Summary
Gas sweetening plant of an LNG train is a vital operating unit, where the sour contents (H2S and CO2) of the feed gas are removed to make it sweet for processing downwards to produce LNG. Any improper removal of sour gases from the feed natural gas would directly affect the quality of LNG and pose operational problem in Cryogenic column, where the LNG is produced. Besides the above, any problem in the Gas sweetening plant would reduce the gas handling capacity and in turn reduce the LNG production rate, which means loss of revenue. A severe operational problem was encountered during early 2001, in ADGAS' LNG Train-3 Gas sweetening plant. Through this article ADGAS shares their operating experience and describes the evaluation of the problem, successful remedial measures adopted and benefits derived.
Abu Dhabi Gas Liquefaction Company (ADGAS), as a part of ADNOC (Abu Dhabi National Oil Company) group, was formed in the year 1973 and started production in 1977 from their industrial facilities located on Das Island. Presently ADGAS operates at a capacity of around 8 million tons per year of LNG, LPG, C5+ and Liquid Sulphur as co-products. ADGAS was a pioneer in setting up the first combined LNG and LPG production facility in the Middle East.
ADGAS operates three LNG Trains. The first two Trains (Train 1 & 2) have been in operation since 1977, each operating at a capacity of 180 tons per hour of LNG. The third one (Train-3) was commissioned in 1994 with a capacity of 380 tons per hour of LNG.
