The Naval Architect Jul/Aug 2020
The Japan Ship Technology Research Association (JSTRA) and the Ministry of Land, Infrastructure, Transport and Tourism (MLIT), in collaboration with the Nippon Foundation, has launched the joint Shipping Zero Emission project. The project, which is outlined in a report now published in English, considers the measures being taken to achieve IMO’s 2030 carbon targets, before looking at the emission pathways and the roadmap toward zero-emission vessels for 2050 and beyond.
It proposes two different feasible emission reduction pathways to 2050 assuming seaborne trade continues on a business as usual (BAU) basis. One option would be to transition from LNG to carbon- recycled methane; i.e. synthetic gas. This could be phased in as a drop-in fuel in the latter part of this decade and, according to the report’s projections, eventually grow to represent around 39% of marine energy consumption by the middle of this century.
Alternatively, it may be preferable to embrace hydrogen and/or ammonia as the best option and the report estimates they could represent 44% of energy consumption by 2050, including both engines and fuel cells. But in either instance, it anticipates that fossil-based LNG will still represent the second-largest share in energy consumption, at 35-36%.
The different fuel and technological options, research and development (R&D), and trial projects will become the focus of the next few years. To avoid R&D duplication, the project advocates the setting up of joint ventures or, alternatively, the establishment of international schemes with an appropriate funding framework.
It further states that it will be essential to develop hydrogen and ammonia- fuelled engines by 2024, apropos trialling them on dual-fuel coastal vessels by 2026 and achieving delivery of a first generation zero-emission vessel by as early as 2028.
Concept designs
As an extension of this, the project has developed concept designs for a variety of different C-ZERO, low or zero-emission vessels based on alternative fuel option. The background research for which is extensively detailed in the report’s appendices.
Hydrogen-fuelled: Designs were created for two different sizes of liquified hydrogen-fuelled ships. Firstly, an 80,000dwt bulk carrier of 229m length, one-way cruising distance of 7,000nm and a 4,000m3 liquified hydrogen tank located above deck at the stern. Second, a 20,000TEU container ship, 399m length with a cruising distance of 11,500nm. This design features a 30,000m3 fuel tank. The assumption was made that bunkering would be available in at least five major ports around the world and that the vessels would be equipped with dual-fuel main engines.
Ammonia fuelled: Also an 80,000dwt bulker but specifically based on the premise that it would serve the Japan-Australia route. The duel-fuel engine would allow for the use of a small quantity of pilot fuel such as methanol or LPG. The 1,550m3 tank would also be situated above deck, to control leakage and release into the atmosphere in the event of emergency.
LNG & wind: This concept, for a 229m 102,000dwt bulker, would achieve an 86% reduction in CO2 by maximising the synergy of LNG and other technologies. These include a hybrid contra-rotating propeller, hullform improvements, wind assistance and an air lubrication system. A similar concept was also developed for a 400m 27,000TEU container ship.
Carbon capture: This dual-fuel vessel, also a 400m 20,000TEU container ship, would operate between the Far East and Europe, powered principally by methanol stored in a 13,200m3 tank. Onboard carbon capturing systems, using the liquid amine absorption method, remain hypothetical at this stage but should be capable of capturing 85.7% of CO2. A set of two 6,400m3 CO2 tanks would be located amidships.
The full report can be downloaded at: www.mlit.go.jp/common/001345627.pdf
