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US4305733A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of treating natural gas to obtain a methane rich fuel gas

Assignee: Linde GmbH
•
Filing: 1980-03-06
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Granted: 1981-12-15
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Expires: 2000-03-06
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Abstract

Abstract A method for the recovery of a methane-rich natural gas from a natural gas containing, apart from methane, also hydrogen sulfide, carbondioxide, higher hydrocarbons and, in most cases, organosulfur compounds. According to the invention a hydrocarbon fraction of C4 hydrocarbons and higher is naturally removed from the natural gas which is then subjected to a selective scrubbing for the removal of hydrogen sulfide with a regeneratable extraction, of scrubbing liquid. Next a C3 fraction is removed, the remaining gas being scrubbed with a second regeneratable washing agent, for the removal of carbondioxide to leave the methane-rich gas.

Inventors

  • 👤 Walter Scholz
  • 👤 Gerhard Ranke
  • 👤 Hans Becker
  • 👤 Boris G. Bergo
  • 👤 Alexander I. Grizenko
  • 👤 Alexej V. Frolov

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 11:55
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/14; B01D53/1456; B01D53/1462; C; C07; C07C; C07C7/00; C07C7/005; Y; Y02; Y02C; Y02C20/00; Y02C20/40; Y02P; Y02P20/00; Y02P20/151; Y10; Y10S; Y10S62/00; Y10S62/928

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 132 words
A method of separating components from a raw natural gas containing methane, hydrogen sulfide, higher hydrocarbons and possibly organosulfur compounds and carbonyl sulfide, which comprises the steps of: (a) removing a higher hydrocarbon fraction from said raw gas which includes hydrocarbons with a carbon number of 4 and greater; (b) selectively scrubbing hydrogen sulfide with a first regeneratable scrubbing liquid from the raw gas subsequent to its treatment in step (a); (c) thereafter removing a C 3 -hydrocarbon fraction from the raw gas from which hydrogen sulfide has been scrubbed in step (b); and (d) selectively scrubbing the gas from which the C 3 -hydrocarbon fraction has been removed in step (c) with a separate second regeneratable scrubbing liquid to remove CO 2 , thereby yielding a gas consisting predominantly of methane.
Claim 2
Independent Claim 132 words
A method of separating components from a raw natural gas containing methane, hydrogen sulfide, higher hydrocarbons and possibly organosulfur compounds and carbonyl sulfide, which comprises the steps of: (a) removing a higher hydrocarbon fraction from said raw gas which includes hydrocarbons with a carbon number of 4 and greater; (b) selectively scrubbing hydrogen sulfide with a first regeneratable scrubbing liquid from the raw gas subsequent to its treatment in step (a); (c) thereafter removing a C 3 -hydrocarbon fraction from the raw gas from which hydrogen sulfide has been scrubbed in step (b); and (d) selectively scrubbing the gas from which the C 3 -hydrocarbon fraction has been removed in step (c) with a separate second regeneratable scrubbing liquid to remove CO 2 , thereby yielding a gas consisting predominantly of methane.
Claim 3
Dependent Claim 24 words
The method defined in claim 1 wherein said first scrubbing liquid is selected from the group which consists of dialkyl ethers of polyethylene glycols.
Claim 4
Dependent Claim 14 words
The method defined in claim 1 wherein said second scrubbing liquid is an alcohol.
Claim 5
Dependent Claim 14 words
The method defined in claim 3 wherein said second scrubbing liquid is a methanol.
Claim 6
Dependent Claim 41 words
The method defined in claim 1, claim 2, claim 3 or claim 4 wherein at least one of the hydrocarbon separations of steps (a) and (c) is carried out at least in part by condensation of the hydrocarbons in the gas.
Claim 7
Dependent Claim 38 words
The method defined in claim 1, claim 2, claim 3 or claim 4 wherein at least one of the hydrocarbon separations of steps (a) and (c) is carried out at least in part by rectification of the gas.
Claim 8
Dependent Claim 42 words
The method defined in claim 1, claim 3 or claim 4 wherein at least one of the hydrocarbon fractions separated in step (a) or (c) is hydrogenated to transform any original sulfur compounds therein to hydrogen sulfide in the resulting hydrogenated mixture.
Claim 9
Dependent Claim 43 words
The method defined in claim 7, further comprising the step of separating said hydrogenated mixture into a hydrogen sulfide-rich fraction and a plurality of low-sulfur hydrocarbon fractions; and circulating the hydrogen sulfide-rich fraction to step (b), for scrubbing with said first scrubbing liquid.
Claim 10
Dependent Claim 57 words
The method defined in claim 1, claim 3, claim 4 or claim 5 wherein the hydrocarbon separation in step (a) is carried out at least in part by a low-temperature condensation of the hydrocarbon fraction, and the hydrocarbon separation in step (c) is carried out by treating the gas therein with a separate third regeneratable scrubbing liquid.
Claim 11
Dependent Claim 16 words
The method defined in claim 9 wherein said third scrubbing liquid is a mixture of hydrocarbons.
Claim 12
Dependent Claim 22 words
The method defined in claim 10 wherein said third scrubbing liquid is a gasoline cut containing C 7 to C 11 hydrocarbons.
Claim 13
Dependent Claim 42 words
The method defined in claim 9, further comprising the steps of: (b 1 ) expanding the charged first scrubbing liquid from step (b) to release gas therefrom; and (b 2 ) afterscrubbing the released gas with a portion of first scrubbing liquid.
Claim 14
Dependent Claim 29 words
The method defined in claim 12 wherein the gas subsequent to step (b 2 ) is subjected to: (b 3 ) a second afterscrubbing with the third scrubbing liquid.
Claim 15
Dependent Claim 73 words
The method defined in claim 1 wherein step (c) is carried out by scrubbing the gas with a separate third scrubbing liquid capable of removing said C 3 hydrocarbons from the gas, said method further comprising the steps of: (c 1 ) expanding said third scrubbing liquid to release a gas therefrom; and (c 2 ) afterscrubbing the gas released in step (c 1 ) with a portion of said third scrubbing liquid.
Claim 16
Dependent Claim 40 words
The method defined in claim 14, further comprising the step of: (c 3 ) expanding said portion of said third scrubbing liquid following step (c 2 ) and heating said portion of said third scrubbing liquid to regenerate the same.
Claim 17
Dependent Claim 53 words
The method defined in claim 15, further comprising the step of: (c 4 ) expanding gases released during the regeneration of said third scrubbing liquid, partly liquefying the compressed gases and recovering a gaseous carbon dioxide fraction and a liquid fraction thereof, the latter liquid fraction containing C 3 hydrocarbons and organosulfur compounds.
Claim 18
Dependent Claim 73 words
The method defined in claim 1, further comprising the steps of: (d 1 ) expanding the charged second scrubbing liquid of step (d) and releasing gas therefrom by such expansion; and (d 2 ) combining the gas released in step (d 1 ) with a gas obtained after an afterscrubbing of a liquid used in scrubbing gas in step (c) and compressing the resulting mixture before scrubing same with the second scrubbing liquid.
Claim 19
Dependent Claim 37 words
The method defined in claim 1 whereby said second scrubbing liquid is regenerated to release carbon dioxide which is combined with carbon dioxide generated by the regeneration of a separate third scrubbing liquid used in step (c).

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-12-14 1985-06-15 1985-12-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-12-14 1989-06-15 1989-12-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-12-14 1993-06-15 1993-12-15 $7700.00 Window Closed / Lapsed

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