Author(s)

HYONJEONG NOH, KWANGU KANG, CHEOL HUH, SEONG-GIL KANG & YOUNGKYUN SEO

Abstract

Carbon capture and storage (CCS) is regarded as one of key technologies to meet global greenhouse gas emission reduction goal. In this manner, South Korea is developing a one-million-ton-scale offshore CCS project to reduce national greenhouse gas emission, entitled the Korea Clean Carbon Storage Project (KCCS) 2025. In this project, the CO₂ is captured from power plants on coast, loaded to CO₂ carriers, and transported to an intermediate storage terminal, which is located on shoreline nearby offshore storage reservoirs at the Ulleung Basin. Then the CO₂ is exported via an offshore pipeline to offshore platform for injection to geological storage site for a permanent containment. Since the concept of the KCCS 2025 includes CO₂ carriers as a transportation method, it requires an intermediate storage terminal that receives the CO₂ from carrier and send out continuous CO2 flow to the offshore pipeline after the pressurization of CO₂ to higher than 100 bar. The intermediate storage terminal will consist of (1) unloading system, (2) CO₂ storage tanks, (3) LP pumps, (4) a reliquefaction package, (5) a vent stack and (6) HP pump and injection pump (a booster station). Because there are few actual projects with an intermediate storage terminal worldwide, researches on intermediate storage facilities are insufficient. To support an optimal concept design of the intermediate storage terminal for the KCCS 2025, this study identified the potential hazardous events for the unloading system and the CO₂ storage tanks. For the unloading system, an unloading arm and LCO₂ recirculating line are found to be major components causing serious damage in case of accident. In the case of the CO₂ storage tanks, where large amounts of CO₂ are stored, they can cause serious damage due to large amounts of CO₂ leakage when the tanks are ruptured, over-pressurized, low-pressurized, overcharged, etc. Because hazardous events may pose significant harm to humans or the environment, these results should be considered in the next phases of the project. The results of this study can be helpful for the development of safe CO₂ transportation technology in the future.

Keywords

CCS, CO2 storage tank, CO2 storage terminal, hazard, PHA, unloading arm