Carbon Capture: CO2 Compression Challenges and Design Options

Abstract

Carbon Capture and Storage are essential technologies to help achieve the ambition of net zero anthropogenic greenhouse gas emissions by 2050 [1]. Independent of the method used to capture the CO2, it remains central to compress carbon dioxide for liquefaction, transportation, and storage. The CO2 stream exiting almost any capture technology is in the gas phase, while it will be transported as a sub-cooled liquid for ship-based transportation or a dense-phase in pipeline-based transportation. The CO2 compression process that involves compressing low-pressure CO2 in gas phase to high-pressure supercritical phase is ‘transcritical’, i.e., with subcritical low-side and supercritical high-side pressure. This paper is intended to provide a summary of the current CO2 compression technologies and design challenges. Different possible pathways to compress CO2 from subcritical to supercritical conditions are explained. Also, the anomalous behavior of supercritical CO2 and its effect on design and performance of the compression system is highlighted. Inline centrifugal compressors and integrally geared compressors are compared for transcritical CO2 compression applications. Also, the use of centrifugal pumps and reciprocating compressors are briefly addressed.