The shipping industry is charting a new route toward cutting fossil fuel use in ocean-going vessels: ammonia.
To date, no ammonia-fueled ships have been built, but that’s not stopping companies including Equinor, Man Energy Solutions and Wärtsilä from rushing to help bring ammonia-fueled ships to market.
Moves to adapt engines and ship designs to ammonia fuel are driven by a 2018 International Maritime Organization (IMO) commitment to cut international shipping’s annual greenhouse gas emissions by at least 50 percent by 2050, compared to 2008 levels.
“Making the target a reality means getting commercially viable deep-sea zero-emission vessels into operation by 2030,” said Katharine Palmer, global head of sustainability at Lloyd’s Register, the maritime classification society.Top Articles
“Fully decarbonizing the shipping sector presents a significant challenge,” Palmer added. “It has the potential to be among the most disruptive transitions that shipping has had to deal with but also to provide significant opportunity for the sector.”
Moving away from fossil fuels in shipping will require different approaches according to the type of vessel involved, experts say. Commuter ferries such as those in operation in Washington state are already moving toward battery power.
Elsewhere, compressed or liquefied green hydrogen could be an option for ships that are able to refuel regularly. But for vessels that spend days or weeks at sea, such as tankers, super trawlers or cargo ships, the size of the fuel tanks needed for hydrogen would be prohibitive.
Another possibility is for the industry to rely on synthetic diesel or other carbon fuels produced using renewable energy. In this instance, though, the problem is cost.
Synthetic diesel would cost approximately twice as much as green hydrogen in terms of energy on a megajoule-per-megajoule basis, said Niels de Vries, lead naval architect at C-Job Naval Architects of the Netherlands.