The Naval Architect: January 2020
So the announcement, at Shanghai’s Marintec trade show in early December, of two ammonia-fuelled ship projects is an encouraging indication that industry players are starting to think seriously about zero-carbon shipping.
First came Dalian Shipbuilding Industry Co (DSIC) with its announcement of a 23,000 TEU ultra-large container ship concept, which has been awarded an AiP by Lloyd’s Register (LR). The ‘C-Future’ solution is proclaimed by DSIC as a pioneering initiative in green shipping development and clean energy applications. LR were particularly involved in the facilitation of hazard identification (HAZID) workshops to determine potential hazards throughout the design phase.
It was followed by the news that Shanghai Merchant Ship Design & Research Institute’s (SDARI) was working with ABS on the compliance and design considerations for a 2,700 TEU ammonia-fuelled ‘Chittagongmax’ container feeder ship.
Significantly, MAN Energy Solutions are attached to both projects as it seeks to promote its ammonia ambitions.The manufacturer announced last January that, in partnership with Japan’s Kyushu University, it was developing its LPG-burning ME-LGIP engine to run on NH3.
These plans were further elaborated upon in a white paper published in November, entitled ‘Engineering the future two-stroke green-ammonia engine’, which anticipates an ammonia-combusting engine will be commercially available in two to four years. Such engines, the paper suggests, might be installed (whether newbuilding or retrofit) as duel fuel ‘ammonia ready’ solution with LPG carriers, which occasionally transport ammonia as cargo, suggested as “first movers”.
Given the growing demands for fuel flexibility, MAN is also looking at onboard power generation, with the MAN B&W engine two-stroke engine said to be capable of fulfilling both roles. Such a solution would require changes to the ship design to accommodate the gensets and the paper states that MAN is currently evaluating the feasibility of directly coupled generators with either fixed or variable rpms, the latter of which might require the safeguard of additional battery power.
Predictably, MAN is keen to downplay the potential of electrical engines (whether batteries or fuel cells) for long-haul shipping. “Low-speed marine engines are already the most efficient propulsion system for trans-oceanic shipping, making them the de facto, standard powertrain for commercial vessels,” argues Bjarne Foldager, senior vice president for MAN’s two-stroke business, in relation to both projects. “In this respect developing ships by ammonia makes perfect sense as it has the potential in the future to be created from renewable, primary-energy sources such as wind, hydro or solar.”
Ammonia’s advocates point to the existing infrastructure for the chemical’s use in industrial processes as an agricultural fertiliser, which would negate to some extent the problems that hindered the rollout of LNG, but widespread implementation of ammonia as an alternative fuel would inevitably require some upscaling of these facilities, even assuming they are favourably located.
In that regard, the SDARI feeder ship project is probably better positioned to become a reality, in that developing bunkering facilities for short-sea routes will be easier to achieve. But it will be interesting to see whether the eventual designs pique the interests of shipowners, given that these are the scale of vessel for which batteries and fuel cell solutions will probably be suited for in the coming years.
Equally, the DSIC announcement has nothing to say about the lower fuel density of ammonia, which would require larger fuel tanks and presumably other energy-saving technologies. Or is there an implication this might be mitigated by slow steaming? All in all, one gets the feeling MAN have scored an ammonia publicity coup while the more difficult questions remain unanswered.
