LNG plant optimization with ammonia precooling

N. Gnanendran and J. Baguley, LNG Ltd., Houston, Texas The selection of liquefaction technology and refrigerants plays a key role in optimizing process efficiency while minimizing costs in LNG plants. Large baseload LNG export facilities incorporate a precooling refrigeration cycle as a proven means to increase both overall liquefaction energy and cost efficiencies. Historically, propane has been selected as the precooling refrigerant since it was available for extraction from feedstock in remote site locations, thereby minimizing dependency on complex delivery logistics. With the migration of new LNG facilities to locations processing lean natural gas feedstock, such as pipeline or coal s