Carbon Capture and Storage (CCS) technology is increasingly recognized by international experts as a pivotal solution for achieving net-zero emissions. This comprehensive guide delves into the intricate processes of CCS, its vital role in global decarbonization efforts, and the innovative advancements shaping its future. We will explore how this critical climate change solution works, from capturing CO2 emissions at their source to its secure, long-term storage, providing a clear understanding for our readers on this essential climate action.
What is Carbon Capture and Storage (CCS) Technology?
Carbon Capture and Storage (CCS) is a comprehensive process designed to mitigate climate change by capturing carbon dioxide (CO2) emissions from large point sources. These sources typically include industrial facilities and power plants. Once captured, the CO2 is transported to safe, long-term storage locations, such as deep geological formations underground or beneath the seabed, preventing its release into the atmosphere. This technology is a critical intermediate and long-term solution for achieving global net-zero emissions targets.
The Process of CCS
The methodology behind carbon capture and storage involves three primary phases: capturing the CO2, transporting it, and finally, storing it securely.
Capturing CO2
This initial stage focuses on separating CO2 from other gases within an emissions stream generated by a specific source. Post-combustion CO2 capture is currently the most widely deployed method. In this approach, emissions are directed through a chemical solvent that selectively absorbs CO2. Within a dedicated separation device, the CO2 is then isolated from the solvent, yielding a pure stream of CO2 ready for storage. The remaining gases, now significantly reduced in carbon content, are released into the atmosphere. Existing technologies utilizing various solvents can effectively remove over 90% of CO2 emissions. Beyond post-combustion, other advanced CO2 capture technologies include pre-combustion CO2 capture, also known as hydrocarbon separation, and oxy-fuel combustion, which captures CO2 during fuel burning using pure oxygen.
Transporting CO2
Once captured, CO2 undergoes compression or liquefaction to facilitate efficient transportation. The most common methods for transporting CO2 today include pipelines, which are ideal for large volumes over significant distances. For even greater distances or specific geographical challenges, ships are utilized. For smaller quantities of CO2 or localized transport needs, trucks and trains provide viable options for carbon utilization and storage preparation.
Storing CO2
After transportation, the CO2 is delivered to carefully selected sites for permanent storage. These underground storage sites include deep saline aquifers, depleted oil and gas reservoirs, subterranean salt layers or caverns, and unmineable coal seams. In certain scenarios, CO2 can also be utilized for commercial purposes, integrating it into various value chains. When CO2 is captured for utilization and subsequent storage, the process is known as CCUS (Carbon Capture, Utilization, and Storage). For example, CO2 can be injected into nearly depleted oil reservoirs to enhance oil recovery (EOR), increasing production from existing fields. Another innovative application is in Bioenergy with CCS (BECCS), where CO2 from biomass processes is captured and stored, contributing to negative emissions.
Carbon capture and storage facility, Quest, in Fort Saskatchewan, Alta (Photo: The Canadian Press)
CCS and the Journey to Net Zero Emissions
Carbon Capture and Storage is considered a vital third pillar in the global journey towards net-zero emissions, following advancements in energy efficiency and accelerated renewable energy development. The International Energy Agency’s (IEA) “Net Zero by 2050: A Roadmap for the Global Energy Sector” report, published in 2021, underscores the escalating importance of CCS. The report projected a gradual increase in CO2 capture and storage, starting with 40 million tons per year in 2020. By 2030, an estimated 1.6 billion tons of CO2 will need to be captured annually, with this figure soaring to 7.6 billion tons by 2050. Of this, 95% of the captured CO2 is intended for permanent storage, while the remaining 5% will be allocated for the production of synthetic fuels, demonstrating how carbon capture works for net zero objectives.
The Future of Carbon Capture Projects
The landscape of CCS projects globally is experiencing significant growth, indicating a robust future for carbon capture projects. According to statistics from the Global CCS Institute, there were 194 CCS/CCUS projects worldwide as of September 2022, marking a substantial 44% increase from September 2021. The United States led this expansion with 34 new CCS projects since 2021, followed by Canada with 19 and the United Kingdom with 13. Currently, thirty CCS projects are operational, collectively boasting a total capacity of approximately 42.58 million tons of CO2 per year. These projects are primarily developed on land, often leveraging enhanced oil recovery techniques. Additionally, 11 CCS projects are under construction, with a further 153 in various stages of development. Global oil and gas companies, such as Exxon Mobil, are at the forefront of this technology, with Exxon Mobil alone accounting for roughly one-fifth of the world’s CO2 capture capacity.
Global CO2 capture sources on the Net Zero 2050 roadmap (Source: IEA)
A significant milestone occurred in March 2023 when Denmark inaugurated the Greensand project, a pioneering CO2 storage initiative located 1,800 meters beneath the North Sea. This made Denmark the first nation globally to bury imported CO2 emissions. Following its testing phase at the end of 2022, the project aims to store 8 million tons of CO2 annually by 2030. Governments worldwide are increasingly supportive of CCS, implementing encouraging policies such as non-repayable grants, operating subsidies, and carbon pricing mechanisms. Notable examples include the CCUS Infrastructure Fund in the United Kingdom and the Innovation Fund in the European Union. Furthermore, operational subsidies based on carbon-based tax credits for captured, stored, and utilized CO2, such as the 45Q and 48A tax credits in the United States, provide significant financial incentives for investment in this critical greenhouse gas reduction technology.
Challenges and Considerations for CCS Technology
While Carbon Capture and Storage has been widely acknowledged as a crucial climate change solution for reducing greenhouse gas emissions, various countries and experts have raised important challenges and considerations for CCS technology. Some nations have cautioned that while essential, these technologies should not be seen as a substitute for the urgent imperative to significantly reduce the use of fossil fuels and for countries to limit their reliance on these energy sources. On July 14, 2023, the European Union (EU) and 17 other countries issued a joint warning, emphasizing that emission-reduction technologies like CCS should serve as a foundation for broader steps towards phasing out fossil fuels, with CCS playing only a minimal role in reducing CO2 emissions within the energy sector itself.
The development of renewable energy remains the primary impetus in the Net Zero journey (Illustration: Internet).
Many experts also assert that CCS should not be considered the singular solution for carbon removal, particularly in industries heavily dependent on fossil fuels. Instead, it is best viewed as a bridge solution for carbon reduction in specific industrial sectors where developing low-emission alternatives requires a longer implementation timeframe, such as in cement production. Furthermore, the broader development of CCS technology faces several other significant hurdles. These include a lack of globally coordinated policies to uniformly foster CCS adoption, the inherently high capital costs associated with building and operating these facilities, and insufficient financial incentives to encourage widespread investment. Diverse perspectives also exist regarding the potential risks and long-term implications associated with underground CO2 storage, contributing to the challenges of CCS technology.
There is no single solution that can comprehensively address the complex issues of climate change. Consequently, alongside the core drivers of increasing renewable energy production and enhancing energy efficiency, solutions such as Carbon Capture and Storage for reducing emissions and achieving carbon neutrality will form an integral part of the overall strategy for global decarbonization and the journey to Net Zero. For Vietnamese insights on carbon capture and storage, further information is available.
Vu Phong Energy Group
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