A New Energy Saving by Self-Heat Recuperation in Post-Combustion CO2 Capture

Carbon capture and storage (CCS) has attracted significant attention in the past two decades to reduce greenhouse gas (GHG) emissions and mitigate global warming. CCS consists of the separation of CO2 from industrial and energy-related sources, transportation of CO2 to a storage location, and long-term isolation of CO2 from the atmosphere. In CCS, CO2 capture is the most costly process because of the high energy requirement for CO2 capture from gas mixtures such as flue gases produced by combustion of fossil fuels.

Self-heat recuperation is applied to CO2 capture with chemical absorption for post-combustion capture to achieve drastic energy saving. In this design, the heat of the exothermic absorption reaction in the absorber and the heat of steam condensation in the condenser of the stripper are recuperated and circulated to reuse for regeneration of solution and vaporization of water under CO2 stripping using self-heat recuperation technology. We evaluated the amount of energy consumption of CO2 capture by using self-heat recuperation in comparison with the conventional CO2 capture. The simulation results show that the energy consumption decreased to one third of that of the conventional CO2 capture with heat recovery.