Of fuel and ships

Ideas new and old for meeting the challenge of sustainable shipping

Even before “IMO 2020” came into effect on January 1^st 2020, the quest to find the “next” fuel to power line haul size vessels was underway. But IMO 2020 kicked the process into high gear. With environmental concerns paramount in the design process, innovations in power plants and fuels have gone from the planning to prototype to mainstream at breakneck speed.

Dubbed “IMO 2020,” the new rule limits the amount of sulphur in the fuel oil used on board ships operating outside designated emission control areas (ECAs) to 0.50% m/m (mass by mass). This represents a significant reduction from the previous limit of 3.5%. Within specific designated ECAs the limits were already stricter at 0.10%. This new limit was made compulsory following an amendment to Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL).

In order to meet these new standards many shipowners retro-fitted scrubbers to remove sulphur oxides from the ship’s engine and boiler exhaust gases. This eliminated the need to find a fuel compliant with the IMO 2020 regulations. A ship fitted with a scrubber could use heavy fuel oil, as the sulphur oxides emissions are reduced to a level equivalent to the required IMO fuel oil sulphur limit.

However, while scrubbers worked, they were in many respects a Band-Aid solution. And  didn’t address the more profound problem of making ships more environmentally sound even beyond the IMO 2020 protocols. This meant taking a whole new approach to powering vessels by finding a substitute fuel for a technology that has been in place for a century. 

But what are the practical alternatives to fuel oil? This isn’t a new problem. Ship designers have been looking for new fuels for ships for decades. The nuclear powered NSS Savannah built in 1959 was an attempt to look at an alternative future for commercial use. The concept behind the ship’s construction was to find non-military uses for nuclear power. Though the ship sailed over 450,000 miles before retirement, nuclear power was never considered a viable option for merchant ships.

But the idea of finding a fuel with little or no polluting exhaust yet capable of powering large commercial vessels has become a holy grail of marine engineering. In a sense, this is a two-fold challenge, the first designing and building a practical powerplant of sufficient strength to propel a ship through its normal sea routes and secondly to build an infrastructure to support the ship’s refueling. With 2030 IMO deadline now looming on the 40% reduction in carbon emissions, finding alternatives to fuel oil is imperative.

LNG Alternatives

So far, the introduction of  Liquified Natural Gas (LNG) powered vessels has been the most successful alternative fuel meeting these two criteria. CMA CGM built the LNG powered  Jacques Saade, 23,000 TEU vessel with a tank capacity of 18,600 m3 that gives the vessel the equivalent to two-months of fuel. Almost as a proof of concept, CMA CGM Jacques Saade set a new world record of the highest number of full containers aboard a single vessel when she departed the port of Singapore on April 8^th carrying 21,433 TEUs. 

LNG storage and handling are proven technology and LNG power plants are relatively common as backup systems. At this early stage, bunkering for LNG is still  in its infancy, although the technology itself is not radically different than already used in existing systems. 

Another LNG based-system is a LNG-hybrid power plant. The first of three LNG battery hybrid PCTCs commissioned by United European Car Carriers (UECC) was launched in an official ceremony April 12th at the Jiangnan Shipyard in Shanghai. The new UECC PCTCs are built to the latest energy efficiency criteria, meeting the Tier 3 IMO NOx emission limitations in place for the Baltic and North Sea. All three will be equipped with battery hybrid solutions that will enable UECC to far exceed the IMO’s target of 40% reduction in carbon emissions by 2030. Glenn Edvardsen, CEO in UECC, “These ships prove that decarbonization of the industry is possible using currently available technologies.”

The vessels are also equipped with dual-fuel LNG engines for main propulsion and auxiliaries. As more biofuels are set to become commercially available in the future, UECC plans to increase the proportion of carbon neutral and synthetic fuels in their future fuel mix.  “We aim to be in front of the move to sustainability in shipping,” says Edvardsen. “This is the motivation behind our decision to invest in dual-fuel solutions for these newbuildings.”

Other Ideas

Besides LNG, hydrogen has been researched as a possible substitute for ship power. A European innovation project called Flagships will deploy the world’s first hydrogen powered commercial cargo transport vessel. The vessel will operate on compressed hydrogen produced from electrolysis, enabling not only zero-emission operations, but also creating a solid base for more local zero-emission transport, both at sea and on land. The power generation system for Zulu will be supplied by ABB Marine & Ports, with fuel cells from Ballard. LMG Marin is responsible for detail design drawings, with hydrogen provided by suppliers in the Paris region. Both the EU and the shipping industry see hydrogen as a key contributor in the efforts to mitigate climate change. The Flagships project was awarded EUR 5 million of funding in 2018 from the EU’s Research and Innovation program Horizon 2020, under the Fuel Cells and Hydrogen Joint Undertaking (FCH JU), to deploy two hydrogen vessels in France and Norway. The project’s initial plan was to deploy a hydrogen push-boat in the Lyon area, but as the broader potential for hydrogen in cargo transport emerged, the demo pusher was changed to an inland cargo vessel. The new vessel will be tasked with moving goods on pallets and in containers along the river Seine. 

Although not exactly a new idea, the use of wind power is again taken hold. One of the latest projects is dubbed Oceanbird –  a three-way project between Wallenius Marine, which initiated the project, the Swedish research institute SSPA and the Royal Institute of Technology in Stockholm. Oceanbird is a PCTC designed to transport up to 7,000 vehicles at an average speed of 10 knots on a North Atlantic crossing. The Oceanbird’s four colossal 80-meter (260-ft) high extendable wing sails could reduce emissions by as much as 90%.

The wing sails, built in metal and composites, can be retracted down to around 20 m (66 ft) when required, allowing them to be stowed during storms reducing the vessels air draft for moving through waters with bridges and other obstructions. Under the plan’s engines largely auxiliary for maneuvering in port and other situations.