Bunker Fuel

DNV: Addressing methane slip in LNG-burning four-stroke Otto-cycle engines

DNV discusses LNG and methane slip in a Maritime Impact report and elaborates on its role in several projects aiming to minimize methane slip.

Published

1 year ago

December 6, 2023

Admin

DNV: Addressing methane slip in LNG-burning four-stroke Otto-cycle engines

Classification society DNV on Monday (27 November) released a Maritime Impact report discussing LNG and methane slip and DNV’s role in several initiatives to minimize it. The following is an excerpt from the article:

LNG offers many benefits as a transitional ship fuel. However, certain engine types have been found to release significant amounts of unburnt methane, a powerful climate gas. DNV is involved in various projects aiming to minimize methane slip.

Methane, the main component of natural gas and LNG, has a global warming potential (GWP) 29.8 times that of carbon dioxide (CO2) over a 100-year timeframe, according to the Intergovernmental Panel on Climate Change (2021). Preventing methane from escaping anywhere along its supply chain is therefore crucial as the world tries to contain the causes of climate change.

New EU regulations increase pressure to reduce methane slip

LNG-fuelled four-stroke Otto-cycle engines, which are often used for gensets on board passenger ships, have been found to release significant amounts of unburnt methane, leading to CO2-equivalent emission values that compromise what is achieved through other carbon reduction efforts.

The shipping sector will be incorporated into the EU’s Emissions Trading System (ETS) from 2024. This expansion will encompass methane and nitrous oxide emissions starting in 2026. Additionally, the FuelEU Maritime requirements for the GHG intensity of energy utilized on board will come into effect in 2025. Consequently, the shipping industry is keenly interested in addressing methane slip issues.

LNG's long-term zero emissions potential hinges on methane slip reduction

“Many think of LNG as a transitional fuel only, but it can also be much more than this,” says Hans Eivind Siewers, Segment Director Passenger Ships and RoRo at DNV. “But in order for this fuel to take passenger ships all the way to zero emissions with bio LNG and e-LNG, it is of major importance that we succeed in reducing methane slip.”

Fabian Kock, Head of Section Environmental Technologies Air at DNV, agrees: “Methane slip is indeed a critical issue for addressing climate change. DNV is actively working with many stakeholders and regulators to find pragmatic solutions to overcome this challenge. In particular we are happy to work closely together with the engine designers to find technical solutions which are safe and feasible to be installed on board of ships.”

GREEN RAY industry initiative addresses methane slip

One major initiative dedicated to reducing methane slip from LNG ship engines is the EU HORIZON project GREEN RAY (new GeneRation marinE ENgines and Retrofit solutions to Achieve methane abatement flexibilitY). Launched in June 2022 under the leadership of the VTT Technical Research Centre of Finland, it aims to establish sound scientific data about methane slip from four-stroke LNG-fuelled engines by conducting on-board exhaust gas measurements, and to promote the development of methane abatement technologies.

The project consortium includes the Finnish Meteorological Institute, Shell Global Solutions, Wärtsilä, MSC, CMA Ships, Chantiers de l’Atlantique, DNV and a number of other stakeholders. A report will summarize the findings after the project ends in 2027.

Focus on engine optimization and exhaust gas aftertreatment

The engine manufacturer Wärtsilä has been conducting research and development on engine modifications to radically reduce methane slip, including efforts to optimize engine design and control. VTT researchers studied methane emissions from two Wärtsilä 31DF engines on the AURORA BOTNIA. One used standard configuration, the other tested new combustion. Results show reduced methane emissions and potential for overall emission cuts for the modified engine.

Shell is developing methane absorption and catalytic conversion technologies for exhaust gas aftertreatment. The role of DNV in the GREEN RAY project will be to witness exhaust gas measurements, verify piping and materials as well as installation, and develop and update its class rules related to emission reduction with the option to introduce a dedicated class notation. Furthermore, DNV will provide know-how and review solution proposals.

MAN takes a two-pronged approach

There are similar initiatives beyond the GREEN RAY project, as well. MAN Energy Solutions SE has been exploring ways to optimize its own engine technology to minimize methane slip. The company’s R&D into engine optimization is well advanced and integrated into every new four-stroke ship engine MAN delivers, says Dr Mathias Moser, Head of Technology and Exhaust Aftertreatment at MAN Energy Solutions SE.

“We optimize the mechanical components to minimize crevice volumes in the cylinder and we adapt the compression ratio towards improved combustion,” he explains. “Furthermore, we fine-tune engine control parameters such as injection timing, pilot-fuel amount, supercharge pressure, ignition timing, valve timing and combustion temperature. Most of these improvements can be implemented as retrofits to existing engines, as well. These engine-based measures alone can reduce methane emissions significantly so the updated engines will comply with future, tighter restrictions.”

T2 Fer Cru 507 Methane oxidation catalyst tcm71 250444 1

Note: DNV’s full Maritime Impact report on ‘Addressing methane slip in LNG-burning four-stroke Otto-cycle engines’ can be found here.

Photo credit: MAN Energy Solutions, Avenir LNG
Published: 6 December, 2023

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Singapore: Sing Fuels appoints Sanket Naik as Managing Director

Sanket joined Sing Fuels in 2016 as a Credit Manager and has ‘immersed himself’ in all departments; will drive company to expand into areas like sustainability and biofuels.

Published

11 hours ago

December 9, 2024

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Singapore: Sing Fuels appoints Sanket Naik as Managing Director

Singapore-based provider of marine fuel solutions Sing Fuels on Saturday (7 December) said Sanket Naik, was recently promoted to Managing Director of Sing Fuels.

The firm said Sanket joined Sing Fuels in 2016 as a Credit Manager.

“He immersed himself across all departments, ranging from investment to business development, gaining a 360-degree understanding of the business and serving as a key driver of growth and success at Sing Fuels,” Sing Fuels said in a social media post.

“As Managing Director, Sanket is poised to drive Sing Fuels 3.0, expanding into areas like sustainability and biofuels, ensuring we stay at the forefront of industry innovation.”

Photo credit: Sing Fuels
Published: 9 December, 2024

Legal

Vietnam: Two vessels seized over 31,000 litres of illegal diesel oil

Vietnam Coast Guard said vessels were transporting various quantities of oil material: “HP-3790” was transporting about 16,000 litres and “Phuong Nam 68” transported about 15,000 liters.

Published

11 hours ago

December 9, 2024

Admin

The Vietnam Coast Guard on Thursday (5 December) said it detained vessel HP-3790 in the sea bordering Hai Phong City and Quang Ninh Province.

The Coast Guard discovered the ship at 2pm on 4 December displaying several suspicious signs and ordered the vessel to stop for administrative inspections.

The authority proceeded to inspect the vessel, which had three crew members on board, and found it to be transporting about 16,000 litres of diesel oil with no invoices or documents proving its legal origin.

HP 3790

The Coast Guard also detained another ship, Phuong Nam 68, that also had three crew members on board at 10am on 5 December.

The ship was transporting about 15,000 liters of DO oil with no invoices or documents proving its legal origin.

As such, the ships were handed over to the Command of Coast Guard Region 1 for further investigation and handling in accordance with the provisions of law.

Photo credit: Vietnam Coast Guard
Published: 9 December, 2024

Alternative Fuels

DNV: Use of ammonia as a bunker fuel among highlights in IMO MSC 109

Amendments to the IGC Code to enable the use of ammonia cargo as fuel were adopted and interim guidelines for the general use of ammonia as fuel were approved during session.

Published

11 hours ago

December 9, 2024

Admin

Classification society DNV on Saturday (7 December) shared a statutory news article that provides a summary of the 109th session of the International Maritime Organization’s (IMO) Maritime Safety Committee (MSC 109) including adopted amendments to the IGC Code to enable the use of ammonia cargo as fuel and approved draft interim guidelines for ammonia as a marine fuel.

The following is an excerpt from the news update relating to bunker fuels:

The 109th session of the IMO’s Maritime Safety Committee (MSC 109) was held from 2 to 6 December 2024. Amendments to the IGC Code to enable the use of ammonia cargo as fuel were adopted, and interim guidelines for the general use of ammonia as fuel were approved. The IGF Code was amended to improve the safety of ships using natural gas as fuel. MSC 109 further approved draft SOLAS amendments to enhance the safety of pilot transfer arrangements and progress was made on the new safety code for Maritime Autonomous Surface Ships.

Meeting highlights

Adopted amendments to the IGC Code to enable the use of ammonia cargo as fuel
Adopted amendments to the IGF Code for ships using natural gas as fuel
Approved draft interim guidelines for ammonia as fuel
Approved draft amendments to SOLAS Regulation V/23 and the related performance standards to improve the safety of pilot transfer arrangements
Advanced the non-mandatory Code on Maritime Autono- mous Surface Ships (MASS)

Amendments to mandatory instruments

Ammonia cargo as fuel (IGC Code) MSC 109 adopted amendments to Paragraph 16.9.2 of the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code) to enable the use of ammonia as fuel on ammonia carriers.

An MSC circular to encourage the voluntary early implementation of the amendments to Chapter 16 was approved.

The amendments will enter into force on 1 July 2026.

Safety of ships using natural gas as fuel (IGF Code)

MSC 109 adopted amendments to the International Code of Safety for Ships Using Gases or Other Low-flashpoint Fuels (IGF Code), based on experience with the code since its entry into force in 2017.

The amendments include:

Clarified application provisions
Alignment with the IGC Code on suction wells for fuel tanks extending below the lowermost boundary of the tank
Alignment with the IGC Code on discharge from pressure relief valves to discharge to tanks under certain conditions
Clarified requirements to fire insulation for deck structures in relation to fuel tanks on open deck
Clarified requirements for hazardous ducts through non-hazardous spaces and vice versa
Updated requirements for the hazardous zone radius for fuel tank vent mast outlets, increasing to 6 metres for zone 1 and 4 metres for zone 2

The amendments will enter into force on 1 January 2028.

Goal-based new ship construction standards

Goal-based standards (GBS) for the new construction of bulk carriers and oil tankers are, conceptually, the IMO’s rules for class rules. Under the GBS, IMO auditors use guidelines to verify the construction rules for bulk carriers and oil tankers of class societies acting as Recognized Organizations (Resolution MSC.454(100)).

Initial GBS verification of Biro Klasifikasi Indonesia (BKI) BKI has requested GBS verification of their ship construction rules for bulk carries and oil tankers. MSC 109 agreed that the BKI rules comply with the GBS, provided non-conformities and observations are rectified and verified in a new audit.

North Atlantic wave data (IACS Recommendation No. 34, Revision 2) MSC 109 noted that IACS is currently undertaking a review of its Common Structural Rules (CSR) for bulk carriers and oil

tankers to reflect advances in data, materials, technologies and calculation methodologies. The CSR are implemented in the individual class rules of the IACS members, which are subject to compliance with the GBS.

MSC 109 further noted that IACS has now issued a revision of the North Atlantic wave data to ensure more scientific data as a basis for the rule formulas in the CSR. The new scatter diagram in Revision 2 of IACS Recommendation No. 34 shows the probability of occurrence of different sea states and is based on wave data from advanced hindcast wave models combined with ships’ AIS data for all SOLAS vessels in the period from 2013 to 2020.

MSC 109 agreed that an observation from the initial CSR audit in 2015, that the scatter diagram in Revision 1 of IACS Recommendation No. 34 was based on past statistics, was now considered addressed.

MSC 109 further invited IACS to provide more information about the assumptions, modelling and technical background for Revision 2 of IACS Recommendation No. 34, and agreed that the GBS audit of the revision to follow should be carried out in conjunction with the consequential rule changes in the CSR.

New technologies and alternative fuels

Identification of gaps in current IMO instruments MSC 109 continued its consideration of potential alternative fuels and new technologies to support the reduction of GHG emissions from ships from a safety perspective. The intention is to identify safety obstacles, barriers and gaps in the current IMO instruments that may impede the use of the various alter- native fuels and new technologies.

MSC 109 agreed to add “swappable traction lithium-ion battery containers” to the list of alternative fuels and new technologies. The list already includes fuels and technologies such as ammonia, hydrogen, fuel cell power installations, nuclear power, solar power, wind power, lithium-ion batteries and supercapacitor energy storage technology.

Recommendations to address each of the identified barriers and gaps in the IMO regulatory framework will be considered in a Correspondence Group until MSC 110 (June 2025). Application of the IGF Code

MSC 109 agreed on draft amendments to SOLAS to clarify that the IGF Code applies to ships using gaseous fuels, whether they are low-flashpoint or not. The term “gaseous fuels” was added to the definitions in SOLAS Regulation II-1/2 and to the application provisions of SOLAS Regulations II-1/56 and 57.

The draft amendments are expected to enter into force on 1 January 2027, subject to adoption by MSC 110 (June 2025).

Carriage of cargoes and containers

Ammonia as fuel

MSC 109 approved draft interim guidelines for the safety of ships using ammonia as fuel.

Ships carrying liquefied gases in bulk (IGC Code)

MSC approved draft amendments to the IGC Code to incorporate the large number of Unified Interpretations developed since the latest major review of the code, which entered into force in 2016. The primary objective of the draft amendments is to remove ambiguity and promote the consistent implementation of the IGC Code requirements.

Photo credit: CHUTTERSNAP on Unsplash
Published: 9 December, 2024