Emission Reduction Technologies

Emission reduction technologies focus on reducing or capturing emissions from vessels and port operations where full electrification or transition to low- and zero-carbon fuels is not yet feasible. These technologies provide near-term solutions to address greenhouse gas emissions and local air pollutants, particularly in operational contexts where infrastructure, vessel compatibility, or economic constraints limit the adoption of alternative fuels or shore power.

This practice includes emissions capture and control systems, exhaust after-treatment technologies, and temporary or mobile solutions that can be deployed flexibly across port environments. Emissions capture systems can collect and treat exhaust gases from vessels at berth, while after-treatment technologies such as scrubbers and filtration systems reduce pollutants at the source. Mobile or barge-based solutions provide additional flexibility, enabling emissions reductions without requiring permanent infrastructure at each berth. It should be noted that open-loop scrubber washwater discharge is restricted in some jurisdictions.

Emission reduction technologies address the core objective of reducing emissions in the near term while supporting compliance with evolving environmental regulations. They are closely linked to other practices, including shore power and future fuels, as complementary or transitional solutions. While not always providing full decarbonization, these technologies play an important role in bridging the gap between current operations and long-term zero-emission pathways.

Emission reduction technologies encompass a range of systems designed to reduce, capture, or treat emissions from vessels and port operations where full electrification or fuel switching is not yet practical. In many ports, particularly those handling diverse vessel types or operating under space and infrastructure constraints, immediate implementation of shore power or alternative fuels may not be feasible. In these contexts, emissions capture and control systems (ECC), exhaust after-treatment technologies, and mobile solutions offer practical alternatives to reduce emissions at berth or during operations.

As a near-term emissions control approach, these technologies address emissions from existing assets, enabling reductions without requiring fundamental changes to vessel propulsion systems or fuel supply chains. Emissions capture and control systems can be deployed at berth to collect exhaust gases from auxiliary engines and route them through treatment systems that remove air pollutants such as particulate matter, nitrogen oxides and sulfur oxides. Capture of carbon dioxide at berth is at an early stage and is a different process. Exhaust after-treatment technologies, including scrubbers and particulate filtration systems, reduce emissions directly at the source. These approaches support compliance with regulatory requirements while allowing ports and operators to continue using existing infrastructure and fleets. In addition, mobile or barge-based systems can provide flexible deployment across multiple berths, reducing the need for permanent infrastructure.

Globally, emission reduction technologies are being implemented and evaluated in response to increasingly stringent environmental regulations. In California, these technologies are being deployed as part of compliance pathways under regulations such as the At-Berth Regulation, which allows for alternatives to shore power where equivalent emissions reductions can be demonstrated. Publicly available feasibility studies for terminals such as Valero Benicia and Phillips 66 Rodeo provide detailed assessments of emissions capture and control systems, including technical design considerations, operational constraints, and cost implications (Moffatt & Nichol, 2022a; Moffatt & Nichol, 2022b). In addition, studies prepared for the United States Maritime Administration (MARAD) evaluate the technical and economic feasibility of carbon capture systems in maritime applications, highlighting both opportunities and limitations of these technologies (Life Cycle Engineering, 2022; Life Cycle Engineering, 2024). Broader industry assessments also examine onboard carbon capture and storage concepts, identifying key challenges related to system integration, energy requirements, and scalability (Transport & Environment, 2026).

In DMCs, deployment of emission reduction technologies is more limited but represents a potential pathway for near-term emissions reductions, particularly in ports where large-scale electrification or alternative fuel infrastructure is not yet available. Given the diversity of vessel traffic and infrastructure constraints in the region, mobile or flexible solutions may offer practical advantages. As regulatory frameworks evolve and emissions reduction targets become more defined, these technologies may play an important role in enabling early compliance and supporting transitional strategies.

Successful implementation of emission reduction technologies depends on several enabling factors.

• Regulatory frameworks are a primary driver, as clear compliance pathways and performance standards are necessary to support adoption.
• Technical guidance and safety standards are also critical, particularly for emissions capture systems that involve handling exhaust gases and potentially hazardous conditions.
• Industry guidance, including recommendations developed by OCIMF, highlights the importance of safety, operational procedures, and system integration for emissions capture at berth (OCIMF, 2025b).
• In addition, successful deployment requires coordination among port authorities, terminal operators, technology providers, and regulators to ensure compatibility with existing operations.

Key challenges include system complexity, energy requirements, operational integration, and cost. While these technologies can provide significant reductions in air pollutants, they are generally considered transitional solutions, and their long-term role will depend on the pace of adoption of zero-emission fuels and electrification pathways. Addressing these challenges through pilot projects, regulatory support, and continued technological development will be essential to scaling emission reduction technologies in port environments.