Techno-economic Evaluation of Processes for Oxygen and Water Removal from the CO2 Product Stream

Abstract According to the findings of the first part of this work, the two impurities in the CO 2 stream, from post-combustion capture, which require deep removal are oxygen and water, down to 10 and 50 ppmv, respectively. In addition, a review and preliminary evaluation of the possible technologies which can be used for oxygen and water deep removal was conducted, and the results showed that the promising technologies are: catalytic oxidation of hydrogen and refrigeration and condensation, respectively. In this paper, detailed process modeling, design and a techno-economic evaluation are performed on these two technologies. Both selected technologies were designed and proved their potential by achieving the required levels of impurities with a total cost of treating and compressing one ton of CO 2 of $13.09 for the coal-fired power plant full purification case and $17.23 for the NGCC full purification process. The cost of CO 2 compression without the purification step was found to be approximately $10.12 per ton of CO 2 for the coal-fired case. This means that adding the purification technologies to the coal fired case will increase the cost of CO 2 compression by around 29.3%. Assuming a total CO 2 capture and compression cost of $73-94 per ton of CO 2 shows that the total CO 2 purification cost is roughly 3-4% of the overall capture cost.