Ammonia at the Quay: Port-Based Marine Fuel Production from Seawater and Air

Shipping burns about 300 mln t of fuel a year, and every proposal to decarbonize it meets the same obstacle: green fuels cost 2–4 times more than the marine fuel they replace. Ammonia produced by electrolysis and conventional synthesis costs USD 600–1,000 per tonne, and ammonia from natural gas costs USD 300–600 per tonne and carries the carbon and the gas dependence with it. This preprint describes a different supply model: ammonia made at the quay, from seawater and air, by ARBOK-Lacmus. The unit releases hydrogen from seawater at low pressure without ultrapure water, takes nitrogen from air, and combines the two into ammonia without the 150–300 bar and 400–500 °C of the conventional process. The stated production cost is USD 120–180 per tonne. One tonne of marine fuel carries the energy of about 2.3 t of ammonia, so the energy of a tonne of marine fuel costs USD 280–410 at production cost against about USD 700 for the fuel itself, a reduction of roughly twofold before delivery, taxes, duties and port fees are counted. Modules of 1–10 t/day and clusters of 50–200 t/day fit a container or a skid on the quay, and the ship is fuelled by hose alongside with no bunker delivery. Heat from the process and from ship exhaust is converted to electricity by TERU and TELORISE. The engine is the next stage of the programme; this paper describes the fuel.