Modelling\simulation and optimization of large-scale post-combustion CO₂ capture using a rotating packed bed absorber and packed bed stripper

Rotating packed bed (RPB) is capable of reducing the size, footprint, and cost of the postcombustion carbon capture (PCC) process when used as absorbers and strippers. RPB can be operated with higher monoethanolamine (MEA) concentration (>55 wt%). At these concentrations, there is potential for higher absorption performance and lower energy demand for solvent regeneration. However, previous studies have not investigated the optimal MEA concentration to operate the RPB absorber and PB stripper for large-scale PCC processes. This study investigates the optimal solvent concentration in MEA-based PCC using an RPB absorber and packed bed (PB) stripper for 250 MW combined cycle gas turbine (CCGT) power plants. The rate-based model of the RPB absorber was developed in Aspen Custom Modeller® (ACM) V11. The accuracy of the RPB absorber model was verified by validating it with experimental data. The RPB absorber model correctly predicted the experimental data and was then scaled up to deal with flue gas from a 250 MW CCGT power plant. The RPB Absorber model was exported to Aspen Plus® and integrated with PB stripper to develop the closed loop of the large-scale PCC process. This large-scale model was used for process analysis and optimization studies. Optimisation results showed that the lowest total energy consumption of 4.46 GJ/tcœ was found at an optimal MEA concentration of 75 wt%. Going forward, we will perform an elaborate economic analysis based on the optimized process to determine the optimal MEA concentration that results in the lowest CO₂ capture cost.