LNG: a pragmatic path to decarbonisation

Shipping needs to reduce its greenhouse (GHG) gas emissions by 40% per vessel by 2030 and 50% for the entire fleet by 2050 to meet IMO targets.

As the former executive vice president at US-flag shipping company Tote, Inc, Mr Keller spearheaded the use of LNG as a fuel in the company’s two 3,100-TEU container ships that have been operating in the Jones Act trade and the North American Emissions Control Area for four years. Tote’s pioneering efforts in the Puerto Rico trade with those Marlin class ships, Isla Bella and Perla del Caribe, set the stage for LNG-powered mammoths like CMA CGM Jacques Saade.

Mr Keller’s current organisation, SEA/LNG, is focused on advancing the use of LNG as a fuel in shipping through education, research and analysis as a means of meeting the industry’s environmental and sustainability goals.

While he does not see LNG as the silver bullet solution for everyone, Mr Keller does think it presents a viable path forward towards decarbonisation for the deep-sea fleet.

“It’s one thing to put batteries in a ferry or a small hydrogen fuel cell in a pilot boat, but it’s another thing to use those technologies in deep-sea vessels,” he said. But Mr Keller does not want to see a policy that is prescriptive: “We would not want to see policy that LNG is the only pathway because that’s just not the case. Is it a dominant pathway today? Yes, we believe so.”

Much of that belief stems from the transition from fossil LNG to ‘drop in’ fuels, such as liquefied biogas (LBG) – also known as biomethane and bioLNG – backed by DNV GL’s Energy Transition Outlook 2020.

In discussing the study, DNV GL Maritime chief executive Knut Ørbeck-Nilssen said: “Gas is the best choice for one or two vessel generations.”

One of the key takeaways from DNV GL’s Maritime Forecast 2050, Energy Transition Outlook 2020 is that installing a dual-fuel LNG engine and fuel system “is consistently the most robust choice” for preparing shipping for a decarbonised future.

By starting with a dual-fuel engine and fuelling system, shipowners have the possibility of transitioning to ‘drop-in’ lower carbon intensity future fuels. The study says that “picking the wrong solution can lead to significant competitive disadvantage. Planning for fuel flexibility could ease the transition and minimise the risk of investing in stranded assets.”

Wärtsilä general manager sales and strategy development, fuel gas supply systems, marine power, Frank Harteveld is also an advocate of the ‘stepping stone’ approach. “You can meet IMO targets by starting to blend LBG now, then increasing the blend and run on pure bio by 2050 without any changes to your combustion engine,” he said. “That is the big advantage of using LNG as a base fuel, offering the shipowner a comfortable feeling of investing in existing and mature technology to meet their future emission targets,” added Mr Harteveld.

Switching to LBG

Gasum, a leading supplier of LNG to the Nordics and Northern Europe, offers LBG as part of its portfolio. “‘Availability’ is one of the three questions that shipowners always ask about LBG,” said Gasum LNG maritime sales director Jacob Granqvist. “The others are: “Is it technically feasible? And, Is it affordable?”,” he said.

Mr Granqvist says Gasum is delivering LBG to some shipowners on a regular basis and pilot testing with others.

“It’s not a fairy tale,” stressed Mr Granqvist. “This is happening right now.” Thus far, there have been no technical difficulties at all, he noted.

Mr Granqvist is also confident that there is ample supply. He feels that shipowners will not go to a 100% blend right away, but start blending in smaller amounts: “There is enough renewable gas for the shipping community if they would like to have it.”

Pricing, too, is commercially viable, with a 10% blend of LBG with LNG on par with 0.10% marine gasoil (MGO), added Mr Granqvist.

Where does it come from?

All biogases are not created equal; much depends on the feedstock for the biogas.

The International Council on Clean Transport (ICCT) explains that feedstock used to produce a gas typically determines the cradle-to-grave greenhouse gas (GHG) emissions of the gas.

For example, biomethane can have a very different climate impact depending on its feedstock. Biomethane made from waste feedstocks, such as dairy manure, can have negative lifecycle GHG emissions because converting this feedstock into biomethane avoids high emissions of methane to the atmosphere that would normally occur during natural decomposition at farms.

Most of Gasum’s LBG is produced from manure. Adopting a circular economy approach – turning waste into high-value renewable energy and fertilisers – Gasum works with local dairy farms, producing LBG from their waste products to supply the facilities with energy. Any byproducts from production of the LBG are used to supply the fertiliser industry.

“By using manure as feedstock for your biogas/natural gas blend, even with low blend ratios, you can achieve significant reductions in CO₂ emissions,” pointed out Mr Harteveld.

Mr Granqvist said Gasum is trying to promote these “huge emission gains” to freight owners and charterers through various supply offerings. One, which he describes as ‘plain vanilla’, is LBG flex; this allows an owner to choose from zero to 100% blend of LBG on any vessel that runs on LNG. Transport and bunkering of the fuel can be performed either via tanker truck or bunker barge.

One of the “much more interesting options,” Mr Granqvist said, is ‘LBG on demand’, which allows the shipper to allocate liquefied biogas to any specific cargo. “This means an owner can decarbonise 150 containers or 1,000 passengers on a cruise vessel. Customers can go into the booking system and click the ‘green button’ instead of the ‘blue button.’ This allows the shipowner to transfer the premium of the LBG to a specific cargo.”

Mr Granqvist says auto manufacturers that produce electrical vehicles using renewable energy, for example, might be able to decarbonise the transport of those vehicles to their customers by using one of the LBG plans, closing a CO₂ emissions gap in their supply chains.

Fuel-cell project and LNG

Wärtsilä has been one of the forerunners in the development of LNG as a fuel in shipping. It is now conducting research into the use of future carbon-neutral fuels in marine engines and is active in investigating alternative means to eliminate emissions, including the use of fuel cells.

“Picking the wrong solution can lead to a significant competitive disadvantage”

As marine propulsion lead, Wärtsilä is working with partners ship operator Odfjell, fuel-cell technology company Prototech and independent oil company Lundin in a Norwegian project to develop fuel-cell technology for oceangoing vessels.

Preliminary results from testing indicate that CO₂ reductions of as much as 45% are possible when using LNG as fuel, and emissions can potentially be reduced even further with other fuels, such as ammonia.

“We see the combustion engine remaining as the stalwart of shipping, because it has the flexibility to operate on future renewable fuels as and when they become compliant, market-ready and available,” said Wärtsilä Marine Power technology manager Ingve Sørfonn.

The project’s fuel-cell technology is first being tested with a 1.2 MW prototype at the Sustainable Energy Catapult Centre in Stord, Norway. The prototype will be installed onboard an Odjfell chemical tanker for sea trials.

Other owners are also using LBG to cut their emissions. Gasum is supplying a 10% LBG blend for two LNG-fuelled tankers chartered by Swedish oil company Preem, while ferry operator Destination Gotland is using an LBG blend in two of its high-speed, ropax ferries. The ferries’ Wärtsilä 50DF dual-fuel main engines and Wärtsilä 20DF auxiliary engines could eventually run on 100% LBG.

By using 100% renewable LBG, the GHG emissions can be reduced by up to 85% compared to fossil fuels.

Concluded Mr Granqvist: “We are seeing a transition in industry. Just to invest in LNG isn’t good enough. You need to have a path forward and future proof that asset you are going to have operating for 20 to 30 years.”

It is a view that finds favour with Mr Keller also: “It does not make sense to wait decades for the ultimate solution when we currently have a safe, available, competitive fuel that does a number of very, very important things, and has a clear pathway forward using new technologies with bio and synthetic LNG. And it’s future proof. So investment decisions that we make today are relevant decades from now; waiting just exacerbates the problem.”