Technical and economic performance assessment of post-combustion carbon capture using piperazine for large scale natural gas combined cycle power plants through process simulation

The main challenges to the commercial deployment of the solvent-based post-combustion carbon capture technology include high energy consumption and high capital and operating costs. New solvents and alternative process configurations are being pursued to reduce the energy consumption and costs of the process. This paper investigates the technical and economic performance of the process using piperazine (PZ) solvent for a 250 MW_e natural gas combined cycle power plant. Three different configurations of the process using PZ were evaluated and compared to the standard process using 30 wt% monoethanolamine (MEA) solvent. The technical performance of the process was evaluated using the rate-based model developed in Aspen Plus® V8.4 and the economic evaluation was carried out in Aspen Process Economic Analyzer®V8.4. The technical results showed that the total energy demand of the process reduces from 5.34 GJ/t_CO2 using 30 wt% MEA to 3.56 GJ/t_CO2 using 30 wt% PZ. The lowest energy demand of 2.76 GJ/t_CO2 was achieved with the advanced flash stripper using 40 wt% PZ. The economic results show that the lowest total annual cost of M$26.58 per year and CO₂ capture cost of $34.65 per tonne_CO2 were obtained using the advanced flash stripper (AFS) with 40 wt% PZ. It was concluded that the 40 wt% PZ solvent would bring practical technical and economic benefits to the large-scale applications of the capture process compared to the current 30 wt% MEA solution. Therefore, this study will inspire policymakers and researchers towards the large-scale deployment of solvent-based PCC process.