Future Fuels in Shipping

Comparing future fuels in shipping

Using alternative fuels in marine transport can play a critical role in decarbonising the shipping sector and contributing towards climate change goals. The market for alternative fuels continues to develop through ship builders, engine manufacturers and classification societies under the guidance of MARPOL regulations (International Convention for the Prevention of Pollution from Ships) adopted by the International Marine Organisation (IMO).

One key consideration for marine alternative fuels is how current maritime legislation, largely shaped towards conventional fuel types, addresses the adoption of alternative fuels. For example, to meet NOx emission limits, an Engine International Air Pollution Prevention (EIAPP) Certificate under MARPOL is required when building a maritime diesel engine according to the NOx Technical code.  In the future EIAPP certificates will need to address emissions from combusting alternative fuels to ensure that the market can provide the necessary solutions to aid in the decarbonisation of the maritime industry.  The table below provides an overview of the major fuel options available within the marine sector. It considers the current advantages, disadvantages, emissions profile as well as where catalytic solutions exist in controlling and reducing these emissions.


Future fuels in shipping

Hydrotreated Vegetable Oil (HVO) / Heavy Fuel Oil (HFO) / Marine Diesel Oil (MDO) Advantages
  • Abundance
  • Low Cost
  • Baseline emissions are controllable with emissions control
  • Local & global
  • High baseline emissions
  • SCR is an established technology – lower reactor size is possible with a cleaner exhaust gas
Emissions profile
Catalytic solutions
  • SCR for NOx Filters for PM (including Black Carbon) at an earlier TRL
Ultra-Low Sulfur Diesel (ULSD) Advantages
  • Can have a more compact aftertreatment system
  • Potential to have a longer life time due to less poisoning
  • Alters the lubricity of diesel
Emissions profile
  • NOx SOX PM
Catalytic solutions
  • Deployment of DPF is possible and lower SOx enables other aftertreatment technologies
Bio / e LNG Advantages
  • Established Fuel – Improved CO2 emissions Lower NOx Lower SOx.
  • Suitable for use in alternative power generation technology.
  • Energy Density relative to diesel fuels.
  • GHG emissions CO2 & CH4
  • CH4 a GHG ~90 x CO2 equil.  Bio LNG emissions risk of catalyst poisoning
Emissions profile
  • NOx PM CO CO2 CH4
Catalytic solutions
  • SCR for NOx OxiCat for Com CH2O and CH4
Bio / e Methanol Advantages
  • Drop in fuel also suitable for Alt technologies – Electrochemical Power
  • Energy density / Toxicity.
  • Limited experience at sea
Emissions profile
Catalytic solutions
  • SCR for NOx OxiCat for CO and CH2O
Ammonia Advantages
  • Zero carbon at point of use.
  • Low lifecycle GHG if Green / Blue
  • Energy density / lack of experience at sea
  • N2O GHG ~300 x CO2 equil.
Emissions profile
  • NOx NH3 N2O
Catalytic solutions
  • SCR/ASC for NOx /NH3  Options for N2O
Hydrogen Advantages
  • Efficient & Zero carbon at point of use
  • Low lifecycle GHG if Green / Blue
  • Suitable for alternative power generation
  • Energy density
  • Lack of  experience at sea
Emissions profile
  • NOx & H2
Catalytic solutions
  • SCR for NOx (SCR for H2) oxicat for H2




SCR Selective Catalytic Reduction
NOx Nitrogen oxides
SOx Sulphur oxides
PM Particulate Matter
NMHC Nonmethane Hydrocarbon
CO Carbon monoxide
CO2 Carbon dioxide
 DPF Diesel particulate filters
GHG Greenhouse gas emissions
CH4 Methane
LNG Liquefied Natural Gas
CH2O Formaldehyde
N2O Nitrous oxide
NH3 Ammonia
ASC Ammonia Slip Catalyst
H2 Hydrogen gas
TRL Technology Readiness Level



Since its formation in 2011, IACCSEA has had a primary focus of demonstrating the technological and economic viability of catalytic technology for reducing emissions from shipping.

We do this by:

  • Sharing objective and factual technical information

We leverage our collective industry expertise and networks to gather and disseminate objective and factual technical information on marine catalytic emission control technologies (including costs and benefits) and promote awareness of this technology, including latest developments.

  • Contributing to industry groups and forums, and regulatory discussions

We use our voice to primarily inform regulators and the shipping community that proposed regulations for reducing emissions from shipping can be met through commercially available catalytic after treatment technology.

  • Working with others in the shipping community

We work closely with other stakeholders in the continued development and implementation of strategies that lead to cleaner shipping and raises awareness of the benefits of this technology among stakeholder groups and in the regulatory arena.