Multi-objective optimization of the dual independent expander gas-phase refrigeration process for LNG

Nipen M. Shah, G. P. Rangaiah, Andrew F.A. Hoadley

Research output: Chapter in Book/Report/Conference proceedingConference PaperOther

2 Citations (Scopus)


A multi-objective optimization study was conducted to optimize the gas phase refrigeration process. A 1000 kmole/hr natural gas stream at 5.5 MPa and ambient temperature consisting of 96.929 mole % methane, 2.938 mole % ethane, 0.059 mole % propane, 0.01 mole % n-butane, and 0.064 mole % nitrogen was liquefied using natural gas as a refrigerant, and subcooled using N2 as a refrigerant. The two objective functions optimized simultaneously were the capital cost and the energy efficiency. An extended range of process parameters such as heat exchanger, pressure ratio in the natural gas as well as the nitrogen refrigeration loop, and the number of refrigeration stages was evaluated. Three natural gas stages were favored over one or two stages, because one or two stages often involved internal pinching in heat exchangers, resulting in very high heat transfer area. In the case of nitrogen refrigeration, one or two refrigeration stages were favored. This is an abstract of a paper presented at the AIChE Annual Meeting (Salt Lake City, UT 11/4-9/2007).

Original languageEnglish
Title of host publication2007 AIChE Annual Meeting
Publication statusPublished - 1 Dec 2007
EventAIChE Annual Meeting 2007 - Salt Palace Convention Center, Salt Lake City, United States of America
Duration: 4 Nov 20079 Nov 2007 (Website/Proceedings)

Publication series

Name2007 AIChE Annual Meeting


ConferenceAIChE Annual Meeting 2007
Abbreviated titleAIChE 2007
Country/TerritoryUnited States of America
CitySalt Lake City
Internet address

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