Containership cuts GHG emissions by using synthetic natural gas

ElbBLUE bunkered some 20 tons of green SNG (synthetic natural gas) at the Elbe port in Brunsbüttel, Germany

By operating on a blend of synthetic natural gas (SNG) and LNG, the 1,036-TEU containership, ElbBLUE has reduced its greenhouse gas (GHG) emissions by 27% compared to using LNG alone. Compared with heavy fuel oil (HFO), the reduction in GHG emissions was as high as 34%.

MAN Energy Solutions reports that this data has emerged from measurements initially carried out on board the ship in September 2021 when the ElbBLUE— the former Wes Amelie — became the first containership worldwide to replace a portion of its bunkered gas fuel (around 50%) with SNG.

“With this project, we have proven the technical viability of our concept of the maritime energy transition,” said Dr Uwe Lauber, CEO of MAN Energy Solutions. “Today, more than ever, we are convinced that climate-neutral, synthetic fuels point the way to green shipping – and even further beyond.”

UKRAINE SITUATION CHANGES SNG PRICE EQUATION

“The current, global, political situation underscores the future role that synthetic fuels can play in a diversified energy supply in that they point the way toward less dependence on raw material deposits, suppliers and price fluctuations.” noted Lauber. “As a result of the military attack on Ukraine in violation of international law, LNG prices, for example, have risen massively in recent weeks and are now at a similar level to synthetic natural gas. If production capacity can be built up quickly and synthetic fuels made available to the market, SNG could become a climate-friendly and – in the long term – economical alternative to fossil fuels in shipping.”

PURE SNG TO CUT GHG BY 80%

“With this pilot project, we have proven that any LNG-powered ship can also operate with green SNG from power-to-X,” said Stefan Eefting, senior vice president and head of MAN PrimeServ Augsburg. “Even with a blend of just 50% SNG, GHG and pollutant emissions are significantly reduced. When operated exclusively on SNG, we would expect a reduction of at least 80% in GHG emissions for modern ships.”

Gas operation also drastically reduces other polluting emissions compared to HFO. In the case of the ElbBLUE, nitrogen oxide emissions (NOx) dropped by almost 87%, while emissions of sulfur oxides (SOx) and particulates were almost completely eliminated (~99%). These values were achieved in both the exclusive operation on LNG and on a blend of LNG and SNG.

Measurements were carried out on a voyage between Brunsbüttel, Germany and Rotterdam, the Netherlands with synthetic natural gas comprising approximately 50% of the bunkered gas at 85% engine load. The ElbBLUE is powered by an MAN 51/60DF four-stroke engine. As a multi-fuel engine, the unit allows operation with either HFO or liquid natural gas (LNG) as fuel. The ship’s test-run proved that the latter can be replaced by SNG without engine modification.

PIONEER

Owned by German shipping company, Elbdeich, and operated by charterer, Unifeeder, the 1,036-TEU container ship, ElbBLUE, sails the North and Baltic Seas. It made headlines back in 2017 under its former name, Wes Amelie, when its MAN 8L48/60B main engine was converted to the current MAN 8L51/60DF four-stroke unit, which enables dual-fuel operation with gas. This was the world’s first conversion of a containership to multi-fuel operation with LNG.

In September 2021, the ship reached another milestone on the road to climate-neutral shipping when, in the Elbe port of Brunsbüttel, it became the world’s first containership to bunker climate-neutral synthetic marine fuel – some 20 tons. The liquefied SNG was produced in a power-to-gas plant operated by kiwi AG in Werlte, Germany and generated from 100% renewable energy.

FURTHER REDUCTIONS IN METHANE SLIP

Synthetic natural gas is considered a carbon-neutral fuel as its combustion releases only as much CO2 as captured during its production using power-to-X technology. However, just like LNG, SNG consists largely of methane (CH4) and, during operation, small unburned quantities of the gas can escape – so-called methane slip. Methane is considered a greenhouse gas that, when released unburned into the atmosphere, is 28 times more harmful to the climate than CO2. MAN already offers solutions for methane-slip-free operation in two-stroke engines. For four-stroke engines, the company is working on various solutions to further reduce the escape of methane from the combustion chamber.

“We have already been able to halve methane slip in our dual-fuel, four-stroke engines in recent years through internal engine measures, and we see further potential in the area of exhaust gas after-treatment,” says Eefting. “We are currently developing special oxidation catalysts with which we have been able to reduce methane slip by a further 70% in laboratory tests. Next year, we will test the catalyst on board a ship for the first time and expect to have a market-ready technology by 2025.”