Ashland Oil, Inc.

Ashland, Inc.

Marathon Ashland Petroleum LLC

Steven M Maggard

William T Welch

Michael B Sumner

Brian K Wilt

Joseph H Walker

James H Higginbotham

Roy Roger Bledsoe

An NIR sampling system designed to provide a stable gasoline sample stream to an NIR analyzer. Preferred design elements include a temperature-controlled stream moving through an inverted coalesce whereby gas bubbles are removed through an overhead stream. Elevated pressure is used to reduce degassing as well. Two or more prototype fuels can be injected to calibrate the instrument over a range and prove accuracy before and/or after analysis of a sample.

Sampling and analysis system

In addition to analysis in the infrared spectra of hydrocarbon group types, it has now been found that certain hydrocarbon species, including preferably aromatic species such as benzene, toluene, xylene, and alkyl benzenes such as ethyl benzene, can be determined by measuring absorption in certain selected wavelengths in the infrared spectra, then manipulating the data, e.g., preferably by taking the first or higher derivative, and applying statistical techniques, preferably multiple linear regression (MLR) to provide an output signal indicative of the concentration of the particular specie. The output signal can be used to control refinery and chemical processes, e.g., reforming, catalytic cracking, alkylation and isomerization. In manufacturing reformulated fuels, government regulations can be complied with by utilizing the invention to blend fuels which have a maximum of benzene or other regulated components.

Process and apparatus for analysis of hydrocarbon species by near

Mid-distillate hydrocarbon fuels, preferably having initial boiling points above 350.degree. F., are separated e.g. by prep-HPLC into non-aromatic and aromatic fractions which are used to set 0% aromatics (the non-aromatics) and 100% aromatics (the aromatics) on an NIR spectrophotometer. From NIR aromatic band absorbances of unknown samples, their percent aromatics is determined using this two-point calibration and the Beer-Lambert equation. Preferred NIR bands of 1650-1700 and 2120-2256 exhibit excel lent correlation with aromatics content.

Determination of aromatics in hydrocarbons by near infrared spectroscopy

Method for determining oxygenate content and/or octane of hydrocarbon fuels suitable for automotive vehicles. Selecting nanometer frequencies in the range 1,300 to 1,350 reduces the temperature dependence of calibration equations that predict values representative of both oxygenate content and octane. This can be further improved by using only derivatives of selected temperature-dependent frequencies in addition to those in the 1,300 to 1,350 nanometer range. The selected frequencies preferably primarily correspond to C-H vibrational modes.

Indirect method for determining oxygenate content using near-infrared

Mid-distillate hydrocarbon fuels, preferably having initial boiling points above 350.degree. F., are separated e.g. by prep-HPLC into non-aromatic and aromatic fractions which are used to set 0% aromatics (the non-aromatics) and 100% aromatics (the aromatics) on an NIR spectrophotometer. From NIR aromatic band absorbances of unknown samples, their percent aromatics is determined using this two-point calibration and the Beer-Lambert equation. Preferred NIR bands of 1650-1700 and 2120-2256 exhibit excellent correlation with aromatics content. Also similar techniques measure sulfur through correlation with the benzothiophenic band and its overtones and combination bands, or possibly directly.

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.

Near infrared analysis of piano constituents and octane number of

Process and apparatus for analysis of hydrocarbons by near-infrared

A calibrated spectrometer can indirectly determine a physical or chemical property of a sample based upon spectral responses measured by the spectrometer with respect to the particular sample. This invention is directed to a method for calibrating or recalibrating a first spectrometer in light of a second spectrometer, or itself, respectively. The calibration employs a unique selection and manipulation of spectral data obtained from both the first and the second instrument. The recalibration employs a unique selection and manipulation of spectral data from the same first instrument, that is obtained both before and after the need for recalibration arises. Instead of modifying the respective responses of the first and second instrument, or the first instrument before and after the need for calibration arises, this invention modifies the calibration equation of the second, or recalibrated instrument, to yield consistent results to those obtained by the first instrument, or the first instrument before it goes out of calibration. A calibration equation is an equation which transforms spectral data of a particular sample at a variety of wavelengths to a calculated value for a chemical or physical property. Generally, the form of such calibration equations is that of a linear combination of absorbances or mathematical transforms of absorbances measured by the first and second instrument for each sample. The accuracy of the calibrated or recalibrated instrument is maintained and in some instances improved.

Spectroscopic instrument calibration

The octane of components used in the blending of gasoline is used to predict the octane of the finished gasoline blend by measuring absorbances, preferably in the near-infrared range, and metering the fraction of each blending component as independent variables and performing a multiple regression on the data modeling the dependent variable of the various octanes. Percent aromatics in diesel fuel and other finished chemical or physical properties of the finished blend can be controlled by feed-forward and/or feed-back techniques.

Process for predicting properties of multi-component fluid blends

Mid-distillate hydrocarbon fuels, preferably having initial boiling points above 350.degree. F., are separated e.g. by prep-HPLC into non-aromatic and aromatic fractions which are used to set 0% aromatics (the non-aromatics) and 100% aromatics (the aromatics) on an NIR spectrophotometer. From NIR aromatic band absorbances of unknown samples, their percent aromatics is determined using this two-point calibration and the Beer-Lambert equation. Preferred NIR bands of 1650-1700 and 2120-2256 exhibit excellent correlation with aromatics content.

The near infrared absorbance of the methyne band measures octane (pump, RON, and MON) with excellent correlation and can be used for gasoline blending. The absorbance may be measured as the first, second, third, fourth or higher derivative or by other signal processing techniques. The signal can be used to control a multi-component gasoline blending system to produce a preset desired octane. Such continuous or frequent measurement of octane (research octane number, RON; motor octane number, MON; and pump octane number (research plus motor times 0.5)) permits constant or frequent optimization of gasoline blending to produce a target octane which is sufficient to meet motorists' needs, yet uses minimum amounts of the more expensive high octane blending stocks.

Growing community of inventors

Huntington, WV, United States of America

Steven M Maggard