In alignment with the State of Qatar environmental and water conservation regulations, RasGas is currently studying the feasibility of providing a Treated Industrial and Process Water (TIPW) treatment facility. This facility will treat approximately 350 m3/hr of Treated Industrial Water (TIW) Process Water and Steam Condensate from all RasGas' seven LNG trains and two sales gas plants to a desalinated water specification enabling re-use for internal purposes.
The sources of TIW are sanitary water, chemical water and oily water. Treated sanitary water will be used as irrigation water for internal landscaping, whereas the remaining two sources will be sent to the new treatment facility. The sources of Process Water are Tail Gas Treatment (TGT), Acid Gas Removal, Dehydration, and LP flare knockout facilities.
The following technologies are proposed:
A pre-treatment facility will be installed to treat Process Water to reduce H2S, Oil Content, Chemical Oxygen Demand (COD) and other parameters that are detrimental to the downstream biological process.
Membrane Bioreactor will be used to further reduce COD and Total Suspended Solids (TSS) in Process Water.
Multimedia Filter (MMF) will lower the TSS content of the incoming TIW.
The combined TIPW stream will be routed to Reverse Osmosis (RO) units to reject dissolved solids, producing freshwater to desalinated water specifications.
Finally, brine from RO units will be treated in a thermal Zero Liquid Discharge (ZLD) facility to recover water and convert dissolved salts to solid waste for easier handling and disposal. Other concepts are also being evaluated for brine disposal.
This project has a number of environmental benefits. It will maximise the internal re-use of TIW, Steam Condensate and Process Water with no discharge to sea or to the buffer zone, and will reduce RasGas fresh water imports. Also, Process Water is currently being injected, so treating for internal re-use will minimise injection volumes and therefore extend the life of the well.
