In this blog post, we will examine the issue of sea level rise caused by global warming and explore whether CCS technology can serve as a realistic solution.
Let’s assume that sea levels around the Korean Peninsula rise by 1 meter. According to data from the Korea Marine Environment Management Corporation, a 1-meter rise in sea level is expected to flood approximately 2,600 square kilometers. Currently, over 1.25 million Koreans live in these flood-prone areas. However, this is not merely a hypothetical scenario. If global warming continues at its current rate, this is a situation that could actually occur. Since the Industrial Revolution, humanity has continuously relied on fossil fuels, and the greenhouse gases emitted during this process have altered the Earth’s climate. Although several international agreements have been made to reduce greenhouse gas emissions, significant challenges persist due to economic conflicts between nations. In this context, Carbon Capture and Storage (CCS) is gaining attention as a practical solution.
Carbon dioxide is identified as a major greenhouse gas. CCS is the technology that liquefies carbon dioxide—which is generated in large quantities in industrial settings—before it is released into the atmosphere and stores it deep underground. CCS is broadly divided into three stages. The first is the capture process, in which carbon dioxide is directly collected; the second is the transport process, in which it is safely moved to a storage site; and the third is the storage process, in which it is stored underground, on the seabed, or on the surface.
The first stage, the capture process, is classified into three technologies based on the timing of capture: post-combustion capture, pre-combustion capture, and oxy-fuel combustion capture. Post-combustion capture technology involves separating and capturing carbon dioxide contained in the gas after the combustion of fossil fuels; it is primarily applied to thermal power plants and utilizes existing technologies such as adsorption, absorption, and separation. Pre-combustion capture technology captures carbon dioxide generated when hydrogen is produced using fossil fuels and water; no carbon dioxide is emitted during the combustion process. Oxy-fuel combustion capture technology involves supplying oxygen instead of air to the combustion process to produce a gas mixture of high-concentration carbon dioxide and water, which is then separated and captured. This stage is critical, as it accounts for two-thirds of the total CCS cost, and research to reduce costs is currently underway.
Safely transporting the captured carbon dioxide to a storage site is also a critical step in CCS. The most commonly used transport method today is pipelines, which allow for the economical transport of large volumes of carbon dioxide. Depending on the distance, onshore or offshore pipelines are used, and ships are sometimes employed for longer distances. Small amounts of carbon dioxide can be transported by truck or train, but this method has the disadvantage of being costly.
The carbon dioxide storage process is broadly divided into three methods. The first is subsea storage, which involves storing carbon dioxide in the form of hydrates in deep waters at depths of 3,000 meters or more. While this method can be maintained for 500 years, it is regulated by international law due to concerns about damage to marine ecosystems and ocean acidification. The second is surface storage, which involves solidifying carbon dioxide within minerals such as magnesium or calcium. This method is economically unfeasible due to the time-consuming solidification process and high costs. Finally, subsurface storage involves storing carbon dioxide in depleted oil or gas fields, or in aquifers more than 800 meters underground, and offers the added benefit of enabling the recovery of oil or natural gas.
The Earth can naturally absorb only 14 billion tons of carbon dioxide annually, yet emissions are projected to reach 62 billion tons by 2050. Consequently, approximately 48 billion tons of carbon dioxide will need to be managed through human technology, and it is estimated that 9.1 billion tons—20% of this total—can be handled via CCS. CCS holds significant value as the only technology capable of directly reducing carbon dioxide. However, it cannot be commercialized until issues such as cost and safety concerns—including the risk of carbon dioxide leaks—are resolved. If these issues are resolved, CCS will bring us significant benefits in the near future.
