Effects of lean alkanolamine temperature on the performance of CO2 absorption processes using alkanolamine solutions

Acid gas removal from the natural gas using alkanolamine processes is the most common technology used for sweetening of natural gas. Based on the sour and sweet gas specifications, several alkanolamine solutions can be used for acid gas removal, all of which are well developed processes. However, one of the remaining issues is the costs associated with the processes. In this study, DEA, DGA and mixed (MDEA+DEA) processes are designed for sweetening the natural gas produced in one of the gas fields having high CO2/H2S ratio. For each process, seven scenarios are designed to investigate the effects of the cooler’s operating parameters on the performance of the process. For each scenario, the duty of the cooler is varied in order to have a specific lean amine temperature entering the absorber. Each scenario is simulated using Aspen HYSYS and economically evaluated using Aspen economic evaluation. Based on the results of this study, the required solution circulation rates slightly increases when the lean amine temperature increases. However, Lower process capital costs and lower cooler’s duty were obtained by operating the DEA and DGA processes at higher values of lean amine temperature. Also, operating at lower lean amine temperatures resulted in lower hydrocarbon pick up in case of MDEA+DEA process.