In the quest to mitigate climate change, scientists and engineers are exploring innovative ways to capture and store carbon dioxide from the atmosphere. A groundbreaking study published in the journal ‘Carbon Neutrality’ (translated from German as ‘Carbon Neutrality’) offers a promising approach to make direct air carbon capture and storage (DACCS) more economically viable. The research, led by Dr. Philipp Postweiler from the Institute of Technical Thermodynamics at RWTH Aachen University, delves into the potential of flexible operation for adsorption-based DACCS systems.
Direct air carbon capture and storage is a technology that extracts carbon dioxide directly from the ambient air, a process that is crucial for compensating for emissions that are difficult to eliminate and for counteracting the overshooting of the Earth’s carbon budget. However, the high energy intensity and costs associated with DACCS have hindered its large-scale deployment. Postweiler’s study aims to address these challenges by exploring the economic benefits of flexible operation, which adapts to fluctuations in electricity prices and greenhouse gas emissions from the electricity supply.
The research introduces a novel approach to enhance the typical steam-assisted temperature vacuum swing adsorption cycle. By incorporating two break phases and variable air and steam mass flows during adsorption and desorption, the system can optimize its operation in response to time-varying conditions. “The key innovation here is the ability to adjust each cycle to optimally address the changing costs and emissions from the electricity supply,” Postweiler explains. “This flexibility allows us to significantly reduce the net carbon removal costs.”
To evaluate the benefits of flexible operation, the researchers developed a comprehensive DACCS system model. This model integrates a detailed dynamic process model with life-cycle greenhouse gas emissions and economic data. The study employs a rolling horizon algorithm combined with particle swarm optimization to optimize the DACCS cycles over a week-long period. The case study focuses on the future German power grid and a DACCS system using amine-functionalized sorbents.
The results are compelling: flexible DACCS operation can reduce net carbon removal costs by up to 20% compared to steady-state operation. This finding underscores the potential of flexible DACCS to support carbon neutrality efforts by enabling cost-effective carbon dioxide removal. The integration with volatile renewable energy systems is particularly noteworthy, as it aligns with the growing trend towards renewable energy adoption.
The implications for the energy sector are significant. As the world transitions to cleaner energy sources, the ability to capture and store carbon dioxide efficiently and cost-effectively will be crucial. Flexible DACCS operation offers a pathway to achieve this, making it an attractive option for energy companies and policymakers alike. “This research opens up new possibilities for the energy sector to meet its decarbonization goals,” Postweiler notes. “By optimizing the operation of DACCS systems, we can make carbon capture more affordable and accessible, paving the way for a more sustainable future.”
The study published in ‘Carbon Neutrality’ provides a roadmap for future developments in the field of carbon capture and storage. As researchers continue to refine and optimize these technologies, the energy sector can look forward to more innovative solutions that support the global effort to combat climate change. The findings highlight the importance of integrating dynamic simulation and optimization techniques to enhance the feasibility and economic viability of carbon dioxide removal technologies. This research is a significant step forward in the journey towards a carbon-neutral future, offering hope and practical solutions for a sustainable energy landscape.
