ClassNK launches Joint Research on Corrosion Rate Evaluation of Low-Temperature, Low-Pressure Liquefied CO₂ Cargo Tanks
TOKYO: ClassNK and National Maritime Research Institute (NMRI), National Institute of Maritime, Port and Aviation Technology, have launched a joint research project on corrosion rate evaluation of liquefied CO₂ (LCO₂) cargo tanks under low-temperature and low-pressure conditions.
This research aims to establish a technical foundation for appropriately assessing corrosion risks in the transportation of liquefied CO₂. The outcomes are expected not only to enhance the safety of LCO₂ cargo tanks, but also to enable rational design and operation that balance corrosion risk and impurity removal costs. Ultimately, this will contribute to improving both the safety and economic efficiency of the entire CCUS (Carbon Capture, Utilization and Storage) value chain.
Background
With the implementation of CCUS technologies gaining momentum, the importance of transporting liquefied CO₂ by ship is increasing. In Europe, cross-border CO₂ transportation has already commenced, indicating that LCO₂ shipping is entering the stage of practical application. In the Asia-Pacific region as well, a significant expansion in transportation demand is anticipated.
On the other hand, it is well known that even trace amounts of impurities such as water and SOx (sulfur oxides) mixed into CO₂ can cause corrosion. Therefore, there is a growing need for technologies capable of estimating corrosion rates in LCO₂ environments based on the type and concentration of such impurities.
Research Overview
In this research, a CO₂ corrosion test facility will be installed at NMRI, where corrosion tests will be conducted under controlled conditions reflecting anticipated impurity types and concentrations. The facility will be capable of simulating low-temperature and low-pressure environments suitable for large-scale LCO₂ transportation.
The experimental data obtained will be analyzed to establish fundamental data required for the design and maintenance of LCO₂ cargo tanks.
Expected Outcomes
The results of this research are expected to be reflected in ClassNK’s rules and guidelines, contributing to the development of rational and safe LCO₂ cargo tank designs.
Furthermore, by proposing a rational approach to impurity management based on corrosion risk, this research is expected to contribute not only to safe ship design but also to the optimization of costs across the entire CCUS value chain*1.
Research Structure
This project is being carried out through collaboration between ClassNK and NMRI, with additional cooperation from the University of Tokyo’s social collaboration program, “Materials for Future Energy Infrastructure Trust (MEIT).” This framework brings together Japan’s leading expertise in material reliability evaluation.
Future Prospects
Through this research, the project aims to establish a foundation for corrosion evaluation in low-temperature, low-pressure LCO₂ transportation and to contribute to the development of future design standards and international rulemaking.
*1 Increasing CO₂ purity by removing impurities incurs additional costs. However, if impurity levels remain below certain thresholds, it may be possible to manage corrosion without increasing corrosion allowance, potentially reducing overall costs. By clarifying the relationship between impurity composition/concentration and corrosion rates, this research will enable informed decisions on CO₂ purity management that contribute to cost optimization across the entire supply chain.
