According to Britannia Club, as the maritime industry faces the urgent challenge of decarbonisation and strives to achieve net-zero emissions, alternative fuels like methanol are emerging as key players in this transformative journey.
Decarbonising shipping is not only an environmental imperative but an emerging area of innovation, reflecting the industry’s shift towards alternative fuels.
Liquefied natural gas (LNG) is currently taking the lead as a transitional fuel; however, several potential zero-emission fuels such as methanol and hydrogen are also on the rise. It is uncertain which fuel will be the preferred choice of the future, and it is likely that a variety of alternative fuels will be required to meet future demand.
As part of their decision making, shipowners need to perform due diligence which includes a thorough risk identification and assessment when choosing an alternative fuel. As part of this assessment, several stakeholders will need to be consulted, for example the engine maker, fuel supplier, classification society, hull & machinery insurers and the ship’s flag state.
Considerations that should be taken into account include:
1. SUITABILITY AND IMPACT ON THE ONBOARD ENGINES: The engine maker should be consulted to determine whether the onboard engines are suitable for consuming the selected alternative fuel or whether the engine will require any retrofitting.
2. FUEL MANAGEMENT: Handling alternative fuel onboard is likely to present different operational hazards compared to fossil fuels. Therefore, it is essential to train the crew properly in handling these new fuels.
3. HEALTH, SAFETY AND ENVIRONMENT (HSE): While the alternative fuels may have their obvious environmental benefits, they may come with some increased safety risks. Therefore, any alternative fuel should be accompanied by a thorough assessment of its HSE risks, and this should form the basis of the onboard safety measures for handling the fuel.
4. QUALITY: With the current lack of international standardisation, a clear and detailed bunker specification needs to be developed by the shipowner to ensure suitable fuel is delivered.
Britannia’s Loss Prevention department has collaborated with Waves Group to provide practical advice on the widely discussed alternative fuels: Biofuels, Liquefied Natural Gas, Methanol, Ammonia, and Hydrogen. The examination for each of these alternative fuel types will focus on good practices in storage, handling, bunkering, safety and emergency response.
This guidance will focus on methanol, a fuel that has been safely transported on chemical tankers for many years. The push to decarbonise the maritime industry has elevated methanol’s status as a readily available, low-carbon fuel, with the first commercial methanol-fuelled vessels already operational. Regarding legal framework, methanol as a fuel will fall under the guidance of the International Code of Safety for Ships using Gas or other Low-flashpoint Fuels (IGF) code and MSC.1/Circ.1621, specifically addressing bunkering, storage, and onboard handling.
Storage
Methanol stays in liquid form at an ambient temperature and pressure and is therefore easier to store than the alternative cryogenic fuels such as lng, ammonia or hydrogen.
With a boiling point of 65 °C, there is minimal concern around vapour pressure control during storage in fuel tanks. However, due to its low flash point, maintaining an inert atmosphere in the fuel tanks is imperative during normal operations. As inert gas will also be used on the safety and purging systems for the methanol consumers, it may be most effective to consider fitting a nitrogen production and storage system to achieve the requirements for inert gas.
Otherwise, permanently maintaining inert gas onboard is essential to cover at least one voyage from port to port, accounting for the anticipated maximum fuel consumption and trip length. Additionally, sufficient inert gas must be available to maintain the fuel tanks in an inert condition for a minimum of two weeks in harbour with minimum port fuel consumption.
A cofferdam must shield integral fuel tanks, excluding areas bound by the shell plating below the lowest possible waterline, along with other fuel tanks housing methanol and fuel treatment preparation spaces. Independent fuel tanks can be located on an open deck or within a fuel storage hold space. If located on an open deck, a drip tray will be required for containment of leakage. A water spray system for emergency cooling should also be fitted. Independent tanks must be securely fixed to the ships structure, able to resist any expected external forces. Portable fuel tanks may be used, ensuring they meet independent tank requirements while incorporating additional specifications for integration into the ship’s control and monitoring systems. Additionally, an approved method for connecting to the ship’s fuel piping systems, such as through a flexible hose must be provided. Pressure and vacuum relief valves should be fitted to each
fuel tank, directing the venting to a safe location on an open deck.
Bunkering
Bunkering methanol to the ship’s permanent tanks, given its liquid state at ambient temperature, follows a process similar to conventional fuel bunkering.
However, as the vessel adheres to the IGF code, the following considerations apply:
- Plan each bunkering operation individually, collaborating closely with the bunker supplier. This planning includes:
- Conducting a combined risk assessment
- Performing a compatibility assessment
- Developing a joint plan of operations
- Creating a separate plan and risk assessment for any simultaneous operations (SIMOPs)
- Confirming the methods of communication
- Install an Emergency Shutdown System (ESD) on the vessel, connecting it to the bunkering sources ESD system during the bunkering operations
- Test the ESD system after connecting the bunkering hose and before methanol transfer
- Fit a filter/strainer at the bunkering source to prevent the ingress of foreign objects
- Purge bunker hoses and lines with nitrogen before starting bunkering, ensuring it is below the Lower Explosion Limit (LEL) of methanol
- Pressure test the manifold connection with nitrogen before commencing methanol transfer to confirm there are no leaks
- Agree on maximum transfer rates with the supplier
- Continuously monitor the fuel tank levels and pressures, considering the tank pressure relief valve capacity
- Drain and purge bunker hoses and lines upon completing bunkering and before disconnection
- Constantly monitor the vessel’s moorings throughout the transfer operation to avoid a breakout situation
- Use a dry break-away coupling/self-sealing quick release to stop methanol transfer and safely disconnect bunker hoses in case the vessel and source
start moving apart (break out) - Ensure portable communication devices in the manifold area adhere to the approved standards.
