Process Simulation and Automated Cost Optimization of CO2 Capture Using Aspen HYSYS

Abstract

A standard process for CO₂ capture based on absorption in mono ethanolamine (MEA) has been simulated and cost estimated with an equilibrium-based model in Aspen HYSYS^TM. The aim has been to calculate cost optimum process parameters and evaluate the possibility of automated cost optimization using a spreadsheet facility. An Excel spreadsheet is used for dimensioning and cost estimation of the specified process. New in this work is that Visual Basic for Application (VBA) was used to automatically update installation factors for next iteration based on cost calculations in previous iteration. The equipment cost was obtained from the Aspen In-plant Cost Estimator^TM, and an enhanced detailed factor (EDF) method was used to estimate the total investment cost. The optimum process was found as the process with minimum calculated total cost. The cost optimum process parameters for the standard process were calculated to 15 m absorber packing height, 9 °C minimum approach temperature and 2.2 m/s superficial gas velocity through the absorber. With this approach, iterative cost estimation and optimization of CO₂ absorption and desorption processes can be performed automatically.