Emissions Scrubbing Technologies for Ships

Detailed overview of innovation with sample startups and prominent university research

What it is

Emissions scrubbing technologies, also known as exhaust gas cleaning systems (EGCS), are onboard systems that remove harmful pollutants, such as sulfur oxides (SOx), nitrogen oxides (NOx), and particulate matter (PM), from ship exhaust gases before they are released into the atmosphere.

Impact on climate action

Emissions scrubbing technologies revolutionize low-carbon marine efforts by drastically reducing ship emissions. These innovations efficiently capture pollutants, like sulfur oxides and particulate matter, mitigating environmental harm. By enabling cleaner maritime transport, they accelerate progress towards global climate action goals, fostering a sustainable marine industry and cleaner air for communities worldwide.


  • Scrubber Systems: These systems use a scrubbing liquid, typically seawater or a chemical solution, to capture and neutralize pollutants from exhaust gas.
    • Open-Loop Scrubbers: Seawater is used as the scrubbing liquid and discharged back into the sea after treatment.
    • Closed-Loop Scrubbers: A chemical solution is used to scrub the exhaust gas, and the solution is then treated and recirculated.
    • Hybrid Scrubbers: These systems can operate in both open-loop and closed-loop modes, offering greater flexibility depending on operational requirements and environmental regulations.
  • Selective Catalytic Reduction (SCR): SCR systems use a catalyst and a reagent, such as urea, to convert NOx emissions into harmless nitrogen and water.
  • Electrostatic Precipitators (ESPs): ESPs use an electrical charge to remove particulate matter from exhaust gas.

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Prominent Innovation themes

  • Advanced Scrubber Designs: Research and development efforts focus on improving the efficiency and reducing the size and cost of scrubber systems.
  • Alternative Scrubbing Liquids: Exploring the use of alternative scrubbing liquids, such as freshwater or alkaline solutions, to minimize environmental impact and reduce operational costs.
  • Hybrid Scrubber Optimization: Developing more sophisticated hybrid scrubbers that can seamlessly switch between open-loop and closed-loop modes based on operational needs and environmental regulations.
  • Integrated Emissions Monitoring: Integrating sensors and data analytics into emissions scrubbing systems to monitor performance, optimize operation, and ensure compliance with emission regulations.
  • Carbon Capture Integration: Exploring the potential to integrate carbon capture technologies with emissions scrubbing systems to capture CO2 from exhaust gas for storage or utilization.

Other Innovation Subthemes

  • Scrubber Efficiency Enhancements
  • Novel Scrubbing Liquid Solutions
  • Hybrid Scrubber Advancements
  • Miniaturized Scrubber Designs
  • Freshwater Scrubbing Technologies
  • Alkaline Solution Scrubbers
  • Flexible Hybrid Scrubber Systems
  • Real-Time Emissions Monitoring
  • Data Analytics for Emissions Control
  • Regulatory Compliance Solutions
  • Carbon Capture Integration Strategies
  • CO2 Storage and Utilization Techniques
  • Pollution Reduction Technologies
  • Green Shipping Initiatives
  • Eco-Friendly Vessel Operations

Sample Global Startups and Companies

  • Yara Marine Technologies:
    • Technology Focus: Yara Marine Technologies specializes in emissions reduction solutions for the maritime industry, particularly focusing on reducing pollutants like sulfur oxides (SOx) and nitrogen oxides (NOx) from ship emissions. They may employ technologies such as scrubbers and selective catalytic reduction (SCR) systems.
    • Uniqueness: Yara Marine Technologies might differentiate itself through innovative scrubbing technologies tailored specifically for maritime applications, ensuring compliance with increasingly stringent environmental regulations while minimizing operational costs.
    • End-User Segments: Their target segments include shipowners, operators, and maritime companies seeking compliance with emissions regulations, particularly in regions with strict sulfur emission control areas (SECAs) like the Baltic Sea and North Sea.
  • Alfa Laval:
    • Technology Focus: Alfa Laval is a global provider of heat transfer, separation, and fluid handling solutions, including emissions scrubbing technologies for various industries, including marine, power generation, and industrial processes. Their solutions may include scrubber systems, exhaust gas cleaning systems, and related services.
    • Uniqueness: Alfa Laval’s uniqueness lies in its comprehensive portfolio of emissions scrubbing solutions across multiple industries, backed by decades of experience and expertise in fluid handling and environmental technologies.
    • End-User Segments: Their target segments encompass a wide range of industries, including marine shipping, power plants, refineries, and industrial manufacturing, where emissions reduction and regulatory compliance are paramount.
  • Wärtsilä:
    • Technology Focus: Wärtsilä is a leading provider of power solutions for the marine and energy industries, offering emissions scrubbing technologies as part of its broader portfolio of environmental solutions. Their offerings may include exhaust gas cleaning systems, hybrid scrubbers, and retrofit solutions for existing vessels and power plants.
    • Uniqueness: Wärtsilä stands out for its integrated approach to emissions reduction, combining scrubbing technologies with advanced propulsion systems, energy storage, and digital solutions to optimize efficiency and minimize environmental impact.
    • End-User Segments: Their target segments encompass marine operators, power plant owners, and energy companies seeking cost-effective solutions for emissions reduction and compliance with regulatory requirements, particularly in regions with strict emissions standards like the IMO’s sulfur cap.

Sample Research At Top-Tier Universities

  1. Technical University of Denmark (DTU):
    • Technology Enhancements: DTU researchers are innovating emissions scrubbing technologies for marine vessels by developing novel materials and processes for capturing and neutralizing pollutants emitted from ship engines. They are exploring advanced chemical and physical scrubbing techniques to achieve higher efficiency and lower operational costs.
    • Uniqueness of Research: DTU’s approach involves the integration of emissions scrubbing systems with renewable energy sources such as solar and wind power to reduce the environmental footprint of marine transportation further. They are also investigating the potential of utilizing waste heat from ship engines to enhance the performance of scrubbing systems.
    • End-use Applications: The emissions scrubbing technologies developed at DTU have direct applications in the shipping industry, enabling vessels to comply with stringent environmental regulations such as the IMO’s sulfur cap and reduce their carbon footprint. Additionally, the research outcomes may have broader implications for other industries seeking to reduce air pollution and greenhouse gas emissions.
  2. University of Manchester:
    • Technology Enhancements: Researchers at the University of Manchester are focusing on the development of next-generation emissions scrubbing technologies for maritime applications, leveraging advancements in materials science and catalysis. They are exploring innovative catalysts and sorbents to improve the efficiency and durability of scrubbing systems while minimizing energy consumption.
    • Uniqueness of Research: The research at the University of Manchester emphasizes the scalability and cost-effectiveness of emissions scrubbing technologies, aiming to make them accessible to a wide range of marine vessels, including small-scale and inland waterway transport. They are also investigating the potential for synergies between emissions control and energy recovery systems onboard ships.
    • End-use Applications: The emissions scrubbing technologies developed at the University of Manchester have implications for both commercial shipping and leisure marine sectors, enabling operators to comply with emissions regulations and enhance environmental sustainability. Moreover, the research outcomes may contribute to the development of cleaner and more efficient propulsion systems for marine vehicles.
  3. Shanghai Maritime University:
    • Technology Enhancements: Researchers at Shanghai Maritime University are exploring emissions scrubbing technologies tailored to the specific requirements of maritime operations in coastal and inland waterways. They are developing compact and modular scrubbing systems that can be easily integrated into existing ship designs and adapted to different vessel types and sizes.
    • Uniqueness of Research: The research at Shanghai Maritime University emphasizes the optimization of emissions scrubbing systems for regional and local environmental conditions, taking into account factors such as water quality, air pollution levels, and shipping traffic patterns. They are also investigating the potential synergies between emissions control and ballast water treatment systems.
    • End-use Applications: The emissions scrubbing technologies developed at Shanghai Maritime University have direct applications in the regulation of air pollution and greenhouse gas emissions from shipping activities in coastal and inland waters. By implementing these technologies, maritime stakeholders can mitigate the environmental impact of their operations and contribute to sustainable coastal development initiatives.

commercial_img Commercial Implementation

Emissions scrubbing technologies are widely implemented in the maritime industry. A large number of ships, particularly those operating in emission control areas (ECAs) with strict sulfur emission limits, have installed scrubber systems to comply with regulations. The adoption of these technologies has significantly reduced SOx emissions from shipping.