Investigation on Using Amine Split Flow to Reduce Maximum Temperature of the Fajr-Jam Refinery Absorption Tower for Control Corrosion Rate

Research subject: 

Regarding to temperature effect on the rate of corrosion in absorption tower of gas refineries, it is very useful to examine and invest on new methods to decrease the temperature in mentioned towers.

Research approach:

 By studying different types of corrosion in amine processes and the influence of different variables on them, the dominant effect of temperature on the rate of corrosion in absorption towers was determined. Due to decreasing temperature in the absorption tower the surface tension of amine solvent and corrosion rate decrease. The reduction in surface tension reduces the foaming and flooding in the tower, which reduces the concentration of sour gases CO2 and H2S from the natural gas outlet. Various methods of reducing temperature in the absorption tower such as increasing flow rate of circulation amine solvent, opening the insulated tower wall and injecting amines into the middle of the tower have been studied. Aspen- HYSYS software was used to investigate the effects of amine injection into the middle of the tower.

According to the simulation results, the maximum temperature in the two-feed absorption tower was reduced to about 3°C and in the three feedstocks the maximum temperature was reduced to about 10°C. Also, as the CO2 and H2S concentration of the gas outlet decreases, the amount of Spent Caustic and catalyst in the lower part of the tower will decrease. Finally, it was found that among the above methods, injection of amine into the middle of the tower had the highest efficiency in decreasing the temperature of it. However, a combination of the above methods can be used to further reduce the temperature in the tower.