Everllence recently presented its first ammonia two-stroke engine. Class societies test the technology to ensure the safe use of new fuels. Bureau Veritas explains the challenges of certification.
One of the leading classes involved in certifying such technological innovations is the French company Bureau Veritas. Ramona Zettelmaier, Marine Chief Executive, Central Europe at Bureau Veritas in Hamburg, explains the challenges involved in certifying ammonia-powered engines.
The introduction of the ammonia engine was a first for Everllence – was it also a first for Bureau Veritas? What made the classification of this engine special or challenging?
Ramona Zettelmaier: Ammonia as a fuel in marine propulsion systems is relatively new. However, Bureau Veritas has already gained experience with alternative fuels such as LNG, methane and methanol as well as with ammonia in research contexts. On this basis, BV was able to approach the topic at an early stage and develop appropriate guidelines.
The toxicity of ammonia is a particular challenge when it comes to classification. NH3 is toxic in gas and vapor phases, which significantly influences safety concepts, leakage detection as well as installation and maintenance concepts. Ammonia is highly flammable in certain concentrations, but has different ignition temperatures than fossil fuels. Oxidation and corrosion aspects therefore had to be carefully evaluated.
High demands were also placed on materials, seals, leakage detection and heat recovery. New fuel-air ratios, combustion maps, NOx emission controls and economies of scale also had to be taken into account. In addition, the use of ammonia requires new safety systems, such as emergency stop functions, emergency fuel shutdown devices, detection systems such as NH3 gas detectors and adapted fire protection concepts.
Compliance with SOLAS, MARPOL, environmental and emission regulations as well as new regulations specifically applicable to NH3 must be observed. Overall, the classification of an ammonia engine requires comprehensive safety, environmental and operational assessments. Typically, BV integrates systematic hazard analyses, risk assessments such as HAZID and HAZOP, technical safety concepts as well as emission and environmental requirements.
In your opinion, are there any risks associated with the use of ammonia as a fuel for ship propulsion systems?
Zettelmaier: As already mentioned, NH3 is toxic. Leaks therefore pose health risks for the crew and the environment. There are also corrosion and compatibility problems, as ammonia can attack certain metals and seals. Careful material selection and suitable protective coatings are therefore essential.
NH3 has specific ignition limits, so mixtures with air must be safely controlled. NOx emissions can occur during combustion, which may require the use of NOx reduction systems such as SCR. High pressure or cryogenic storage also requires specialized infrastructure, safe handling and reliable leak detection.
A particularly important point is the increased safety and operating costs. This goes hand in hand with higher training requirements for the crew, detailed emergency plans and regular maintenance. Operators must also reckon with stricter environmental and regulatory requirements, for example in the form of route and operating requirements, environmental standards and liability issues in the event of NH3 releases or seepage.
Last but not least, cost aspects such as infrastructure investments, fuel prices, availability and insurance premiums for this fuel must be reassessed.
In your opinion, for which types of ships are ammonia engines best suited?
Zettelmaier: Due to the current regulatory framework, certain ship sizes and types with clearly defined sailing areas are the main candidates. The comparatively high energy density and low viscosity make ammonia particularly interesting for long-distance shipping. A prerequisite is sufficient space for the fuel tanks, as the tank volume is a decisive factor. The availability of the fuel also plays a decisive role. Ammonia is also suitable as a liquid energy carrier for transporting hydrogen over long distances.
