US4012212A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for liquefying natural gas
Assignee: Lummus Technology LLC
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Filing: 1975-07-07
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Granted: 1977-03-15
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Expires: 1995-07-07
Abstract
Abstract There is disclosed a novel process and apparatus for liquefying a hydrocarbon gas under a pressure greater than the critical pressure thereof wherein the gas is first expanded to below the critical pressure thereof to permit the facile separation of C 5 and heavier hydrocarbons with the lighter components being re-pressurized to above the critical pressure thereof by such expanding gas prior to the further cooling of such re-compressed lighter components for eventual liquefaction.
Inventors
- 👤 Ludwig Kniel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:49
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/0228; F25J3/0247; F25J1/00; F25J1/0002; F25J1/0022; F25J1/003; F25J1/0032; F25J1/0035; F25J1/0037; F25J1/004; F25J1/02; F25J1/0201; F25J1/0202; F25J1/0228; F25J1/0235; F25J1/0237; F25J1/0238; F25J1/0243; F25J1/0244; F25J1/0245; F25J1/0247; F25J1/0257; F25J1/0259; F25J1/0275; F25J1/0277; F25J1/0278; F25J3/0204; F25J3/0209; F25J3/0233; F25J2200/00; F25J2200/02; F25J2200/74; F25J2200/78; F25J2205/00; F25J2205/02; F25J2205/04; F25J2205/30; F25J2205/50; F25J2220/00; F25J2220/60; F25J2220/64; F25J2220/66; F25J2220/68; F25J2230/00; F25J2230/60; F25J2240/00; F25J2240/02; F25J2245/00; F25J2245/02; F25J2270/00; F25J2270/04; F25J2270/06; F25J2270/90; F25J2280/00; F25J2280/10; F25J2290/00; F25J2290/42; F25J2290/72
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
111 words
A method of liquefying natural gas having a pressure above the critical pressure thereof, which comprises: a. expanding said natural gas to a pressure below the critical pressure thereof; b. introducing the expanded gaseous stream of step (a) into a fractionating zone to remove as a liquid a C 5 + hydrocarbon stream; c. compressing the resulting gas stream recovered from step (b) to a pressure above the critical pressure thereof; d. cooling the cooled gas stream of step (c); e. expanding said cooled gas stream from step (d) to effect liquefaction of a major portion of said cooled gas stream of step (d), and f. recovering said liquified major portion.
Claim 2
Independent Claim
111 words
A method of liquefying natural gas having a pressure above the critical pressure thereof, which comprises: a. expanding said natural gas to a pressure below the critical pressure thereof; b. introducing the expanded gaseous stream of step (a) into a fractionating zone to remove as a liquid a C 5 + hydrocarbon stream; c. compressing the resulting gas stream recovered from step (b) to a pressure above the critical pressure thereof; d. cooling the cooled gas stream of step (c); e. expanding said cooled gas stream from step (d) to effect liquefaction of a major portion of said cooled gas stream of step (d), and f. recovering said liquified major portion.
Claim 3
Dependent Claim
29 words
The process as defined in claim 1 wherein the work necessary to compress the gas stream in step (c) is obtained by the energy of expansion of step (a).
Claim 4
Dependent Claim
36 words
The process as defined in claim 1 wherein said C 5 + hydrocarbon stream includes minor portions of light hydrocarbons and additionally comprising the step of separating such lighter hydrocarbons from C 5 and heavier hydrocarbons.
Claim 5
Dependent Claim
16 words
The process as defined in claim 3 wherein said lighter hydrocarbons are returned to step (c).
Claim 6
Dependent Claim
35 words
The process as defined in claim 1 wherein cooling of said compressed gas is effected by passage in indirect heat transfer relationship with a compressed gaseous refrigerant after the expansion of said compressed gaseous refrigerant.
Claim 7
Dependent Claim
29 words
The process as defined in claim 5 wherein the work necessary to compress the gas stream in step (c) is obtained by the energy of expension of step (a).
Claim 8
Dependent Claim
21 words
The process as defined in claim 1 wherein liquefied natural gas recovered from step (f) is passed to a storage area.
Claim 9
Dependent Claim
25 words
The process as defined in claim 1 wherein said compressed gas is expanded by throttling across a valve to a pressure of about atmospheric pressure.
Claim 10
Dependent Claim
110 words
In an apparatus for liquefying natural gas having a pressure above the critical pressure thereof, which comprises: expander means for reducing the pressure of said natural gas below that of the critical pressure thereof; separation means for separating a C 5 + hydrocarbon stream from said expanded natural gas to obtain a resulting gas stream of C 4 or less; compressor means for compressing the resulting gas stream to a pressure above the critical pressure thereof; means for cooling said resulting gas stream; means for expanding said resulting gas stream to effect liquefaction of a major portion thereof; and means for recovering a major portion of said resulting gas stream.
Claim 11
Dependent Claim
110 words
In an apparatus for liquefying natural gas having a pressure above the critical pressure thereof, which comprises: expander means for reducing the pressure of said natural gas below that of the critical pressure thereof; separation means for separating a C 5 + hydrocarbon stream from said expanded natural gas to obtain a resulting gas stream of C 4 or less; compressor means for compressing the resulting gas stream to a pressure above the critical pressure thereof; means for cooling said resulting gas stream; means for expanding said resulting gas stream to effect liquefaction of a major portion thereof; and means for recovering a major portion of said resulting gas stream.
Claim 12
Dependent Claim
17 words
The apparatus as defined in claim 9 wherein said compressor means is driven by said expander means.
Claim 13
Dependent Claim
24 words
The apparatus as defined in claim 9 wherein said separation means includes fractionator means for separating C 5 and heavier hydrocarbons from lighter hydrocarbons.
Claim 14
Dependent Claim
38 words
The apparatus as defined in claim 9 wherein said cooling means is comprised of a compressor means, an expander means and heat exchanger means wherein a gaseous refrigerant is compressed, expanded and passed through said heat exchanger means.
Claim 15
Dependent Claim
32 words
The apparatus as defined in claim 9 wherein said apparatus is disposed on a vessel and wherein storage means for liquefied natural gas is provided at a location remote from said vessel.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-03-14 | 1980-09-13 | 1981-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-14 | 1984-09-13 | 1985-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-14 | 1988-09-13 | 1989-03-15 | $7700.00 | Window Closed / Lapsed |