Comparison study of activators performance for MDEA solution of acid gases capturing from natural gas: Simulation-based on a real plant

Energy requirements and environmental regulations are the main limiting issues behind the continuous developments of amine absorption processes. Steady state simulation has been performed using the Aspen HYSYS program version 8.8 to determine the effects of adding various concentrations of activators up to 10% with maintaining the constancy of the entire amine strength of 45%. The present investigation addresses the performance of using piperazine/MDEA and sulfolane/MDEA on the absorption process in terms of energy consumption and acid gases loading. Four scenarios have been analyzed under the same operating conditions, 5% activator/ 40% MDEA has shown better performance superior to other scenarios regarding the balance between energy consumption and absorption capacity of acid gases. The results revealed that the addition of 5% piperazine improves the absorption of CO2 and H2S by 92.1% and 28.2% respectively. Correspondingly, 5% sulfolane enhances the absorption efficiency of CO2 and H2S by 80.48% and 48.18%. In terms of energy, the sulfolane system saved more reboiler energy compared to the piperazine system. Reboiler energy consumption was investigated by changing some effective parameters, namely sour gas temperature, lean amine temperature, reflux ratio, and rich amine temperature. Sulfolane promoter is more applicable for the study plant conditions due to its high absorption capacity for H2S and low reboiler duty requirements. (C) 2019 Elsevier B.V. All rights reserved.