Pre-Cooled Liquefaction Process
AssigneeAir Products and Chemicals, Inc.
InventorsMark Julian Roberts, Vishal Anandswarup Varma
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Abstract
A system and method for liquefying a natural gas stream, the method including the steps of providing a dehydrated natural gas stream for liquefaction, pre-cooling the dehydrated natural gas stream in a pre-cooling apparatus, where the pre-cooling is performed by using a pre-coolant that consists essentially of a hydroflorocarbon (HFC) refrigerant, further cooling the pre-cooled dehydrated natural gas stream in a main heat exchanger through indirect heat exchange against a vaporized hydrocarbon mixed refrigerant coolant to produce a liquefied natural gas product stream, where the mixed refrigerant coolant comprises ethane, methane, nitrogen, and less than or equal to 3 mol % of propane.
Claims20
A method for liquefying a natural gas stream, the method comprising the steps of:
- providing a dehydrated natural gas stream for liquefaction;
- pre-cooling the dehydrated natural gas stream in a pre-cooling apparatus, wherein the pre-cooling is performed by using a pre-coolant that consists essentially of a hydroflorocarbon (HFC) refrigerant;
- further cooling the pre-cooled dehydrated natural gas stream in a main heat exchanger through indirect heat exchange against a vaporized hydrocarbon mixed refrigerant coolant to produce a liquefied natural gas product stream,
- wherein the mixed refrigerant coolant comprises ethane, methane, nitrogen, and less than or equal to 3 mol % of propane.
A system for liquefying a natural gas stream, comprising:
- a multistage hydroflorocarbon (HFC) compressor;
- a pre-cooling apparatus fluidly connected to the multistage HFC compressor, the pre-cooling apparatus comprising at least one evaporator for pre-cooling a dehydrated natural gas stream using a HFC refrigerant;
- a main heat exchanger fluidly connected to the pre-cooling apparatus for further cooling the pre-cooled dehydrated natural gas stream to produce a liquid natural gas product stream,
- wherein a vaporized mixed refrigerant coolant comprising ethane, methane, nitrogen, and less than or equal to 3 mol % of propane provides refrigeration in the main heat exchanger.
A method for liquefying a natural gas stream, the method comprising the steps of:
- providing a dehydrated natural gas stream for liquefaction;
- pre-cooling the dehydrated natural gas stream in a pre-cooling apparatus, wherein the pre-cooling is performed by using a pre-coolant that consists essentially of a hydroflorocarbon (HFC) refrigerant;
- further cooling the pre-cooled dehydrated natural gas stream in a main heat exchanger through indirect heat exchange against a vaporized hydrocarbon mixed refrigerant coolant to produce a liquefied natural gas product stream,
- wherein the mixed refrigerant coolant is a mixture comprising a methane stream derived from a natural gas stream, an ethane enriched stream, wherein the ethane enriched stream is predominantly ethane, and a nitrogen stream, wherein the nitrogen stream is predominantly nitrogen.
Dependencies are inferred from the claim text.