Transport

Safely and reliably transporting carbon dioxide (CO₂) from where it is captured to a storage site is an
important stage in the carbon capture and storage (CCS) process. The transportation of CO₂ and other gases is already a reality, occurring daily in many parts of the world. However to reduce greenhouse gases at the required level through CCS, significant investment will have to be made in developing extended infrastructure.

Transportation methods

The transportation of gases such as CO₂ has been occurring around the world for most of the 21st century.

Pipelines are, and are likely to continue to be, the most common method of transporting the very large quantities of CO₂ involved in CCS. There are already millions of kilometres of pipelines around the world that transport various gases, including CO₂.

Transport of small quantities of CO₂ by truck and rail is possible. Trucks are currently used at some project sites, moving the CO₂ from capture to very nearby storage locations. Given the large quantities that would be captured via CCS in the long term, it is unlikely that truck and rail transport will be significant.

Ship transportation can be an alternative option for many regions of the world. Shipment of CO₂ already takes place on a small scale in Europe, where ships transport food-quality CO₂ (around 1000 tonnes) from large point sources to coastal distribution terminals.

Larger-scale shipment of CO₂ is likely to have much in common with the shipment of liquefied petroleum gas (LPG), an area in which there is already a great deal of expertise and which has developed into a worldwide industry over a period of 70 years.

Design work on larger CO₂ carrier vessels is already underway in Norway and Japan. It is expected that the CO₂ carriers will be very similar in design to that of semi-refrigerated LPG carriers which carry their cargoes at temperatures around minus 50°C. The likely capacities are in the range of 10,000 to 40,000m³.

Safety

Pipelines are an established technology, both on land and under the sea. In the United States, there is approximately 800,000km of pipeline that has been safely and reliably transporting hazardous liquid and natural gas for as long as 40 years, in addition to 3.5 million kilometres of natural gas distribution lines. Some 6000km of pipelines actively transport CO₂ today.
Europe, the Middle East, China and other parts of the world also have some pipelines for transporting CO₂ and other gases.

Clusters, hubs and networks

In the early days of commercial CCS deployment, it is likely that projects will rely on a complex transport infrastructure with many carbon sources being linked to storage sinks through a shared network using pipelines and other methods of transport.
Such networks have environmental and commercial benefits and require early and close cooperation between all the stakeholders, particularly industry and governments.
A clustered transport system could potentially save over 25 per cent of expenditure compared to a point-to-point system, depending on the scale of the cluster. Developing such a network can also significantly reduce barriers to future investment.
Large-scale deployment of CCS should result in the linking of clusters of proximate CO₂ sources, through a hub, to clusters of sinks by trunk pipelines. Then shorter collection, feeder or distribution pipelines would link the individual sources and sinks into the network. A simple network would consist of a ‘tree’ where each of the branches represented feeder pipelines from sources of CO₂, the trunk of the tree would be the main CO₂ pipeline and the roots would be the distribution pipelines linking to the various sinks.
The participation of multiple stakeholders and industries has the potential to develop business and financing structures to underpin future commercial CCS markets. Networks can also encourage and increase the speed of deployment in the region, for example, by reducing the total number of permits that would need to be issued for pipelines.
Networks also provide the opportunity to connect small emitters for whom point-to-point solutions may be too expensive and to build up regional employment and expertise in the necessary technologies.
There are a number of CO₂ transport hubs and clusters being proposed or developed in Australia, Europe and North America.