US4701200A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process to produce helium gas
Assignee: Praxair Technology Inc
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Filing: 1986-09-24
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Granted: 1987-10-20
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Expires: 2006-09-24
Abstract
Abstract A process to produce helium gas from a feed to a nitrogen rejection unit comprising employing refrigeration from the nitrogen rejection unit to increase the recovery of helium by cooling crude helium prior to further processing.
Inventors
- 👤 Theodore F. Fisher
- 👤 Thomas C. Hanson
- 👤 Joseph A. Weber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:20
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/0228; F25J3/0233; F25J3/0204; F25J3/0209; F25J3/0257; F25J3/028; F25J3/029; F25J2200/00; F25J2200/04; F25J2200/06; F25J2200/74; F25J2200/78; F25J2200/80; F25J2205/00; F25J2205/02; F25J2205/40; F25J2205/60; F25J2205/64; F25J2235/00; F25J2235/60
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
127 words
A process for the production of helium gas comprising: (A) cooling, expanding and partially liquefying a feed comprising methane, nitrogen and helium; (B) introducing resulting two-phase feed into a column operating at a pressure within the range of from 250 to 450 psia; (C) within the column, separating the feed into methane liquid and nitrogen-helium vapor; (D) withdrawing nitrogen-helium vapor from the column; (E) partially condensing nitrogen-helium vapor to produce helium-richer vapor and nitrogen-richer liquid; (F) partially condensing helium-richer vapor to produce crude helium gas and nitrogen-rich liquid; (G) warming crude helium gas by indirect heat exchange with cooling feed; (H) purifying crude helium gas to produce product helium gas and helium-containing waste gas; and (I) passing helium-containing waste gas to helium-richer vapor upstream of step (F).
Claim 2
Dependent Claim
127 words
A process for the production of helium gas comprising: (A) cooling, expanding and partially liquefying a feed comprising methane, nitrogen and helium; (B) introducing resulting two-phase feed into a column operating at a pressure within the range of from 250 to 450 psia; (C) within the column, separating the feed into methane liquid and nitrogen-helium vapor; (D) withdrawing nitrogen-helium vapor from the column; (E) partially condensing nitrogen-helium vapor to produce helium-richer vapor and nitrogen-richer liquid; (F) partially condensing helium-richer vapor to produce crude helium gas and nitrogen-rich liquid; (G) warming crude helium gas by indirect heat exchange with cooling feed; (H) purifying crude helium gas to produce product helium gas and helium-containing waste gas; and (I) passing helium-containing waste gas to helium-richer vapor upstream of step (F).
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein the feed comprises from 0.5 to 3 percent helium.
Claim 4
Dependent Claim
20 words
The process of claim 1 wherein the column is the single column of a single column cryogenic nitrogen rejection unit.
Claim 5
Dependent Claim
20 words
The process of claim 1 wherein the column is the high pressure column of a double column cryogenic nitrogen-rejection unit.
Claim 6
Dependent Claim
16 words
The process of claim 1 wherein the crude helium gas is purified by pressure swing adsorption.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein the product helium gas has a helium-concentration in excess of 99.99 percent.
Claim 8
Dependent Claim
26 words
The process of claim 1 wherein the partial condensation of step (F) is carried out at least in part by indirect heat exchange with nitrogen-rich liquid.
Claim 9
Dependent Claim
29 words
The process of claim 7 wherein the nitrogen-rich liquid is expanded, divided into two portions, and one of said portions is further expanded prior to said indirect heat exchange.
Claim 10
Dependent Claim
37 words
The process of claim 7 wherein the nitrogen-rich liquid is expanded and partially vaporized, the resulting liquid divided into two portions, and one of said portions is expanded and partially vaporized prior to said indirect heat exchange.
Claim 11
Dependent Claim
24 words
The process of claim 9 wherein resulting vapor from the expansion of nitrogen-rich liquid is combined with helium-containing waste gas upstream of step (I).
Claim 12
Dependent Claim
39 words
The process of claim 7 wherein the nitrogen-rich liquid is expanded, partially vaporized by indirect heat exchange with helium-richer vapor, separated into vapor and liquid portions, and the liquid portion further warmed by indirect heat exchange with helium-richer vapor.
Claim 13
Dependent Claim
19 words
The process of claim 11 wherein said vapor portion is combined with helium-containing waste gas upstream of step (I).
References Cited (Backward Citations)
US2940271A
Cited
US3233418A
Cited
US3389565A
Cited
US3347055A
Cited
US3373574A
Cited
US3512368A
Cited
US3643452A
Cited
US3599438A
Cited
US3609984A
Cited
US3815376A
Cited
US3719053A
Cited
US3740962A
Cited
US3838553A
Cited
US4238211A
Cited
US4267701A
Cited
US4421537A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-19 | 1991-04-20 | 1991-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-19 | 1995-04-20 | 1995-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-19 | 1999-04-20 | 1999-10-20 | $7700.00 | Window Closed / Lapsed |