The Maritime Technologies Forum (MTF) released its latest report providing recommendations regarding the development and implementation of safe onboard carbon capture and storage (OCCS).
MTF’s Safe onboard carbon capture and storage report highlights the potential of OCCS as a technology for reducing GHG emissions in the maritime sector, in line with global decarbonisation goals, including the IMO’s target of net-zero emissions by 2050.
The IMO is developing a regulatory framework for the safe adoption of OCCS, focusing on lifecycle emissions, but as of now, no international regulations fully govern OCCS. The European Union is expected to formalize its stance by 2027 under its ‘Fit for 55’ climate package.
According to the report, the successful implementation of OCCS in the maritime industry relies on two essential prerequisites from the economic and operational perspectives: cost-effectiveness and a secured downstream value chain. These factors are essential for attracting investment, ensuring operational feasibility, and maximizing the environmental benefits of the technology as the captured CO2 needs to be securely stored/utilized effectively.
A secured downstream value chain is the most important prerequisite for OCCS implementation. This contains the infrastructure and processes for offloading, transporting, and permanently storing (or utilizing) the captured CO2.
Prerequisites for an assured value chain and commercial adoption
Establishing a robust downstream value chain potently requires:
Development of offloading infrastructure: investment is required in dedicated terminals or receiving vessels equipped to safely and efficiently offload liquefied CO2 from ships.
Integration with CCUS infrastructure: Integrating the captured CO2 from ships into existing or planned carbon transportation and storage networks to ensure the permanent sequestration of captured CO2.
Standardization of CO2 quality: Establishing clear specifications for the purity and composition of captured CO2 is crucial for ensuring compatibility with different transportation, storage, and utilization options.
Accepted certification: a robust certification scheme for quantifying, monitoring, and verifying carbon removal needs to be in place to ensure value chain elements for accepting proposed CO2 transportation and storage as solutions.
Cost-effectiveness is crucial for the widespread adoption of OCCS. The technology requires significant capital expenditure for the installation of capture units, CO2 conditioning systems, and storage tanks. Operating costs are also a major consideration, including additional energy consumption for capture, CO2 compression and liquefaction, and potential fuel penalties.
There is a need to minimize both capital and operating costs to enhance the economic viability of OCCS.
These can potentially be achieved through various means:
Technological advancements: Research and development of more efficient capturing technologies and systems that can reduce energy consumption and operating cost.
Optimization of system design: Minimizing the size of process equipment and storage tanks to reduce both capital costs and the impact on space.
Economies of scale: As the OCCS market matures and standardization increases, production costs are expected to decrease.
Policy incentives: Government support through subsidies, funds, or carbon pricing mechanisms can help offset the initial investment costs and make OCCS more attractive to shipowners.
Rules and Regulations for OCCS
There are currently no international regulations governing OCCS installations onboard ships (nor how to offload the captured CO2 and transport it to an acceptable permanent storage site). This introduces uncertainties in terms of compliance requirements and standards, and it delays investment and adoption of OCCS technology by shipowners and operators. In the context of ongoing discussions, the regulatory framework for onboard carbon capture has seen some progress.
Regulatory Gaps for Onboard Carbon Capture Systems
Despite the efforts of classification societies to close regulatory gaps, further evaluation and clarification are needed for the following topics. These items can be assessed as part of the larger carbon value chain ecosystem and require industry-wide understanding. However, in the context of the OCCS, the maritime sector and its specific requirements should be taken into consideration.
- Carbon Dioxide Impurities: Impurities in captured CO2 affect its triple point and the reliquefaction process, which impacts the design of CO2 tanks and piping. These impurities, such as water and other gases like SOx and NOx, can cause corrosion and operational issues. The CO2’s chemical composition should be carefully considered when selecting materials for onboard systems.
- Toxicity: While CO2 is typically classified as an asphyxiant, there is growing consideration to also classify it as toxic due to its potential risks. The IGC Code for CO2 transportation has been updated, requiring fixed gas detection systems on ships carrying CO2 cargo. However, for ships using carbon capture systems, there may be a need for clarification from IMO on whether these same safety standards should apply.

- Other Onboard CCS Technologies: Technologies such as Cryogenic, Membrane, and Calcium Looping are emerging as alternatives to chemical absorption for carbon capture. These technologies are still in development and will be reviewed on a case-by-case basis, with prescriptive rules to be established for clarity.
- Crew Training: Proper training is crucial for the safe and efficient operation of OCCS. Training programs should include operational procedures, safety protocols, and maintenance, alongside knowledge of environmental regulations. The IMO is working on developing training provisions for seafarers operating ships with alternative fuels, which will include considerations for new technologies like OCCS.
- Safety Management: The ISM Code should be adapted to address the specific challenges of OCCS operations, including maintenance and emergency procedures. The implementation of a Safety Management System (SMS) should reflect the unique safety requirements of new technologies and alternative fuels to ensure safe operations.
The report proposes several key next steps to facilitate the adoption of OCCS in the maritime industry:
- Collaborate to create a secured downstream value chain comprising of CO2 offloading facilities, transport infrastructure and long-term storage, together with associated MRV schemes, aiming that captured CO2 emissions are permanently stored.
- Establish clear and consistent regulations on safety and environmental performance, which include:
- Develop safety guidelines specifically for OCCS, covering aspects like equipment design, risk assessment, and emergency response procedures.
- Consistently incorporate OCCS into existing regulations, such as the EEDI, EEXI and CII as well as into the EU ETS and FuelEU Maritime.
- Develop certification schemes for downstream CO2 value chain infrastructure.
- Define acceptable levels of CO2 impurities and develop standardized guidelines for safe CO2 handling, including offloading procedures and port infrastructure requirements.
- Amend the Safety Management Systems and develop specialized training programs for crew members covering the operation, maintenance and emergency procedures for OCCS systems.
- Focus on development of OCCS technologies to increase CO2 capture rates, reduce energy demand and, thus, increase cost-effectiveness and demonstrate OCCS systems in pilot projects to gather operational experience.