Ammonia, unlike traditional marine fuels, does not produce carbon dioxide during combustion, aligning it closely with global decarbonization goals. The potential for ammonia to be produced from renewable energy sources further enhances its appeal, promoting the creation of “green ammonia” and reducing dependency on fossil fuels. Economically, the shift to ammonia is supported by advancements in technology, making ammonia engines and fuel systems more efficient and safer to operate.

Conversion Challenges and Solutions

“The conversion of vessels to ammonia fuel represents a significant step towards a greener maritime industry. With careful planning and implementation of safety measures, ammonia can serve as a viable and sustainable marine fuel, contributing to the reduction of greenhouse gas emissions and fostering a cleaner, more resilient future for global shipping,” Tommy Hivand, CCO of Breeze Ship Design says.

Converting an existing LNG-fueled vessel to ammonia operation involves several technical modifications. Key areas include:

• General Arrangement and Safety: Ensuring that accommodation, service control spaces, and muster stations are safe from ammonia’s toxic properties. This involves installing protective equipment, enhancing ventilation, and revising the layout to include gas-tight doors and airlocks.
• Bunkering Station: The bunkering station must be designed to contain ammonia leakages, featuring dedicated ventilation systems, water safety systems, and fire protection measures. Personal protective equipment and a robust purging and gas-freeing protocol are essential.
• Tank and Tank Connection Space: The fuel storage and connection spaces require significant adjustments, including the installation of pressurized or refrigerated tanks designed to handle ammonia’s unique properties. Proper ventilation, water safety systems, and fire protection are critical in these areas.
• Fuel Supply System: Ammonia fuel supply piping needs secondary enclosures to contain leaks, trace heating to prevent freezing, and monitoring equipment to ensure safe operation. The system also requires a specialized ammonia release mitigation system (ARMS) to handle purging and leakage scenarios.
• Engine Room Modifications: The engine room must be gas-safe, with protective measures in place to contain potential leaks. Suitable decontamination facilities and eye washes must be available.
• Venting and Dispersion Studies: Given ammonia’s toxicity, venting systems must be designed to minimize exposure risks. Dispersion studies are necessary to analyze potential leak scenarios and inform design decisions, ensuring the safety of crew and the environment.

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