Ammonia: an answer to decarbonizing shipping 

Organizations worldwide are under pressure from consumers, governments and international bodies to combat climate change. For the maritime industry, this means finding new ways to limit ships’ carbon emissions and meet IMO ambitions, which include at least 40% reduction in CO₂ emissions per transport work by 2030. Further aims include reaching a 70% reduction by 2050, and a global annual GHG emissions reduction of at least 50% by 2050, as compared to 2008.

One of the key ways to achieve IMO’s objectives is to use a carbon-free alternative fuel, and shipowners are looking ever more favorably to one particular option: ammonia.

A multitude of advantages

Intrinsically carbon-free and generating zero CO₂ emissions when sourced renewably, ammonia is a clear contender for the title of fuel of the future, offering myriad advantages. The processes for storage and transport of ammonia are well established, and it is one of the most widely used chemicals in the world, with a global production level of approximately 190 million tons per year. It is therefore readily available, although marine bunkering infrastructure needs to be further developed to make it fully viable.

Challenges to address

However, ammonia is also one of the less developed alternative fuels currently under consideration, leading to several challenges that must be addressed.

Firstly, there are safety issues associated with ammonia’s toxicity and caustic properties, which create a need for careful storage and handling, problems that will ultimately be addressed through regulation. Further challenges include developing the technology that ensures a safe combustion process for ammonia, and conducting tests to determine the total fuel consumption necessary to achieve stable combustion.

Secondly, engine manufacturers will need to measure and find a way to limit nitrogen oxide (NOx) emissions when using ammonia, in line with existing regulations (MARPOL Annex VI). To do this, experts are looking to employ proven technologies, such as Exhaust Gas Recirculation (EGR) and Selective Catalytic Reduction (SCR).

Finally, ship owners need to account for questions of ship design and cost impact. Ammonia has a much lower energy density than traditional fuel oils, weighs twice as much and requires three times the space to contain the same amount of energy. These aspects will need to be factored in when designing the zero-carbon ships of the future.

Our part to play

While it is still in the R&D phase, ammonia has great potential as an alternative fuel for shipping. Bureau Veritas is involved in various JIPs to assess the technical feasibility and safety risks of ammonia-fueled ships with thermal engines and fuel cells. Working in partnership with major industry stakeholders, we are also developing relevant new and updated rules, notations and guidelines.

Carbon-free fuels are no longer just an option, but a key solution for curtailing climate change. Bureau Veritas is working actively to move this burgeoning technology forward and ensure the maritime industry is ready to play its part in society’s energy transition.