Paper No. 404 CORROSION PROFILE IN A GAS SWEETENING PLANT R. Case and A, Viloria INTEVEP, S.A. Dept. Materials Technology B. Luciani CORPOVEN, S.A. Corrosion and Metallurgy Department ABSTRACT A study was performed to assess the corrosion rate in a gas sweetening plant using electrrxhemical methods. The tests were performed by using samples of the amine in service. Coupons made of A- 106 carbon steel were tested, as this material is tipically used in most vessels. The variables studied included the actual temperature of different plant units at both rich ad lean amine conditions, and the degree of C02 satoration. The results show an increase of the uniform corrosion rate with temperature, which reflects the effect of heat stable salts in the corrosivity of the amine evrrhsated.Also, from the analysis of the potentiodynamic carves at different conditions, the risk for Alkaline Stress Corrosion Cracking (ASCC) was assessed. The association of this risk with actual plant conditions shows which vessels are susceptible to both amine corrosion and ASCC which allowed to develop a corrosion profile for both the lean and rich amine parts of the circuit, Keywords: amine corrosion, gas sweetening, electrochemical methodologies INTRODUCTION In the oil and gas industry, the amount of acid gases COZ and HIS must be kept under rigorous control, due to their corrosive influence upon the processes and equipment used downstream from the oilfield patch. The most widesprwrdmethod of C02/H2S control is the use of amine process, where removal of these natural gas contaminants occurs by chemical equilibrium reactions with amine solvents, such as MEA, DEA, TEA “]. The basic layout for an amine sweetening plant consists of a close circuit process, where the natural gas containing the C02/H2S contacts, in counter current, the amine solvent at the gas scmbber or contactor, Then, this loaded amine solution Copyright 01998 by NACE International. Requests for permission to pubkh t~s manuscript in anY fOrm, in Paaor in whole must be made in writing to NACE International, Conferences Division, P.O. Box 218340, Houston, Texas 77218-8340. The material presented and the views expressed (n this paper are solely those of the author(s) and are not necessarily endorsed by the Association. Printed in the U.S.A.