Process Simulation and Cost Estimation of CO2 Capture configurations in Aspen HYSYS

Abstract

A CO2 capture process from a natural gas based power plant has been simulated and cost estimated using an equilibrium-based model in Aspen HYSYS using the amine acid gas package. The aim has been to calculate cost optimum process parameters for the standard process and also for a vapor recompression process. After process simulation using Aspen HYSYS, the process equipment was dimensioned and cost estimated using Aspen In-plant. The Enhanced Detailed Factor (EDF) method was used to select factors to calculate the total investment. Operating cost for heat and electricity was calculated from the simulation with estimated cost on consumed heat and electricity. The cost was calculated to 21.2 EURO per ton CO2 removed and a vapor recompression process was calculated to 21.6 EURO per ton. A recompression case with 1.2 bar flash pressure was calculated to 21.3 EURO/ton CO2. The ΔTMIN in the amine/amine heat exchanger was varied, and the optimum at 15°C was 20.9 EURO per ton CO2. The vapor recompression alternative was in this work slightly more expensive than the traditional case. In earlier works, the vapor recompression process has been claimed to be more economical than the standard process. The difference in this work is mainly due to different cost estimates of the compressor investment. This work shows that Aspen HYSYS is well suited for optimizing process parameters in a CO2 capture process with and without vapor recompression.