Model development and process simulation of postcombustion carbon capture technology with aqueous AMP/PZ solvent

Abstract

This study presents the development, application, and uncertainty analysis of a process simulation model for postcombustion CO₂ capture with an AMP/PZ solvent blend based on state of the art knowledge on AMP/PZ solvent technology. The development includes the improvement of the physical property models of a software package designed for simulation of acid gas treatment and CO₂ capture technologies. The improvement particularly consisted of regression of AMP-PZ binary interaction parameters. The model was applied to a case study of postcombustion CO₂ capture from an Advanced Super Critical Pulverized Coal power plant. Uncertainly analysis was undertaken by validating the physical property models against laboratory measurements reported in literature; by comparing model results with pilot study results, and by evaluating the strength of the model with a novel method called pedigree analysis. The results show that AMP/PZ postcombustion technology performs better than MEA technology on most performance indicators, e.g., the Specific Reboiler Duty is reduced from 3.6 GJ/t CO₂ for MEA, to 2.9 GJ/t CO₂ for AMP/PZ, and the specific cooling water requirement is reduced from 4.1 to 3.4 GJ/t CO₂. Only amine slip to the atmosphere increases with AMP/PZ technology: from 0.18 g/t CO₂ to 15.3 g/t CO₂, although this value is still within emission limits from existing regulatory frameworks. The coal power plant net efficiency with AMP/PZ capture amounts to a value of 37.2%_LHV, compared to 46.1%_LHV for the case without CCS and 36.2%_LHV in case of CCS with MEA. The uncertainty analysis shows that the model is well capable of predicting experimental and pilot result. The remaining uncertainty is mostly in the reaction kinetics and in the flowsheet design. Validation could be further improved, by more elaborate comparison to independent measures of physical properties, and by comparison of the model outputs to results from large demonstration or commercial size capture plants.