In the gas sweetening unit of Ilam Gas Refinery, the circulating amine temperature fluctuates with the ambient temperature throughout the seasons of the year. In the present study, it is tried to simulate the sweetening unit of Ilam Gas Refinery regarding various ambient temperature conditions during a year. Considering the variation of ambient temperature from -4 to 46 °C, the simulation results illustrated that the inlet amine temperature in the absorption tower would shift between 47.69 and 65.6 °C, while the amine inlet temperature of the regeneration tower varies from 95.72 to 103.5 °C. Under the same operating condition, the values of H2S and m-mercaptan augment from 0.1884 and 0.0012 to 0.1888 and 0.0016, respectively. Specifically, in winter, as the temperature of the absorption tower declines to 47 °C, the amount of CO2 and H2O decreases with a downward slope from 12 and 689 ppm to 3 and 338 ppm, respectively. This will result in reducing the inlet solvent temperature in the regeneration tower from 103 to 95 °C, leading to a rise in the values of the acidic gases. Regarding this, the mole fraction values of CO2 and m-mercaptan in reboilers heighten from 0.03249 and 0.00016 to 0.03255 and 0.00020, respectively. Comparing the leakages caused by corrosion with the inlet amine temperature of the regeneration tower, it was found that by rising the temperature of the rich inlet amine in the regeneration tower to 103 °C, the corrosion in the regeneration area can be reduced by 76.7 %.
