Patent US4839211A successfully refreshed from Google Patents.
EP0444946A2
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A method for quantitatively measuring saturates, olefins and aromatics in a composition
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1991-03-01
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Granted: —
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Expires: 2011-03-01
Abstract
Abstract A method for quantitatively determining the amount of saturate, olefin and aromatic components in a composition or mixture is described. The method involves contacting a sample of a composition with a stationary phase; separating the saturates, olefins and aromatics loaded on the stationary phase by passing a supercritical fluid mobile phase through the stationary phase to obtain an eluent, wherein the amount of saturates, olefins and aromatics in the eluent varies over time and passing the eluent through an ultraviolet absorption (Uv) detector for irradiating the eluent with ultraviolet light at a wavelength capable of producing a uniform ultraviolet absorbance response for the olefins in the sample; measuring the ultraviolet absorbance of the olefins in the eluent; and passing the eluent through a mass detector (FID), capable of measuring the mass response to saturates, olefins and aromatics in the eluent and determining the quantitative amounts of saturates, olefins and aromatics in the composition from the detectors.
Inventors
- 👤 Wolfgang Walter Schulz
- 👤 Mark Wayne Genowitz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 11:33
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/62; G01N30/78; G01N33/00; G01N33/26; G01N33/28; G01N33/2829; G01N30/64; G01N30/68; G01N30/74
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
277 words
A method for determining the quantitative amount of saturates, olefins and aromatics in a composition comprising : (a) contacting a chromatographic stationary phase with a sample of the composition for a time sufficient to load said saturates, olefins and aromatics onto said stationary phase; (b) separating said saturates, olefins and aromatics, loaded on said stationary phase, by passing a mobile phase, under super critical conditions, through said stationary phase in a sufficient amount and for a time sufficient to obtain an eluent wherein the amount of saturates, olefins and aromatics in said eluent varies over time such that the amount of saturates and olefins in said eluent obtained over a first time interval is substantially higher than over a second time interval, being a time interval at least after said first time interval and the amount of aromatics in said eluent obtained over said second time interval is substantially higher than over said first time interval; (c) passing said eluent through an ultraviolet absorption detector for irradiating said eluent with ultraviolet light at a wavelength capable of producing a uniform ultraviolet absorbance response for said olefins and measuring said ultraviolet absorbance response over said first time interval; (d) passing said eluent through a mass detector capable of producing a mass response to saturates and olefins in said eluent obtained over said first time interval and capable of producing a mass response to said aromatics in said eluent obtained over said second time interval and measuring said mass response over said first time interval and said second time interval; (e) determining the quantitative amount of saturates, olefins and aromatics from said measurements obtained in steps (c) and (d).
Claim 2
Dependent Claim
246 words
The method of claim 1 wherein said measurements generated by said ultraviolet absorption detector are stored and integrated over said first time interval to obtain an integral of absorbance and said measurements generated by said mass detector are stored and integrated over said first and second time intervals to obtain a first integral of mass and a second integral of mass wherein: (i) the amount of aromatics expressed as weight percent of aromatics is represented by the ratio of said second integral of mass to the sum of said first and said second integral of mass; (ii) the amount of saturates and olefins expressed as the weight percent saturates and olefins is represented by the ratio of the first integral of mass to the sum of the first and second integral of mass; and (iii) the amount of olefins expressed as the weight percent olefins is determined from the equation: 0 = R/F (S + 0) where 0 is the weight percent olefins; (S + 0) is the weight percent saturates and olefins, R is the ratio of said integral of absorbance to the said first integral of mass; F, an olefin calibration factor, is the ratio of said integral of absorbance to the first integral of mass for a known olefin; (iv) the amount of saturates expressed as the weight percent saturates is determined by subtracting the weight percent of olefins obtained in (iii) from the weight percent of saturates and olefins obtained in (ii).
Claim 3
Dependent Claim
29 words
The method of claim 1 or claim 2 wherein the wavelength capable of producing a uniform ultraviolet absorbance response for olefins is equal to or less than 190 nanometers.
Claim 4
Independent Claim
25 words
The method of any one of claims 1 to 3 wherein the amount of aromatics in said eluent over said first time interval is negligible.
Claim 5
Independent Claim
40 words
The method of any one of claims 1 to 4 wherein the composition is selected from hydrocarbons in the naphtha to middle distillate boiling range, and/or C₅ to C₂₀ hydrocarbons, and/or wherein the composition is in the gasoline boiling range.
Claim 6
Independent Claim
35 words
The method of any one of claims 1 to 5 wherein the stationary phase is selected from the group consisting of silica, alumina, zeolites, surface chemical modified silica, alumina and zeolites and any mixture thereof.
Claim 7
Independent Claim
32 words
The method of any one of claims 1 to 6 wherein the mobile phase is selected from the group consisting of carbon dioxide, nitrous oxide, sulfur hexafluoride, xenon and any mixture thereof.
Claim 8
Independent Claim
35 words
The method of any one of claims 1 to 7 wherein said supercritical conditions consist of temperatures of from about 30°C to about 50°C and pressures of from about 100 atmosphere to about 350 atmosphere.
Claim 9
Independent Claim
25 words
The method of any one of claims 1 to 8 wherein said mass detector is either a flame ionization detector or a mass spectrometer detector.
Claim 10
Independent Claim
44 words
The method of any one of claims 1 to 9 wherein said stationary phase has a pore diameter ranging from about 60 angstroms (6 nm) to about 300 angstroms (30 nm) and a particle size ranging from about 3 micrometers to about 10 micrometers.
References Cited (Backward Citations)
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