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VPS discusses mitigating risks in sustainable vessel operations with its APS

Harun Rashid, Senior Technical Manager of VPS explains how to safeguard vessels against bunker fuel instability with VPS Additional Protection Service.

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VPS discusses mitigating risks in sustainable vessel operations with its APS

Harun Rashid, Senior Technical Manager of marine fuels testing company VPS on Tuesday (19 March) published an article on how to safeguard vessels against marine fuel instability with VPS Additional Protection Service (APS):

Stability has long been a highly unpredictable character of marine fuels, which is extremely sensitive to a fuel’s formulation and its storage and handling conditions. For these reasons, fuel buyers have no direct control on fuel stability, unlike other physical parameters, other than relying upon a supplier’s due diligence regarding the fuel formulation and the ship’s engineer’s professionalism in managing the fuel on board.

Asphaltenes within residual-based fuels can precipitate as sediment/sludge whenever a fuel’s available solvency to retain asphaltenes in suspension drops below the fuel’s stability reserve. The ISO 8217:2012/17 standard has a sediment limit of a maximum 0.10% m/m to protect buyers’ interest where an elevated sediment value can be indicative of an unstable fuel. Today’s fuels are no longer produced from straight run refining processes, but undergo a series of complex processes, for example, vacuum distillation, vis-breaking, catalytic cracking, in order to extract the lighter end components as much as possible, leaving the bottom end components with reduced reserve stability. The solvency can further diminish with unregulated blending in order to meet the Sulphur compliance levels within MARPOL Annex VI & statutory regulations.

During 2023, VPS handled numerous sludge formation cases which led to severe filter & separator blockages. The majority of these cases involved VLSFO fuels and for a sizeable number, the sediment content at the ship’s manifold was actually below the 0.10%m/m specification limit. In one case, a ship received a VLSFO in an Asian port with sediment content 0.07%m/m and reported severe sludge formation soon after the fuel was put into use, with sludge formation continuing throughout the use of the fuel.

The sludge formation was so severe that the engineers had to clean the purifier bowl assembly every 4 hours, compared to a usual cleaning interval of 250 hours. At one point, the engineers discontinued using the fuel, as the vessel ran out of spare parts. Analysis of system samples later confirmed that the sludge formation was indeed due to unstable fuel and not from on-board mixing.

While the number of sludge formation cases clearly singles out VLSFO as more unstable and challenging to manage on-board, compared to HSFOs, another challenge is to prevent wax formation without exposing fuel to excessive heat and accelerated fuel ageing. With VLSFOs being  more parafinnic in nature, a good number may require heating beyond their pour point to prevent wax formation.

VPS discusses mitigating risks in sustainable vessel operations with its APS

VPS 2023 data shows, at least 15.8% of VLSFO samples had a wax appearance temp (WAT) above 40C, including 1.6% above 50C. These samples will precipitate wax if storage temps are not kept above the WAT, compared to the lower storage temperature requirements based on their tested pour points.

Wax formation is a reversible process, so theoretically, it should not cause any operational issue as long as fuel remains stable, but unfortunately, fuel stability is not guaranteed. Moreover, if wax is allowed to form, wax and aspheltenes (sludge) can co-mingle together as a result, the wax disappearance temperature may increase significantly and in the worst case, the wax may no longer disappear.

Taking a middle approach and striking a balance could be one option where the fuel is not severely overheated, nor the wax allowed to form freely during storage and only increase temperatures during transfer if needed. VLSFO with such high WAT/WDT will need close attention and care during storage, transfer, treatment and use. Prolonged storage should also be avoided for such fuels.  

Sludge formation on the other hand is an irreversible process, meaning it is not possible to convert the precipitated sludge back into the fuel. As there is no quick fix, efficient handling of fuel treatment plants becomes so critical otherwise, severe clogging of filters and separators can lead to fuel starvation to the engine and a loss of propulsion placing greater risk to the safety of the crew, ship, and the environment.

Avoiding a catastrophic situation requires visiting the entire fuel management chain and adhering to best practices. It starts with buying fuel from trusted suppliers, followed by verifying the fuel quality in one of the VPS, ISO17025 accredited laboratories.

VPS offers  an Additional Protection Service (APS) package which includes a stability assessment of the fuel.

VPS discusses mitigating risks in sustainable vessel operations with its APS

VPS additional protection service (APS) package

Parameters such as Separability Number (Reserve Stability Number) and Total Sediment Existent (TSE) together with Total Sediment Potential (TSP) results provides an excellent indication of fuel stability while GC/MS screening and follow up testing ensures the fuel is not contaminated with harmful chemical species at levels considered “unfit for use”. Testing Wax appearance & disappearance temperatures assist in maintaining optimal heating to prevent wax formation whilst also avoiding overheating and fuel ageing.

If a vessel uses stability additives, then its performance evaluation should not only be in assessing the improvement of the reserve stability number, but to conduct a broader assessment across fleet including assessing sediment reduction. Crew training is key, as poor handling of fuel by incompetent crew can also trigger a sludge formation situation.

A deeper understanding of the fuel’s quality can be achieved, coupled with a further reduction of any associated risk, by going beyond ISO 8217 and using the APS test scope. This service will ultimately save time, money and company reputation.

 

Photo credit: VPS
Published: 20 March 2024

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Alternative Fuels

Yang Ming orders six LNG dual-fuel, ammonia-ready containerships from Hanwha Ocean

Each of the six new vessels will have a capacity of up to 13,650 TEU and feature LNG dual-fuel propulsion and Ammonia Fuel Ready specifications.

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Yang Ming orders six LNG dual-fuel, ammonia-ready containerships from Hanwha Ocean

Taiwanese shipping firm Yang Ming Marine Transport Corporation (Yang Ming) and South Korean shipbuilder Hanwha Ocean on Wednesday (2 September) signed a shipbuilding contract for six 13,000 TEU class LNG dual-fuel container vessels. 

The contract was signed by Dr. Chuck Tsai, Chairman of Yang Ming, and Mr. Charles Kim, CEO of Hanwha Ocean. The vessels are scheduled for delivery between 2028 and 2029. 

They will complement Yang Ming’s existing fleet of 10,000+ TEU vessels and serve as key vessels on East-West services, with deployment flexibility across trade lanes connecting Asia with the East and West Coasts of North America, South America, and the Mediterranean. 

Each of the six new vessels will have a capacity of up to 13,650 TEU and feature LNG dual-fuel propulsion and Ammonia Fuel Ready specifications.

“As Yang Ming transitions toward net-zero emissions, LNG provides a relatively mature and economically viable alternative fuel solution, capable of reducing greenhouse gas emissions by approximately 20%,” the company said. 

“At the same time, ammonia can serve as a carbon-free fuel by utilising converted LNG storage facilities, while offering relatively lower conversion costs and comparatively well-developed supply chains and infrastructure. The Ammonia Fuel Ready design will therefore provide Yang Ming with greater flexibility in responding to increasingly stringent international regulations on greenhouse gas emissions.”

In addition, the vessels will be equipped with Type B LNG fuel tanks with a design pressure of 1.0 bar to enhance the safety and efficiency of LNG operations, together with a range of energy-saving technologies, including Wind Shields, Rudder Bulbs, Pre-Swirl Stators, and Shore Power Systems. Smart ship technologies and cybersecurity protection features will also be incorporated to enhance operational efficiency, safety, and reliability while effectively reducing fuel consumption and greenhouse gas emissions.

Deliveries under Yang Ming’s next-generation fleet optimization plan commenced earlier this year. By 2030, a total of 24 new vessels are expected to enter service. 

This includes 18 LNG dual-fuel vessels—comprising five 15,500 TEU, seven 16,000 TEU, and the six 13,000 TEU vessels under this contract—alongside six 8,000 TEU methanol dual-fuel-ready ships. 

 

Photo credit: Yang Ming Marine Transport
Published: 4 September, 2026

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Alternative Fuels

LR, China’s MARIC unveil tanker concept ready for three future bunker fuels

Both secured AiP for a new 114,000 DWT product and crude oil tanker designed to accommodate future conversion to LNG, methanol or ammonia.

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LR, China’s MARIC unveil tanker concept ready for three future bunker fuels

Lloyd’s Register (LR) and the Marine Design and Research Institute of China (MARIC) on Thursday (3 September) have secured Approval in Principle (AiP) for a new 114,000 DWT product and crude oil tanker designed to accommodate future conversion to LNG, methanol or ammonia.

Announced at SMM 2026, the concept addresses one of the biggest investment challenges facing shipping today: the need to develop vessels and capabilities that can support a range of alternative fuel options and pathways as technologies, infrastructure and regulations evolve.

While LNG is already a mature fuel pathway, methanol and ammonia remain at an earlier stage of development, with questions around global fuel availability, infrastructure development, economics and long-term adoption.

The 114,000 DWT tanker concept has been designed as a product and crude oil carrier that can accommodate future conversion to LNG, methanol or ammonia as technologies, regulations and fuel supply chains mature. By incorporating conversion readiness at the design stage, the concept aims to reduce future retrofit complexity and provide owners with greater confidence when planning long-term fleet investments.

The design concept was reviewed against LR’s July 2026 class rules and regulations, including requirements relating to ships using gases and other low-flashpoint fuels, alongside relevant IACS Common Structural Rules for oil tankers. Final classification and statutory approval remain subject to full compliance with all applicable rules and regulations.

Theo Kourmpelis, Global Business Director for Tankers, Lloyd’s Register, said: “Shipowners are being asked to make major investment decisions today despite continued uncertainty around which fuels will dominate in the decades ahead. Alternative fuel solutions each offer potential pathways to compliance, but fuel infrastructure, regulation and economics continue to evolve at different speeds around the world.

“Designs that preserve flexibility will be critical in helping owners manage risk while preparing for multiple future scenarios.”

Si Nan, Marine & Offshore Marketing Department Vice Director, MARIC, said: “As the industry explores different decarbonisation pathways, shipowners need vessel designs that can adapt alongside technological and regulatory developments. This concept was developed specifically to provide greater fuel flexibility and long-term resilience, allowing owners to respond to changing market requirements without being locked into a single fuel strategy.

“Receiving Approval in Principle from Lloyd’s Register is an important milestone that validates the design concept and supports its future development.”

 

Photo credit: Lloyd’s Register
Published: 4 September, 2026

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Alternative Fuels

DNV: Alternative-fuelled vessel orders hit highest monthly level since October 2024

LNG-fuelled vessels accounted for the vast majority of August activity while the strong summer performance marked a significant acceleration in ordering activity after a relatively slow start to the year.

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DNV: Alternative-fuelled vessel orders hit highest monthly level since October 2024

Latest data from classification society DNV’s Alternative Fuels Insight (AFI) platform alternative-fuelled vessel ordering was strong in August, with 52 new vessels added to the platform.

This is the highest monthly total since October 2024 and follows another active month in July, when 47 vessels were added to the database.

LNG-fuelled vessels accounted for the vast majority of August activity, with 46 orders recorded. The container segment led the way with 30 orders, while the car carrier segment contributed a further 12 LNG-fuelled vessels. In addition, four ethanol-fuelled bulk carriers and two hydrogen-powered bulk carriers were added during the month, as well as one LNG bunker vessel.

The strong summer performance marked a significant acceleration in ordering activity after a relatively slow start to the year. In total, 242 alternative-fuelled vessel orders have been placed in the first eight months of 2026, representing a 27% increase compared with the same period in 2025.

LNG remains the dominant fuel choice, accounting for 63% of all alternative-fuelled vessel orders registered so far this year. Container vessels represent the largest share of these LNG orders (59%), followed by car carriers (30%).

Jason Stefanatos, Global Decarbonization Director at DNV Maritime, said: “The past two months have been particularly strong for alternative-fuelled vessel ordering, with August recording the highest monthly total we’ve seen since October 2024. This has helped lift year-to-date orders to a level well above the same period last year.

“LNG remains the leading fuel choice, driven largely by activity in the container and car carrier segments. These sectors have been among the earliest adopters of alternative fuels, supported by predictable liner operations and increasing demand from cargo owners to reduce emissions across supply chains. 

“For many owners, LNG offers a combination of emissions reductions, fuel availability and future flexibility while the longer-term fuel landscape continues to evolve. 

“At the same time, the latest figures include orders for ethanol- and hydrogen-fuelled vessels, highlighting that owners continue to explore a range of decarbonization pathways. Different segments are making different fuel choices, but the overall level of activity demonstrates continued investment in lower-emission shipping.”

Screenshot 2026 09 04 at 12.29.26 PM Screenshot 2026 09 04 at 12.29.36 PM

 

Photo credit: DNV
Published: 4 September, 2026

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