Energy optimization of a non-aqueous solvent CO2 absorption system with pressure swing regeneration

Abstract

This study focuses on optimizing the energy requirement in the post-combustion CO₂ capture system using pressure swing regeneration through a model-based design (MBD). The simulation results highlight the significant impact of CO₂ recovery, inlet gas and liquid flow rate, and CO₂ concentration in the flue gas on the overall energy demand of the system. Moreover, an investigation into the de-sublimation chamber was undertaken, revealing a relationship between dry ice formation and the heat transfer between the LNG stream and CO₂ in the heat exchanger. The parametric analysis study reveals that the sensible heat of the lean solvent is significantly influenced by the CO₂ concentration in the liquid, consequently affecting the overall system energy. According to the results, the utilization of cold energy from LNG could save 80 % of the total energy requirement. The optimization results found the best working condition, which consumes energy of 0.190 GJ/ton CO₂, 31 % lower than the basic scenario.