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US4424121A Expired / Lapsed US ⏱️ 0.0 years remaining

Selective removal of nitrogen-containing compounds from hydrocarbon mixtures

Assignee: Occidental Research Corp
•
Filing: 1982-07-30
•
Granted: 1984-01-03
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Expires: 2002-07-30
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Abstract

Abstract A method is disclosed for reducing the nitrogen content of hydrocarbon liquids. The method comprises contacting the hydrocarbon liquid with a solid metal salt capable of selectively extracting nitrogen-containing compounds from the hydrocarbon liquid to thereby form a nitrogen-rich solid extract. Nitrogen-lean hydrocarbon liquid is then separated from the solid extract. The solid extract is washed with a solvent capable of selectively dissolving non-nitrogen-containing compounds entrained in the solid extract. The solid extract is then treated with a release agent for selectively dissolving nitrogen-containing compounds to thereby recover the metal salt. The presently preferred metal salt is cupric chloride.

Inventors

  • 👤 Henry W. Choi
  • 👤 Martin B. Dines

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 18:35
CPC Classifications
C; C10; C10G; C10G25/00; C10G25/003

Claims Analysis

Total Claims: 45
Claim 1
Independent Claim 117 words
A process for reducing the nitrogen content of hydrocarbon liquids comprising: mixing a hydrocarbon liquid containing nitrogen-containing compounds with at least one solid metal salt selected from the group consisting of cobalt molybdate, cobalt metaborate, the halides of copper, nickel, cobalt, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium, and the nitrates, sulfates and tetrafluoroborates of copper, nickel, cobalt, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium for a time sufficient for at least a portion of the nitrogen-containing compounds to be extracted from the hydrocarbon liquid by the solid metal salt to thereby form a nitrogen-lean hydrocarbon liquid and a solid nitrogen-rich extract; and separating the solid nitrogen-rich extract from the nitrogen-lean hydrocarbon liquid.
Claim 2
Dependent Claim 117 words
A process for reducing the nitrogen content of hydrocarbon liquids comprising: mixing a hydrocarbon liquid containing nitrogen-containing compounds with at least one solid metal salt selected from the group consisting of cobalt molybdate, cobalt metaborate, the halides of copper, nickel, cobalt, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium, and the nitrates, sulfates and tetrafluoroborates of copper, nickel, cobalt, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium for a time sufficient for at least a portion of the nitrogen-containing compounds to be extracted from the hydrocarbon liquid by the solid metal salt to thereby form a nitrogen-lean hydrocarbon liquid and a solid nitrogen-rich extract; and separating the solid nitrogen-rich extract from the nitrogen-lean hydrocarbon liquid.
Claim 3
Dependent Claim 15 words
A process as claimed in claim 1 wherein the solid metal salt comprises cupric chloride.
Claim 4
Dependent Claim 68 words
A process as claimed in claim 1 further comprising recovering the solid metal salt from the nitrogen-rich extract by: mixing the solid nitrogen-rich extract with a liquid release agent capable of selectively dissolving nitrogen-containing compounds to thereby form a liquid phase comprising the liquid release agent and nitrogen-containing compounds and a solid phase comprising the solid metal salt; and separating the solid metal salt from the liquid phase.
Claim 5
Dependent Claim 23 words
A process as claimed in claim 3 wherein the liquid release agent has a dielectric constant of from about 2 to about 8.
Claim 6
Dependent Claim 88 words
A process as claimed in claim 1 further comprising recovering the solid metal salt from the nitrogen-rich extract by: mixing the solid nitrogen-rich extract with a liquid release agent capable of selectively dissolving the metal salt to form a first liquid phase comprising the liquid release agent and dissolved metal salt and a second liquid phase comprising nitrogen-containing compounds; separating the first liquid phase from the second liquid phase; and vaporizing substantially all of the liquid release agent from the first phase to regenerate the solid metal salt.
Claim 7
Dependent Claim 107 words
A process as claimed in claim 1 further comprising recovering the solid metal salt from the nitrogen-rich extract by: mixing the solid nitrogen-rich extract with a two-phase liquid release agent comprising an aqueous solvent capable of selectively dissolving the metal salt and an organic solvent capable of dissolving nitrogen-containing compounds to thereby form a first liquid phase containing the aqueous solvent and the dissolved metal salt and a second liquid phase containing the organic solvent and nitrogen-containing compounds; separating the first liquid phase from the second liquid phase; and vaporizing substantially all of the aqueous solvent of the first liquid phase to regenerate the solid metal salt.
Claim 8
Dependent Claim 84 words
A process as claimed in claim 1 further comprising: recovering non-nitrogen-containing compounds entrained in the solid nitrogen rich extract by: contacting the solid nitrogen-rich extract with a solvent capable of selectively dissolving non-nitrogen-containing compounds; separating the solvent and dissolved non-nitrogen-containing compounds from the remaining solid nitrogen-rich extract; and distilling the solvent and dissolved non-nitrogen-containing compounds sufficiently to vaporize at least a portion of the solvent to thereby form a residue comprising non-nitrogen-containing compounds; and adding the recovered non-nitrogen-containing compounds to the nitrogen-lean hydrocarbon liquid.
Claim 9
Dependent Claim 20 words
A process as claimed in claim 7 wherein the solvent has a dielectric constant of no more than about 2.
Claim 10
Dependent Claim 12 words
A process as claimed in claim 8 wherein the solvent is pentane.
Claim 11
Dependent Claim 141 words
A process for reducing the nitrogen content of shale oil comprising: contacting shale oil feed with a solid extraction agent comprising at least one solid metal salt capable of selectively removing nitrogen-containing compounds from shale oil for a time sufficient to form a nitrogen-lean shale oil raffinate and a solid nitrogen-rich extract; separating the shale oil raffinate from the solid extract; mixing the solid nitrogen-rich extract with a solvent capable of selectively dissolving non-nitrogen-containing compounds for a time sufficient to dissolve substantially all non-nitrogen-containing compounds entrained by the nitrogen-rich extract to thereby form a liquid phase consisting essentially of solvent and non-nitrogen-containing compounds and a solid phase consisting essentially of the metal salt and nitrogen-containing compounds; separating the liquid phase from the solid phase; removing the solvent from the non-nitrogen-containing compounds; and combining the non-nitrogen-containing compounds with the shale oil raffinate.
Claim 12
Dependent Claim 141 words
A process for reducing the nitrogen content of shale oil comprising: contacting shale oil feed with a solid extraction agent comprising at least one solid metal salt capable of selectively removing nitrogen-containing compounds from shale oil for a time sufficient to form a nitrogen-lean shale oil raffinate and a solid nitrogen-rich extract; separating the shale oil raffinate from the solid extract; mixing the solid nitrogen-rich extract with a solvent capable of selectively dissolving non-nitrogen-containing compounds for a time sufficient to dissolve substantially all non-nitrogen-containing compounds entrained by the nitrogen-rich extract to thereby form a liquid phase consisting essentially of solvent and non-nitrogen-containing compounds and a solid phase consisting essentially of the metal salt and nitrogen-containing compounds; separating the liquid phase from the solid phase; removing the solvent from the non-nitrogen-containing compounds; and combining the non-nitrogen-containing compounds with the shale oil raffinate.
Claim 13
Dependent Claim 63 words
A process as claimed in claim 10 wherein the extraction agent comprises at least one metal salt selected from the group consisting of cobalt molybdate, cobalt metaborate, the halides of copper, nickel, cobalt, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium, and the nitrates, sulfates and tetrafluoroborates of copper, zinc, nickel, cobalt, iron, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium.
Claim 14
Dependent Claim 24 words
A process as claimed in claim 10 wherein the extraction agent comprises CuCl 2 .xH 2 O wherein x is from 0 to 2.
Claim 15
Dependent Claim 23 words
A process as claimed in claim 10 wherein the nitrogen content of the shale oil raffinate is no more than about 3,000 ppm.
Claim 16
Dependent Claim 20 words
A process as claimed in claim 10 wherein the shale oil raffinate is separated from the solid extract by decanting.
Claim 17
Dependent Claim 20 words
A process as claimed in claim 10 wherein the solvent comprises a dielectric constant from no more than about 2.
Claim 18
Dependent Claim 12 words
A process as claimed in claim 10 wherein the solvent comprises pentane.
Claim 19
Dependent Claim 37 words
A process as claimed in claim 10 wherein the extraction agent comprises at least one metal salt selected from the group consisting of the phosphate and phosphate derivatives of zirconium and the copper II exchanged counterparts thereof.
Claim 20
Dependent Claim 46 words
A process as claimed in claim 10 wherein the extraction agent comprises at least one metal salt selected from the group consisting of the substituted and non-substituted acetates, carboxylates, and acetylacetonates of copper, zinc, nickel, cobalt, iron, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium.
Claim 21
Dependent Claim 121 words
A process for reducing the nitrogen content of shale oil comprising: contacting the shale oil with a solid metal salt capable of selectively removing nitrogen-containing compounds from shale oil for a time sufficient to form a nitrogen lean shale oil raffinate and a nitrogen-rich solid extract; separating the shale oil raffinate from the solid extract; contacting the solid extract with a solvent capable of selectively dissolving nitrogen-containing compounds for a time sufficient to dissolve substantially all of the nitrogen-containing compounds in the solid extract to thereby form a liquid phase comprising the solvent and nitrogen-containing compounds and a solid phase comprising the solid metal salt; separating the liquid phase from the solid phase; and recovering the solvent from the liquid phase.
Claim 22
Dependent Claim 121 words
A process for reducing the nitrogen content of shale oil comprising: contacting the shale oil with a solid metal salt capable of selectively removing nitrogen-containing compounds from shale oil for a time sufficient to form a nitrogen lean shale oil raffinate and a nitrogen-rich solid extract; separating the shale oil raffinate from the solid extract; contacting the solid extract with a solvent capable of selectively dissolving nitrogen-containing compounds for a time sufficient to dissolve substantially all of the nitrogen-containing compounds in the solid extract to thereby form a liquid phase comprising the solvent and nitrogen-containing compounds and a solid phase comprising the solid metal salt; separating the liquid phase from the solid phase; and recovering the solvent from the liquid phase.
Claim 23
Dependent Claim 64 words
A process as claimed in claim 19 wherein the solid metal salt comprises at least one metal salt selected from the group consisting of cobalt molybdate, cobalt metaborate, the halides of copper, nickel, cobalt, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium, and the nitrates, sulfates and tetrafluoroborates of copper, zinc, nickel, cobalt, iron, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium.
Claim 24
Dependent Claim 25 words
A process as claimed in claim 19 wherein the solid metal salt comprises CuCl 2 .xH 2 O wherein x is from 0 to 2.
Claim 25
Dependent Claim 26 words
A process as claimed in claim 19 wherein the solvent is recovered by distilling the liquid phase sufficiently to form a distillate consisting essentially of solvent.
Claim 26
Dependent Claim 21 words
A process as claimed in claim 19 wherein the solvent has a dielectric constant of from about 2 to about 8.
Claim 27
Dependent Claim 38 words
A process as claimed in claim 19 wherein the solid metal salt comprises at least one metal salt selected from the group consisting of the phosphate and phosphate derivatives of zirconium and the copper II exchanged counterparts thereof.
Claim 28
Dependent Claim 47 words
A process as claimed in claim 19 wherein the solid metal salt comprises at least one metal salt selected from the group consisting of the substituted and non-substituted acetates, carboxylates, and acetylacetonates of copper, zinc, nickel, cobalt, iron, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium.
Claim 29
Dependent Claim 223 words
A process for reducing the nitrogen content of shale oil comprising: contacting shale oil with an extraction agent comprising at least one solid metal salt capable of selectively removing nitrogen-containing compounds from shale oil for a time sufficient to remove at least a portion of the nitrogen-containing compounds from the shale oil to thereby form a nitrogen lean shale oil raffinate and a high-nitrogen extract; separating the high-nitrogen extract from the shale oil raffinate; washing the high-nitrogen extract with a solvent capable of selectively dissolving non-nitrogen-containing compounds sufficiently to dissolve substantially all of the non-nitrogen-containing compounds entrained in the extract to thereby form a solvent wash comprising the solvent and non-nitrogen-containing compounds and a high-nitrogen solid extract comprising the metal salt and nitrogen-containing compounds; separating the solvent wash from the high-nitrogen solid extract; distilling the solvent wash sufficiently to form a distillate comprising at least a portion of the solvent substantially free of non-nitrogen-containing compounds and a bottoms comprising non-nitrogen-containing compounds; combining the bottoms and the raffinate; mixing the high-nitrogen solid extract with a liquid release agent capable of selectively dissolving nitrogen-containing compounds to thereby form a liquid phase comprising the liquid release agent and nitrogen-containing compounds and a solid phase comprising the metal salt; separating the liquid phase from the solid phase; and recovering the liquid release agent from the liquid phase.
Claim 30
Dependent Claim 223 words
A process for reducing the nitrogen content of shale oil comprising: contacting shale oil with an extraction agent comprising at least one solid metal salt capable of selectively removing nitrogen-containing compounds from shale oil for a time sufficient to remove at least a portion of the nitrogen-containing compounds from the shale oil to thereby form a nitrogen lean shale oil raffinate and a high-nitrogen extract; separating the high-nitrogen extract from the shale oil raffinate; washing the high-nitrogen extract with a solvent capable of selectively dissolving non-nitrogen-containing compounds sufficiently to dissolve substantially all of the non-nitrogen-containing compounds entrained in the extract to thereby form a solvent wash comprising the solvent and non-nitrogen-containing compounds and a high-nitrogen solid extract comprising the metal salt and nitrogen-containing compounds; separating the solvent wash from the high-nitrogen solid extract; distilling the solvent wash sufficiently to form a distillate comprising at least a portion of the solvent substantially free of non-nitrogen-containing compounds and a bottoms comprising non-nitrogen-containing compounds; combining the bottoms and the raffinate; mixing the high-nitrogen solid extract with a liquid release agent capable of selectively dissolving nitrogen-containing compounds to thereby form a liquid phase comprising the liquid release agent and nitrogen-containing compounds and a solid phase comprising the metal salt; separating the liquid phase from the solid phase; and recovering the liquid release agent from the liquid phase.
Claim 31
Dependent Claim 20 words
A process as claimed in claim 26 wherein the solvent has a dielectric constant of no more than about 2.
Claim 32
Dependent Claim 23 words
A process as claimed in claim 26 wherein the liquid release agent has a dielectric constant of from about 2 to about 8.
Claim 33
Dependent Claim 31 words
A process as claimed in claim 26 wherein the liquid release agent is recovered by distilling the liquid phase sufficiently to form a distillate consisting essentially of the liquid release agent.
Claim 34
Dependent Claim 283 words
A process for reducing the nitrogen content of shale oil comprising: contacting shale oil with an extraction agent comprising at least one solid metal salt selected from: the group consisting of cobalt molybdate, cobalt metaborate, the halides, nitrates, sulfates and tetronfluoroborates of copper, zinc, nickel, cobalt, iron, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium; or the group consisting of the phosphate and phosphate derivatives of zirconium and the copper II exchanged counterparts thereof; or the group consisting of the substituted and non-substituted acetates, carboxylates and acetylacetonates of copper, zinc, nickel, cobalt, iron, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium, for a time sufficient to remove at least a portion of the nitrogen-containing compounds from the shale oil to thereby form a nitrogen-lean shale oil raffinate and a high-nitrogen extract; separating the high-nitrogen extract from the shale oil raffinate; washing the high-nitrogen extract with a first solvent having a dielectric constant of no more than about 2 for dissolving non-nitrogen-containing compounds entrained in the extract to thereby form a solvent wash comprising the first solvent and non-nitrogen containing compounds dissolved therein, and disstilling the solvent wash sufficiently to form a distillate comprising the first solvent substantially free of non-nitrogen-containing compounds and a bottoms comprising non-nitrogen-containing compounds; combining the bottoms and the raffinate; mixing the high-nitrogen solid extract with a second solvent having a dielectric constant of from about 2 to about 8 to thereby form a solvent phase comprising the second solvent and nitrogen-containing compounds and a solid phase comprising the metal salt; separating the solvent phase from the solid phase; and distilling the solvent phase sufficiently to form a distillate comprising the second solvent substantially free of nitrogen-containing compounds.
Claim 35
Dependent Claim 283 words
A process for reducing the nitrogen content of shale oil comprising: contacting shale oil with an extraction agent comprising at least one solid metal salt selected from: the group consisting of cobalt molybdate, cobalt metaborate, the halides, nitrates, sulfates and tetronfluoroborates of copper, zinc, nickel, cobalt, iron, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium; or the group consisting of the phosphate and phosphate derivatives of zirconium and the copper II exchanged counterparts thereof; or the group consisting of the substituted and non-substituted acetates, carboxylates and acetylacetonates of copper, zinc, nickel, cobalt, iron, manganese, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium, for a time sufficient to remove at least a portion of the nitrogen-containing compounds from the shale oil to thereby form a nitrogen-lean shale oil raffinate and a high-nitrogen extract; separating the high-nitrogen extract from the shale oil raffinate; washing the high-nitrogen extract with a first solvent having a dielectric constant of no more than about 2 for dissolving non-nitrogen-containing compounds entrained in the extract to thereby form a solvent wash comprising the first solvent and non-nitrogen containing compounds dissolved therein, and disstilling the solvent wash sufficiently to form a distillate comprising the first solvent substantially free of non-nitrogen-containing compounds and a bottoms comprising non-nitrogen-containing compounds; combining the bottoms and the raffinate; mixing the high-nitrogen solid extract with a second solvent having a dielectric constant of from about 2 to about 8 to thereby form a solvent phase comprising the second solvent and nitrogen-containing compounds and a solid phase comprising the metal salt; separating the solvent phase from the solid phase; and distilling the solvent phase sufficiently to form a distillate comprising the second solvent substantially free of nitrogen-containing compounds.
Claim 36
Dependent Claim 15 words
A process as claimed in claim 30 wherein the solid metal salt comprises cupric chloride.
Claim 37
Dependent Claim 23 words
A process as claimed in claim 30 wherein the nitrogen content of the shale oil raffinate is no more than about 3,000 ppm.
Claim 38
Dependent Claim 214 words
A process for reducing the nitrogen content of shale oil comprising: contacting shale oil with a solid extraction agent comprising cupric chloride for a time sufficient to remove at least a portion of the nitrogen-containing compounds from the shale oil to thereby form a nitrogen-lean shale oil raffinate and a high-nitrogen extract; decanting the nitrogen-lean raffinate from the high-nitrogen extract; washing the high-nitrogen extract with a first solvent having a dielectric constant of no more than about 2 sufficiently to dissolve non-nitrogen-containing compounds entrained in the extract to thereby form a solvent wash comprising the first solvent and non-nitrogen-containing compounds and a high-nitrogen solid extract comprising the metal salt and nitrogen-containing compounds; decanting the solvent wash from the high-nitrogen solid extract; distilling the solvent wash sufficiently to form a distillate comprising the first solvent substantially free of non-nitrogen-containing compounds and a bottoms comprising non-nitrogen-containing compounds; combining the bottoms and the raffinate; mixing the high-nitrogen solid extract with a second solvent having a dielectric constant from about 2 to about 8 to thereby form a solvent phase comprising the second solvent and nitrogen-containing compounds and a solid phase comprising cupric chloride; separating the solvent phase from the solid phase; and distilling the solvent phase sufficiently to form a distillate consisting essentially of the second solvent.
Claim 39
Dependent Claim 214 words
A process for reducing the nitrogen content of shale oil comprising: contacting shale oil with a solid extraction agent comprising cupric chloride for a time sufficient to remove at least a portion of the nitrogen-containing compounds from the shale oil to thereby form a nitrogen-lean shale oil raffinate and a high-nitrogen extract; decanting the nitrogen-lean raffinate from the high-nitrogen extract; washing the high-nitrogen extract with a first solvent having a dielectric constant of no more than about 2 sufficiently to dissolve non-nitrogen-containing compounds entrained in the extract to thereby form a solvent wash comprising the first solvent and non-nitrogen-containing compounds and a high-nitrogen solid extract comprising the metal salt and nitrogen-containing compounds; decanting the solvent wash from the high-nitrogen solid extract; distilling the solvent wash sufficiently to form a distillate comprising the first solvent substantially free of non-nitrogen-containing compounds and a bottoms comprising non-nitrogen-containing compounds; combining the bottoms and the raffinate; mixing the high-nitrogen solid extract with a second solvent having a dielectric constant from about 2 to about 8 to thereby form a solvent phase comprising the second solvent and nitrogen-containing compounds and a solid phase comprising cupric chloride; separating the solvent phase from the solid phase; and distilling the solvent phase sufficiently to form a distillate consisting essentially of the second solvent.
Claim 40
Dependent Claim 13 words
A process as claimed in claim 33 wherein the first solvent is pentane.
Claim 41
Dependent Claim 27 words
A process as claimed in claim 33 wherein the second solvent is selected from the group consisting of tetrahydrofuran, toluene, acetic acid, methyl acetate and ethyl acetate.
Claim 42
Dependent Claim 91 words
A process for reducing the nitrogen content of hydrocarbon liquids comprising: mixing a hydrocarbon liquid containing nitrogen-containing compounds with at least one metal salt selected from the group consisting of the phosphate and phosphate derivatives of zirconium and the copper II exchanged counterparts thereof for a time sufficient for at least a portion of the nitrogen-containing compounds to be extracted from the hydrocarbon liquid by the solid compound to thereby form a nitrogen-lean hydrocarbon liquid and a solid nitrogen-rich extract; and separating the solid nitrogen-rich extract from the nitrogen-lean hydrocarbon liquid.
Claim 43
Dependent Claim 91 words
A process for reducing the nitrogen content of hydrocarbon liquids comprising: mixing a hydrocarbon liquid containing nitrogen-containing compounds with at least one metal salt selected from the group consisting of the phosphate and phosphate derivatives of zirconium and the copper II exchanged counterparts thereof for a time sufficient for at least a portion of the nitrogen-containing compounds to be extracted from the hydrocarbon liquid by the solid compound to thereby form a nitrogen-lean hydrocarbon liquid and a solid nitrogen-rich extract; and separating the solid nitrogen-rich extract from the nitrogen-lean hydrocarbon liquid.
Claim 44
Dependent Claim 100 words
A process for reducing the nitrogen content of hydrocarbon liquids comprising: mixing a hydrocarbon liquid containing nitrogen-containing compounds with at least one metal salt selected from the group consisting of the substituted and non-substituted acetates, carboxylates and acetylacetonates of copper, zinc, nickel, cobalt, iron, magnesium, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium for a time sufficient for at least a portion of the nitrogen-containing compounds to be extracted from the hydrocarbon liquid by the solid compound to thereby form a nitrogen-lean hydrocarbon liquid and a solid nitrogen-rich extract; and separating the solid nitrogen-rich extract from the nitrogen-lean hydrocarbon liquid.
Claim 45
Dependent Claim 100 words
A process for reducing the nitrogen content of hydrocarbon liquids comprising: mixing a hydrocarbon liquid containing nitrogen-containing compounds with at least one metal salt selected from the group consisting of the substituted and non-substituted acetates, carboxylates and acetylacetonates of copper, zinc, nickel, cobalt, iron, magnesium, chromium, vanadium, niobium, zirconium, molybdenum, thorium and uranium for a time sufficient for at least a portion of the nitrogen-containing compounds to be extracted from the hydrocarbon liquid by the solid compound to thereby form a nitrogen-lean hydrocarbon liquid and a solid nitrogen-rich extract; and separating the solid nitrogen-rich extract from the nitrogen-lean hydrocarbon liquid.

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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) 1987-01-02 1987-07-04 1988-01-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-01-02 1991-07-04 1992-01-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-01-02 1995-07-04 1996-01-03 $7700.00 Window Closed / Lapsed

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