A Rigorous Optimization Method of Operating Parameters for Amine-Based CO2 Capture Processes

AbstractImplementation of amine-based CO2 capture and compression systems on coal-fired power plants would lead to a significant loss on power plant efficiency. This energy penalty can be reduced using new solvents and/or modifications of the process flowsheet. As the complexity of the flowsheet increases, more parameters have to be considered and classic parametric analysis is no longer sufficient. The aim of this work is therefore to develop a systematic and rigorous method able to automatically assess the minimum energy consumption of a given process. Such an approach is based on a thorough phenomenological model, using a rigorous thermodynamic framework (extended UNIQUAC) and considering chemically enhanced heat and mass transfer. Afterwards, a reduced but representative model is obtained in order to save computational effort and ensure robustness during process simulations. Finally, the optimization problem is solved in order to evaluate the process energy minimum.This method has been validated on two flow schemes operating with MEA, the conventional process and a split feed stripper, leading to energy penalties of respectively 383 and 361 kWh/tCO2. This robust and generic method will thereafter be used in order to determine the energy minimum of advanced flow schemes, using different solvents (e.g. activated tertiary amine)