Pioneering spirit

from The Motorship November 2021

FBG tech for Aframaxes

WÄRTSILÄ EYES END-2023 FOR AMMONIA RETROFIT TRIAL

A partnership that extends back to 2003 with Eidesvik Off shore’s adoption of LNG is being extended again as the company embarks on a retrofi t project to test Wärtsilä’s ammonia engine technology

This project will be the fi rst of its kind in the world and is expected to be completed by the end of 2023. The specifi c vessel is yet to be chosen, there are several candidates for having their multiple 4-stroke dual fuel engines retrofi tted to run on 70/30 ammonia/LNG mix, but the engines involved will likely either be Wärtsilä 34 or 20 series engines.

The properties of ammonia are well-known, and a lot of work has been done by class societies regarding onboard safety, says Cato Esperø, Sales director Marine Solutions & Services, Wärtsilä Norway. “Safety is the most important aspect of the conversion,” he says, and he anticipates that DNV will provide class services. Onboard systems will be designed as zero-leakage, but safety features will include sensors for detecting ammonia as well as automatic shutdown valves in the supply system. It is still to be decided whether an existing cargo tank will be used to store the ammonia onboard; deck tanks are also an option.

The engine conversion will involve modification of the fuel injection system as well as control systems and the piping system to adjust for ammonia’s unique properties and energy density. Wärtsilä has already successfully laboratory tested an engine fuelled with a 70 percent liquid ammonia blend. In the retrofit project, the ammonia will enter the combustion chamber in gaseous form.

The ultimate goal is to achieve operation with 100 percent ammonia with a minimum diesel ignition fuel requirement. On-going laboratory testing involving gaseous ammonia will examine engine performance and emissions at different loads and with different proportions of ammonia and LNG. To date, testing has shown that NOx emissions are about half of that of diesel when burning a 70/30 ammonia/MDO mix This means that the chosen vessel’s existing selective catalytic reduction system will continue to be used. Esperø notes that ammonia itself is capable of cleaning exhaust emissions, just like the urea is currently used with diesel fuel. The engine will be optimized for low N2O emissions, current measurements indicate around 7 ppm N2O in the exhaust .

Eidesvik has a strong track record in supporting sustainable innovations, having used LNG fuel in its fleet from as early as 2003 and fuel cells from 2006. “It was not Apollo 1 that landed on the moon, it was Apollo 11,” says CEO Jan Fredrik Meling of the company’s track record in supporting sustainable innovations.

Wärtsilä and Eidesvik are also partners in the EU-funded ShipFC project to equip a platform supply vessel, the Viking Energy, with a 2MW fuel cell running on green ammonia. The installation is scheduled to take place in late 2023. Viking Energy will then become the world’s first supply vessel to sail long distances without greenhouse gas emissions. Testing will take place while the vessel is on contract for Equinor.

It is anticipated that 60-70% of the vessel’s energy consumption will come from ammonia, but the partners want to demonstrate that the technology can supply up to 90% of the total power demand. The remaining energy consumption on board will be powered by LNG, which has been Viking Energy’s main fuel since delivery in 2003. In 2016, the vessel became the world’s first hybrid supply vessel with the installation of a battery system.

The engine retrofit and fuel cell projects tie in with one of the ongoing work streams of the Wärtsilä-led Zero Emissions Energy Distribution at Sea (ZEEDS) project, aimed at developing ammonia-powered newbuilds and converting suitable existing vessels. The concept involves offshore fuel production and distribution hubs set up next to offshore wind turbines. Renewable energy would be used to produce hydrogen from water, and clean fuels would then be made from hydrogen and nitrogen extracted from the air. Ammonia would be stored in seabed tanks using water pressure to keep the fuel liquid. It would then be brought to the surface at bunkering buoys that would take one hour to provide ships with enough fuel for 11 days of operation.

Although initially modelled for the North Sea and Baltics, where some of the busiest shipping corridors are located and the development of renewables is already highly advanced, the same concept could be adapted for deepsea, long-haul shipping.

In another related development, Wärtsilä signed a joint development program with Korean shipbuilder Samsung Heavy Industries for ammonia-fuelled newbuildings with 4-stroke auxiliary engines in September. The most likely initial newbuild targets will be container vessels and very large crude carriers, operating with 2-stroke main engines and 4-stroke Wärtsilä auxiliary engines.

8 Wärtsilä and