Direct carbon capture and storage in geological systems: Innovations and challenges
Chandan Kumar Singh, MTech
IIT(ISM) Dhanbad
Direct carbon capture and storage (DCCS) is a critical technology in the fight against climate change, offering a way to reduce atmospheric CO2 levels by capturing it directly from the air and storing it in geological formations. Innovations in this field are rapidly advancing, with new methods improving efficiency and scalability. For instance, recent developments include the integration of renewable energy sources to power the capture process, enhancing the sustainability of the technology. Additionally, advancements in material science have led to the creation of more effective sorbents that can capture CO2 more efficiently. With countries around the world investing in DCCS, such as the United States' significant policy support and the European Commission's ambitious storage goals, the technology is poised to play a pivotal role in global efforts to achieve carbon neutrality.
Advanced Capture Technologies: Innovations in capture technologies, such as solvent-based absorption, membrane separation, and solid sorbents, are improving the efficiency and cost-effectiveness of capturing CO2 from flue gases.
Enhanced Oil Recovery (EOR): CO2 can be used for enhanced oil recovery in depleted oil fields, where it is injected underground to help extract additional oil. This process not only sequesters CO2 but also generates revenue from increased oil production.
Carbon Mineralization: Researchers are exploring methods to mineralize CO2 into stable carbonates, which can be permanently stored underground. This approach offers the potential to accelerate the carbonation of CO2 and reduce the risk of leakage from storage reservoirs.
Hybrid Technologies: Hybrid approaches, combining direct air capture with CCS, offer the potential to remove CO2 directly from the atmosphere. These technologies could play a crucial role in achieving negative emissions, helping to offset remaining emissions from hard-to-abate sectors.
Monitoring and Verification Technologies: Advances in monitoring and verification technologies, such as seismic imaging, satellite remote sensing, and geochemical analysis, enable better characterization of storage reservoirs and verification of CO2 storage integrity over time.
One of the primary challenges is the cost of capturing CO2 directly from the atmosphere, which remains high compared to other methods of carbon reduction. Additionally, the integration of CCS with existing industrial processes has not been demonstrated on a large scale, raising concerns about its practicality and long-term viability. There is also a need for confidence that the storage of CO2 in geological formations can be safe and effective over extended periods, potentially thousands of years. Furthermore, clear access to pore space for CO2 storage and proven methodologies for demonstrating storage integrity are critical to the success of CCS. These challenges underscore the need for continued research, development, and policy support to advance CCS technologies.
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Cost: The high cost of CCS technology remains a significant barrier to widespread deployment. Capturing, transporting, and storing CO2 requires substantial investment, and cost reduction efforts are needed to make CCS economically viable, particularly in the absence of carbon pricing mechanisms.
Storage Capacity and Security: Identifying suitable geological storage sites with sufficient capacity and security to store large volumes of CO2 is a challenge. Ensuring the long-term integrity of storage reservoirs and minimizing the risk of CO2 leakage are critical considerations for CCS projects.
Public Acceptance and Social License: CCS projects often face public opposition and regulatory hurdles due to concerns about environmental risks, such as groundwater contamination and induced seismicity. Building public trust and obtaining social license to operate are essential for the successful implementation of CCS projects.
Regulatory and Policy Frameworks: The lack of consistent regulatory frameworks and supportive policies for CCS deployment hinders investment and project development. Clear and stable regulatory regimes, including legal frameworks for liability and long-term liability management, are necessary to incentivize CCS deployment.
Scale-up and Infrastructure: Scaling up CCS technology to achieve significant emissions reductions requires the development of large-scale infrastructure for CO2 capture, transport, and storage. Coordinating infrastructure development and overcoming logistical challenges, such as pipeline construction and rights-of-way, are critical for realizing the full potential of CCS.
Addressing these challenges will require collaboration between governments, industry, research institutions, and civil society to advance CCS technology, reduce costs, and create an enabling environment for deployment at scale. Despite the challenges, CCS remains a crucial technology for mitigating climate change and achieving net-zero emissions targets.