**2.3 Compression**

To be transported, CO2 needs to be compressed. The compression range depends on how it will be transported. For pipeline transport, the CO2 needs to be compressed in the range between 1100 and 3100 psi to assure single phase flow, because above 1100 psi, CO2 remains in single phase within a broad range of temperatures. Since pipelines are subject to great temperature variations, it is important to avoid the formation of two phases, which can cause pressure spikes that can in turn rupture pipes (Barrie et al., 2004).

The pressure required is much lower for transport in tank trucks, railcars or ships, because the temperature can be kept low through thermal insulation, something that is uneconomic in the case of pipelines. Therefore, pressures of 250 to 400 psi are sufficient to keep the CO2 in the liquid phase.
