ADGAS LNG Plant 26 contains two identical multi-wheel single stage Centrifugal Compressors. Their function is to compress atmospheric gas from ADMA to 2.0 barg pressure. The compressor is designed for running parallel both, in load sharing mode by master pressure control to be able to maintain Atmospheric gas pressure at about 29"of H2O. The suction of both Booster compressors draw from common suction drum (26-C-0101) which has two separate demister pads and suctions.
The inlet pressure of south and north dropped to min of 15 & 9"WG respectively Due to the difference in the suction flow, the LNG Operations started facing the difficulties to maintain south (26K101) and north booster compressor (26K2O1) in AUTO load sharing mode.
Due to sticky oily viscous sludge type material coming along with the incoming Atmospheric feed gas stream, demister pads were fouled and the high DP made it difficult to pull, all the available atmospheric gases from ADMA & resulted in flaring of about 9mmscfd. To open the suction drum & clean/replace the demister pads it required 9 days outage of both the booster compressors.
Both LNG trains’ Feed gas compressors had to be run without atmospheric gases, which was never attempted earlier It was required to capture all Atmospheric gases in OAG. The challenge was running both LNG FGC-1/2 without any ATM gases & OAG with Minimum required 35 Psig Gas.
LNG boosters were unloaded and FGC’s were loaded with more 35# gas. OAG booster compressors were fully loaded with all the available atmospheric gases (100mmscfd).
LNG Booster compressor demister pad replacement require 10 days shutdown, Traditionally FGC also stopped and LNG trains run with HP Gas only
By Implementing the innovation of Feed Gas compressor is running without Atmospheric gas, there were no impact on ADMA oil production, LPG loss reduced by 2581 tonnes per day and LP Gas Flaring of 2 MMSCFD saved. Demister pads were replaced and High DP problem resolved