REVAMPING OF GAS REFINERIES USING AMINE BLENDS

Abstract: The use of mixed amine system in gas treating processes is increasing today. For natural gas sweetening purposes, mixed amines are typically mixtures of MDEA and DEA or MEA that enhance CO2 removal while retaining desirable characteristics of MDEA such as reduced corrosion problems and low heats of reaction. In this work, a process simulator was used to predict the performance of an Iranian gas sweetening plant with a sour gas feed containing 6.41% CO2 and 3.85% H2S on molar basis. Various mixtures of diethanolamine (DEA) and Methyl diethanolamine (MDEA) were used to investigate the potential for an increase in plant capacity. It was noticed that the process simulator is quite capable in predicting the existing plant performance and can potentially guide in selecting the optimum blend composition. It was also noticed that a substantial increase in plant capacity is quite possible by just adding MDEA to the existing solvent and keeping the solvent flow rate and stripper reboiler heat duty. In another word, it is possible to increase the plant capacity from 293 to 357 MMSCFD using a mixed amine system.