Method and apparatus for analysis of relative levels of biodiesel in fuels by near-infrared spectroscopy

A process for the control of biodiesel content of a complex mixture comprising hydrocarbons and/or substituted hydrocarbons and at least one type of biodiesel material by near infrared spectroscopy, comprising predicting said biodiesel content by:

• a) measuring the near infrared absorbance of at least one wavelength in a portion of the range of 800-2500 nm;
• which are used to quantify the biodiesel content,
• b) periodically or continuously outputting a periodic or continuous signal 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,
• c) mathematically converting said signal to an output signal indicative of the biodiesel content of said mixture,
• d) controlling a blending or other process which correlates with biodiesel content 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 biodiesel content in a finished blended mixture.

A process for the control of hydrocarbons and substituted hydrocarbons and biodiesel material in a complex mixture to determine biodiesel content concentration, comprising, in combination:

• a) measuring the near infrared absorbance of at least one wavelength in a portion of the range of 800-2500 nm;
• which are used to quantify the biodiesel content,
• b) taking each of the absorbances measured, or a mathematical function thereof,
• c) performing statistical treatment using said absorbances or functions as the individual independent variables,
• d) assigning and applying weighting constants or their equivalents to said independent variables,
• e) applying the above steps using known compositions in a calibration step to calibrate the instrument and determine said weighting constants or equivalents,
• f) repeating said steps a) and b) with unknown compositions, applying the weighting constants or equivalents determined during said calibration with known compositions to output a signal or signals indicative of a biodiesel component or biodiesel components concentration, and
• g) controlling blending, hydrocarbon refining or chemical process by means of apparatus responsive to said signal or signals.

A process for the analysis and control of hydrocarbons and substituted hydrocarbons and at least one type of biodiesel material in complex mixtures to determine component concentration, the improvement comprising, in combination:

• a) measuring the near infrared absorbance of at least one wavelength in a portion of the range of 800-2500 nm;
• which are used to quantify the biodiesel content,
• b) outputting a periodic or continuous signal indicative of a derivative of said absorbance in said wavelength or wavelengths in said band, or of a combination of mathematical functions thereof,
• c) performing statistical treatment using said signal derivative of said absorbance or functions as the individual independent variables,
• d) assigning and applying weighting constants or their equivalents to said independent variables,.
• e) applying the above steps using known compositions in a calibration step to calibrate the instrument and determine said weighting constants or equivalents,
• f) repeating said steps a) and b) with unknown compositions, applying the weighting constants or equivalents determined during said calibration with known compositions to output a signal or signals indicative of a biodiesel component or biodiesel components concentration, and
• g) controlling a blending, hydrocarbon refining or chemical process by apparatus responsive to said output signal.

A system for blending hydrocarbon and/or substituted hydrocarbon feeds and at least one type of biodiesel material, comprising, in combination:

• a) NIR absorbance sensing means for emitting a signal indicative of absorbance in at least one band from a portion of the range of 800-2500 nm;
• selected from bands which are used to quantify biodiesel content
• b) computer means for mathematically converting said signal to an output indication of biodiesel content or other measure of fuel quality;
• and,
• 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 biodiesel.