Patent US3886758A successfully refreshed from Google Patents.
US3886758A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Processes for the production of nitrogen and oxygen
Assignee: Air Liquide SA
•
Filing: 1973-08-23
•
Granted: 1975-06-03
•
Expires: 1993-08-23
Abstract
Abstract The present invention relates to a process and an installation for obtaining oxygen and nitrogen, in gaseous form, wherein a part of the reheated pure gaseous nitrogen originating from the separation stage is compressed, cooled and condensed by exchange with a liquid natural gas being revaporised, expanded, a part of the expanded liquid fraction being at least utilized for ensuring the reflux of the said separation stage and the vaporised fraction being reunited with the nitrogen compressed before the said compression wherein liquid nitrogen and gaseous nitrogen and oxygen, are obtained at different pressure levels, the said part of the reheated pure gaseous nitrogen reunited with a part of this gaseous nitrogen extracted before the end of reheating, after condensation and before its expansion, is subcooled counter-current flow of the fraction vaporised during the said expansion after being recondensed by exchange with the pure oxygen liquid fraction obtained at the bottom of the separation and reunited after subcooling with nitrogen at intermediate pressure.
Inventors
- 👤 Guy Perrotin
- 👤 Jean-Pierre Anselmini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:57
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/04; F25J3/04248; F25J3/04254; F25J3/0426; F25J3/04266; F17; F17C; F17C9/00; F17C9/02; F17C9/04; F25J3/04006; F25J3/04012; F25J3/04018; F25J3/04024; F25J3/04048; F25J3/04054; F25J3/0406; F25J3/04078; F25J3/0409; F25J3/04109; F25J3/04145; F25J3/04151; F25J3/04187; F25J3/04218; F25J3/04224; F25J3/04284; F25J3/04309; F25J3/04315; F25J3/04333; F25J3/04351; F25J3/044; F25J3/04406; F25J3/04412; F17C2265/00; F17C2265/05; F25J2200/00; F25J2200/20; F25J2200/76; F25J2205/00; F25J2205/02; F25J2210/00; F25J2210/62; F25J2230/00; F25J2230/02; F25J2230/04; F25J2245/00; F25J2245/42; F25J2245/50; F25J2270/00; F25J2270/08; F25J2270/90; F25J2270/904
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
247 words
A process for separating air into oxygen and nitrogen, while vaporizing liquefied natural gas, comprising: a. cooling and at least partially liquefying a compressed feed stream of air, by heat exchange with at least a part of oxygen and nitrogen separated from air; b. separating said liquefied air feed stream in at least a rectification zone under a pressure substantially above atmospheric pressure, into oxygen and nitrogen, whereby at least said nitrogen is obtained under said pressure substantially above atmospheric; c. work expanding at least a part of said nitrogen in gaseous phase to around atmospheric pressure, and heating said expanded part in heat exchange with the compressed air feed stream; d. compressing a stream of said oxygen in liquid phase above said pressure substantially above atmospheric; e. vaporizing and heating said compressed oxygen stream in heat exchange with at least said air feed stream; f. heating another part of said nitrogen in gaseous phase to a temperature below ambient temperature; g. compressing a stream of said heated nitrogen; h. at least partially condensing said compressed nitrogen stream in countercurrent heat exchange with liquefied natural gas being vaporized, wherein said compressed stream of nitrogen is liquefied under a lower pressure than the pressure at which liquefied natural gas is vaporized in heat exchange with said compressed stream; i. expanding at least a part of said liquefied nitrogen stream to said pressure substantially above atmospheric and returning said part to the top of said rectification zone as reflux.
Claim 2
Dependent Claim
247 words
A process for separating air into oxygen and nitrogen, while vaporizing liquefied natural gas, comprising: a. cooling and at least partially liquefying a compressed feed stream of air, by heat exchange with at least a part of oxygen and nitrogen separated from air; b. separating said liquefied air feed stream in at least a rectification zone under a pressure substantially above atmospheric pressure, into oxygen and nitrogen, whereby at least said nitrogen is obtained under said pressure substantially above atmospheric; c. work expanding at least a part of said nitrogen in gaseous phase to around atmospheric pressure, and heating said expanded part in heat exchange with the compressed air feed stream; d. compressing a stream of said oxygen in liquid phase above said pressure substantially above atmospheric; e. vaporizing and heating said compressed oxygen stream in heat exchange with at least said air feed stream; f. heating another part of said nitrogen in gaseous phase to a temperature below ambient temperature; g. compressing a stream of said heated nitrogen; h. at least partially condensing said compressed nitrogen stream in countercurrent heat exchange with liquefied natural gas being vaporized, wherein said compressed stream of nitrogen is liquefied under a lower pressure than the pressure at which liquefied natural gas is vaporized in heat exchange with said compressed stream; i. expanding at least a part of said liquefied nitrogen stream to said pressure substantially above atmospheric and returning said part to the top of said rectification zone as reflux.
Claim 3
Dependent Claim
242 words
A PROCESS FOR SEPARATING AIR INTO OXYGEN AND NITROGEN, WHILE VAPORIZING LIQUEFIED NATURAL GAS, COMPRISING: A COOLING AND AT LEAST PARTIALLY LIQUEFYING A COMPRESSED FEED STREAM OF AIR, BY HEAT EXCHANGE WITH AT LEAST A PART OF OXYGEN AND NITROGEN SEPARATED FROM AIR, B. SEPARATING SAID LIQUEFIED AIR FEED STREAM IN AT LEAST A RECTIFICATION ZONE UNDER A PRESSURE SUBSTANTIALLY ABOVE ATMOSPHERIC PRESSURE, INTO OXYGEN AND NITROGEN, WHEREBY AT LEAST SAID NITROGEN IS OBTAINED UNDER SAID PRESSURE SUBSTANTIALLY ABOVE ATMOSPHERIC, C. WORK EXPANDING AT LEAST A PART OF SAID NITROGEN IN GASEOUS PHASE TO AROUND ATMOSPHERIC PRESSURE, AND HEATING SAID EXPANDED PART IN HEAT EXCHANGE WITH THE COMPRESSED AIR FEED STREAM, D. COMPRESSURE SUBSTANTIALLY ABOVE ATOMOSPHERIC, ABOVE SAID PRESSURE SUBSTANTIALLY ABOVE ATMOSPHERIC, E. VAPORIZING AND HEATING SAID COMPRESSED OXYGEN STREAM IN HEAT EXCHANGE WITH AT LEAST SAID AIR FEED STREAM, F. HEATING ANOTHER PART OF SAID NITROGEN IN GASEOUS PHASE TO A TEMPERATURE BELOW AMBIENT TEMPERATURE, G. COMPRESSING A STREAM OF SAID HEATED NITROGEN, H. AT LEAST PARTIALLY CONDENSING SAID COMPRESSED NITROGEN STREAM IN COUNTERCURRENT HEAT EXCHANGE WITH LIQUEFIED NATURAL GAS BEING VAPORIZED, WHEREIN SAID COMPRESSED STREAM OF NITROGEN IS LIQUEFIED UNDER A LOWER PRESSURE THAN THE PRESSURE AT WHICH LIQUEFIED NATURAL GAS IS VAPORIZED IN HEAT EXCHANGE WITH SAID COMPRESSED STREAM, I. EXPANDING AT LEAST A PART OF SAID LIQUEFIED NITROGEN STREAM TO SAID PRESSURE SUBSTANTIALLY ABOVE ATMOSPHERIC AND RETURNING SAID PART TO THE TOP OF SAID RECTIFICATION ZONE AS REFLUX.
Claim 4
Dependent Claim
242 words
A PROCESS FOR SEPARATING AIR INTO OXYGEN AND NITROGEN, WHILE VAPORIZING LIQUEFIED NATURAL GAS, COMPRISING: A COOLING AND AT LEAST PARTIALLY LIQUEFYING A COMPRESSED FEED STREAM OF AIR, BY HEAT EXCHANGE WITH AT LEAST A PART OF OXYGEN AND NITROGEN SEPARATED FROM AIR, B. SEPARATING SAID LIQUEFIED AIR FEED STREAM IN AT LEAST A RECTIFICATION ZONE UNDER A PRESSURE SUBSTANTIALLY ABOVE ATMOSPHERIC PRESSURE, INTO OXYGEN AND NITROGEN, WHEREBY AT LEAST SAID NITROGEN IS OBTAINED UNDER SAID PRESSURE SUBSTANTIALLY ABOVE ATMOSPHERIC, C. WORK EXPANDING AT LEAST A PART OF SAID NITROGEN IN GASEOUS PHASE TO AROUND ATMOSPHERIC PRESSURE, AND HEATING SAID EXPANDED PART IN HEAT EXCHANGE WITH THE COMPRESSED AIR FEED STREAM, D. COMPRESSURE SUBSTANTIALLY ABOVE ATOMOSPHERIC, ABOVE SAID PRESSURE SUBSTANTIALLY ABOVE ATMOSPHERIC, E. VAPORIZING AND HEATING SAID COMPRESSED OXYGEN STREAM IN HEAT EXCHANGE WITH AT LEAST SAID AIR FEED STREAM, F. HEATING ANOTHER PART OF SAID NITROGEN IN GASEOUS PHASE TO A TEMPERATURE BELOW AMBIENT TEMPERATURE, G. COMPRESSING A STREAM OF SAID HEATED NITROGEN, H. AT LEAST PARTIALLY CONDENSING SAID COMPRESSED NITROGEN STREAM IN COUNTERCURRENT HEAT EXCHANGE WITH LIQUEFIED NATURAL GAS BEING VAPORIZED, WHEREIN SAID COMPRESSED STREAM OF NITROGEN IS LIQUEFIED UNDER A LOWER PRESSURE THAN THE PRESSURE AT WHICH LIQUEFIED NATURAL GAS IS VAPORIZED IN HEAT EXCHANGE WITH SAID COMPRESSED STREAM, I. EXPANDING AT LEAST A PART OF SAID LIQUEFIED NITROGEN STREAM TO SAID PRESSURE SUBSTANTIALLY ABOVE ATMOSPHERIC AND RETURNING SAID PART TO THE TOP OF SAID RECTIFICATION ZONE AS REFLUX.
Claim 5
Dependent Claim
230 words
A process for separating air into oxygen and nitrogen, while vaporizing liquefied natural gas, comprising: a. cooling and at least partially liquefying a compressed feed stream of air, by heat exchange with at least a part of oxygen and nitrogen separated from air; b. separating said liquefied air feed stream in at least a rectification zone under a pressure substantially above atmospheric pressure, into oxygen and nitrogen, whereby at least said nitrogen is obtained under said pressure substantially above atmospheric; c. work expanding at least a part of said nitrogen in gaseous phase to around atmospheric pressure, and heating said expanded part in heat exchange with the compressed air feed stream; d. heating another part of said nitrogen in gaseous phase to a temperature below ambient temperature. e. compressing a stream of said heated nitrogen; f. at least partially condensing said compressed nitrogen stream in countercurrent heat exchange with liquefied natural gas being vaporized, wherein said compressed stream of nitrogen is liquefied under a lower pressure than the pressure at which liquefied natural gas is vaporized in heat exchange with said compressed stream; g. expanding at least a part of said liquefied nitrogen stream to said pressure substantially above atmospheric and returning said part to the top of said rectification zone as reflux; h. withdrawing from said top of said rectification zone in vapor phase a substantially pure nitrogen product.
Claim 6
Dependent Claim
230 words
A process for separating air into oxygen and nitrogen, while vaporizing liquefied natural gas, comprising: a. cooling and at least partially liquefying a compressed feed stream of air, by heat exchange with at least a part of oxygen and nitrogen separated from air; b. separating said liquefied air feed stream in at least a rectification zone under a pressure substantially above atmospheric pressure, into oxygen and nitrogen, whereby at least said nitrogen is obtained under said pressure substantially above atmospheric; c. work expanding at least a part of said nitrogen in gaseous phase to around atmospheric pressure, and heating said expanded part in heat exchange with the compressed air feed stream; d. heating another part of said nitrogen in gaseous phase to a temperature below ambient temperature. e. compressing a stream of said heated nitrogen; f. at least partially condensing said compressed nitrogen stream in countercurrent heat exchange with liquefied natural gas being vaporized, wherein said compressed stream of nitrogen is liquefied under a lower pressure than the pressure at which liquefied natural gas is vaporized in heat exchange with said compressed stream; g. expanding at least a part of said liquefied nitrogen stream to said pressure substantially above atmospheric and returning said part to the top of said rectification zone as reflux; h. withdrawing from said top of said rectification zone in vapor phase a substantially pure nitrogen product.
Claim 7
Dependent Claim
233 words
A process for separating air into oxygen and nitrogen, while vaporizing liquefied natural gas, comprising: a. cooling and at least partially liquefying a compressed feed stream of air, by heat exchange with at least a part of oxygen and nitrogen separated from air; b. separating said liquefied air feed stream in at least a rectification zone under a pressure substantially above atmospheric pressure, into oxygen and nitrogen, whereby at least said nitrogen is obtained under said pressure substantially above atmospheric; c. compressing a stream of said oxygen in liquid phase above said pressure substantially above atmospheric; d. vaporizing and heating said compressed oxygen stream in heat exchange with at least said air feed stream; e. heating a part of said nitrogen in gaseous phase to a temperature below ambient temperature; f. compressing a stream of said heated nitrogen; g. at least partially condensing said compressed nitrogen stream in countercurrent heat exchange with liquefied natural gas being vaporized, wherein said compressed stream of nitrogen is liquefied under a lower pressure than the pressure at which liquefied natural gas is vaporized in heat exchange with said compressed stream; h. expanding at least a part of said liquefied nitrogen stream to said pressure substantially above atmospheric and returning said part to the top of said rectification zone as reflux; i. withdrawing from said top of said rectification zone in vapor phase a substantially pure nitrogen product.
Claim 8
Dependent Claim
233 words
A process for separating air into oxygen and nitrogen, while vaporizing liquefied natural gas, comprising: a. cooling and at least partially liquefying a compressed feed stream of air, by heat exchange with at least a part of oxygen and nitrogen separated from air; b. separating said liquefied air feed stream in at least a rectification zone under a pressure substantially above atmospheric pressure, into oxygen and nitrogen, whereby at least said nitrogen is obtained under said pressure substantially above atmospheric; c. compressing a stream of said oxygen in liquid phase above said pressure substantially above atmospheric; d. vaporizing and heating said compressed oxygen stream in heat exchange with at least said air feed stream; e. heating a part of said nitrogen in gaseous phase to a temperature below ambient temperature; f. compressing a stream of said heated nitrogen; g. at least partially condensing said compressed nitrogen stream in countercurrent heat exchange with liquefied natural gas being vaporized, wherein said compressed stream of nitrogen is liquefied under a lower pressure than the pressure at which liquefied natural gas is vaporized in heat exchange with said compressed stream; h. expanding at least a part of said liquefied nitrogen stream to said pressure substantially above atmospheric and returning said part to the top of said rectification zone as reflux; i. withdrawing from said top of said rectification zone in vapor phase a substantially pure nitrogen product.
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) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |