Reducing Ship Emissions: Could We Ever Replace Traditional Bunkers?

Dr Michael Traut, Research Associate at the Tyndall Centre, University of Manchester

Decarbonisation and the replacement of traditional bunkers with alternative fuels or other technology is the only way the shipping industry can adequately reduce its emissions in line with the COP21 global climate deal, Dr Michael Traut, Research Associate at the Tyndall Centre, University of Manchester, has told Ship & Bunker.

However, at the moment he says there are no known readily available alternatives to make that happen.

While the industry is currently under no obligation to make those reductions, it is coming under increasing pressure to do so.

Traut, who is currently researching how this might be achieved, recently talked to Ship & Bunker to discuss the possibilities.

The first thing he makes clear is that there are currently very few known options for replacement bunkers, and the main choices that are available - key amongst them being liquefied natural gas (LNG) and biofuel - he does not see as viable long term solutions.

"Fuels, especially low carbon fuels, are a really big and under-researched topic. There are no obvious candidates to replace oil-based bunkers right now but that's because of the lack of research," he said.

Lifecycle Emissions

As previously reported by Ship & Bunker, Traut discounts LNG bunkers because he says they will not sufficiently reduce GHG emissions to meet shipping's obligations under the COP21 climate deal.

Methanol bunkers suffer a similar problem, he says, with issues relating particularly to production meaning it is questionable whether there is a reduction in total lifecycle GHGs.

Similarly, he sees biofuel bunkers as being an equally unlikely solution.

"Lifecycle emissions are absolutely key, whether and how much can you save in terms of GHG emissions. For biofuels the resources to produce them also raise big questions, as does competition with food production," he said.

"Hydrogen may be one choice, and it has the potential for zero emissions, but that depends on if we can produce it in a low carbon way across the whole lifecycle. Storage and infrastructure is a big issue for hydrogen, though."

Synthetic fuels, such as synthetic methane or other hydrocarbons might be an option, but Traut says this is only viable if it can come from a renewable energy source.

"Perhaps the use of offshore renewable energy, such as wind power, could be used to produce them, but there are serious obstacles to getting such a project online. It is not a ready solution," he said.

Beyond replacement bunkers, Traut says wind and solar power (WASP) technologies "will definitely be needed" but they will only ever form part of the bigger emissions reduction picture.

Similarly, he says battery and fuel cell technology appears to be promising, but looks to be decades away from playing more than just a bit part in any global solution; "but that's something that might change if we really give it a go," he adds.

"Nuclear power is probably the only currently known technology that could meet the required emissions targets, but this comes with a lot of questions, and they're not all political ones. There are still big, big questions about now to make it viable."

For his part, Traut says his research is starting with wind power.

"We'll have the first answers by the end of the year and complete a report on the potential of wind, and the barriers to adoption. We'll also provide answers in terms of overcoming those barriers," he said.

"For other fuels and energy sources, it will take some time. One of the most interesting things will be to see how it will play out with the IMO, and where shipping sits in the Paris Agreement.

"All I can say right now is that in the current price environment, as far as I can tell there isn't a ready alternative to replace traditional bunkers, and we simply don't yet have the answers as to how we will sufficiently reduce shipping emissions. All we know is that what we have now isn't enough.

"The positive is that we have a clear and unambiguous goal in decarbonisation – there really is something to aim for, that holds potential promises."