In the heart of Australia, a groundbreaking study is redefining the future of carbon capture and mineral processing. Led by Dia Milani at the CSIRO Energy Centre in New South Wales, this research integrates concentrated solar power (CSP), accelerated mineral carbonation (AMC), and direct air capture (DAC) technologies to create a closed-loop system that could revolutionize the mining industry’s approach to carbon emissions and waste management.
The study, published in Cleaner Engineering and Technology, focuses on a hypothetical nickel mine site, demonstrating how high-temperature steam from a solar central receiver system can drive both mineral carbonation and direct air capture processes. This innovative integration not only reduces greenhouse gas emissions but also significantly cuts down on diesel consumption, a critical factor for remote mining operations.
At the core of this system is a 10 MWe closed-loop Rankine cycle, which generates electricity for mining operations while simultaneously facilitating carbon capture. “The beauty of this design is its efficiency,” Milani explains. “We’re using the same heat source to drive multiple processes, maximizing energy use and minimizing waste.”
The process begins with high-temperature steam generated by a solar central receiver system, which is complemented by a 10-hour thermal energy storage system to ensure continuous operation. This steam first passes through an accelerated mineral carbonation heat exchanger, providing the necessary enthalpy for the carbonation process. After expanding in the turbine to produce electricity, the low-enthalpy exit steam is then used in the direct air capture heat exchanger as a final heat sink before condensation and recycling back to the boiler.
The results are impressive. The system can produce an annual 175.7 kilotons of carbonates, permanently locking away 92.2 kilotons of atmospheric CO2. Moreover, it reduces diesel consumption by nearly 90%, bringing all power-related CO2 emissions of the mine to zero and offsetting an additional 68.55 kilotons of non-power related emissions annually.
This integration of technologies represents a significant step forward in the quest for net-zero emissions in the mining sector. “We’re not just capturing carbon; we’re creating a valuable product,” Milani notes. “The carbonates produced can be used in various industrial applications, adding economic value to the process.”
The implications for the energy sector are vast. As the demand for critical minerals continues to rise, so does the need for sustainable mining practices. This study provides a blueprint for how solar power and carbon capture technologies can be integrated to meet these challenges head-on. The use of a solar central receiver system and thermal energy storage ensures that the process is not only environmentally friendly but also economically viable.
The research also underscores the importance of life cycle assessments in evaluating the true impact of such integrated systems. While the technical and economic feasibility of this design has been verified, a full life cycle assessment relative to business-as-usual practices is crucial for achieving the 2050 net-zero emissions target in the mining sector.
As the world looks towards a more sustainable future, innovations like this one are paving the way. By harnessing the power of the sun and turning atmospheric CO2 into valuable products, we can reduce our carbon footprint and create a more sustainable mining industry. The study published in Cleaner Engineering and Technology, which translates to Cleaner Engineering and Technology, offers a glimpse into what’s possible when we think beyond traditional boundaries and embrace the power of integration.
