Steve Bee, Group Marketing and Strategic Projects Director, and Emilian Buksak, Decarbonisation Advisor of marine fuels testing company VPS, on Wednesday (16 April) broke down what the newly approved IMO net-zero framework means for ship operators and how VPS can support compliance through fuel testing, emissions measurement, and strategic advisory:

On Friday 11th April 2025, the International Maritime Organization (IMO) achieved another important step towards establishing a legally binding framework to reduce greenhouse gas (GHG) emissions from ships globally, aiming for net-zero emissions by or around 2050.

The IMO Net-zero Framework is the first in the world to combine mandatory emissions limits and GHG pricing across an entire industry sector.   Approved by the Marine Environment Protection Committee during its 83rd session (MEPC 83), the measures include a new fuel standard for ships and a global pricing mechanism for emissions.

These measures, set to be formally adopted in October 2025 before entry into force in 2027, will become mandatory for large ocean-going ships over 5,000 gross tonnage, which emit 85% of the total CO2 emissions from international shipping.  This Net-Zero Framework will be included in a new Chapter 5 of MARPOL Annex VI.

With an estimated 900 renewable-fuel-ready vessels expected to be sailing the seas by 2030, it is felt necessary to implement global regulation to deliver renewable fuels at a commercially viable price, as current pricing for “green fuels” is 3-4 times the price of fossil fuels. Such regulations will make it possible for ships to operate on green fuels and also incentivise fuel and energy providers to invest in new production capacity.

Under the draft regulations, ships will be required to comply with: 

Global fuel standard: Ships must reduce, over time, their annual greenhouse gas fuel intensity (GFI) – that is, how much GHG is emitted for each unit of energy used. This is calculated using a well-to-wake basis, meaning total emissions are measured from fuel production through to its use on board.  

Global economic measure: Ships operating above GFI thresholds will need to acquire remedial units to balance their excess emissions, while those using zero or near-zero GHG  fuels or technologies will be eligible for financial rewards for their lower emissions profile.

Two-tier Compliance Targets: Each ship will have to meet both a Base Target and a Direct Compliance Target for its annual GFI. Vessels that stay under the stricter Direct Compliance Target are eligible to earn surplus units, whereas those over the thresholds face a compliance deficit that must be remedied.

Data Collection & Reporting: Operators must calculate and report their attained annual GFI each calendar year, verifying it against their target annual GFI. This includes rigorous recordkeeping and submission to the IMO GFI Registry, which tracks each vessel’s emissions performance and any remedial or surplus units.

IMO Net-Zero Fund Contributions: Ships that exceed their GFI limits are required to make GHG emissions pricing contributions to the new IMO Net-Zero Fund. Collected revenues will be used to reward ships using zero/near-zero fuels, support research and technological innovation in cleaner shipping, and help ensure a just and equitable transition for the maritime sector.

Net-Zero Framework Implementation and Green Balance Mechanism

From 2028 to 2030, ships will be subject to a tiered levy linked to their well-to-wake (WtW) carbon intensity. Based on a 2008 baseline of 93.3 gCO₂eq/MJ (the industry average in 2008), operators will face no charge for fuel emissions at or below approximately 77.44 gCO₂eq/MJ, a moderate levy of $100/mtCO₂eq for emissions between 77.44 and 89.57 gCO₂eq/MJ, and a higher rate of $380/mtCO₂eq for emissions exceeding 89.57 gCO₂eq/MJ. These thresholds and levies align with the overarching goal of driving down overall carbon intensity by a minimum of 4% by 2028 and 17%for direct compliance targets—with further, more stringent reductions taking effect in subsequent years. 

Surplus Units and Over-Compliance

A ship’s carbon intensity below the lower threshold (77.44 gCO₂eq/MJ) constitutes “over-compliance,” generating surplus units that can be banked or traded. Conversely, exceeding thresholds will require the purchase of remedial units to cover the compliance deficit.

Sustainable Fuel Certification Scheme (SFCS) and Fuel Lifecycle Label (FLL)

Under the new framework, all fuels must carry a Fuel Lifecycle Label (FLL), which documents their GHG intensity and other sustainability attributes on a well-to-wake basis. These values must be certified by a recognized Sustainable Fuel Certification Scheme (SFCS), ensuring accurate, transparent calculations and preventing any misrepresentation of environmental impact. 

Zero or Near-Zero GHG Technologies, Fuels, and Energy Sources

Recognising the importance of incentivising advanced solutions, the regulation sets specific lifecycle emission thresholds for what qualifies as a zero or near-zero GHG (ZNZ) fuel or technology: Initial threshold (valid until 31 December 2034): ZNZ fuels must not exceed 19.0 g CO₂eq/MJ on a well-to-wake basis. Post-2035 Threshold: Starting 1 January 2035, the permissible GHG intensity tightens to no more than 14.0 g CO₂eq/MJ.

Ships adopting fuels and technologies below these thresholds can earn financial rewards through the IMO Net-Zero Fund, effectively offsetting some of the initial costs of transitioning away from conventional fossil fuels. By gradually lowering the allowable GHG intensity, the regulation encourages ongoing innovation, investment, and broader adoption of advanced, low-emission solutions across the global fleet.

Green Balance Mechanism

Central to this approach is the Green Balance Mechanism, which integrates closely with the GFI. In essence, it applies a fee on higher-intensity fossil fuels and allocates those proceeds to green fuels, balancing costs across a diverse energy mix. The greater the well-to-wake emission reductions a fuel delivers, the larger the financial allocation it receives—effectively levelling the playing field and stimulating a shift to sustainable alternatives.

Disbursement of Revenues

All revenues from levies and remedial unit purchases will be directed to the IMO Net-Zero Fund, which will then distribute the funds to:

• Reward low-emission ships
• Support innovation, research, infrastructure, and just-transition initiatives (particularly in developing countries)
• Fund training, technology transfer, and capacity-building aligned with the IMO GHG Strategy
• Mitigate impacts on vulnerable States, such as Small Island Developing States (SIDS) and Least Developed Countries (LDCs)
• By steadily lowering the permissible carbon intensity and introducing financial incentives for clean fuels, the new framework aims not only to reduce overall emissions but also to accelerate the maritime sector’s transition to sustainable energy solutions.

Note: The full article, including on how VPS can support compliance through fuel testing, emissions measurement, and strategic advisory, can be found here. 

Related: IMO MPEC 83 approves net-zero regulations for global shipping

Photo credit: VPS
Published: 17 April, 2025

Steve Bee, Group Marketing and Strategic Projects Director of marine fuels testing company VPS, on Monday (14 April) explored how Fuel System Check Monitoring can play a vital role in protecting a vessel’s engine as engine damage can be a very costly risk for vessel operators:

Statistically, data indicates that a vessel will suffer between one and two incidences of main engine damage over the course of its operational lifetime. The average damage costs have been estimated at around $650,000 per incident, with even more damaging incidents costing up to $1.2 million per claim. Therefore, it is important to identify the main causes of this damage and understand how it can be prevented.

Prevention of damage is, of course, preferable to cure. Fuel quality and handling issues remain a leading contributor to critical main engine failures. VPS frequently observe that such issues could have been prevented through the implementation of a robust and well-structured fuel management programme onboard vessels.

A common misconception is that a fuel meeting the international marine fuel quality standard, ISO 8217, means it is “fit for purpose”. But this is definitely not the case as even fuels that are “on specification”, at the point of delivery to the vessel, can cause major engine damage if not properly managed post-delivery. ISO 8217 specifies the requirements for petroleum fuels for use in marine diesel engines and boilers, prior to appropriate treatment before use, which means that fuels should then be treated onboard between delivery and being burnt

Catalysts used in petroleum refining are made of Aluminium Silicates, which over time breakdown. The resulting, coarse, dense fragments composing of aluminium and silicon, eventually reside in the residual portion of the refining stream. Known as “Cat-Fines”, these particles are highly abrasive and can cause severe damage to vessel engine parts.

Major marine engine manufacturers recommend a fuel should contain less than 10-15 mg/kg Aluminium plus Silicon (Al+Si) at the engine inlet. However, assuming a delivered fuel meets the stringent ISO8217:2024 limits of 40-60 mg/kg Al+Si, dependent upon the fuel grade, the fuel treatment plant would have to operate at an efficiency level capable of removing 75%-83% of these highly abrasive particles in order to meet the engine manufacturers’ requirements.

Furthermore, the International Council on Combustion Engines' (CIMAC’s) recommendation regarding fuel quality states “Fuel analysis is the only way to monitor the quality of fuel as delivered at the time and place of custody transfer, before and after the fuel cleaning onboard and at the engine inlet. Regular monitoring of the fuel cleaning plant will provide information, which will help to make decisions about the maintenance cycles of the equipment as well as potential engine problems resulting from malfunctioning or inadequate operation.”

Yet one of the most important, but often overlooked processes, is that of regular Fuel System Checks (FSCs) in order to assess the level of aluminium and silicon catalytic fines within fuel. The presence of “cat-fines” within fuel can be extremely damaging, causing rapid engine-part wear. Monitoring cat-fine levels before they can enter vessel engines, can prevent such damage. Therefore, sending samples for analysis which are taken Before & After purification processes, on a quarterly basis is the most effective way to monitor cat-fine levels. FSCs will also help comply to the engine manufacturers general recommendation of a maximum of 10-15 mg/Kg level of cat-fines in the fuel, entering the engines and assess purifier efficiency.

There are numerous reasons why regular fuel system checks are critical:

• Help identify potential risks & operational issues before major damage occurs.
• Confirm that the system’s flow rate, temperatures, discharge cycles are properly adjusted to handle the specific fuel that is being treated
• Verify that the fuel treatment system is properly maintained
• Reduce operating cost and increase lifecycles of critical components
• Identify presence of unusual components that can enter fuel post- delivery.

Periodic sampling from the fuel treatment system will also identify problems such as water ingress from ballast systems, leaking heating coils and cargo contamination. The last thing anyone wants to see is a purifier working as a pump!

A prime example and case study is highlighted below:

An LPG Tanker bunkered HSFO in Fujairah where its fuel met ISO 8217 specifications. However, after using the bunkered fuel, the Chief Engineer reported the main engine expansion tank low level alarm, with the main engine exhaust gas temperature high on cylinder unit 2 & 4. The vessel commenced a gradual slowdown of the main engine. The Chief Engineer reported the vessel was unable to run the engine due to suspected leaks on the main engine cylinders. The vessel drifted for about 10 hours before dropping anchor off the coast of India.

Upon dismantling the engine, the following findings were made:

The VPS Technical Advisor recommended the vessel submit fuel system samples and upon checking, the results from the system, these indicated that the purifier was in fact only working like a pump.

The screening size of Al+Si on the before engine sample further confirmed why the vessel was having problems, as the physical size of Al+Si particles ranged: 5-45 µm.

The ideal particle size range of cat-fines that can be effectively removed by a marine vessel's purifier system typically falls between 5 to 15 µm. Purifiers are designed to target these smaller particles, as they are the most common size found in heavy fuel oil and can cause significant wear and damage to engine components

If the particle size of catalytic fines is greater than 15 µm, it can pose significant risks to marine engines. Larger particles are more abrasive and can cause severe wear and damage to critical engine components such as cylinder liners, piston rings, and fuel injectors.

Note: The full article by VPS can be found here. 

Photo credit: VPS
Published: 15 April, 2025

Lloyd’s Register Fuel Oil Bunkering Analysis and Advisory Service (FOBAS) on Friday (11 April) released a bulletin regarding its testing of several samples of high sulphur residual fuels from Civitavecchia withTotal Sediment Potential (TSP) results exceeding the ISO8217 specification limit of 0.10% m/m:

In recent days, FOBAS has tested several samples from Civitavecchia with Total Sediment Potential (TSP) results exceeding the ISO8217 specification limit of 0.10% m/m. The samples were all high sulphur residual fuels and TSP results ranged from 0.83% m/m to 1.05% m/m.

Further analysis on these fuels suggests a possible mix of both asphaltenes and some extraneous dirt.

Fuels with high sediments can result in excessive sludge deposition in tanks and throughout the handling and treatment/fuel injection systems.

In view of the above, if your ships are planning to bunker in this port, we recommend that suppliers are advised of your concerns regarding the stability of the fuel in the area, and that they provide you with additional reassurance that they will adhere to the ISO 8217 requirements for the grade ordered. Ideally including providing full TSA, TSE and TSP sediment test results.

Additional attention should be given to the collection of bunker samples. It should be ensured that all parties have witnessed the sampling process and have signed witness forms accordingly, and that the supporting documentation includes records of all the samples considered representative of the fuel as loaded.

Photo credit: Louis Reed from Unsplash
Published: 14 April, 2025