Extended Operational and Trade Vocabulary

Methanol, Ammonia and Alternative Marine Fuels glossary

The alternative-fuel vocabulary: the methanol dual-fuel newbuildings (the Maersk A-class), ammonia properties (lower heating value 18.6 MJ/kg) as a zero-carbon fuel, algal and other biofuel pathways, and the production-pathway and bunkering-safety terms. Grounds each term in the fuel chemistry or the named dual-fuel vessel it belongs to.

168 defined terms.

A

Aleksandra Maersk: 16,200 TEU methanol dual-fuel container ship in the A.P. Moller-Maersk A-class series built by Hyundai Heavy Industries for delivery from 2025.
Alexandra Maersk: 16,200 TEU methanol dual-fuel container ship in the Maersk A-class series built by Hyundai Heavy Industries from 2025.
Algal Biofuel: Marine biofuel pathway derived from cultivated microalgae lipids that remains at demonstration scale rather than commercial bunkering.
Ammonia (NH3): Carbon-free fuel candidate; combustion produces no CO2 but raises NOx and N2O concerns and requires SCR aftertreatment.
Ammonia Auto-Ignition Temperature: Approximately 651 degrees Celsius for NH3, well above diesel and methanol, which is why ammonia engines require a pilot fuel for reliable ignition.
Ammonia Bunker Barge (Hanwha Ocean): Ammonia bunker vessel program announced by Hanwha Ocean of South Korea for delivery from 2025 to support early ammonia bunkering operations.
Ammonia bunkering: Ship-to-ship or shore-to-ship transfer of liquid ammonia at approximately minus 33 C atmospheric pressure or semi-refrigerated.
Ammonia Carrier: Liquefied gas tanker designed to transport NH3 cargo, increasingly studied as a platform for ammonia-fueled propulsion since the cargo and fuel are identical.
Ammonia cracker: Onboard unit decomposing NH3 to H2 + N2 for fuel cell feed.
Ammonia Density: 681 kg/m3 as liquid at typical storage conditions, lower than HFO and methanol, increasing required tank volume per unit of energy.
Ammonia Flame Speed: Around 0.07 m/s in air, much slower than methane, which drives the use of pilot fuel and combustion chamber redesign in marine ammonia engines.
Ammonia IDLH: The Immediately Dangerous to Life or Health value of 300 ppm for ammonia under NIOSH guidance, with an occupational exposure limit of 25 ppm.
Ammonia LHV: Lower heating value of 18.6 MJ/kg for NH3, roughly 47 percent of HFO on a mass basis.
Ammonia Pilot Fuel: Small fraction of diesel, MGO, or alternative fuel injected to ignite the main ammonia charge in dual-fuel marine engines.
Ammonia Pioneer (MV): Mitsubishi and MOL ammonia-fueled demonstrator vessel project targeted for 2026 service.
Ammonia Storage Pressure: Approximately 8 to 10 bar at ambient temperature, or atmospheric pressure when refrigerated to about minus 33 degrees Celsius.
Ammonia Toxicity: Acute inhalation hazard with strong pungent odor at low ppm levels and life-threatening exposure above 300 ppm.
Ane Maersk: First A-class 16,200 TEU methanol dual-fuel container ship delivered to A.P. Moller-Maersk by Hyundai Heavy Industries in 2024.
Antonia Maersk: 16,200 TEU methanol dual-fuel container ship in the Maersk A-class series delivered from Hyundai Heavy Industries from 2025.
Astrid Maersk: 16,200 TEU methanol dual-fuel container ship delivered to A.P. Moller-Maersk by Hyundai Heavy Industries in 2024.
Australian Ammonia Bunker Pilot: Joint industry studies at the Port of Newcastle and Pilbara Port Authority in Western Australia evaluating ammonia ship-to-ship bunkering procedures.
Auto Ignition Temperature: Minimum temperature at which a substance ignites without external flame.

B

B100: Marine biofuel grade composed of 100 percent FAME or HVO, used in trials and select coastal services.
B24: Bunker blend of approximately 24 percent biofuel with VLSFO base, commonly sold as VLSFO-B24 in Singapore and Rotterdam.
B30: Blend of about 30 percent biofuel with conventional MGO or VLSFO used in commercial marine bunkering.
B50: 50 percent biofuel blend with petroleum bunker fuel, used in select trials and ferry routes.
Bio-MGO: Biofuel blend with marine gas oil base meeting ISO 8217:2024 grade DMA or DMB with renewable content.
Biodiesel (Marine): FAME-based renewable diesel substitute blended with petroleum bunker fuels to reduce lifecycle greenhouse gas intensity.
Biofuel: Liquid or gaseous fuel from biomass; covered by ISCC EU or RED II certification for FuelEU.
Biofuel Bunker Delivery (CMA CGM 2019): First commercial biofuel bunker delivery to a CMA CGM container ship in 2019, scaled up from 2022 onward.
Biofuel Bunker Volume Singapore 2023: 460,000 metric tons of marine biofuel bunkered at the Port of Singapore in 2023 as reported by MPA Singapore.
bp Marine Biofuel: BP's marine biofuel supply offering integrating FAME and HVO blends with conventional bunker fuels.
BTL: Biomass-to-Liquid fuel produced via gasification of biomass followed by Fischer-Tropsch synthesis, yielding a synthetic diesel suitable for marine use.
Bunker Delivery Note (Alternative Fuels): Required document under MARPOL Annex VI specifying fuel grade, sulfur content, and biofuel blend ratio for marine bunker deliveries.

C

CCS-Ready Methanol: Methanol produced from natural gas with capture of process CO2, yielding lower lifecycle greenhouse gas intensity than conventional methanol.
CH3OH: Chemical formula for methanol, the simplest alcohol used as a marine fuel under the IGF Code low-flashpoint regime.
CII: Carbon Intensity Indicator: the annual operational efficiency rating (A to E) of a ship of 5,000 GT and above under MARPOL Annex VI Reg.28, read with MEPC.336(76).
CMA CGM Biofuel Bunkers: Container line program initiating marine biofuel bunkering from 2019 with scaled-up volumes from 2022.
CMA CGM Methanol Container Ships: Series of 9,000 TEU and 13,000 TEU methanol dual-fuel container ships ordered by CMA CGM.
CMB.TECH: Belgian shipowner subsidiary of Compagnie Maritime Belge developing hydrogen-powered vessels including the Hydrocat 48 CTV.
Cryogenic Storage: Tank system that maintains a liquefied gas such as LH2 or NH3 at low temperature and near-atmospheric pressure for fuel use onboard.

D

Damen HydroCat 48: 2022 hydrogen dual-fuel crew transfer vessel built by Damen with CMB.TECH technology for Windcat Workboats.
DME: Dimethyl ether, a candidate marine fuel with handling similar to LPG, less commercialized than methanol or ammonia for shipping.
Drop-In Biofuel: Renewable fuel chemically compatible with conventional marine diesel engines and bunker infrastructure without modification, typified by HVO.
Dual-fuel engine: Engine running on both liquid and gaseous fuels (e.g., WinGD X-DF).

E

EEDI: Energy Efficiency Design Index, MARPOL Annex VI Chapter 4.
EEDI Phase IV: Strengthened EEDI reduction factors applying to certain ship types and sizes contracted from 2025 onward.
EEXI: Energy Efficiency Existing Ship Index, MARPOL Annex VI Chapter 4.
Energy Density (Volumetric): Energy per unit volume of fuel, a key driver of tank sizing for alternative marine fuels with lower density than HFO.
Energy Observer: 30 meter catamaran demonstrator operating since 2017 on 100 percent renewable hydrogen, solar, and wind.
EPS (Eastern Pacific Shipping): Singapore-based shipping company among the first ammonia dual-fuel engine order customers via MAN and WinGD.
Equatorial Marine Fuel: Singapore-based bunker supplier active in biofuel and methanol marine bunkering.

F

FAME: See Biodiesel.
Fischer-Tropsch: Catalytic process that synthesizes liquid hydrocarbons from syngas, forming the basis of BTL marine biofuels.
Flash point: Lowest temperature at which fuel vapor ignites with a pilot flame; minimum 60 C for SOLAS marine fuels (Pensky-Martens closed cup, ISO 2719).
Fuel Cell (Marine): Electrochemical device converting hydrogen or reformed fuels directly to electricity for shipboard propulsion or auxiliary power.
FuelEU Compliance Balance: Annual surplus or deficit of greenhouse gas intensity performance against the FuelEU Maritime trajectory for each ship.
FuelEU Maritime: European Union regulation imposing greenhouse gas intensity limits on shipping fuels, driving development of pooling mechanisms and compliance instruments.
FuelEU Pooling: Mechanism by which operators combine compliance balances across vessels to satisfy FuelEU greenhouse gas intensity targets.
FuelEU Trajectory: Reduction schedule of 2 percent from 2025, 6 percent from 2030, 14.5 percent from 2035, 31 percent from 2040, 62 percent from 2045, and 80 percent from 2050 versus the 2020 baseline.

G

Goodfuels: Netherlands-based marine biofuel supplier active since 2015 and one of the largest dedicated bunker biofuel providers.
Green Ammonia: Ammonia produced from renewable hydrogen via the Haber-Bosch process.
Green Hydrogen: Hydrogen produced via electrolysis using renewable electricity.
Green Methanol: Methanol produced from renewable feedstocks.

H

H2: Chemical formula for hydrogen, an alternative marine fuel with the highest LHV per mass of 120 MJ/kg.
Hanwha Ocean Ammonia Bunker Vessel: Korean ammonia bunker barge program announced for delivery from 2025.
HiMSEN H22/32 Methanol: Hyundai Heavy Industries medium-speed methanol-fueled engine variant in the HiMSEN H22/32 series.
HMM Methanol Containerships: 9,000 TEU methanol dual-fuel container ship orders by Korean line HMM.
HVO: Hydrotreated vegetable oil, a drop-in renewable diesel used in inland vessel engines.
Hydrocat 48: Dual-fuel hydrogen-powered crew transfer vessel introduced by Windcat and CMB.TECH for low-emission offshore wind service.
Hydrogen: Lightest chemical element used as a marine fuel either as liquid LH2 at minus 253 degrees Celsius or as compressed gas at 700 bar.
Hydrogen Auto-Ignition Temperature: About 500 degrees Celsius for H2, with wide flammability limits in air requiring careful gas detection.
Hydrogen Fuel Cell: Electrochemical device producing electricity from hydrogen.
Hydroville: 14 meter hydrogen dual-fuel crew shuttle launched by CMB.TECH in 2017 in Antwerp.
HySeas III: Hydrogen PEM fuel cell ferry development project for Kirkwall to Aberdeen service designed for around 1,000 passengers in hybrid hydrogen configuration.

I

IDEMITSU: Japanese energy company involved in the Pioneer methanol tanker project for Mitsui Chemicals in 2019.
IDLH: Immediately Dangerous to Life or Health exposure level used to characterize acute toxicity of alternative fuels such as ammonia at 300 ppm.
IGF Code: International Code of Safety for Ships Using Gases or Other Low-Flashpoint Fuels.
IMO MEPC 311(73): MEPC resolution of 2018 addressing biofuel reporting under the IMO Data Collection System.
IRPC: Thailand's IRPC Public Company Limited, a member of the Methanol Institute.
ISCC: International Sustainability and Carbon Certification scheme used to certify sustainable biofuels for marine and other transport applications.
ISO 1644:2024: International specification for methanol used as a marine fuel.
ISO 8217:2024: Specification of petroleum products for fuels for marine diesel engines, including grades incorporating biofuel content.

K

Kawasaki Heavy Industries Suiso Frontier: World's first liquid hydrogen carrier delivered by Kawasaki Heavy Industries in 2019.
KPI OceanConnect: Marine fuel broker active in methanol and biofuel bunker transactions.

L

LH2: Liquid hydrogen at approximately minus 253 degrees Celsius and 71 kg/m3 used as cryogenic marine fuel.
LHV: Lower Heating Value, the net energy released per unit mass of fuel after subtracting the latent heat of water vapor in combustion products.
Lindanger: One of the early Waterfront Shipping methanol-fueled product tankers entering service from 2016 with MAN B&W ME-LGIM main engines.
Liquid Gas Injection Ammonia (LGIA): MAN Energy Solutions designation for the ME-LGIA two-stroke ammonia dual-fuel engine series.
Liquid Gas Injection Methanol (LGIM): MAN Energy Solutions designation for the ME-LGIM two-stroke methanol dual-fuel engine series.
Low-Flashpoint Fuel: Regulated through MARPOL/IGF interface.

M

Maersk Halifax: Methanol dual-fuel container ship in the Maersk H-class series of 16,000-plus TEU vessels.
Maersk Hartford: Methanol dual-fuel container ship in the Maersk H-class large container series.
Maersk Helsingor: Methanol dual-fuel container ship in the Maersk H-class large container series.
Maersk Holesovice: Methanol dual-fuel container ship in the Maersk H-class large container series.
Maersk Houston: Methanol dual-fuel container ship in the Maersk H-class large container series.
MAN 51/60DF Methanol: Methanol-capable variant of the MAN four-stroke 51/60DF dual-fuel engine for marine and stationary use.
MAN B&W ME-LGIA: Two-stroke dual-fuel ammonia main engine family under development by MAN Energy Solutions.
MAN B&W ME-LGIM: Two-stroke dual-fuel methanol main engine family from MAN Energy Solutions covering bores including 50, 60, 70, 80, and 90 centimeters.
Mari Boyle: Methanol dual-fuel product tanker in the Waterfront Shipping fleet powered by a MAN B&W 6G50ME-LGIM engine.
Mari Couva: Methanol dual-fuel product tanker in the Waterfront Shipping fleet.
Mari Jone: Methanol dual-fuel product tanker in the Waterfront Shipping fleet.
Mari Tellus: 50,000 dwt methanol bunker and product tanker associated with Methanex Marine of Vancouver.
Marinor: Methanol dual-fuel product tanker in the Waterfront Shipping series.
MEPC 80: 80th session of the Marine Environment Protection Committee, adopting the 2023 GHG Strategy.
MEPC.339(76): IMO resolution adopting the CII rating framework for ships of 5,000 GT and above.
Methanex: Vancouver-based methanol producer and a founding member of the Methanol Institute, owner of methanol-fueled tonnage through Waterfront Shipping.
Methanex Marine: Marine arm associated with Methanex coordinating methanol-fueled tanker operations and bunker initiatives.
Methanol: IBC Category Y; flammable; common chemical tanker cargo.
Methanol Auto-Ignition Temperature: Approximately 470 degrees Celsius for methanol.
Methanol Bunker Vessel: Dedicated ship configured for ship-to-ship transfer of methanol as marine fuel, such as the Mari Tellus.
Methanol Density: 791 kg/m3 at typical storage conditions, about half the density of HFO at 1,000 kg/m3.
Methanol Flash Point: 11 degrees Celsius, classifying methanol as a low-flashpoint fuel under the IGF Code.
Methanol Institute: Industry body publishing safe handling and bunkering guidance for methanol.
Methanol LHV: Lower heating value of 19.9 MJ/kg for methanol, roughly half that of HFO.
Methanol Tank Requirement: Approximately twice the volume of HFO is required to store an equivalent amount of energy as methanol.
Methanol Toxicity: Toxic to humans by ingestion, inhalation, and skin absorption, but biodegradable in the marine environment.
MF Hydra: Norled hydrogen PEM fuel cell ferry operating in Norway from 2023 as the first commercial hydrogen-fueled ferry.
MGO: Marine gas oil, distillate fuel per ISO 8217 DMA.
Mitsubishi: Member of the Methanol Institute and partner in MV Ammonia Pioneer and other ammonia and methanol marine projects.
MOL: Mitsui O.S.K. Lines, now part of Ocean Network Express.
MPA Singapore: Maritime and Port Authority of Singapore, the regulator licensing bunker suppliers and bunker craft operators in the Port of Singapore.

N

N2O: Nitrous oxide, an ozone-depleting greenhouse gas with global warming potential exceeding 200 times that of CO2 over 100 years per IPCC AR6, a concern in ammonia combustion.
NH3: Chemical formula for ammonia used as a zero-carbon marine fuel.
Norled MF Hydra: World's first commercial hydrogen-fueled passenger ferry, operating in Norway from 2023.
NOx: Oxides of nitrogen, regulated under MARPOL Annex VI Tier I, II, and III for marine engines and a key concern for ammonia and biofuel combustion.
NYK Line: Nippon Yusen Kaisha, Japanese shipping group with vessels under Japan, Singapore, and Marshall Islands flags.

O

Oceanbird: Wallenius Marine and Stena RoRo wind-assisted vessel concept exploring methanol auxiliary fuel and sail-assisted propulsion.
ONE: Ocean Network Express, Japanese container line.

P

Pavilion Energy: Singapore LNG trading company since 2014 active in LNG bunker supply and shareholder in Pavilion Bunker pilots before the 2024 Shell acquisition.
PEM Fuel Cell: Proton exchange membrane fuel cell.
Pilbara Port Authority: Western Australian port authority partnering in ammonia bunkering pilot studies for bulk export terminals.
Pioneer (Methanol Tanker): 11,000 dwt methanol-fueled tanker built for Mitsui Chemicals in 2019.
Port of Newcastle Ammonia Pilot: Australian east coast bunkering pilot evaluating ammonia ship-to-ship transfer procedures.
PROMAN: Trinidad and Switzerland-based methanol producer active in methanol shipping and marine bunkering.

R

Renewable Diesel: Drop-in diesel produced from biomass-derived oils.
RSB: Roundtable on Sustainable Biomaterials, an international sustainability certification body covering marine biofuels.
RSPO: Roundtable on Sustainable Palm Oil, a certification scheme used where palm-derived FAME enters marine biofuel blends.

S

SABIC: Saudi Basic Industries Corporation, methanol producer and member of the Methanol Institute.
Saudi Arabian Methanol Company: Methanol producer and member of the Methanol Institute.
SBOM: Singapore Bunkering Operational Manual issued by MPA Singapore setting bunker delivery and metering procedures including for alternative fuels.
SF-BREEZE: Sandia National Laboratories concept study for a 150 passenger high-speed hydrogen fuel cell ferry in the San Francisco Bay.
SOFC: Solid Oxide Fuel Cell technology evaluated for marine ammonia and natural gas applications due to high electrical efficiency.
Stena Bulk: Swedish tanker operator and methanol bunker market participant.
Stena Germanica: Stena Line ferry retrofitted in 2015 to dual fuel methanol operation marking the first methanol bunker stems in commercial service.
Stena Pro Marine: 50,000 dwt methanol dual-fuel product tanker in the Stena fleet.
Stena Pro Patria: 50,000 dwt methanol dual-fuel product tanker in the Stena fleet.
Stena Promise: 50,000 dwt methanol dual-fuel product tanker in the Stena fleet.
Stena RoRo: Swedish ro-ro vessel owner and partner in the Oceanbird wind-assisted concept.
Suiso Frontier: First liquid hydrogen carrier built by Kawasaki Heavy Industries and delivered in 2019.
Sulzer 8RT-flex68DF Methanol: Methanol-capable variant of the Sulzer RT-flex68 large bore two-stroke engine.

V

VLSFO: Very Low Sulfur Fuel Oil with sulfur content at or below 0.5 percent mass, used to meet IMO 2020 outside emission control areas.
VLSFO-B24: VLSFO blend containing approximately 24 percent biofuel offered as a marine bunker grade in Singapore.
VLSFO-B30: VLSFO blend containing approximately 30 percent biofuel used in commercial marine bunkering.

W

Wallenius Marine: Swedish ro-ro and car carrier operator and partner in the Oceanbird wind-assisted methanol concept.
Wartsila 31 Ammonia Engine: Ammonia-capable variant of the Wartsila 31 medium-speed engine under development by Wartsila.
Wartsila W31DF Methanol Retrofit: Methanol retrofit of the Wartsila W31DF dual-fuel medium-speed engine.
Wartsila W32-Methanol: New methanol-fueled variant of the Wartsila 32 medium-speed engine.
Wartsila W34DF Methanol Retrofit: Methanol retrofit of the Wartsila W34DF dual-fuel medium-speed engine.
Waterfront Shipping: Methanex subsidiary that operates the first commercial fleet of methanol dual-fuel product tankers from 2016.
Windcat Workboats: See Windcat.
WinGD: Winterthur Gas and Diesel, the company developing two-stroke crosshead engines descended from the Sulzer line, with associated cylinder oil specifications.

X

X-Press Feeders Methanol Series: Series of 1,170 TEU methanol dual-fuel feeder container ships operated by X-Press Feeders.
X-Press Iris: 2023 delivery in the X-Press Feeders methanol dual-fuel feeder series.
X72DF-A: WinGD low-speed two-stroke ammonia dual-fuel variant of the X72 platform entering early commercial service.
X92DF-A: WinGD two-stroke ammonia dual-fuel main engine in the 92 centimeter bore class for large container ships and tankers.

Y

Yangzhou: Chinese methanol producer member of the Methanol Institute.
Yangzijiang: Chinese shipbuilder constructing methanol dual-fuel container ships including units in the A.P. Moller-Maersk methanol newbuild program.