Reducing Shipping Pollution: Strategies For Cleaner Seas

Shipping is essential to the world's economy and well-being, but it is also a major contributor to global air pollution. Ships are responsible for about 3% of global greenhouse gas emissions, and the effort to reduce these emissions is not going well. However, there are measures that can be taken to reduce shipping pollution. These measures can be classified into three broad categories: technological improvements, operational changes, and market-based strategies. For example, switching to alternative fuels such as liquified natural gas (LNG) or methanol can help reduce emissions. Additionally, slow steaming, or reducing the speed of ships, can also lead to significant emission reductions.

Use carbon-neutral or green fuel

The use of carbon-neutral or green fuel is essential to reducing shipping pollution and achieving the International Maritime Organization's (IMO) goal of decarbonizing ships. Here are some key points on this topic:

The Need for Carbon-Neutral and Green Fuels

The shipping industry contributes significantly to global carbon emissions, with cargo shipping accounting for nearly 3% of annual greenhouse gas emissions. To address this issue, there is a growing focus on adopting carbon-neutral and green fuels. The IMO has set targets to reduce total shipping emissions by 50% by 2050 and to completely decarbonize ships by the end of the century.

Types of Carbon-Neutral and Green Fuels

Carbon-neutral and green fuels can be categorized into three main types:

• 'Blue' fuels: These are derived from reformed natural gas with carbon capture and storage (CCS) technology.
• Biofuels: This includes bio-gas and bio-diesel produced from sustainable bioenergy sources.
• Electrofuels: These fuels are created using renewable electricity and non-fossil carbon or nitrogen sources, such as synthetic natural gas (SNG), e-ammonia, and e-methanol.

Benefits of Carbon-Neutral and Green Fuels

Carbon-neutral and green fuels offer several advantages over traditional fossil fuels:

• Reduced emissions: These fuels can significantly lower greenhouse gas emissions, nitrogen oxides (NOx), sulphur oxides (SOx), and particulate matter, improving air quality and reducing the impact on climate change.
• Improved human health: By reducing harmful emissions, the use of these fuels can positively impact human health, reducing respiratory and cardiovascular diseases, and premature deaths associated with air pollution.
• Fuel flexibility: Some vessels are being designed to be fuel-flexible, capable of using multiple types of fuel, including conventional and alternative options, ensuring they can adapt to the changing fuel landscape.

Challenges and Future Prospects

While carbon-neutral and green fuels offer a promising path towards reducing shipping pollution, there are some challenges to their widespread adoption:

• Cost and availability: Producing green fuels, such as green methanol, can be extremely costly, and the current production levels are insufficient to meet the demands of the shipping industry.
• Infrastructure development: The transition to alternative fuels requires significant investments in infrastructure, such as building specific fueling facilities in ports around the world.
• Technology advancements: The shift to carbon-neutral fuels must be accompanied by advancements in onboard fuel technology, including the development of fuel cells and improvements in energy efficiency.

In conclusion, the use of carbon-neutral and green fuels is a crucial step towards reducing shipping pollution. While challenges remain, the shipping industry is taking steps to adopt more sustainable practices, with companies like Maersk leading the way. The development and widespread adoption of these alternative fuels will play a key role in achieving the IMO's decarbonization goals and creating a more sustainable future for the shipping industry.

Reduce ship speed

Reducing the speed of ships is a highly effective way to curb emissions and combat the negative impacts of the shipping industry on human health, climate change, and ocean pollution. This approach, known as slow steaming, involves operating a ship's engine at less than full power, thereby reducing fuel consumption and lowering emissions of carbon dioxide and other pollutants.

The benefits of slow steaming are significant and far-reaching. Firstly, it offers substantial environmental benefits. A reduction in ship speed by 10% can lead to a 19% decrease in CO2 emissions across the world fleet, even when accounting for the additional ships required to maintain the same level of transport work. This immediate emissions cut can be achieved without any prior investment or adverse impact on ship operations. Furthermore, slow steaming contributes to a significant decrease in harmful air pollutants such as nitrogen oxides (NOx) and sulphur oxides (SOx), which have detrimental effects on human health and the environment.

In addition to its environmental advantages, slow steaming also offers economic benefits. Implementing a global regime that limits average ship speeds can result in economic gains of USD 178-617 billion, depending on future fuel prices. This approach is particularly appealing as it incurs little to no cost for the shipping industry, with the potential to generate operational savings.

The feasibility of slow steaming has been demonstrated by Maersk, one of the world's largest shipping operators, which has successfully employed this method since 2007, reducing engine load by 35% without encountering any technical issues. The practice is also legally and technically enforceable, as it can be monitored and imposed using existing systems such as the Automatic Identification System (AIS).

The impact of slow steaming on reducing emissions was evident during the 2008 global financial crisis when cargo ships slowed down to cut costs. The resulting 12% decrease in average speeds led to a 27% reduction in daily fuel consumption, demonstrating the effectiveness of this approach in curbing emissions.

While slow steaming is a powerful tool in the short term, it is important to acknowledge that the shipping industry will need to transition to alternative fuels and adopt new technologies in the long term to achieve its decarbonization goals.

Improve fuel efficiency

The shipping industry is exploring the use of LNG fuel, dual-fuel engines, and design modifications to reduce fuel consumption and meet environmental regulations. One such design modification is the Air Lubrication System, which reduces friction between the ship's hull and the seawater by creating a layer of tiny bubbles along the hull's underside. This system is estimated to achieve a 10-15% reduction in CO2 emissions and significant fuel savings.

Another way to improve fuel efficiency is by optimising the shape of the ship's hull, propeller, and rudder. Optimising the hull shape alone can reduce fuel consumption by up to 15% for all types of vessels over 5,000 gross tonnes.

Additionally, fuel savings can be achieved through the use of energy-saving devices such as Hyundai Heavy Industries' Hi-FIN, which is attached to the hub of the ship propeller and improves propulsion efficiency. According to a year-long trial, Hi-FIN saved up to 2.5% of fuel compared to similar vessels without the device.

The Onboard DC Grid System introduced by ABB is another way to improve fuel efficiency. This system allows engines to run at variable speeds for top fuel efficiency at each load level and has been shown to reduce specific fuel oil consumption by up to 27%.

Low Loss Hybrid Energy System

The Low Loss Hybrid (LLH) System by Wartsila is an innovative technology that combines different power sources and energy storage devices to optimise the performance of prime movers. The system reduces transient engine loads, which leads to increased fuel consumption and emissions. The LLH system offers annual fuel savings of up to 15% and significantly reduces exhaust gas emissions.

Modifying the ship's bulbous bow

Modifying the ship's bulbous bow is an effective way to reduce fuel consumption. For example, the NYK group made adjustments to the bulbous bow of a container ship, resulting in a 23% reduction in CO2 emissions over six months. Similarly, the Maersk group reduced fuel costs by approximately 8% using the same technique.

Implement new regulations

Implementing new regulations is a crucial aspect of reducing shipping pollution. Here are some detailed suggestions for new regulations to address this issue:

Regulate Shipping Emissions:

• The International Maritime Organization (IMO) has a crucial role in regulating shipping emissions. The IMO should set stringent emission standards and targets for the industry, focusing on reducing nitrogen oxides (NOx), sulphur oxides (SOx), and particulate matter emissions. These emissions have detrimental effects on human health and the environment.
• Regulations should aim for a significant reduction in greenhouse gas (GHG) emissions from the shipping industry, in alignment with the Paris Agreement goals.
• Implement a global, mandatory charge on GHG emissions from the shipping industry. This can incentivize the reduction of emissions and provide funding for further environmental initiatives.

Improve Fuel Standards:

• Regulate and reduce the use of high-sulfur fuels in the shipping industry. Sulfur emissions contribute to air pollution and have harmful effects on human health and the environment.
• Encourage the development and use of alternative fuels, such as sustainably produced methanol, liquefied natural gas (LNG), or other synthetic fuels. These alternative fuels can reduce emissions and provide a more environmentally friendly option for the industry.

Enhance Energy Efficiency:

• The IMO's Energy Efficiency Design Index (EEDI) is a step in the right direction. However, the regulations should be strengthened to incentivize the adoption of new technologies and further improve energy efficiency.
• Implement stricter fuel efficiency standards for ships, with targets for reducing fuel consumption and improving vessel design. This can lead to lower emissions and fuel costs.
• Promote slow steaming, where ships reduce their operational speed. This practice has been shown to significantly reduce fuel consumption and lower CO2 and air pollutant emissions.

Address Ballast Water Discharges:

• Implement regulations to control and treat ballast water discharges from ships. Ballast water often contains invasive species and pollutants that can cause ecological damage and harm aquatic ecosystems.
• Require ships to use ballast water management systems or treatment technologies to minimize the impact on the marine environment.

Mitigate Noise Pollution:

• Establish regulations to reduce noise pollution from shipping activities. Noise produced by ships can disrupt marine life, particularly whales and other species that rely on sound for communication and navigation.
• Encourage the development and use of quieter propulsion technologies and engine designs to minimize the impact of shipping on marine ecosystems.

These regulatory suggestions provide a starting point for addressing shipping pollution through new policies and standards. It is important to note that the effectiveness of these regulations will depend on international cooperation and enforcement, as well as the adoption of complementary initiatives by the shipping industry.

Develop new technologies

Developing new technologies is crucial to reducing shipping pollution. Here are some ways this can be achieved:

Alternative Energy Sources

The shipping industry can explore alternative energy sources such as wind, solar power, batteries, biofuels, and hydrogen fuel cells. While these technologies are not yet viable for ocean-going commercial ships, they show promise for coastal transport.

Exhaust Gas Cleaning Systems

Exhaust gas cleaning systems, or scrubbers, can remove up to 99% of sulphur oxides (SOx) and 98% of particulate matter from high-sulphur fuel. As an equivalent method to compliant fuels, scrubbers play a crucial role in meeting sulphur emissions regulations.

Selective Catalytic Reduction

Selective catalytic reduction treats exhaust gases before release, reducing nitrogen oxide (NOx) emissions by up to 95%. This technology can be a vital tool in mitigating air pollution from ships.

Engine Modifications

Internal engine modifications, such as adding water, recirculating exhaust gas, cooling water temperatures, or adjusting valve timing, can almost eliminate NOx emissions. These modifications offer a significant opportunity to reduce air pollution from marine engines.

Energy Efficiency Design Index (EEDI)

The IMO's EEDI, approved in 2011, is the first globally binding design standard aimed at mitigating climate change from shipping. It requires new ships to be more energy-efficient, with standards becoming increasingly stringent over time. This incentivises the development and adoption of more efficient ship designs.

Slow Steaming

Slow steaming involves reducing the operational speed of ships, resulting in lower fuel consumption and, consequently, reduced CO2 and air pollutant emissions. This practice can lead to significant emissions reductions without requiring major technological changes.

Frequently asked questions