Apparatus for the liquefaction of natural gas and methods relating to same

Abstract

A liquefaction plant (102) comprising: a plant inlet (112) configured to be sealingly and fluidly coupled with a source of unpurified natural gas; a turbo expander (156) positioned and configured to receive a first stream of natural gas drawn through the plant inlet and produce and expanded cooling stream therefrom; a compressor (158) mechanically coupled to the turbo expander and positioned and configured to receive a second stream of natural gas drawn through the plant inlet and produce a compresses process stream therefrom; a first heat exchanger (166) positioned and configured to receive the compressed process stream and the expanded cooling stream in a countercurrent flow arrangement to cool the compressed process stream; a first plant outlet (132) positioned and configured to be sealingly and fluidly coupled with the source of unpurified gas and to discharge the expanded cooling stream thereinto subsequent to passage thereof through the heat exchanger; a first expansion valve (174) positioned and configured to receive and expand a first portion of the cooled compressed process stream to form an additional cooling stream, the plant further including conduit structure to combine additional cooling stream with the expanded cooling stream to the expanded cooling stream entering the first heat exchanger; a second expansion valve (176) positioned and configured to receive and expand a second portion of the cooled compressed process stream to form gas-solid-liquid mixture therefrom; a first gas-liquid separator (180) positioned and configured to receive the gas-solid-liquid mixture; and a second plant outlet (114) positioned to be sealingly and fluidly coupled with a storage vessel, the first gas-liquid separator being positioned and configured to deliver a liquid contained therein to the second plant outlet.

Description

[0001] Cross References to Related Applications [0002] This application claims priority to US Patent Application Serial No. 10 / 086066, filed February 27, 2002, entitled "Natural Gas Liquefaction Apparatus and Related Methods." [0003] government rights [0004] Pursuant to Contract No. DE-AC07-99ID13727 between the US Department of Energy and Bechtel BWXT Idaho, LLC, the US Government has rights in the following inventions. field of invention [0005] The present invention relates generally to the compression and liquefaction of gases, and more particularly to the small-scale partial liquefaction of gases such as natural gas through the use of a combined refrigeration and expansion process. Background of the invention [0006] Natural gas is a known substitute for fuels such as gasoline and diesel. Much effort has been made to develop natural gas as an alternative fuel to overcome various disadvantages of gasoline and diesel, including production costs and post-use emis...

AI Technical Summary

Problems solved by technology

[0015] Because many sources of natural gas, such as residential or industrial supplies, are considered "dirty", the requirement to provide "clean" or "pre-purified" gas actually requires the arrangement of expensive and often complex filtration prior to the liquefaction process and purification system

this requirement does add to the cost and complexity of constructing and operating such liquefaction plants or equipment

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