For the full compression system, a comparison is made against the Integrated Environmental Control Model (IECM) developed for the U.S. Department of Energy's National Energy Technology Laboratory (DOE/NETL) by Carnegie Mellon University and University of Wyoming . Data has been generated for a four-stage compression of CO 2 up to 159 bar with an inter-cooling temperature of 35 • C and a compressor efficiency of 80%. The inlet pressure to the compression system in IECM is not clearly stated, but since it is coupled with MEA-based amine capture, an assumed inlet pressure of 1.5 bar seems reasonable. The IECM model is set up with a maximum compressor duty of 20 MW driver power and so is the model of this study. The comparison between calculations and the IECM model is depicted in Figure . From the CAPEX data, the discontinuous nature of the cost models is clearly visible. When the mass flow reaches certain levels, the power surpasses the maximum allowable drive power, and a parallel train is added. This occurs at approx. 60 and 120 kg/s. As seen, the two approaches match remarkably well, with the only exception being the point at 120 kg/s. This is likely due to slight differences in the models, which means the point when the total required power surpasses a multi-plum of 20 MW is a bit off.