FEED GAS DRIER PRECOOLING IN MIXED REFRIGERANT NATURAL GAS LIQUEFACTION PROCESSES

摘要

A closed loop (100, 106, 108, 112, 116, 118) single component, e.g. propane or Freon refrigerant, refrigeration cycle is added to a single or dual mixed refrigerant natural gas liquefaction process to precool (in 100) the natural gas prior to adsorptive drying. By means of pressure control (104), the single component refrigerant temperature can be accurately controlled to ensure against hydrate formation in the natural gas feed and to maximize the precooling of the natural gas feed prior to drying. The addition of the single component refrigeration cycle overcomes the difficulty of controlling the precooling temperature which occurs when cooling by a multicomponent refrigerant, and thus improves plant reliability and minimizes the equipment sizes associated with the drying operation.