US3837172A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Processing liquefied natural gas to deliver methane-enriched gas at high pressure
Assignee: SYNERGISTIC SERVICES Inc
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Filing: 1972-06-19
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Granted: 1974-09-24
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Expires: 1992-06-19
Abstract
Abstract Liquefied natural gas is pumped to high pressure and divided into a major portion which is heated and introduced into a rectifying column and a minor portion which enters the column as subcooled reflux. Methane-enriched gas leaves the top of the column at high pressure while liquid ethane and heavier hydrocarbons are withdrawn from the bottom thereof. When the methane-enriched gas is to be delivered at a pressure above the critical pressure of the gas in the column, the heated major portion is expanded with the performance of work before being introduced into the column; the work thus performed is utilized to compress the methane-enriched gas to a pressure above that in the column.
Inventors
- 👤 S Markbreiter
- 👤 I Weiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:19
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/0204; F25J3/0209; F25J3/0214; C; C07; C07C; C07C7/00; C07C7/04; F25J3/0228; F25J3/0233; F25J3/0238; F25J2200/00; F25J2200/02; F25J2200/70; F25J2210/00; F25J2210/06; F25J2230/00; F25J2230/60; F25J2240/00; F25J2240/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
55 words
The process of claim 1 wherein the unheated minor portion is not more than about 35 percent of the pressurized liquefied natural gas and is introduced into the top of the rectifying column as reflux liquid sub-cooled at least 50*F. below the temperature of the methane-enriched gas withdrawn from the top of said rectifying column.
Claim 2
Dependent Claim
24 words
The process of claim 1 wherein the high pressure in the rectifying column is in the range of about 500 to 550 psi gauge.
Claim 3
Dependent Claim
92 words
The process of claim 3 wherein the liquefied natural gas is pressurized so that at least the major portion thereof attains a pressure at least 200 psi higher than the high pressure in the rectifying column, said major portion, after being heated to effect vaporization and before being introduced into said rectifying column, is expanded with the performance of work, and said performance of work is utilized to compress the methane-enriched gas withdrawn from the top of said rectifying column to a pressure higher than the high pressure in said rectifying column.
Claim 4
Dependent Claim
58 words
The process of claim 4 wherein the unheated minor portion is in the range of about 15 to 25 percent of the pressurized liquefied natural gas and is introduced into the top of the rectifying column as reflux liquid subcooled at least 100*F. below the temperature of the methane-enriched gas withdrawn from the top of said rectifying column.
Claim 5
Dependent Claim
92 words
In the process of separating C2 and higher hydrocarbons from methane in liquefied natural gas wherein said liquefied natural gas is pumped to a high pressure, heated and introduced into the middle section of a rectifying column at high pressure, the improvement which comprises passing an unheated minor portion of at least 10 percent of said liquefied natural gas pumped to a high pressure into the top of said rectifying column as reflux liquid subcooled at least about 50*F. below the temperature of the vapor leaving the top of said rectifying column.
Claim 6
Dependent Claim
29 words
The process of claim 6 wherein the unheated minor portion is in the range of about 15 to 25% of the liquefied natural gas pumped to a high pressure.
Claim 7
Dependent Claim
43 words
The process of claim 6 wherein the unheated minor portion is not more than about 35 percent of the liquefied natural gas pumped to a high pressure and passes into the top of the rectifying column at a pressure above 300 psi gauge.
Claim 8
Dependent Claim
126 words
Apparatus for processing liquefied natural gas supplied at substantially atmospheric pressure by rectification at high pressure and for delivering methane-enriched gas resulting from said rectification at an increased pressure, comprising pumping means for pressurizing said liquefied natural gas, a vaporizing coil connected to the discharge of said pumping means and to the inlet of a turbo-expander coupled to a turbo-compressor, a rectifying column, a pipe connecTed to the discharge of said turbo-expander and to the middle section of said column, a valved pipe connected to the discharge of said pumping means and to the top of said column forming a by-pass of said vaporizing coil and said turbo-expander, and a warming coil connected to the top of said column and to the inlet of said turbo-compressor.
Claim 9
Dependent Claim
20 words
The apparatus of claim 9 wherein the vaporizing coil and the warming coil are disposed in the same heating chamber.
References Cited (Backward Citations)
US2666303A
Cited
US2763138A
Cited
US2823523A
Cited
US2952984A
Cited
US3261169A
Cited
US3524897A
Cited
US3362175A
Cited
US3383873A
Cited
US3570261A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |