Parametric study and optimisation of hot K2CO3‐based post‐combustion CO2 capture from a coal‐fired power plant

Abstract

AbstractDetailed parametric analyses on a post‐combustion carbon dioxide (CO2) capture system using a hot potassium carbonate solution was completed using a rate‐based simulation study. The system was simulated in Aspen Plus® V10, adopting the electrolyte non‐random two‐liquid property package. A base case study of the system was validated using literature data. Parametric analyses were then performed to study the effect of vital system parameters on CO2 capture rate and stripper reboiler duty. These system parameters include: (i) reflux ratio of stripping column (ii) lean solvent flowrate (iii) flue gas flowrate (iv) lean solvent concentration (v) lean solvent temperature (vi) flue gas temperature and (vii) absorber operating pressure. Changes in the lean solvent concentration (from 25 to 45 wt%) and absorber operating pressure (from 0.5 to 2.5 MPa) were observed to have the most significant effects on the overall performance of the capture system. Increasing both parameters showed substantial declines in the reboiler duty and resulted in remarkable increases in the corresponding carbon capture levels, and vice versa. The performance of various packing types in the absorber and stripper columns were also studied. Among the packing types examined, Flexipac Koch Metal 1Y was observed to yield the best system performance. The results from the parametric analyses were used to propose an optimised model that was able to improve carbon removal rate by 12.61% and decreased stripper reboiler duty by 14.86%. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.