Although sometimes overshadowed by other alternative fuels, successful operation on board ocean-going vessels is giving methanol greater credibility
The adoption of methanol as a meaningful part of the fuel spectrum has seen some significant progress over the past 12 months. Methanol-fuelled vessels and engine technologies are growing and, with each new piece of ground broken, methanol is gaining more credibility as a viable fuel option in commercial shipping.
One organisation that has never had any doubt this would be the case is Methanex. As its name implies, though, Methanex is more than a little biased, being the world’s largest producer and supplier of methanol.
April 2017 marked a year since Methanex’s wholly owned subsidiary, Waterfront Shipping, welcomed into its fleet seven of the world’s first ocean-going vessels capable of running on methanol.
These vessels have achieved accolades from the marine industry for their use of methanol as an alternative marine fuel. Over the past year, the seven 50,000 dwt methanol tankers – powered by two-stroke dual-fuel engines capable of running on methanol, fuel oil, marine diesel oil or gas oil – have been operating safely and reliably across the globe.
Jone Hognestad, former president of Waterfront Shipping, said: “Investing in methanol-based marine fuel is an important step in the right direction, and reinforces our commitment to sustainable proven technology that provides environmental benefits and meets emission regulations.”
Three of these vessels are operated by Mitsui OSK Lines (MOL). These were singled out for glory in the form of the ‘Technology Special Prize’ in the Ship of the Year 2016 awards sponsored by the Japan Society of Naval Architects and Ocean Engineers (JASNAOE).
The three MOL-operated carriers (Taranaki Sun, Manchac Sun, and Cajun Sun) received the accolade having been evaluated for their technological advancement as cutting-edge ‘eco ships.’ Every year, the Ship of the Year judges select the made-in-Japan vessels that represent the highest levels of technology, design, and social responsibility. The Technology Special Prize goes to the most technologically advanced, and only four vessels, including the series of three MOL methanol carriers selected this year, have ever received this prize.
To give some idea of the emission-reduction capabilities of these vessels, in April this year Marinvest celebrated two of its vessels together attaining over 3,000 hours running on clean-burning methanol, and estimated that the use of methanol rather than conventional marine fuel had prevented more than 80,000kg of SOx emissions.
MAN has been intimately involved in the development of these vessels, which are powered by its ME-LGI two-stroke, dual-fuel engine. The engine can run on methanol, fuel oil, marine diesel oil, or gas oil. It is based on the company's proven ME-series, with its approximately 5,000 engines in service, and works according to the diesel principle (methanol is a low-flashpoint, liquid fuel).
When operating on methanol, the ME-LGI uses HFO, MDO, or MGO as a pilot fuel (significantly reducing emissions of CO2, NOx and SOx) and eliminates methanol slip. Additionally, any operational switch between methanol and other fuels is seamless. Tests on the ME-LGI engine when running on methanol have recorded the same or a slightly better efficiency compared with conventional HFO-burning engines.
"MAN developed these two-stroke engines in response to interest from the shipping world to operate on alternatives to heavy fuel oil and meet increasingly stringent emissions regulations. To hedge the risk of fuel price volatility, the vessels can switch between fuels, and operate cost-effectively," said MAN Diesel & Turbo head of marketing and sales Ole Grøne.
MAN Diesel & Turbo sales and promotion manager René Sejer Laursen told Marine Propulsion: "Tests in blending water with methanol also show promising results in terms of meeting IMO’s NOx Tier III requirements. Such a new Tier III solution could become a game-changer. Tier III can be met with a mixture of 40 per cent water and 60 per cent methanol.” But he did concede that the long-term effect on liner and piston ring wear needs to be investigated, and that further tests are scheduled in the near future to determine if this could be a new way forward.
Key to the efficient operation of these engines and the vessels themselves are Alfa Laval’s FCM One Low-Flashpoint (LF) booster systems, which have now seen 4,500 hours of successful operation.
In late 2013 Alfa Laval was selected by MAN Diesel & Turbo to deliver Low-Flashpoint Supply Systems (LFSS) for the world’s first methanol-fuelled tankers. Since 2012, the two companies had been collaborating broadly on fuel conditioning for MAN Diesel & Turbo’s new two-stroke diesel engines with liquefied gas injection (LGI) technology. But when the the enginebuilder contracted to equip nine vessels with methanol-burning ME-LGI engines, methanol came quickly into focus.
“The effectiveness and market-readiness of our ME-LGI engine technology has been clearly demonstrated by the fleet," said MAN Diesel & Turbo customer director Kjeld Aabo. “Alfa Laval’s low-flashpoint booster technology has played a significant role in that success, and we look forward to further co-operation as the application develops,” he added.
In fact, new booster developments are already underway. MAN Diesel & Turbo is modifying the ME-LGI engine series to use LPG as an alternative fuel, and once again Alfa Laval is preparing the booster system. “Tests of the engine and booster are expected to be completed by the end of 2017,” said Alfa Laval business manager for fuel conditioning systems Roberto Comelli. “In the meantime, Alfa Laval is preparing to support MAN Diesel & Turbo when the first LPG-related orders come in,” he explained.
Methanol – The facts
- Methanol is a clear, colourless biodegradable fuel that can be produced from natural gas, coal, ‘biomass’ or even CO2
- Methanol as a ship fuel does not contain sulphur and is liquid in ambient air conditions, which makes it easy to store on board ships. So for ships operating in IMO emission control areas (ECAs), methanol could be a feasible solution to meet sulphur requirements
- When using methanol, the emission reductions are similar to the advantages obtained by using LNG, though the installation cost is only a fraction of that for LNG
- Methanol can be stored in normal non-pressurised tanks, and is easy to transport
- The 240m ferry Stena Germanica became the first ship in the world to run on methanol in early 2015