A research team of the University of Tokyo, headed by Professor Masahiko Ozaki, invented a shuttle transport system for carbon dioxide capture and storage (CCS) in which smaller ships are used to carry carbon dioxide (CO2) to storage sites. Compared with the conventional method in which pipelines are laid to storage sites, CO2 can be transported to sea areas further away from the coast with this system. This will allow more latitude in storage site selection, without worrying about the impact on fishing industries and port regulations.
The selection process of the storage site for a large-scale demonstration of CCS is currently under way in Japan. Once the site is selected, a pipeline will be laid and CO2 will actually be transported from emission sources such as coal-fired power plants and chemical plants. In commercializing the CCS process afterward, difficulties may arise when negotiating with fishermen depending on the location of the storage site, and laying a pipeline on the seafloor of a port under strict regulations may incur significant costs. If ships are used for transport, CO2 can be stored in sea areas far from fishing grounds. It is also possible to collect CO2 from multiple emission sources into one storage site.
It is quite challenging to develop a large CO2 transport vessel. Unlike liquefied natural gas (LNG), CO2 has to be kept at high pressures as well as low temperatures; otherwise it solidifies into dry ice. Besides, expensive materials are needed to keep it at low temperatures. Professor Ozaki therefore invented a shuttle transport system in which two ships take turns transporting approximately 3,000 tons of CO2 once every day. Although the amount of CO2 transported each time is small, if it is continued for a year, the total amount will reach 1 million tons, which is the target value for the large-scale demonstration of CCS. This system is feasible with mostly utilizing existing technologies. The research team aims to bring the system into full-scale operation between 2020 and 2030, when CCS is expected to be commercialized.
