Process flowsheet design optimization for various amine-based solvents in post-combustion CO2 capture plants

This work focuses on the development and evaluation of several combinations of amine solvents and flowsheet structures for the efficient separation of CO2 from a flue gas stream. The proposed flowsheets are generated using a module-based generalized design framework which serves as a mathematical tool able to reproduce any potentially favorable representation of solvent based CO2 capture processes supported by an underlying process superstructure. Flowsheet configurations aiming at the intensification of the process through the overall enhancement of the main driving forces in the process units are initially identified and subsequently developed and optimized in order to determine the optimal operating point. Flowsheet designs including different stream topologies, heat redistribution through suitably incorporated heat injection or removal modules and cascades of desorption columns are among the proposed options. Commercially available candidate solvents including monoethanolamine (MEA), diethanolamine (DEA), 2-amino-2-methyl-1-propanol (AMP) and 3-amino-l-propanol (MPA) are tested for their performance in optimized flowsheet configurations. Vapor liquid equilibrium calculations are performed using the statistical associating fluid theory for potentials of variable range (Mac Dowell et al., Ind Eng Chem Res 49:1883-1899, 2010). Significant economic improvements in the range of 15%-35% depending on the employed solvent are observed on optimized flowsheet configurations, whereas impressive energetic reductions in the reboiler duty of up to 55% are achieved using an aqueous AMP solution for CO2 capture. (C) 2015 Elsevier Ltd. All rights reserved.