A new chapter – ammonia two-stroke engines

Advancing ammonia engine innovation 

The Everellence B&W ammonia two-stroke engine builds on the proven ME-LGI concept and the development is currently well underway at our Research Centre Copenhagen. Designed as a newbuild engine, which will become available as retrofit solution for electronically controlled ME-C engines, this ammonia-fuelled marine engine is engineered to enable low-emission operation for tomorrow’s fleet. 

Our engineering teams are incorporating essential safety features such as ammonia containment systems, sensors, system ventilation and double-walled piping. In July 2023, the first ammonia combustion was successfully achieved on our research engine, with highly stable performance data. 

Full-scale engine testing began in November 2024 and focuses on combustion behavior, emissions, engine tuning, atomizer validation and control system verification. The testing phase is scheduled to continue through mid-2025. 

Key benefits of ammonia engines 

Ammonia-powered engines offer a compelling combination of efficiency, sustainability, and flexibility – making them a future-proof choice for clean marine propulsion. 

• High energy efficiency with low emissions
  Ammonia can be used as an energy carrier of sustainable hydrogen and is carbon free. The two-stroke ammonia engine is designed to run with as little as 5% pilot oil at 100% load (L1 rating*), with the remaining 95% of energy coming from ammonia.  This results in high power output, excellent engine efficiency, and extremely low emissions - making it a future-proof solution for clean propulsion.
  * Performance values indicated refer to energy fraction for L1 rated engines operating at 100% load point in Tier II mode. Actual values may vary depending on engine rating and load conditions.
• Carbon- and sulphur-free combustion
  Ammonia produces no carbon or sulphur emissions, enabling clean and sustainable combustion. Green ammonia is especially promising as a marine fuel due to its potential for lower production costs compared to other e-fuels such as e-methanol and synthetic natural gas. This positions the ammonia-fuelled engine as a strong candidate for large-scale decarbonization in shipping.
• Flexible retrofit options
  Ammonia-fuelled engines can be adapted to customer needs – either as newbuilds or as modular, dual-fuel retrofit solutions for existing electronically controlled engines. Whether you operate a modern fleet or look to decarbonize existing vessels, our experts can help you implement the most suitable ammonia engine configuration for your operation.

Engineered safety:
ammonia auxiliary system

The auxiliary systems have been optimized for the Everllence B&W ammonia engine and ensure safe and efficient operation. The ammonia catch system and the addition of absorbers make sure that no ammonia above 5 ppm will be vented to the atmosphere at our Research Centre Copenhagen. These engineered safety measures are critical for enabling ammonia as engine fuel at scale – while maintaining strict environmental protection standards.