Simulation of Natural Gas Treatment Process Based on Alkanolamine Solvent for South Pars Gas Complex Company by Aspen HYSYS Software

In South Pars natural gas treatment unit (phase ۱۹) for the treatment of natural gas with an intensity of ۲۶۶۹۰ kmol/h, methyl diethanolamine solvent ۴۵.۵۴ wt% with a flow rate of ۹۵۹۱ kmol/h has been used. In this thesis, this process has been simulated with high accuracy by using Aspen Hysys software. The results showed that in order to solvent recover and reach loading ۰.۰۰۲۲ (Mole Acid Gas)/(Mole MDEA), energy equivalent to ۲.۹ gigajoules should be consumed in the reboiler of the stripper tower for each ton of acid gases. Also, the flow sheet of Aspen Hysys determined that the absorption rate of carbon dioxide and hydrogen sulfide in the current conditions are ۹۰.۲۸% and ۹۹.۸۹%, respectively. According to the sensitivity analysis, a good absorption of acid gases can be achieved with a reflux less than ۶۷۱.۶ kmol/h, and this value according to the parametric curves is equal to ۴۰۰kmol/h. In these conditions and with less reflux, the duty of the reboiler and the intensity of the solvent recovery energy will also be lower. According to the investigations, increasing the feed temperature of the stripper tower is an important factor in reducing energy consumption for gas sweetening. On the other hand, it was found that by increasing the flow rate of feed gas, the acid gas production of the process will increase and the solvent recovery energy will also decrease.

Keywords:

Natural gas , Solvent , Simulation , Reboiler , Acid gas , Sensitivity analysis