FLEXSORB? SE A Proven Reliable Acid Gas Enrichment Solvent

摘要

ExxonMobil Research and Engineering Company developed FLEXSORB? SE gas treating solvent in the late 1970s to improve H_2S selectivity in Claus plant tailgas cleanup processes. From this modest beginning, FLEXSORB SE has spread to over 100 commercial units designed to treat over 9 Billion SCFD of gas. Recently, FLEXSORB SE has been selected for use in several world-scale LNG facilities located in the Middle East where it is used as both the Acid Gas Enrichment (AGE) solvent and the Tail Gas Treating Unit (TGTU) solvent. FLEXSORB SE solvent has the desirable characteristic of absorbing all the H_2S (below 10 vppm), while rejecting as much as 95% of the CO_2 into the treated gas stream. It is also extremely effective at low pressure which makes it well suited for TGTU and AGE services. In recent years, Acid Gas Enrichment has become a preferred gas treating option to boost the H_2S concentration in the sulfur recovery unit (SRU) feed, thereby reducing the size and cost of the SRU equipment and reducing the complexity of the SRU operation. AGE technology can also be used to enable production of natural gas fields with unfavorable CO_2 to H_2S ratios. This paper will present detailed examples of AGE design capabilities. There are a limited number of these AGE units in operation (some report as few as 25 worldwide). FLEXSORB SE has been specified for 20 AGE units including the QatarGas II Train 4 gas treating facilities which successfully started in 2009. Keywords: amine; sulfur; gas absorption; hydrogen sulfide; selective removal