Investigation into an energy-saving mechanism for advanced stripper configurations in post-combustion carbon capture

Abstract

Abstract In a standard post-combustion carbon capture (PCC) process, the regeneration energy of CO2 lean solvent constitutes the majority of overall energy consumption. The energy reduction achieved by advanced stripper configurations, such as the cold-split bypass (CSB), interheated (IH) stripper, and lean vapor compression (LVC), have been reported in relevant literature. Energy-saving performance may be enhanced by combining the different modifications. In this study, the energy-saving mechanism for advanced stripper configurations was investigated using a standard amine-based process, in which 30 wt% monoethanolamine (MEA) aqueous solution was applied. Contrary to the literature reviewed, the energy-saving performance attained by combining the different modifications was limited. This was due to the major contribution of energy reduction in the various modifications sharing the similar mechanism. In addition, this study demonstrated that the overall energy required, as needed by the heat recovery in the cross-flow heat exchanger (HX) and the reboiler duty, is dominated by overhead vapor generation. Reducing the amount of vapor generated may effectively relieve the overall energy burden. Thus, when energy reduction is reliant on a HX with a poor heat recovery system, the energy-saving purpose is not fulfilled. Therefore, a successful energy-saving design may significantly reduce the amount of vapor generated, whilst maintaining a reliable heat recovery.