Carbon dioxide (CO2) captured from coal flue gas or synthesis gas must be compressed (to a pressure between 1,500 and 2,200 psi) to transport it via pipeline for geologic storage, enhanced oil recovery, or CO2 utilization.
Compression of CO2 is challenging because it represents a potentially large auxiliary power load on the overall power plant system. For example, in an August 2007 study conducted for NETL, CO2 compression was accomplished using a six-stage centrifugal compressor with interstage cooling that required an auxiliary load of approximately 7.5 percent of the gross power output of a subcritical pressure, coal-fired power plant.