Near infrared analysis of piano constituents and octane number of hydrocarbons

• US 5,349,188 A
• Filed: 04/09/1990
• Issued: 09/20/1994
• Est. Priority Date: 04/09/1990
• Status: Expired due to Term

• Current Assignee: Marathon Petroleum Company LLC (Marathon Petroleum Corporation)
• Original Assignee: Ashland Oil, Inc. (Ashland Global Holdings, Inc.)
• Inventors: Maggard, Steven M.
• Primary Examiner(s): FIELDS, CAROLYN
• Application Number:
  US07/506,391
• Time in Patent Office: 1,625 Days
• Field of Search: 250/339, 250/343, 250/340
• US Class Current: 250/339.12
• CPC Class Codes: G01N 21/3577 for analysing liquids, e.g. polluted water
• CPC Class Codes: G01N 21/359 using near infrared light
• CPC Class Codes: G01N 2201/129 Using chemometrical methods
• CPC Class Codes: G01N 33/2829 mixtures of fuels, e.g. determining the RON-number

Abstract

Certain selected wavelengths in the near infrared spectra permit analysis of weight percent, volume percent, or even mole percent of each component, e.g. PIANO (paraffin, isoparaffin, aromatic, napthenes, and olefins), octane (preferably research, motor or pump), and percent of various hydrocarbons, e.g. alpha olefins. Analysis can be nearly continuous analysis on-line or at-line, as well as batch analysis, e.g. in a quality control laboratory. Preferably the NIR data is converted to a second derivative of the spectra and multiple linear regression performed to model the individual PIANO concentrations, and to predict physical properties of fuel blending components, e.g. research octane of reformate, etc.

Claims

1. In a process for the control of octane number, or cetane number, of a complex mixture comprising hydrocarbons and/or substituted hydrocarbons, by near infrared spectroscopy, the improvement comprising predicting said octane number, or cetane number by:

a. measuring the near infrared absorbance at at least one wavelength in one or more bands selected from the group consisting essentially of;

1672-1698, 1700-1726, 1622-1650, 1092-1156, 824-884, 1656-1692, 880-974, 1152-1230, 1320-1380, 1470-1578, 1614-1644, 1746-1810, 1940-2000, and/or 2058-2130 nanometers (nm);

b. outputting a periodic or continuous signal indicative of a derivative of said absorbance in said wavelength, or wavelengths in said one or more bands or a combination of mathematical functions comprising a derivative thereof;

c. mathematically converting said signal to an output signal indicative of the octane number or cetane number of said mixture; and

d. controlling a blending or other process which correlates with octane number or cetane number by apparatus responsive to said output signal.

3. A process according to claim 1, or 2, wherein said absorbance is measured at wavelength within the 824-884 nm band.

4. A process according to claim 1, or 2, wherein said absorbance is measured in the 1152-1230 nm band.

5. A process according to claim 1, or 2, wherein said absorbance is measured in the 2064-2234 nm band.

6. A process according to claim 1, or 2, wherein comprising measuring said absorbance in the 880-974 nm band.

9. A process according to claim 1, 7, or 2, wherein said functions are obtained by a process comprising a base line offset correction.

10. A process according to claim 1, 7, or 2 wherein the mixture is a stream and said output signal is indicative of pump octane.

11. A process according to claim 1, 7, or 2 wherein the mixture is a stream and said output signal is indicative of motor octane.

12. A process according to claim 1, 7, or 2 wherein said output signal is indicative of cetane number.

17. A process according to claim 1, 7, 2, or 13 wherein said hydrocarbons comprise reformer feed, reformate (stabilized and/or unstabilized), fluid catalytic cracker product, alkylate gasoline, polymerization gasoline, isomerate gasoline, and raffinate, or other refinery blending streams or mixtures thereof.

18. A process according to claim 1, 7, 2, or 13 wherein said mixture flows substantially intermittently or continuously past the point of measuring said absorbance.

19. A process according to claim 1, 7, 2, or 13 wherein the mixture is a stream and said output signal is indicative of research octane.

20. A process according to claim 1, 7, 2, or 13 wherein said signal controls a fuel blending system feeding blending components having different octane or cetane into a common zone, whereby a product having a desired octane or cetane is produced.

21. A process according to claim 1, 7, 2, or 13 wherein said complex mixture comprises gasoline.

22. A process according to claim 1, 7, 2, or 13 wherein said complex mixture comprises diesel fuel.

23. A process according to claim 1, 7, 2, or 13 wherein the hydrocarbons and/or substituted hydrocarbons are involved in a chemical reaction.

24. A process according to claim 1, 7, 2, or 13 wherein said mathematically converting step comprises multiple regression analysis.

25. A process according to claim 1, 7, 2, or 13 wherein said mathematically converting step comprises partial least squares analysis.

26. A process according to claim 1, 2, or 13 wherein said absorbance is measured in the 1092-1156 nm band.

27. A process according to claim 1, 7, 2, or 13 wherein said absorbance is measured in the 1320-1380 nm band.

28. A process according to claim 1, 7, 2, or 13 wherein said absorbance is measured in the 1470-1578 nm band.

29. A process according to claim 1, 7, 2, or 13 wherein said absorbance is measured in the 1614-1644 nm band.

30. A process according to claim 1, 7, 2, or 13 wherein said absorbance is measured in the 1746-1810 nm band.

31. A process according to claim 1, 7, 2, or 13 wherein said absorbance is measured in the 1940-2000 nm band.

32. A process according to claim 1, 7, 2, or 13 wherein said absorbance is measured in the 2058-2130 nm band.

33. A processing according to claim 1, 7, 2, or 13 wherein said mathematically converting step comprises principal component regression analysis.

2. In a process for the control of octane number, or cetane number of a complex mixture comprising hydrocarbons and/or substituted hydrocarbons by near infrared spectroscopy, the improvement comprising predicting said octane number or cetane number by:

a. measuring the near infrared absorbance at at least one wavelength, in two or more bands selected from the group consisting essentially of;

1672-1698, 1700-1726, 1622-1650, 2064-2234, 1092-1156, 824-884, 1656-1692, 880-974, 1152-1230, 1320-1380, 1470-1578, 1614-1644, 1746-1813, 1940-2000, and/or 2058-2130 nanometers (nm).

b. periodically or continuously outputting a periodic or continuous signal indicative of the intensity of said absorbance in said wavelength, or wavelengths in said two or more bands or a combination of mathematical functions thereof; and

c. mathematically converting said signal to an output signal indicative of the octane number or cetane number of said mixture;

d. controlling a blending or other process which correlates with octane number or cetane number by apparatus responsive to said output signal;

wherein said mathematically converting includes taking a first or higher derivative and wherein said output signal is used to control proportioning pumps, automatic control valves, or other flow control means to control the addition rate of each of a series of components fed from different sources to provide a target octane number or, cetane number in a finished blended mixture.

7. In a process for the control of octane number, or cetane number of a complex mixture comprising hydrocarbons and/or substituted hydrocarbons by near infrared spectroscopy, the improvement comprising predicting said octane number, or cetane number by:

a. measuring the near infrared absorbance at at least one wavelength, in one or more bands selected from the group consisting essentially of;

1672-1698, 1700-1726, 1622-1650, 1656-1692, 1320-1380, 1470-1578, 1614-1644, 1746-1810, 1940-2000, and/or 2058-2130 nanometers (nm).

b. outputting a periodic or continuous signal indicative of the intensity of said absorbance in said wavelength, or wavelengths in said one or more bands or a combination of mathematical functions thereof; and

c. mathematically converting said signal to an output signal indicative of the octane number or cetane number of said mixture,

d. controlling a blending or other process which correlates with octane number or cetane number by apparatus responsive to said output signal.

8. A process according to claim 7, wherein said functions comprise a derivative of said absorbance.

13. A system for blending hydrocarbon and/or substituted hydrocarbon feeds having various values of octane or cetane comprising in combination:

A. NIR absorbance sensing means for emitting a signal indicative of absorbance in at least two bands selected from the group consisting essentially of;

1672-1698, 1700-1726, 1622-1650, 2064-2234, 1092-1156, 824-884, 1656-1692, 880-974, 1320-1380, 1470-1578, 1614-1644, 1746-1810, 1940-2000, and/or 2058-2130 nanometers (nm);

B. computer means for mathematically converting said signal to an output indication of octane or other measure of fuel quality;

C. flow control means responsive to said output, for controlling respective flows of said feeds to produce a blended mixture having substantially a preset value of said octane or cetane.

14. A system according to claim 13 wherein said computer means take a first or higher derivative of said signal.

15. A system according to claim 13 wherein said flow control means controls the flow of streams of two or more components of said mixture.

16. A process according to claim 13 wherein said composition comprises alpha olefins or mixtures thereof.

34. In a process for the control of octane number, or cetane number, of a complex mixture comprising hydrocarbons and/or substituted hydrocarbons, by near infrared spectroscopy, the improvement comprising predicting said octane number, or cetane number by:

a. measuring the near infrared absorbance at least one wavelength in one or more bands selected from the group consisting essentially of;

1672-1698, 1700-1726, 1622-1650, 1656-1692, 1320-1380, 1614-1644, 1746-1810, and/or 1940-2000 nanometers (nm);

b. outputting a periodic or continuous signal indicative of a derivative of said absorbance in said wavelength, or wavelengths in said one or more bands or a combination of mathematical functions comprising a derivative thereof;

c. mathematically converting said signal to an output signal indicative of the octane number or cetane number of said mixture; and

d. controlling a blending or other process which correlates with octane number or cetane number by apparatus responsive to said output signal.

35. In a process for the control of octane number, or cetane number of a complex mixture comprising hydrocarbons and/or substituted hydrocarbons by near infrared spectroscopy, the improvement comprising predicting said octane number or cetane number by:

a. measuring the near infrared absorbance at at least one wavelength, in two or more bands selected from the group consisting essentially of;

1672-1698, 1700-1726, 1622-1650, 1656-1692, 1320-1380, 1470-1578, 1614-1644, 1746-1810, and/or 1940-2000 nanometers (nm).

b. periodically or continuously outputting a periodic or continuous signal indicative of the intensity of said absorbance in said wavelength, or wavelengths in said two or more bands or a combination of mathematical functions thereof; and

c. mathematically converting said signal to an output signal indicative of the octane number or cetane number of said mixture;

d. controlling a blending or other process which correlates with octane number or cetane number by apparatus responsive to said output signal;

wherein said mathematically converting includes taking a first or higher derivative and wherein said output signal is used to control proportioning pumps, automatic control valves, or other flow control means to control the addition rate of each of a series of components fed from different sources to provide a target octane number or, cetane number in a finished blended mixture.

36. A system for blending hydrocarbon and/or substituted hydrocarbon feeds having various values of octane or cetane comprising in combination:

A. NIR absorbance sensing means for emitting a signal indicative of absorbance in at least two bands selected from the group consisting essentially of;

1672-1698, 1700-1726, 1622-1650, 1656-1692, 1320-1380, 1470-1578, 1614-1644, 1746-1810, and/or 1940-2000 nanometers (nm);

B. computer means for mathematically converting said signal to an output indication of octane or other measure of fuel quality;

C. flow control means responsive to said output, for controlling respective flows of said feeds to produce a blended mixture having substantially a preset value of said octane or cetane.