative solutions in carbon capture and waste utilization.
Carbide slag, a byproduct of industrial processes, has long been considered a nuisance. However, Kothari and her team have discovered that it could play a crucial role in mitigating CO2 emissions. “Mineral carbonation of industrial wastes is a promising approach for reducing CO2 emissions,” Kothari explains. “Our study focuses on the wet-phase mineral carbonation of carbide slag waste under realistic conditions for CO2 capture and storage.”
The research team employed Response Surface Methodology with a central-composite design to optimize and model the carbonation process. They analyzed five operational parameters: temperature, pressure, relative humidity, liquid-to-solid ratio, and CO2 loading rate. Their findings revealed that pressure and the liquid-to-solid ratio were the most influential factors for CO2 capture capacity. Meanwhile, the CO2 loading rate and pressure significantly impacted the reaction kinetics.
The study developed quadratic models to predict CO2 capture capacity and the time required for 50% carbonation conversion. These models, with R2 values of 0.9863 and 0.9986 respectively, accurately predicted the experimental results. Under optimized conditions, the team achieved a maximum CO2 capture capacity of 11.9 mol kg−1 at 10 bar pressure, 65°C, with a 0.2 L/S ratio and 75% relative humidity. Notably, 50% conversion occurred within the first 52 minutes.
The implications of this research are significant for the energy sector. As the world seeks sustainable solutions to reduce CO2 emissions, carbide slag waste could emerge as a viable candidate for large-scale carbon capture applications. “The high CO2 capture capacity achieved under various experimental conditions demonstrates carbide slag as a promising candidate for large-scale CO2 capture applications,” Kothari notes.
However, the journey from lab-scale success to industrial application is not without challenges. Techno-economic analysis and scalability assessments will be crucial in advancing this approach to industrial relevance. As Kothari and her team continue their work, the energy sector watches closely, hopeful that this innovative use of industrial waste could shape the future of carbon capture and storage.
This research not only highlights the potential of carbide slag waste but also underscores the importance of a circular economy. By transforming industrial waste into a valuable resource for CO2 capture, we can take a significant step towards a more sustainable future. As the world grapples with the challenges of climate change, such innovative solutions offer a glimmer of hope and a path forward.