In order to comply with sulphur emission limits, a large part of the global fleet uses scrubbers for exhaust gas cleaning. In the meantime, this technology has advanced to such an extent that NOx, Particles or CO2 could also be reduced through modular additions
With the recent Intergovernmental Panel on [ds_preview]Climate Change (IPCC) report making for stark reading on the future of the climate, plus the IMO’s intensifying regulatory efforts on the environment, shipowners and operators now face the huge, immediate and certain challenge of having to adapt to a future based on more sustainable operations.
Scrubbers are a well-understood compliance solution for the International Maritime Organization’s (IMO) global Sulphur Cap rules. This regulation marked an important step on shipping’s pathway to curb the key pollutants generated by the segment. Indeed, a significant portion of the global fleet continues to use high sulphur fuel options with scrubbers, or are specifying their newbuild orders to include exhaust gas abatement technology.
The broad success of the Sulphur Cap since it entered into force sets the stage perfectly for shipping to think about how it tackles other harmful elements in exhaust gases. CO2 emissions are in the crosshairs thanks to new rules on ship carbon intensity and energy efficiency. Meanwhile, more stringent legislation is also expected from the IMO concerning NOx and Particulate Matter (PM), which will require us to deploy technologies capable of flexibly tackling regulatory demand.
One way that this is possible is by taking a modular approach towards sustainable technological innovation. In doing so, we can create a platform of complementary technologies that can scale to meet the challenges of the future, and therefore safeguard shipowners’ assets. Today, scrubbers – thanks to the experience gained from years of innovation – are perfectly placed to help the industry meet these challenges.
Moving beyond tackling SOx
We must all adopt the mindset that scrubbers can work beyond just tackling sulphur, and are a key technology route for shipping to meet its sustainability challenges. We are now at a point in scrubber technology’s evolutionary journey where most common pollutants can be tackled through modular additions around the stack.
For example, developments are already underway to trap PM via a modular add-on to Wärtsilä’s scrubbers. By adding an electrostatic precipitator to an already existing scrubber system, a vessel could reduce PM emissions to at least as low as those required by land-based regulations. This also means that a large proportion of CO2 is captured. The PM automatically enters the scrubber washwater, which means it can potentially be removed from the biosphere, provided a washwater treatment system is installed.
Meanwhile, on the NOx front, exhaust gas recirculation (EGR) systems can be fitted around the stack to enable emissions reductions in line with MARPOL requirements. This provides a futureproofed solution against the IMO’s current NOx emissions requirements, as well as future regulations that may come into force.
The capacity to reduce PM and NOx further provides ship owners and operators with the assurance that they are safeguarded against any future emission reduction targets. It also proves that scrubbers have a key and lasting role to play in shipping’s holistic sustainability journey.
Developments on carbon capture
Perhaps the most important development of them all for scrubbers is the potential to incorporate carbon capture and storage (CCS) within the stack, and in doing so directly tackle the IMO’s carbon reduction mandate for 2030 and 2050.
Research shows that both CCS and carbon offsetting could be instrumental in reducing CO2-emissions from the shipping industry, but many have argued that carbon offsetting alone as a solution is not enough.
The experience gained from installing scrubbers puts us in a prime position to capture CO2 at the point of exhaust. Technological innovations in this area must be mindful of the unique challenges of installing a carbon capture solution on a ship. For example, space is at a premium – a challenge generally not faced as acutely as on land – so it’s crucial that CCS systems for ships don’t impact overall profitability whilst also delivering on carbon reduction claims.
The CO2 captured will be stored in tanks and be offloaded at port reception facilities. Currently, permanent sequestration options are mostly in Northern Europe, where the CO2 is pumped into used oil fields. However, it seems almost certain that more infrastructure will follow as the world rallies around the potentially transformative impact of CCS on the global fight to decarbonise. One example is the infrastructure package currently making its way through US Congress. This bill earmarks $ 8.58 bn USD for developing CO2 capture and removal.
Wärtsilä is currently applying extensive research and development on a CCS solution, with a view to bringing it to market as soon as possible. We are installing a 1 MW pilot plant at our test facility in Moss, Norway to test the technology in a range of scenarios and conditions.
There is no single solution to shipping’s environmental and regulatory challenges, but CCS will have an important role to play in the fight to reduce the industry’s GHG emissions by 2050. Given the increasing urgency, it is also important to highlight that a CCS solution could be retrofitted to the existing fleet, with a potential to achieve even greater reductions, at a faster pace.
It is undoubtable that shipping faces a high level of variability in its future decarbonisation pathway from a regulatory and technological standpoint. Lacking any single solution, the investment today in modular exhaust treatment systems can provide considerable assurance to shipowners and operators who must chart a profitable path through the new requirements.
By embracing the potential for an ecosystem of modular technologies around the stack to tackle a range of shipping’s pollutants, we will help the industry to solve its decarbonisation puzzle. This proves that the expertise, skills and resilience gained from regulations like the Sulphur Cap will only have stood to benefit our sector in the long run; a useful thing to remember for anyone debating the impact of environmental regulation into the medium and long term.
Author: Sigurd Jenssen, Director Wärtsilä Exhaust Treatment
