The main options are pipelines, ships and tanker trucks. For pipeline transport, the carbon dioxide gas is usually compressed. At a pressure of more than 74 atmospheres it enters what’s known as dense phase: dense like a liquid, but highly compressible and low viscosity like a gas. Pipeline transport is the lowest-cost option for large volumes of carbon dioxide or where pipeline infrastructure already exists. This is the solution being used by Net Zero Teesside in the UK and Port of Rotterdam in the Netherlands, for example.
Where stores or pipelines are not readily available or volumes are smaller, carbon dioxide can be chilled into a liquid state to go on ships and/or tanker trucks for transport to the injection location. The transport cost per tonne is higher, but the solution offers greater flexibility for collecting multiple sources, requires less capital expenditure upfront and is lower risk in built-up areas. Northern Lights in Norway is developing an innovative solution to allow emissions to be collected by truck from emitters from across Europe, brought to ports where it is shipped to Norway and stored in a saline aquifer in the North Sea.