Cost Optimization of Absorption Capture Process

In this work, a CO2 absorption process using aqueous monoethanol amine (MEA) as solvent for a post combustion capture plant was simulated using Aspen HYSYS. An Aspen HYSYS spreadsheet was used for equipment dimensioning, cost estimation and cost optimization. A standard process and a vapor recompression process for 85 % CO2 removal were simulated using the Li-Mather thermodynamic model. The energy consumptions and the total cost were calculated and compared. Cost optimum process parameters were calculated from sensitivity analysis. The vapor recompression process was shown to be both energy and cost optimum. With 20 years calculation period, the cost optimum absorber packing height was 16 meter, optimum temperature approach was 14 K and optimum recompression pressure was 130 kPa. With 10 years calculation period, the optimum values for the same parameters were 16 meter, 17 K and 140 kPa. Calculations of optimum process parameters dependent on factors like the calculation period have not been found in literature. Except from the temperature approach, the optimum values varied only slightly when the calculation period was changed.