A one-meter rise in sea level on the Korean Peninsula due to global warming is expected to inundate an area of about 2,600 square kilometers, putting more than 1.25 million South Koreans at risk. To address this issue, carbon capture and storage (CCS) technology is gaining traction, which aims to reduce greenhouse gases in the atmosphere by capturing, transporting, and storing carbon dioxide. However, the cost and safety of CCS is still a challenge.
Imagine a one-meter rise in sea level on the Korean Peninsula. According to data from the Korea Marine Environment Management Agency, a one-meter rise in sea level is expected to inundate about 2,600 square kilometers. Currently, more than 1.25 million Koreans live in this flood risk area. But this is more than just a hypothetical. If global warming continues on the current trend, it could actually happen. Since the Industrial Revolution, humans have been burning fossil fuels relentlessly, and the greenhouse gases produced in the process have changed the Earth’s climate. There have been several international agreements to reduce greenhouse gas emissions, but they have been hampered by economic conflicts between countries. In this situation, CCS, a carbon dioxide capture and storage technology, is gaining attention as a realistic solution.
Carbon dioxide is considered a major greenhouse gas. CCS is a technology that liquefies carbon dioxide produced in large quantities at industrial sites before it is released into the atmosphere and stores it deep in the ground. CCS is divided into three main phases. The first is capture, which is the direct collection of carbon dioxide; the second is transportation, which is the safe transfer to storage; and the third is storage, which is underground, on the seabed, or on the surface.
The first step, capture, is categorized into three technologies based on the point of capture: post-combustion capture, pre-combustion capture, and net oxy-combustion capture. Post-combustion capture is a method that separates and captures the carbon dioxide contained in the gas after combustion of fossil fuels, and is mainly applied to thermal power plants, and conventional technologies such as adsorption, absorption, and separation are used. Pre-combustion capture technology is a method of capturing carbon dioxide generated when fossil fuels and water are used to generate hydrogen, and no carbon dioxide is produced during the combustion process. Pure oxy-combustion capture involves feeding oxygen instead of air into the combustion process, resulting in a gas with a high concentration of carbon dioxide and water, which is then separated and captured. This step is so important that two-thirds of the cost of CCS is spent on the capture process, and research is currently underway to reduce costs.
Safely transporting the captured carbon dioxide to storage is also a critical step in CCS. Currently, the most commonly used transportation method is pipelines, which can economically transport large volumes of carbon dioxide. Depending on the distance, pipelines can be onshore or offshore, with ships used for longer distances. Smaller amounts of carbon dioxide can be transported by truck or train, but these are more expensive.
There are three main ways to store carbon dioxide. The first is undersea storage, which involves storing carbon dioxide in the form of hydrates in the ocean at depths below 3,000 meters. This method can last for 500 years, but is regulated by international law due to the destruction and acidification of ocean ecosystems. The second is surface storage, which involves solidifying carbon dioxide in minerals such as magnesium or calcium. Solidification is time-consuming and expensive, making it uneconomical. Finally, underground storage involves storing carbon dioxide in abandoned oil or gas fields, or in aquifers deeper than 800 meters underground, with the added benefit of recovering oil or natural gas.
While the Earth can only self-correct 14 billion tons of carbon dioxide per year, the amount of carbon dioxide that will be emitted by 2050 is expected to reach 62 billion tons. This leaves about 48 billion tons of carbon dioxide to be treated by human technology, of which 9.1 billion tons, or 20%, could be treated by CCS. CCS has significant value as the only technology that can directly reduce carbon dioxide. However, cost and safety concerns, such as the risk of carbon dioxide leaks, still need to be addressed before it can be commercialized. If these issues are resolved, CCS could bring us significant benefits in the near future.
