Piégeage et stockage du CO₂

4. How can CO₂ be transported once it is captured?

• 4.1 What are the methods of CO₂ transport?
• 4.2 How expensive is CO₂ transport?

4.1 What are the methods of CO₂ transport?

Except when the source is located directly over the storage site, the CO₂ needs to be transported to the storage site. There are several ways of doing this.

Concentrated streams of CO₂ can safely be transported through pipelines at high pressure. Such pipelines have been used in the USA since the early 1970s for enhanced oil recovery (EOR) and are currently the main method for transporting CO₂. Experience over the past decades, mainly with gas pipelines, has shown that very few accidents occur and that risks associated with appropriately designed pipelines are low.

CO₂ can also be transported as a liquid, in ships similar to those transporting liquefied petroleum gas (LPG).

In liquid form, CO₂ could technically also be transported on road tankers or railcars in insulated tanks at low temperature and at much lower pressure than in pipelines, but this option is not economical for large scale CO₂ transport. More...

4.2 How expensive is CO₂ transport?

For both pipeline and marine transportation of CO₂, costs depend on the distance and the quantity transported. For pipelines costs are higher when they are routed offshore or across heavily congested areas, mountains or rivers. Fluctuations in the price of steel would also have an impact on the cost of pipeline transport. For a distance of 250 km (about 155 miles), the estimated cost of pipeline transport typically ranges from 1-8 US$ per tonne CO₂.

In ship transport, costs depend on characteristics such as tanker volume. If transport by ship is possible, it is generally cheaper than pipeline transport for distances over 1000 km and for amounts of CO₂ smaller than a few million tonnes per year (see Figure TS.6 ). More...