Christos Chryssakis, Business Development Manager, DNV GL

The IMO has made a commitment to reduce the CO2 intensity of international shipping by at least 40% by 2030, moving to 70% by 2050, compared with 2008. At the same time, it aims to reduce absolute greenhouse gas emissions by 50% over the same period, using the same metric.

It’s not going to be easy to switch 300m tons of conventional fuel over to new, low/zero carbon alternatives. To meet this bold target our industry will need to develop new fuels and propulsion technologies, which could further complicate vessel operations.

These fuels may well contain the same molecules as those found in today’s bunker options but produced in different ways, resulting in biogas or bio-methanol. There could also be synthetic fuels produced by capturing CO2.

The good thing about biofuels is that they can be a drop-in alternative to conventional fuels but there are many variants. Derived from different types of biomass, using a variety of production technologies, they have also differing levels of CO2 emission reduction potential, so we need to be very careful about how we produce them. With biofuels it’s a bit more complicated than it might seem at first but we’re witnessing lots of interesting developments in this field.

There is also the technology for using hydrogen. Fuel cell technology has been improving a lot over the last 20 years and there’s also research into hydrogen engines. A major drawback is storage – tanks will need to be very big: five to 10 times that needed for fuel oil.

Another drawback is that hydrogen needs to be stored at extremely low temperatures, which requires cryogenic technology, or extremely high pressures. The cost and complexity are likely to limit the use of the gas to smaller vessels because they can have smaller fuel tanks. The first hydrogen ferry will be built in Norway next year and DNV GL is involved, so we’re learning as the project develops.

There’s a significant uptake of LNG in new builds – it’s definitely going to be one of the fuel options in the short-to-medium-term – but it’s unlikely to be retrofitted into existing vessels due to cost and complexity. Despite this, it will cut the discharge of GHGs by around 20% for the vessels selecting it. Until other options are available it’s the best fuel we have for reducing emissions, it’s just not the ultimate solution.

Waiting to see what will happen while new fuels are tested and developed during the next ten years could be a very risky bet. LNG is therefore a good short-to-medium-term option, especially when you look at it as a first step to enabling wider use of biofuels and synthetic fuels.

LNG is mainly methane and it’s therefore one of the simplest biofuels to produce – in the form of biogas. If we want to synthesise fuels using captured CO2 and hydrogen, methane is once again one of the simplest molecules to produce. It’s at this stage that we can start to replace fossil LNG with alternative fuels. That’s why LNG is a choice that can help shipping reduce GHG emissions now, while also, in terms of bunkering infrastructure and engine technology, be laying a path to the future.

Another fuel option attracting headlines is ammonia. Major engine designers are already developing engines for use with the gas, which are probably three to four years away from completion. However, there’s a problem: ammonia is very toxic. Many ports are worried about potential leaks and won’t allow vessels to dock if they’re carrying the gas. Ammonia therefore needs to be very carefully handled and stored. But even so, ammonia looks to be one of the potential future fuel options.

Even though it will be the most important factor – meeting the IMO 2050 goals isn’t all about fuel. Anything that can help improve efficiency is important. There are a number of technologies under investigation, such as wind assisted-propulsion, but many are dependent on vessel type, route and weather conditions and so on. As with fuels, there are going to be a range of options and we should be investigating all of them.

The good news is that the insights gained from IMO 2020 will help our industry adapt in the future. The route to compliance will once again be determined by a range of factors including vessel type, route, speed and location. The new reality is that there isn’t a ‘one-size-fits-all’ solution.