Preparing for a Multi-Fuel Future with GTT’s Mark III Technology
The shipping industry, responsible for approximately 3% of global CO emissions, is under increasing pressure to reduce its environmental impact. Global and regional regulations are pushing for lower emissions, but the path forward remains complex and uncertain. While Liquefied Natural Gas (LNG) has established itself over the past decade as a viable marine fuel beyond its traditional use in LNG carriers, alternative fuels like ammonia and methanol are being actively explored. However, these alternatives face significant challenges, including supply constraints, readiness of large engine technology, and infrastructure development.
The Growing Need for Fuel Flexibility
Given these challenges, the ability to accommodate multiple fuel options is becoming increasingly important for ship-owners aiming to future-proof their vessels. With the demand for fuel flexibility on the rise, GTT has been exploring how its Mark III membrane containment system can be adapted to store ammonia and methanol alongside LNG, offering a practical solution for multi-fuel readiness.
Ammonia and methanol present specific challenges due to their unique physical and chemical properties. Ammonia is toxic and corrosive, requiring stringent safety measures, while methanol has a high liquid density and heavy gas characteristics that demand careful handling. To safely store these fuels, GTT has applied safety measures similar to those used for LNG, such as double-wall piping and a double segregation philosophy. These adaptations ensure that the containment system meets the necessary safety standards for these alternative fuels.
GTT has achieved Approvals in Principle (AIPs) from Bureau Veritas for ammonia and methanol readiness in LNG-fueled ships. This recognition confirms the technical viability of using the Mark III system for multiple fuels, providing ship-owners with the flexibility to transition to alternative fuels in the future without significant modifications after an initial period of operating with LNG.
Beyond Fuel Storage: Modifying Fuel Gas Supply Systems and Engines
Fuel storage is just one aspect of multi-fuel readiness. Transitioning to alternative fuels like ammonia and methanol also requires adjustments to fuel gas supply systems and engines. Each fuel - LNG, ammonia, and methanol - has distinct properties that influence the design and operation of these systems. For example, ammonia's toxicity necessitates different safety measures compared to LNG, and methanol's physical properties impact piping class and venting arrangements.
Regulatory frameworks differ between fuels as well. The International Code of Safety for Ships Using Gases or Other Low-flashpoint Fuels (IGF Code) governs LNG use, providing guidelines for safe handling and storage. Interim guidelines are in place for methanol, while regulations for ammonia are still being developed by the International Maritime Organization (IMO) and class societies. These standards cover aspects such as piping configurations, venting systems, and machinery setups, reflecting the unique safety requirements of each fuel.
GTT has assessed the technical feasibility of ships using multiple fuels or transitioning between them, focusing on practical solutions for both newbuilds and retrofitting existing ships. This included analyzing the necessary modifications to fuel gas supply systems and engines to accommodate the different fuels' properties.
While ammonia and methanol are positioning themselves as future marine fuels alongside LNG, they also face hurdles such as supply chain limitations, the need for further development of large-scale engine technology, and infrastructure challenges.
GTT's approach is to offer solutions that prepare ships for a range of fuel options, thereby reducing the need for extensive retrofits later on. By incorporating multi-fuel readiness into the design of new Mark III vessels, shipowners gain the option to switch to alternative fuels as they become available and economically viable.
