Jong-Kap AHN’s research while affiliated with Gyeongsang National University and other places

This study addresses the control challenges associated with loading low-pressure liquid carbon dioxide carriers (LCO2Cs), which are crucial components of the carbon capture, utilization, and storage (CCUS) chain. It explores the need for stable pressure and temperature control to prevent dry ice formation and ensure efficient cargo handling. The research employed HYSYS dynamic simulations to assess three different control strategies. The simulations assessed each strategy’s effectiveness in maintaining stable operating conditions and preventing risks, such as dry ice formation and valve blockages. The study concluded by examining the necessity of pressurization for safe and efficient LCO2 loading and by determining which control strategy is most effective and reliable based on the simulation outcomes. Among the three scenarios examined, Case A, which utilized two control valves, exhibited initial instability due to significant flow coefficient differences, resulting in temperature drops below the CO2 triple point and increasing the risk of dry ice formation. Case C, operating without pressurization, experienced severe pressure fluctuations and prolonged exposure to temperatures below the triple point, posing risks of valve blockages. In contrast, Case B, which uses a remote pressure-reducing valve and a control valve, demonstrated the most stable performance, effectively avoiding dry ice formation and pressure fluctuations, making it the most reliable method for safe LCO2 cargo loading.

The energy required for the transportation of raw materials and the production of most manufactured goods depends on crude oil. For these reasons, FPSOs (Floating, Production, Storage, and Offloading) have become the primary production units of crude oil offshore. It is leading to an increase in the number and expanding of the production and storage facilities of the FPSOs. An increase in the oil production at the topside facilities of FPSOs will contain more gases, which leads to a rise in blow-by gas. Changes to the blanket gas system may be necessary as the flow rate of the blow-by gas is expected to increase. The purpose of this paper is to suggest a novel blanket gas system with a proper control method for controlling the cargo tank pressure when the blow-by gas is occurring. Unlike the existing system, in this proposal, the purge header that supplies the inert gas is possible for a use of the vent purpose in the situation where the blow-by gas is generated. By using the vent header and purge header for the purpose of venting, the pipe size can be drastically reduced. To quickly convert the purge header for the purpose of venting, the application of an appropriate control method is essential. A simulation was carried out for confirming the efficacy of the pressure control and the processible blow-by gas quantity compared to the existing system. In addition, as the amount of blow-by gas increased, a study on the possibility of installing large pipes used in the existing system configuration and the dual pipes suggested by this proposal was investigated. As a result of the simulation, this proposal presented better results in terms of both the pressure control performance of the cargo tanks and the arrangement of the piping compared to the existing system.