The Naval Architect: January 2017
Many observers have dismissed hydrogen as a green fuel due to the expense of producing the gas, but Kawasaki Heavy Industries (KHI) believes that it has a solution that will allow it to meet all of Japan’s power needs for more than 200 hundred years.
Often the production process considered has been electrolysis, but KHI is considering the benefits of hydrogen produced in Australia from gasified brown coal. The extracted and liquefied hydrogen would then be transported to Japan in purpose built tankers to provide a carbon-free fuel for the foreseeable future. According to the company it is building the infrastructure, including a prototype LH2 tanker, which will allow the company to meet its goal of developing the gas supply chain which it calls the Hydrogen Road.
The LH2 prototype liquefied hydrogen tanker is to be built at KHI’s Kobe shipyard and the front end engineering design of the prototype vessel is now complete. The ship with two prototype 1,250m3 liquefied hydrogen tanks has a length of 110m, which was elongated to ensure the design would allow the ship to safely transit from Australia’s southern province of Victoria to Japan with the liquefied hydrogen cargo onboard.
Yukichi Takaoka, a hydrogen ship development officer at KHI, told The Naval Architect that the extra space adjacent to the cargo holds will be used to conduct tests for when the full sized ship is built some years in the future.
The concept of the Hydrogen Road will see the production of hydrogen in Australia from brown coal, which will then be liquefied and stored in tanks at -253°C before it is transported by the newly developed LH2 tanker to a terminal in Japan for use in the production of power.
“Hydrogen has two advantages, it is clean and it is powerful,” says Seiichi Sugawa, a hydrogen project development officer. “The fuel has a high power density in terms of weight and a high calorific value in terms of weight,” he added. Further pointing out that hydrogen is used as a rocket fuel, which shows the possibilities for its development as a power source, both for producing electric power from a power station and as fuel in cars or ships in the shape of a fuel cell, currently under development in a number of countries, including Japan.
According to Sugawa, a massive amount of hydrogen can be imported to Japan if the cost simulation that searched for the optimum energy combination remained in the CIF price range of ¥;25-45/m3. This, he continues, is a competitive price compared with other energies and is cost combined with energy output and the condition of the hydrogen. “If we consider the lowest cost case (¥;25), hydrogen will provide 40% of all of Japan’s energy needs, and in the highest cost case (¥;45) it will be 20% of Japan’s needs by 2050,” explains Sugawa.
KHI says it will establish a test run for the technology necessary to develop, store, transport and deliver liquefied hydrogen from Australia to Japan.
Gasification of brown coal mined in the Australian state of Victoria will split the fuel into its component parts, carbon, which will be captured and stored securely underground, and hydrogen, which will be liquefied and stored at -253°C in tanks specially designed by KHI, before being transferred to an LH2 tanker and transported to Japan, for example Kobe in the case of the pilot chain, where it will be stored on land and distributed to outlets.
The prototype Hydrogen Road has been under discussion since 2009 and, with much of the technology already tried and tested, the company is confident that it will be able to develop the complete logistical chain for the fuel within four years with a view to providing the first commercial power station with fuel by 2025.
The technology for the storage tanks already exists, for example. KHI has more than 20 years of experience in handling hydrogen rocket fuel, storing it in double skinned stainless steel tanks that have a vacuum between each of the walls to provide insulation for the cryogenically stored liquefied gas.
This same technology will be adapted for use on the LH2 tanker; however, unlike LNG tankers, the pilot tanker will use conventional diesel electric power for propulsion. Much of the technology that will be used in the construction of the LH2 tanker prototype has already been tried and tested either in Japan’s space programme or on the LNG tankers that the company itself builds, including double walled piping, valves and loading systems.
In the meantime, “Kobe City will provide a suitable area for a hydrogen Terminal, and it is now designing the terminal which will be built by 2020,” explained Seiichi, adding: “At this moment this CO2 free chain is achievable, and the pilot chain will prove it is possible.”
