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Marine emission legislations drive the technical development of marine engines forward

The emission legislations in the marine industry have had a remarkable development since late eighties. The legislations are not only beneficial for the environment but have also contributed to the technical development of marine engines. More effective injection methods, combustion processes and aftertreatment systems are just a few examples of improvements that have been made on marine engines over the years. And, according to me, this is only the beginning.  

Marine emission legislations seen through history

During the mid-sixties, the US was the first country in the world to start recognising the negative aspects coming from exhaust emissions. In order to reduce the exhaust emissions, the US started investigating where the largest exhaust volumes came from. The largest emission source was engines in road vehicles, leading to a first emission legislation that applied to cars, trucks and buses. Later, the legislation expanded to also include the second largest emission source, which was industrial engines and off-road vehicles. The third largest emission source was marine engines. It was not until the late eighties that the first marine emission legislation came, which was a local legislation regarding the protection of a European lake. However, the marine industry had to wait until the beginning of the 21st century before marine emission legislations became a fact.    

Global marine emission legislations are executed by IMO, the US and EU

There is a high demand in the marine industry for a harmonised, global legislation. Many different legislations result in administrative costs for the engine manufacturers, money that instead could have been invested in developing new environmental-enhanced engine techniques. Today, legislations regarding marine emission levels are mainly executed by three actors: IMO, the US and EU.

International shipping, American waters and European inland waterways

The UN agency IMO, International Maritime Organization, is the global standard-setting authority for the safety, security and environmental performance of international shipping. The legislations coming from IMO relate to marine diesel engines over 130 kWa operating in international traffic as well as for most countries in domestic traffic. IMO presents legislative proposals, coming into effect when a majority of the member countries have approved of the proposals.

The US and EU are the biggest marine markets and have requirement profiles that are very much alike. The US EPA (Environmental Protection Agency) has, over time, implemented the marine emission legislations: EPA – Tier 1, Tier 2, Tier 3 and Tier 4. The first three “Tiers” can be met with in-engine development, such as injection methods and combustion methods, while the Tier 4 stringent limits require an effective aftertreatment system to decrease emissions. Today, Tier 3 is valid for engines up to 600 kW of power while Tier 4 is applicable for engines above 600 kW.

EU’s marine emission legislations for commercial vessels are directed only to inland waterways while recreational vessels are regulated both inland and at sea within EU. One of the objectives with EU’s emission legislations is to improve air quality. European shipping on inland waterways often passes through densely populated areas that become affected by the emissions from the vessels. Therefore, EU has implemented a marine legislation regarding inland waterways, which is very similar to the US EPA Tier 2 legislation.

In 2019/2020, EU will introduce a new Stage V for inland waterways, which in general will enforce same aftertreatment systems as being used today for on-road trucks. This is especially valid for engines above 300 kW where not only SCR (Selective Catalytic Reduction) but also particulate filters will be needed. This new regulation will be the world’s toughest emission legislation for marine engines. Thus, this will be the first time that EU has tougher requirements than the US.   

Development of injection systems and electronic controls of the engines

The development of marine emission legislations has resulted in a huge technical development on marine engines. What in the past were considered impossible emission levels to achieve, we have today outdone by far. The biggest changes on marine engines relate to injection systems, electronic controls of the engines, as well as supercharging systems containing turbos and air coolers to create a more effective combustion process. When decreasing emission levels, there is only so much that can be done with the engine. The next step, to decrease the damaging emission levels even more, is to focus on the aftertreatment system. When adding an aftertreatment system the engine is complemented with additional features that transform the exhaust gases, leading to a heavy reduction of the harmful emissions with up to 90%. This can be done by adding a filter that captures the harmful particles, which then are subjected to a combustion process. Another alternative is to use a catalyst substance (SCR technology) that converts chemical gaseous substances to non-harmful substances.  

Marine engines over 130 kWa will be required to have aftertreatment systems within IMO emission control areas

Volvo Penta IMO Tier III solution

IMO introduced already in 2008 a Tier III with stringent NOx limits for selected areas. These areas are designated NOx Emission Control Areas (NECA) and are today in force in North America (Since 2016) and will come into force on January 1, 2021 in the Baltic Sea, part of the North Sea and the English Channel. Most high speed and medium speed engines will be introduced to the SCR technology to be able to meet the limits. In US, the IMO Tier III is only valid for ships in international voyage while domestic vessels are covered by domestic EPA Tier 3 and Tier 4. For Europe, the IMO Tier III will be valid for both domestic vessels and ships in international voyage. Thus, smaller engines meeting the IMO Tier III are being developed for the NECA introduction in Europe i.e. 2021.

Engine installations with aftertreatment systems are generally bigger and release more heat in the engine room than those without. Therefore, it will be a challenge to design engines with aftertreatment systems that will fit in smaller boats such as taxi boats and small ferries that operate in these areas. Therefore, this legislation will affect the design work of smaller vessels.

Supercharging systems, high uptime and good fuel efficiency

Volvo Penta works hard to adjust the marine engines according to the emission legislations. The development of our marine engines has benefited from the Volvo Group’s technical knowledge based on the development of engines operating in trucks, buses and construction equipment. The technology coming from the Volvo Group’s road vehicles has helped Volvo Penta develop marine engines with excellent supercharging systems, high uptime and good fuel efficiency, while at the same time fulfilling tough environmental requirements. Without proper knowledge and investments, it can be challenging to manufacture engines that live up to all those requirements.  

Environmental care has always been a top priority for our marine customers. Since Volvo Penta’s products are exported globally, our engines must be allowed to operate all over the world. Therefore, we design our engines to stay at the forefront when it comes to emission levels to give our customers a competitive edge on the global market.  

The goal for the marine industry is to reduce emission levels to zero

The goal everyone in the marine industry is striving for is to reduce emission levels to zero. If focus in the past has been on dangerous emissions, the focus now certainly includes greenhouse gases and fuel efficiency. That will be a journey full of different innovations and solutions, such as different combustion techniques, hybrid solutions and alternative fuels.

Probably, there is not one right solution to the problem, but several. We, at Volvo Penta, are eager to take on the future and what it holds for us when it comes to designing marine power solution systems.

I hope you enjoyed reading my article about marine emission legislations and how they have influenced the technical development on marine engines. Feel free to contact me if you have any questions or visit our website for more information. If you liked the article, you are welcome to like and share the article in our social media channels.    

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