Classification society Bureau Veritas (BV) and energy major TotalEnergies have carried out a joint study aiming at de-risking the use of ammonia as a marine fuel, with a specific focus on leak mitigation and treatment.
The joint preliminary study evaluated the health and safety risks from ammonia leaks for crew and passengers and pinpointed key safety criteria, broadening the shipping industry’s understanding of ammonia as a marine fuel.
So far, the study has examined different leak scenarios for single-wall and double-wall containment, as well as during bunkering operations – also providing key insights on the efficiency of ventilation and vapour processing systems, the size of safety zones needed, and the health risks to people exposed to leaks, BV informed.
Ammonia is seen as one of the main zero-carbon fuel options to decarbonise the shipping industry. However, it presents several safety challenges as it is toxic to humans.
To help de-risk ammonia as fuel, BV is building on a tried-and-tested approach that was used in the last decade to propel the development of LNG as fuel. BV’s Rule Note NR 671 was also used as a guideline, given its focus on preventing ammonia leaks and requirements for onboard vapour processing systems.
The partners began by assessing what concentrations of ammonia in the air would be problematic and compared those levels to LNG. The LNG-fueled tanker served as the model for the comparison, showing a stark contrast between the two fuels.
As explained, LNG becomes dangerous at around 50,000 parts per million (ppm), while ammonia starts to have health effects above 30 ppm when permanently exposed, or around 300 ppm when exposed for one hour.
Based on this finding, BV noted that unless modifications are made to the design, safety distances should be much greater for ammonia than LNG.
“While further experimentation and analysis are required to reach definitive conclusions, this preliminary study helped identify future areas to explore for de-risking ammonia as fuel. Additional tests could be performed for leak design scenarios, bunkering safety zones, bunkering arrangements, and the effect of weather conditions, for example”, said Laurent Leblanc, senior VP of Technical & Operations at Bureau Veritas Marine & Offshore.
“Until technology developments can eliminate ammonia leaks completely, leak mitigation and treatment remain the best course of action for ship owners and designers. Our preliminary study with TotalEnergies forms a strong basis for future industry collaboration. By pairing the right questions with the right tests, marine stakeholders can begin the journey to de-risking ammonia as fuel, as they did for LNG.”
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