The ME-LGI Engine and Methanol as a Marine Fuel
With the growing demand for cleaner marine fuel to meet environmental regulations, methanol is a promising alternative fuel for ships that can meet the industry’s increasingly stringent emissions regulations. Methanol is a biodegradable, clean-burning marine fuel that significantly reduces smog-causing emissions such as particulates, sulphur oxides and nitrogen oxides.
MAN Diesel & Turbo has developed the ME-LGI dual-fuel engine for operation on methanol, heavy fuel oil (HFO), marine diesel oil (MDO), or marine gas oil (MGO). The engine is based on the company’s proven ME-series, with its approximately 5,000 engines in service, and works according to the Diesel principle as methanol is a low-flashpoint, liquid fuel. When operating on methanol, the ME-LGI uses HFO, MDO, or MGO as a pilot fuel, significantly reduces emissions of CO2, NOx and SOx, and eliminates methanol slip.
The methanol booster injector with cooling oil (blue) and sealing oil (red) supply fully integrated
Cylinder cover equipped with fuel booster injectors and an LGI control block. All fuel pressure pipes are double-walled
The ‘Taranaki Sun’, one of seven chemical and oil-product tankers, powered by MAN B&W ME-LGI dual-fuel engines and running on methanol, launched by Waterfront Shipping during 2016
The MAN B&W ME-LGI engine aboard the ‘Mari Jone’, one of the seven tankers Waterfront Shipping took delivery of in 2016
Furthermore, any operational switch between methanol and other fuels is seamless. Tests on the two-stroke MAN B&W ME-LGI engine, when running on methanol, have recorded the same or a slightly better efficiency compared to conventional HFO-burning engines.
Fuel injection is accomplished by a Booster Fuel Injection Valve (BFIV), using 300 bar hydraulic power to raise the fuel pressure to injection pressure. The BFIV is an integration of our fuel oil booster design and our old slide injector design, which have been used for more than 10 years, now operating on more than 1,000 engines.
Both designs are well-proven, and the combined solution has the advantage that it minimises the total weight and removes the HP pipes in-between. By using this design, the total inertia increases the response time of the valve, and tests in service have demonstrated better controlled injection profiles.
Methanol has a flash point of 11°C, which is not Safety of Life at Sea (SOLAS) compliant. However, since the ME-LGI employs a double-wall design for all methanol components, and all leakages are monitored and collected in the double barrier, there are no problems related to this. Indeed, it is far easier to handle methanol than LNG.
To be able to use methanol fuel on the ME-LGI, the cylinder covers are equipped with fuel booster injector valves designed specifically for methanol operation. For a 50-bore engine, this means that each cylinder cover is equipped with two additional methanol booster injectors. A liquid gas injection (LGI) block is also fitted on the cylinder cover.
Methanol - key points
- Methanol is a safe, cost-effective, innovative marine fuel of today and the future.
- With the growing demand for cleaner marine fuel, methanol is a promising alternative fuel for ships that meet the industry’s increasingly stringent emissions regulations. Methanol significantly reduces emissions of sulphur oxides (SOx), nitrogen oxides (NOx) and particulate matter.
- In 2016, Waterfront Shipping Company Ltd., Mitsui O.S.K. Lines, Ltd., Marinvest/Skagerack Invest, and Westfal-Larsen Management are welcoming the world’s first seven new innovative, clean-burning, fuel-efficient, ocean-going vessels to the sea.
- Adopting dual-fuel engine technology enables shippers to operate cost-effectively and diversify fuel options regardless of market conditions. Methanol has been cost-competitive with other low-sulphur marine fuels and remains competitive in many key shipping regions.
The cost to modify storage and fuelling infrastructure to handle methanol is low. As a liquid fuel, only minor modifications are needed for current fueling infrastructure to handle methanol.
The cost to build new and convert existing vessels to run on methanol is significantly less than alternate fuel conversions.
As one of the top five chemical commodities shipped around the world each year, methanol is available around the world through existing global infrastructure