CO2 Transportation: Sealing Solutions for Tomorrow's CCUS Infrastructure
January 20, 2025
6 Minute Read
In the Net Zero Emissions Scenario put forth by the International Energy Agency (IEA), around one billion tons of carbon dioxide (CO2) must be sequestered annually to meet the Paris Agreement's goal of limiting global temperature increase by 1.5° Celsius. Carbon capture, utilisation and storage (CCUS), which involves sequestering and storing CO2 emissions is critical to achieving this goal.
CCUS is a widely adopted approach to decarbonisation and the total number of projects is growing; according to the IEA, "2023 saw continued year-on-year growth in project announcements, final investment decisions (FIDs) and plant commissioning." However, successfully leveraging CCUS to reduce emissions depends on the creation of CO2 transportation infrastructure capable of connecting capture facilities and storage sites at scale.
CO2 Transport for Various Phases
Any effective strategy for handling CO2 must reflect its dynamic physical properties. CO2 is not easy to handle around the critical point, as relatively minor temperature and/or pressure fluctuations can cause it to change phase, i.e., from liquid to supercritical phase. CO2's particularity comes from possessing an additional sCO2 phase, which occurs close to ambient temperature.
Supercritical CO2 Condition
Carbon dioxide in the supercritical phase exhibits both gas and liquid properties. This phase requires maintaining pressure and temperature above CO2's critical point. We are observing a trend of increasing pressures in pipeline transport, due to larger volumes leading to a supercritical CO2 phase (also known as the dense phase; abbreviated as sCO2) where in the right conditions, pumps are being used rather than compressors.
View this on-demand webinar for a deeper dive into the physical properties of sCO2.
Understanding the characteristics of CO2 in liquid, gaseous and supercritical phases is key to developing safe, efficient carbon dioxide transportation.
Liquid CO2 Transport
As a liquid, CO2 can be pumped through pipelines and shipped by sea, road or rail in insulated vessels, with a pressure high enough and/or temperature low enough to prevent it from changing to a gaseous phase. This method is commonly used for transporting carbon dioxide from an industrial facility to a storage site.
Gaseous CO2 Transport
In the gaseous phase, large quantities of CO2 can be moved via pipeline over long distances from capture facilities to storage sites or utilisation plants. Carbon dioxide pipelines are currently used to transfer CO2 to enhanced oil recovery (EOR) sites and other permanent storage locations.
Challenges and Solutions for CO2 Transport
Although marine shipping is sometimes the only option for long-distance, intercontinental transportation pipelines could be a more practical choice for carbon dioxide transport. Whether retrofitting existing pipelines or building new ones specifically for CO2, numerous challenges must be addressed to ensure transportation development keeps pace with that of CO2 capture and storage.
Facilitating Pipeline Conversion
One potential answer to stimulate infrastructure growth, involves converting unused capacity in existing pipeline networks to CO2 service. Any pipelines being considered would require a thorough assessment to determine their suitability for handling CO2.
The conversion of oil pipelines is unlikely, as their design pressure is often lower than the requirements for carbon dioxide. Converting natural gas pipelines is more feasible as they are typically designed to operate under higher pressures.
Maintaining CO2 Purity
The quantity of impurities in captured carbon dioxide — which can include glycols, oxygen, argon, carbon monoxide, hydrogen and methane — varies depending on the industry type and capture method. The presence of these materials can change the phase envelope and behaviour of CO2 which makes transportation even more complex. When combined with water, for example, impurities can cause corrosion due to carbonic acid build-up and shorten the design life of a pipeline.
Minimising Fugitive Emissions
By effectively monitoring and detecting fugitive emissions, operators can reduce the environmental impact of CO2 pipelines. Taking action to address and prevent future releases supports the overall efficiency of carbon dioxide transportation and protects against the potential hazards of CO2 release throughout the process.
Strategies such as tailored asset management programs that check assets for leakage and necessary repairs can help carbon dioxide transporters make progress toward net zero goals.
Developing Tomorrow's CCUS Infrastructure
As carbon capture and storage increase, transportation infrastructure must scale to keep pace. Global CO2 capture and storage is increasing annually; according to IEA data, announced capture capacity for 2030 increased by 35% in 2023, while announced storage capacity rose by 70%.
Available storage options and locations will influence which transportation methods best serve the CO2 value chain.
Geological Storage
In addition to previously drilled oil and gas reservoirs, offshore rock formations with high porosity and a fault-free sealing layer offer potential CO2 storage, as do inland features like salt caverns. Its development has the potential to expand the global carbon dioxide economy to include countries rich in favourable storage geology.
Optimising the Value Chain Using Collection Points
Rather than a single project that takes on all aspects of CCUS, implementing a "hub" can optimise infrastructure use and allow smaller industry players to participate in the value chain.
A CCUS hub is a grouping of carbon capture facilities that share CO2 transport, utilisation and storage. Hubs can decrease building costs through economies of scale and reduce operational and investment risks. Large-scale cooperation is also more likely to garner governmental visibility and support than an effort by an individual organisation.
According to a 2023 McKinsey report, there have been numerous government funding calls for hub developments in Canada, Europe and the US. About 15 CCUS hubs are under various stages of development globally, with many more being planned.
The McKinsey report goes on to discuss five emerging hub archetypes: large emitter-dominated hubs; cross-industry hubs; storage-led hubs; smaller, higher-purity emitter hubs; and carbon removal-led hubs. Increased investment in transportation infrastructure is essential regardless of the hub structure.
Market-Ready Sealing Solutions for CO2 Transportation
Responsible emissions management includes the operation of equipment and facilities used to transport carbon dioxide. By pairing sealing technologies designed specifically for CO2 with asset management, operators can bolster emissions reduction efforts and overall sustainability.
CO2 Sealing Technologies
John Crane's market-ready mechanical sealing technologies support the transportation link of the CO2 value chain. Our patented spiral groove technology is a non-contacting sealing solution for pumps and compressors in CO2 service — whether it involves a gaseous or supercritical phase.
Very few non-contacting mechanical seals increase operational reliability by controlling the phase change that causes traditional sealing methods to wear or fail prematurely. However, John Crane's Type 8628VL, uses spiral groove technology to seal ethene and ethylene at pipeline pressures without face contact — helping keep mechanical seals operating efficiently and reliably in the liquid, supercritical or vapour phase. And we're continuing to invest in engineering enhancements that can be used for CO2 transportation for tomorrow's CCUS infrastructure.
Asset Management
By implementing a comprehensive asset management strategy, operators can increase the lifespan and reduce downtime of their transportation infrastructure. Customised to our customers' business objectives and operations, John Crane's Asset Management Solutions provide the data and processes to help increase reliability and extend asset life. Components of an effective asset management strategy include maintenance strategy, reliability services, Condition Monitoring (CM) and Condition-based Monitoring (CBM), spares optimisation services, lubrication management and other services designed to lower total cost of ownership (TCO) of an asset.
The proper technology, planning and maintenance practices form the backbone of reliable CO2 transport — with benefits that extend across the CCUS value chain. Leak-free assets and equipment are a piece of the decarbonisation puzzle, but more efforts will be needed to achieve net zero.
Policy and Regulatory Considerations
Around the world, policymakers are taking decarbonisation seriously. Government support for CO2 transport and storage infrastructure is growing, with the U.S. DOE announcing $500 million for building carbon dioxide transportation in 2024.
Furthermore, the European Union's 2023 Connecting Europe Facility-Energy fund offers €594 million for cross-border energy infrastructure projects.
Supporting decarbonisation with policies and regulations is an important step, but it can take years to get from approved project funding to completion. Accelerating emissions reduction requires both industry and governing bodies to address potential bottlenecks, such as permitting, early in the project process. Incentivising CCUS hubs can help scale up infrastructure and lower the entry barrier for new capture and storage initiatives.
Navigate CO2 Transportation With John Crane
Carbon capture solutions are pivotal to John Crane's vision for the energy industry's sustainable future, and we're investing now in sealing, filtration and couplings technologies that accelerate progress across the CCUS value chain — including the mission-critical challenge of safe, scalable transportation.
Learn more about John Crane's market-ready CCUS solutions for carbon dioxide transport.