In the race to net-zero emissions by 2050, direct air capture (DAC) technology is emerging as a critical player. A recent study led by Sylvanus Lilonfe from the Faculty of Engineering at the University of Nottingham has shed new light on the potential and challenges of this technology. The research, published in the journal ‘Carbon Capture Science & Technology’, delves into the technical, economic, and lifecycle greenhouse gas emissions of solid sorbent DAC technologies, offering a comprehensive roadmap for the energy sector.
The study assesses five different solid sorbents, evaluating their design, operations, costs, and greenhouse gas (GHG) emissions under various technology scenarios. The findings reveal a wide range in both cost and emissions, primarily driven by the raw materials used in sorbent manufacture. In 2024, the cost of these sorbents is estimated to range from $20241,200 to $40,400 per ton, with GHG emissions ranging from 3.1 to 12.3 tons of CO2 equivalent per ton of sorbent.
Lilonfe emphasizes the multifaceted nature of the cost dynamics, stating, “The costs of DAC are heavily influenced by economic factors such as capital expenses and energy costs, design elements like plant scale, and technical parameters including the sorbent’s adsorption rate and time.” This complexity underscores the need for a nuanced approach to cost reduction and efficiency improvement.
The study also projects significant cost reductions in the future. By 2025, the best capture technologies could range from $202497 to $168 per gross ton of CO2 captured, potentially dropping further to $202487 to $140 per gross ton by 2050. These projections highlight the potential for DAC to become a commercially viable solution, especially as carbon prices are expected to rise to $140–240 per ton of CO2 by 2030–2050.
However, the study also underscores the critical role of energy sources in determining GHG emissions. This finding is particularly relevant for the energy sector, which is already under pressure to decarbonize. As Lilonfe notes, “The GHG emissions of DAC are mostly determined by the source of energy,” suggesting that the shift towards renewable energy sources could significantly enhance the environmental benefits of DAC.
The research also points to the inadequacy of current carbon market price signals in supporting DAC projects. This indicates a need for policy interventions to create a more favorable economic environment for DAC technologies. As the energy sector continues to evolve, this study provides valuable insights into the future of carbon capture technologies, highlighting the need for continued innovation and investment. The findings published in ‘Carbon Capture Science & Technology’ are a step forward in understanding the potential and challenges of DAC, paving the way for more effective strategies to achieve net-zero emissions.
