LNG process block diagram and key Process

Block diagram of  LNG process:

Key Process Units

SInlet Facilities (onshore):

             Reception and separation of offshore feed wet gas into gas, condensate, and water. 

SAcid Gas Removal (AGR):

             Remove acid gas (H2S and CO2) by amine system                     ( Ucarsol ).

SSulphur Recovery Unit (SRU) / Acid Gas Injection (AGI): 

              Recover H2S and Mercaptans (RSH) into pure liquid Sulphur (Claus process), or inject the acid gas into onshore acid gas injection wells.

SGas Treating (Dehydration & SELEXOL):  

                 Remove mainly water, Mercaptans (RSH) and Sulphur compounds from saturated gas

SMercury Removal: 

                 Remove mercury (Hg) form the dry gas

. 

SNGL Recovery:

                 Recover NGL (mainly C2+ or C3+).

SFractionation:

               Recover Ethane (C2), Propane (C3), Butane 

(C4), also iso-Pentane (i-C5) and plant condensate (n-C5+)

SRefrigeration: 

              Use Propane and Mixed Refrigerant (MR) for   gas      pre-cooling and liquefaction.  

SLiquefaction: 

              Liquefy the dry sweet gas by Main Cryogenic Heat Exchanger (using C3-MR).