Gas liquifaction process using a single mixed refrigerant circuit

• Main Authors: AGRAWAL, RAKESH, DAUGHERTY, TAMARA LYNN, ROBERTS, MARK JULIAN
• Format: Patent
• Language: English; French; German
• Published: 15.12.2004
• Edition: 7
• Subjects: ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE ORUNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; BLASTING; CHEMISTRY; COMBINED HEATING AND REFRIGERATION SYSTEMS; FIRELIGHTERS; FUELS; FUELS NOT OTHERWISE PROVIDED FOR; HEAT PUMP SYSTEMS; HEATING; LIGHTING; LIQUEFACTION SOLIDIFICATION OF GASES; LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS; LIQUEFIED PETROLEUM GAS; LUBRICANTS; MANUFACTURE OR STORAGE OF ICE; MECHANICAL ENGINEERING; METALLURGY; MIXTURES BY PRESSURE AND COLD TREATMENT; NATURAL GAS; PEAT; PERFORMING OPERATIONS; PETROLEUM, GAS OR COKE INDUSTRIES; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; REFRIGERATION OR COOLING; SEPARATION; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BYSUBCLASSES C10G, C10K; TECHNICAL GASES CONTAINING CARBON MONOXIDE; TRANSPORTING; WEAPONS

A method of gas liquefaction wherein the refrigeration to cool and liquefy an essentially water-free feed gas (100) is provided by a single recirculating mixed refrigerant cycle in which refrigeration is provided by the vaporization of two mixed refrigerant streams of different compositions at a lower and higher pressure levels respectively. A lower pressure level vaporizing refrigerant cools the feed gas stream (100) in a first cooling zone (106) and a higher pressure level vaporizing refrigerant further cools and condenses the cooled gas in a second cooling zone (124) to provide the final liquid product (136). The lower pressure level vaporizing refrigerant is provided by one or more liquids obtained by ambient cooling of compressed mixed refrigerant vapor (176). The vaporized lower pressure level refrigerant (114) can be returned to the refrigerant compressor at a temperature below ambient, without further warming, and this cool refrigerant (114) is compressed and combined with the vaporized higher pressure level refrigerant (176), which is returned at about ambient temperature.