Effect of Different Types of Amines and Amine Blends on Acid Gases Removal, Energy Consumption and Amine Losses: A Case Study

The gas sweetening unit of NGL-X plant is designed for removing H2S and CO2 from natural gas stream to 4 ppm and 20 ppm, respectively (optimum removing in this plant). Currently, 30 wt% DEA solution at circulation rate of 15700 Kgmole/h is used to achieving optimum removing of acid gases. In this simulation study, the effects of eleven different types of amines and amine blends on acid gases removal, consumed energy for amine regeneration and mine losses of this gas sweetening unit have been investigated. The results clearly show that 30 wt% DEA, blend of 20 wt% TEA and 20 wt% DEA and blend of 10 wt% MEA and 30 wt% MDEA have the potential of H2S and CO2 removal to optimum removing. Blend of 10 wt% MEA and 30 wt% MDEA is not recommended for gas sweetening due to high amine losses during gas sweetening process. Blend of 20 wt% TEA and 20 wt% DEA has the ability of acid gases removal to optimum removing at lower amine circulation rate, LP steam consumption and amine losses compared to the 30 wt% DEA. However, TEA is not recommended for gas sweetening and then use of 30% DEA is a logical choice for this plant.