Thermodynamic assessment of amine based CO₂ capture technologies in power plants based on European Benchmarking Task Force methodology

Post combustion CO₂ capture (PCC) with amine solvents is seen as one of the possible technologies which can be implemented in the near term to significantly reduce CO₂ emissions from fossil fuel power plants. One of the major concerns for its implementation at large scale in power plants is the high capital and operating costs of the technology. This paper examines the performance of advanced supercritical (ASC) pulverised coal and natural gas combined cycle (NGCC) power plants with two post-combustion CO₂ capture units. The capture units are based on chemical absorption with an advanced amine solvent, CESAR-1, which is an aqueous solution of 2-Amino-2-Methyl-Propanol (AMP) and piperazine (PZ), and the conventional Monoethanolamine (MEA) solvent. The comparison between the mentioned technologies is based on the technical assumptions and method provided by the European Benchmarking Taskforce (EBTF) methodology, which is a first attempt for establishing a common European Standard for comparative studies. The resulting net electric efficiencies for the power plants without capture are 45.25% and 58.3% for the ASC PC and NGCC cases respectively. When CO₂ capture is applied, the net electrical efficiencies of the studied plants decreases. In the ASC power plant, the MEA capture unit decreases the efficiency by 11.7 percentage points, while the CESAR-1 capture unit decreases the efficiency by 9.4 percentage points. For the NGCC power plant, the reductions are 8.4 and 7.6 percentage points for the MEA and CESAR-1 capture units respectively. Therefore, the evaluation of CESAR-1 under the EBTF standards shows a reduction on power production penalty of 25% for the coal fired plant and 12% for the gas fired plant compared to conventional MEA.