A simulation model of a CO2 absorption process with methyldiethanolamine solvent and piperazine as an activator

CO2 capture technologies have recently attracted considerable attention because of the need to reduce CO2 emission. A highly effective technology is chemical absorption using activated methyldiethanolamine (a-MDEA), a mixed solvent of piperazine (PZ) and MDEA. In this study, a physical property package for a-MDEA was assembled and inserted into Aspen Plus to simulate an acid gas removal unit (AGRU). Data from an actual natural gas sweetening process were used to validate the model, whose results were found to fit the data well. Subsequent sensitivity analyses showed that the PZ concentration had a more significant impact on the process performance than the solvent to feed ratio. At low concentrations of PZ, every 1 wt% increase in PZ enhanced the percent CO2 recovery by about 10%. Finally, the results also indicated that the best trade-off between CO2 recovery and energy consumption occurred at the PZ concentration of 5 wt%, in a 45 wt% aqueous MDEA solvent. (c) 2013 Elsevier Ltd. All rights reserved.