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DNV: Challenging road ahead for retrofitting to dual-fuel engines

Cost of retrofitting, including fuel storage and fuel supply system, ranges between USD 5 mil – USD 15 mil and, as a rule of thumb, this should not exceed 25% of newbuild cost of a ship to be economically viable.





Classification society DNV on Tuesday (16 May) released a Maritime Impact report on retrofitting ships with dual-fuel engines to run on alternative bunker fuels and discusses the challenges that comes with it:

The maritime industry’s decarbonization goals are multi-pronged and complex. A collaboration between DNV and engine designer MAN Energy Solutions examines how retrofitting the existing maritime fleet to dual-fuel engines capable of running on sustainable fuels can contribute to these goals.

In order for the shipping industry to achieve decarbonization that is sufficiently in line with the Paris Agreement’s goal of limiting global warming to 1.5 degrees Celsius, a full life-cycle approach – also known as a ‘well-to-wake emissions’ perspective – needs to be adopted. This forces the maritime industry to assess the emissions of shipping in a comprehensive way and moves shipowners away from the ‘tank-to-wake’ approach, where emissions reporting can be pushed upstream to the production of the fuel. At IMO’s MEPC 80 this approach will be further discussed. 

‘Well-to-wake emissions’ perspective raises standards for existing fleet

While a number of innovations are being applied to the 1,500–2,000 two-stroke and 750 four-stroke new vessels that are launched per year, the greatest challenge to achieving maritime GHG reductions is for the existing merchant fleet, which consists of approximately 55,000 ships with two-stroke engines and 30,000 ships with four-stroke engines.  

Retrofitting these existing ships to be able to run on alternative fuels like ammonia and methanol is one of the options available to the maritime industry to achieve desired reductions in emissions. However, the path ahead for retrofitting is uncertain. 

“Apart from efficiency improvements and the use of biofuels, retrofitting is another option for the existing fleet to achieving decarbonization targets,” says DNV’s Business Development Manager Christos Chryssakis. “However, there is no requirement for retrofitting so the future timeline for achieving this is not clear.” 

Biofuels not scalable for maritime industry

Currently, the most straightforward way of reducing emissions on the existing fleet is by running single-fuel engines on sustainable biofuels. Several biofuels, such as FAME and HVO, have ‘drop-in’ properties which means that they can be blended with existing fossil fuels. This is an attractive option to shipowners as it provides them with a flexible way of achieving decarbonization without having to make large capital investments.  

However, a number of key challenges remain with biofuels. Although 2022 was a record-breaking year for the consumption of biofuels, this still accounted for just 0.1% of the maritime energy mix.  

“Demand for biofuels is high from other industries, and supply is limited,” says Chryssakis. “This means that the maritime industry may struggle to acquire as much biofuel as it needs and that prices will be high. Therefore, it currently seems quite unlikely that biofuels will be a magic bullet for decarbonizing the entire existing maritime fleet.”

Retrofitting fleet provides long-term solution

With biofuels currently unscalable, converting large ships to dual-fuel engines is increasingly seen as one of the ways that the maritime industry could achieve its decarbonization targets. Retrofitting a single-fuel engine to dual-fuel enables a ship engine to run on a second sustainable fuel, as long as this is accompanied by a pilot injection of conventional fuel. While this conventional fuel will primarily be a traditional fossil fuel, sustainable biofuels or synthetic fuels can also be used.  

Dual-fuel conversions have already been applied to converting the engines of energy carriers to the fuel being carried, most frequently to LNG and LPG. This has generally resulted in around a 15–20% reduction in exhaust emissions, highlighting the key role that both of these fuels occupy as transition fuels. However, in order to achieve decarbonization targets, dual-fuel conversions need to be made for fuels which can be produced to emit close to zero ‘well-to-wake emissions’, such as green ammonia, green methanol and e-fuels.  

Larger ships most suitable for retrofitting

According to assessments by DNV and MAN ES, key retrofitting requirements for ships with two-stroke engines are electronically controlled engines, a bore size of at least 50 centimetres and a sea trial conducted after 1 January 2015. The cost of retrofitting, including the fuel storage and fuel supply system, ranges between USD 5 million and USD 15 million depending on the type of fuel and, as a rule of thumb, this should not exceed 25% of the newbuild cost of a ship to be economically viable.  

A ship should typically have a minimum newbuild cost of around USD 50 million to be suitable for retrofitting. Ships fitting these criteria include tankers above 50,000 DWT, bulkers above 160,000 DWT and containers above 7,000 TEU, among others. However, in some cases, such as for ships retrofitting to methanol, this cost can be lower. For four-stroke engines, ships with large bore sizes that conducted a sea trial 8–15 years ago appear to be the best fit for dual-fuel retrofitting. 

“Less than 10% of the existing global merchant fleet are regarded as theoretic candidates for retrofitting,” says Chryssakis. “We don’t see this happening today due to costs and uncertainties but think that this could be achieved over the next five to ten years, particularly after 2030 when regulations really start biting. However, it is difficult to predict how many of these will actually materialize.” 

IMO regulations hindering shipowners from dual-fuel retrofitting

Although several states are pushing the IMO to be even more ambitious and aim for zero emissions by 2050, some of the organization’s regulations are standing in the way of a swift, large-scale dual-fuel retrofitting of the global fleet. Of most concern to advocates of retrofitting, the IMO currently demands that a parent engine test of exactly the same electronically controlled engine type is required for a dual-fuel conversion to be NOx compliant. However, relatively new engine technologies such as methanol and ammonia are not available for all bore sizes, which means that a parent test engine is often unavailable for some desired retrofits to dual-fuel engines.  

In addition, certain older engine models, such as those running on heavy fuel oil (HFO), are not made for newbuilds anymore. This means that a newbuild parent engine is not available for testing in cases where a shipowner wishes to convert a HFO engine to dual fuel, thus making retrofitting extremely difficult under current IMO rules. Unless this regulation is amended, or new guidelines are developed, the pace of retrofitting will be significantly hindered.  

Retrofitting engines also faces practical challenges

A number of other hurdles lie on the road to large-scale retrofitting. The implementation of dual-fuel conversions is expected to be carried out by a limited number of shipyards, due to varying commercial priorities. This may lead to capacity issues if there is high demand for conversions. Furthermore, the complexity of these kinds of projects and current uncertainty around best practices leaves shipowners and yards open to potentially large cost overruns. The higher costs of alternative fuels will also increase the economic worries of shipowners. 

“The cost of fuels like ammonia and methanol presents an issue to shipowners wishing to reduce GHG emissions while also maintaining a profit,” says Chryssakis. “The price of these kinds of fuels is currently much higher than conventional marine fuels and shipowners will need to ensure that their charterers will be willing to cover the increased cost of fuels before committing large amounts of CAPEX to retrofitting projects.” 

Note: The full DNV Maritime Impact report titled ‘Challenging road ahead for retrofitting to dual-fuel engines’ can be found here


Photo credit: DNV/ MAN ES
Published: 23 May, 2023

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GCMD concludes its final biofuel blend supply chain trial with Hapag-Lloyd

bp provided the B30 biofuel blend to the “TIHAMA”, a 19,870 TEU container vessel operated by Hapag-Lloyd in final trial; marks the end of a series of trials initiated in July 2022.





GCMD concludes its final biofuel blend supply chain trial with Hapag-Lloyd

The Global Centre for Maritime Decarbonisation (GCMD) on Thursday (18 July) said it has successfully completed its final supply chain trial for biofuel blended with very low sulphur fuel oil (VLSFO). 

This marks the end of a series of trials initiated in July 2022 as part of a larger pilot to develop a framework to provide quality, quantity and GHG abatement assurances for drop-in fuels.

In this final trial, bp provided the B30 biofuel blend to the TIHAMA, a 19,870 twenty-foot equivalent unit (TEU) container vessel operated by Hapag-Lloyd.

The biofuel component used is certified to the International Sustainability & Carbon Certification (ISCC) standard – a multistakeholder certification scheme for biobased materials. The biofuel component comprised neat Fatty Acid Methyl Ester (FAME) produced from food waste.

Authentix, a tracer solutions provider, supplied and dosed the FAME with an organic-based tracer at the storage terminal outside the Netherlands. The dosed FAME was then transported to the Port of Rotterdam for blending with VLSFO to achieve a B30 blend, before the blend was bunkered onboard the TIHAMA.

Similar to previous trials, GCMD engaged fuel testing company Veritas Petroleum Services (VPS) to witness the operations at all stages – from biofuel cargo transfer to bunkering. VPS also collected and conducted extensive laboratory tests on samples of the biofuel and biofuel blend collected at pre-determined points along the supply chain to assess quality per Standards EN 14214 and ISO 8217.

With well-to-wake emissions of 13.74 gCO2e/MJ, the neat FAME presented a 85.4% emissions reduction compared to the emissions of the fossil marine fuel. The reduced emissions complies with the MEPC 80, which requires a minimum emissions reduction of 65% in order for biofuels to be classified as sustainable.

GCMD and Hapag-Lloyd determined that consumption of the 4,500 MT B30 blend of FAME and VLSFO resulted in 27.9% emissions reduction compared to sailing on VLSFO.

A newly developed tracer deployed with this supply chain

GCMD collaborated with Authentix to develop and deploy a new organic-based tracer to authenticate the origin and verify the amount of FAME present in the blend. The proprietary tracer blended homogeneously with FAME and was detected at expected concentrations at all sampling points along the supply chain.

This trial marks the first deployment of this tracer in a marine fuel supply chain. Previously, similar tracers were used to authenticate and quantify biofuels in road transport and LPG supply chains.

Development of a comprehensive biofuels assurance framework underway

With the completion of this trial, GCMD has deployed a diverse range of tracer technologies, including synthetic DNA and element-based tracers, in addition to the organic-based tracer used in this trial. The trials have also included the development of a chemical fingerprinting methodology and the evaluation of lock-and-seal and automatic identification systems (AIS) as additional solutions to ensure the integrity of the biofuels supply chain.

Learnings on tracer limitations and benefits will be incorporated into a framework that recommends appropriate use to ensure consistent and robust performance. This effort will complement existing ISCC by providing additional supply chain assurance through physical traceability.

The insights from these trials will be shared in a series of reports covering issues, such as traceability, biofuel degradation, supply chain optimisation and abatement costs. These findings will culminate in a comprehensive assurance framework to provide guidance on biofuels use, slated for release in the fourth quarter of 2024.


Photo credit: Global Centre for Maritime Decarbonisation
Published: 19 July 2024

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MPA, ITOCHU and partners sign MoU on ammonia-fuelled bulk carriers study

As a government agency, MPA,will review and provide their views to the designs of the ammonia-fuelled ships to ensure their safe operations, says ClassNK.





RESIZED venti views

Classification society ClassNK on Thursday (18 July) said it signed a Memorandum of Understanding (MoU) with ITOCHU Corporation, Nihon Shipyard Co., Ltd., and Maritime and Port Authority of Singapore (MPA) regarding a joint study for the design and safety specifications of ammonia-fuelled ships which are under development by ITOCHU and partners.

“The discussion for a specification of ammonia-fuelled ships with a governmental body related to their operation is essential for a social implementation of ammonia-fuelled ships,” ClassNK said. 

“As one of parties of the MoU, MPA, a government agency overseeing the world’s busiest bunkering hub, will review and provide their views to the designs of the ammonia-fuelled ships to ensure their safe operations.”

The MoU is based on the premise that 200,000 deadweight ton class bulk carriers will be built by Nihon Shipyard with an ammonia dual-fuelled engine.

“The necessary clarifications of the specification for the ammonia-fueled ship to carry out ammonia bunkering in Singapore will be conducted among parties of this MoU, for the commercialisation of ammonia-fuelled ships,” ClassNK added.


Photo credit: Venti Views on Unsplash
Published: 19 July 2024

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Methanol Institute: Methanol fuel innovations and expansions (Week 28, 8 to 14 July 2024)

This week, advancements in methanol as a marine fuel included new additives reducing the need for pilot fuel, new eco-friendly tankers, and methanol-powered feeder ships in Rotterdam.





Methanol Institute logo

The Methanol Institute, provides an exclusive weekly commentary on developments related to the adoption of methanol as a bunker fuel, including significant related events recorded during the week, for the readers of bunkering publication Manifold Times:

Technology around the use of methanol as a marine fuel has continued to move forward, with the latest developments including an additive which removes the need for pilot fuel, further saving carbon emissions. Elsewhere, bunker networks, fuel transport and cargo capacity using cleaner methanol has continued to expand.

Methanol marine fuel related developments for Week 28 of 2024:

Terntank orders Fifth Eco-Friendly Tanker with Methanol and Wind Propulsion

Date: July 8, 2024

Key Points:

Terntank has placed an order for a fifth vessel featuring wind-assisted propulsion and methanol fuel capabilities from China Merchants Jinling Shipyard. Scheduled for delivery between March 2025 and July 2027, the 15,000 DWT chemical and product tanker aims to enhance environmental performance. The company emphasized the benefits of these technologies, including reduced emissions and expanded shore power usage, reinforcing its commitment to sustainable shipping practices.

Fratelli Cosulich Orders Two New Bunker Vessels with Methanol and Biofuel Capabilities

Date: July 8, 2024

Key Points:

Fratelli Cosulich has ordered two 7,999 DWT bunker delivery vessels from Taizhou Maple Leaf Shipbuilding, capable of handling methanol, biofuel, and fuel oil. The first ship is expected in early 2026. This move reflects the company's commitment to sustainability and technological innovation. Methanol, known for its ability to significantly reduce greenhouse gas emissions, is a focal point of this initiative, supporting the transition to cleaner marine fuels.

X-Press Feeders Launches Methanol-Powered Feeder Ships in Rotterdam

Date: July 10, 2024

Key Points:

X-Press Feeders has introduced its first methanol-fueled ship, Eco-Maestro, in Rotterdam, launching Europe's first scheduled feeder network powered by green methanol. The network, comprising 14 ships, will operate routes in Northern Europe with methanol bunkering exclusively in Rotterdam. This initiative aims to support sustainable shipping and help companies achieve environmental goals by reducing greenhouse gas emissions.

WinGD Completes Successful Tests on New Short-Stroke Methanol-Compatible Engine

Date: July 11, 2024

Key Points:

WinGD has successfully completed testing of its new X52-S2.0 short-stroke engine at the Yuchai Marine Power Co facility. This engine, now type-approved, is available in diesel, LNG, and methanol configurations, with an ammonia option in development. It features a compact design and high fuel efficiency, making it suitable for smaller vessels. The engine's methanol compatibility underscores its role in reducing greenhouse gas emissions and advancing sustainable maritime practices.

Infineum Explores Methanol Fuels for Heavy-Duty and Marine Engines with Innovative Additives

Date: July 11, 2024

Key Points: 

Paul Cooper and Joanna Hughes of Gane Energy spoke to Infineum Insight to discuss the advantages of methanol as fuel for heavy-duty and marine engines and how fuel additives can help to overcome some of the challenges.

One of the issues associated with methanol – in common with many alternative fuels  in marine applications – has been the need to use a pilot fuel to ignite it in the engine. Gane Energy has developed performance additives to methanol fuel, overcoming challenges like lubricity and corrosion. Their approach also eliminates the need for a diesel pilot fuel by converting methanol to dimethyl ether (DME) for ignition.

As the use of methanol grows in various transportation applications, the use of high quality fuel additives will be vital to ensure hardware protection, according to Infineum.


Photo credit: Methanol Institute
Published: 19 July, 2024

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